V6(1)International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies

A New Methodology for Assessing the Minimum Need of Bedrooms Number and Size in Dwellings: A Case Study of Iraq Structural Strength Evaluation

by NDE and Load Test of RC Slab Structure, Case Study: RC Deck Slab of Primary Hospital Building, Faculty of Medicine, Thammasat University, Thailand Effect of Exchangeable Cations on Bentonite Swelling Characteristics of Geosynthetic Clay Liners Roles of Bangkok Vanpool Commuter Services Towards Livable City Volume 6 Issue 1 (January 2015) ISSN 2228-9860 eISSN 1906-9642

http://TuEngr.com Cover Photo is from Buddhawanna et al. research article in this issue (Setting location for installation of dial gauges for structural load test.

2015 International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies.

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International Editorial Board

Editor-in-Chief Ahmad Sanusi Hassan, PhD Associate Professor Universiti Sains Malaysia, MALAYSIA

Executive Editor Boonsap Witchayangkoon, PhD Associate Professor Thammasat University, THAILAND

Noble Editorial Board:

Professor Dr.Mikio SATOMURA (Shizuoka University, JAPAN) Professor Dr.Chuen-Sheng Cheng (Yuan Ze University, TAIWAN) Professor Dr.I Nyoman Pujawan (Sepuluh Nopember Institute of Technology, INDONESIA) Professor Dr.Neven Duić (University of Zagreb, CROATIA) Professor Dr.Lee, Yong-Chang (Incheon City College SOUTH KOREA) Professor Dr.Dewan M. Nuruzzaman (Dhaka University of Engineering & Technology, BANGLADESH) Professor Dr. Lutero Carmo de Lima (State University of Ceará, BRAZIL )

Scientific and Technical Committee & Editorial Review Board on Engineering, Technologies and Applied Sciences:

Associate Prof. Dr. Paulo Cesar Lima Segantine (University of São Paulo, BRASIL) Associate Prof. Dr. Kurt B. Wurm (New Mexico State University, USA ) Associate Prof. Dr. Truong Vu Bang Giang (Vietnam National University, Hanoi, VIETNAM ) Dr.H. Mustafa Palancıoğlu (Erciyes University, TURKEY) Associate Prof.Dr.Peter Kuntu-Mensah (Texas A&M University-Corpus Christi, USA) Associate Prof. Dr. Masato SAITOH (Saitama University, JAPAN ) Assistant Prof.Dr. Zoe D. Ziaka (International Hellenic University, GREECE ) Associate Prof.Dr. Junji SHIKATA (Yokohama National University, JAPAN) Assistant Prof.Dr. Akeel Noori Abdul Hameed (University of Sharjah, UAE) Assistant Prof.Dr. Rohit Srivastava (Indian Institute of Technology Bombay, INDIA) Madam Wan Mariah Wan Harun (Universiti Sains Malaysia, MALAYSIA ) Dr. David Kuria (Kimathi University College of Technology, KENYA ) Dr. Mazran bin Ismail (Universiti Sains Malaysia, MALAYSIA ) Dr. Salahaddin Yasin Baper (Salahaddin University - Hawler, IRAQ ) Dr. Foong Swee Yeok (Universiti Sains Malaysia, MALAYSIA)

2015 International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies.

:: International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies Volume 6 Issue 1 (January, 2015) http://TuEngr.com

ISSN 2228-9860 eISSN 1906-9642

FEATURE PEER-REVIEWED ARTICLES

A New Methodology for Assessing the Minimum Need of Bedrooms Number and Size in Dwellings: A Case Study of Iraq

001

Structural Strength Evaluation by NDE and Load Test of RC Slab Structure, Case Study: RC Deck Slab of Primary Hospital Building, Faculty of Medicine, Thammasat University, Thailand

013

Effect of Exchangeable Cations on Bentonite Swelling Characteristics of Geosynthetic Clay Liners

021

Roles of Bangkok Vanpool Commuter Services Towards Livable City

031

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2015 International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies.

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A New Methodology for Assessing the Minimum Need of Bedrooms Number and Size in Dwellings: A Case Study of Iraq Mohamed M. Saeed Almumar a* a

Department of Architecture, Salahiddin University, Kirkuk road, Erbil, IRAQ

ARTICLEINFO

A B S T RA C T

Article history: Received 22 April 2014 Received in revised form 18 July 2014 Accepted 24 July 2014 Available online 01 August 2014

When comparing dwellings size and percentages in most of the current housing developments in Iraq with household’s size and distribution, they rarely match. That may lead to reducing the accessibility of families to satisfy their housing need. Since there is no up-to-date practical local methodology or criterion available for assessing minimum need of bedrooms number and size for dwellings and their percentages, this research established one.

This research suggested a methodology to classify families of a community to subgroups by their children’s number and gender, calculate their percentages and allocating the appropriate size of dwellings. The research results show that the methodology can determine the various required types and percentages of dwellings that can match minimum need of low income families. It also shows that greater diversification of dwelling units size is essential in local residential developments which differs from what is implemented in The research recommends the majority of these developments. extending studies to assess the need for other local governorates of bigger average family size and assess the future required bedrooms extension for originating and growing families to reduce their movements.

Keywords: Housing standard; Low income family; Family classification; Children age; Children gender.

2015 INT TRANS J ENG MANAG SCI TECH.

Nomenclature and Symbols Symbol Meaning G Major gender of children (male or female) g Minor gender of children (male or female) B Children bedroom. Numbers on the left and right of the letter represent bedrooms number and size respectively. The symbol (2B3) as an *Corresponding author (Mohamed M. Saeed Almumar). Tel: 964 750 4120951. E-mail: mmsaid49@yahoo.com. 2015. International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. Volume 6 No.1 ISSN 2228-9860 eISSN 1906-9642. Online Available at http://TUENGR.COM/V06/001.pdf.

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Bm đ?‘?đ?‘?đ?‘‹đ?‘‹ đ?‘›đ?‘› đ?‘Ľđ?‘Ľ đ?‘?đ?‘?

example means two bedrooms accommodating three children each.

Master bedroom Percentage of a subgroup Total number of children (male and female) Number of children of the same gender A case of children gender.

1. Introduction 1.1 Background of the Problem It is observed in most of the current residential developments in both, the public and private sectors in Iraq, that dwelling types are limited to specific sizes, and lack variety. Two and three bedroom dwellings are usually offered, other sizes such as studio, single bedroom and four bedroom dwellings are usually missing. Percentages of various dwellings sizes do not often match families need. This inconsistency, as a paper hypothesis, has been inferred by investigating some local well known residential developments, presented in the research appendix.

The “National Housing Policy Report� (AECOM, 2010) referred to the role of the Iraqi government in the housing sector to analyze the demand for housing, and to develop a housing policy to increase choice and facilitate access among Iraqis to the type of decent housing. Institute for International Law & Human Rights (July 2009) defined the “Adequate Housing for Iraq as the one that must be habitable, provide individuals with adequate space, its cost at a level that allows for the attainment and the percentage of housing-related costs is in general commensurate with income levels.� These two reports support the importance of finding methodologies capable to form a regulation for assessment of minimum need of bedrooms number and size in dwellings that can ensure the household need and meeting standards. Such regulations acquire increasing importance in most of the Iraqi cities due to the high average family size which exceeds significantly other countries of the world. Due to the lack of such regulations, the offered dwelling sizes and percentages are subjectively estimated, or may be determined to achieve greater revenue and not the ones that meet the actual need.

Recent researches suggest a diversity of housing sizes to meet households basic needs for improving quality of life by providing an opportunity for interaction with persons of different backgrounds (King & L. Anne 2008). Therefore, many city councils introduce regulations and codes to ensure a reasonable mix of dwelling sizes within new developments. These codes may refuse permission for a residential development that does not help to achieve a planned mix of dwelling types (Warwick District Council, 2007).

Housing is considered a commodity in the developed world. Assessing the demand there, is achieved by choosing samples of the community to estimate the current dwellings in terms of size, type, condition and tenure (County Durham, 2008). Whereas,

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Mohamed M. Saeed Almumar

in Iraq, housing is a social good and a highly productive economic activity at the same time (MOCH & UN-HABITAT, 2010). The amount of housing that Iraqi households in the lowest 20 percent of incomes can afford monthly is less than the cost of one square meter (MOCH & UN-HABITAT, 2006). Those households need to be supported by the government to accommodate them in a decent housing of a minimum need that they can afford. Therefore, this research adopt the task to derive a methodology to assess the minimum need of bedrooms number and size. This methodology is depending on the demographical attributes of families and their income level regardless to the demand factors.

It is worthy to notify that the developed world, in general, don’t need such assessment due to their low averages of family size and higher income as their occupation rate (family size divided by number of habitable rooms) equals one or less (Jennifer A. Rode, 2005) & (P. Huiginn, 1959), compared to the accepted overcrowding in Iraq of three according to the UN standard for developing countries ( MOPDC, COSIT, 2009).

1.2 Research Objectives and Importance This Research aims to assess the minimum need of bedrooms number and size for dwellings and their percentages in residential developments. The research importance is: - To ensure households stability when possessing dwellings matching their need.

- To provide an academic evident base and methodologies supporting the design process.

Other important reasons are as stated in the housing market assessment manual of New Zealand (DTZ New Zealand, 2009) are completely coinciding with the Iraqi requirements, as follows: “Housing market assessments can provide valuable insight into the housing market and assist policy development, strategic planning, decision making and resource allocation processes by: - Ensuring the most appropriate and cost effective use of public funds.

- Enabling local and regional government to develop long term strategic views of housing need and demand to inform spatial strategies and regional housing strategies.

- Providing evidence to inform polices about the level of affordable housing required, including the need for different sizes of affordable housing.”

1.3 Discussion of Previous Works Two studies were achieved locally before the year (2003) for composing housing standards and methodologies. They are “Urban Housing Basics and Standards” by the Ministry of Planning in (MOP,BRP,1977) and the “Housing Technical Standard and Code of Practice for Iraq” (Pole Service & MOHC, 1982). Both studies had not indicated a clear methodology to assess dwellings size and percentages for the various family sizes.

*Corresponding author (Mohamed M. Saeed Almumar). Tel: 964 750 4120951. E-mail: mmsaid49@yahoo.com. 2015. International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. Volume 6 No.1 ISSN 2228-9860 eISSN 1906-9642. Online Available at http://TUENGR.COM/V06/001.pdf.

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“Pole-Service Standards” abbreviated the demographic and economic diversities of Iraqi families into a single case of the whole nation average. On that basis they proposed two Tables comprising limited types of dwellings for all over Iraq. As an example for the diversities in Iraqi families: the average family size in Erbil governorate is 4.8 while it is 8.2 in Al-Muthanna (MOPDC,GBS, 2009). Even in the same governorates, this average varies depending on the city (MOP,KRSO, 2007), (MOPDC,COSIT, 2008). As for the economic situation of people, there is also a great diversity among governorates ,while a poverty line in Erbil is 3%, it is 49% in Muthanna, (MOPDC,COSIT, 2009) and even in the same governorates, it varies between its cities (WFP/VAM-MPDC/CSP-MOH/NRI, 2004).

Table 1: Pole-Service allocation of bedrooms number and size (Pole Service & MOHC, 1982).

Family size 1 2-4 4-6 6-8 8-10 10-12 Bedroom area (m2 ) 12 21 27 39 51 63 Bedrooms number 1 1,2 2 3 4 5

12 75 6

Table 1 indicates “pole-service” allocation of bedrooms number and size. It is supposed that for each family size, there should be various sizes of dwellings to satisfy the need due to the demographic and economic diversities, whereas, the suggested Table shows the reverse, each three sizes of families share equal size dwellings. In addition, it is impossible to assess the dwellings percentages, by this proposed allocation.

After the year 2003, two basic local housing studies have been completed. They are: Iraq Housing Market Study (MOCH & UN-HABITAT, 2006), and Iraq National Housing Policy (AECOM, 2010): The first comprises a general survey for the local housing market and concluded that reducing bedrooms number and size to the accepted minimum can help solving the housing crises. The reduction in the housing cost will allow families (22% of the population) to possess housing units with the government support by lending them loans. The study suggests a methodology for assessing housing sizes depending on purely economic basis regardless to families need. The study were completed in the year (2006) when the cost of a built-up square meter was estimated by 247 000 ID (Iraqi Dinar). This cost in the year (2011) is nearly doubled compared to (2006), while the average income raised only by 23% ,( MOPDC, 2011), (MOPDC, COSIT, 2009). It is expected that some of the average income families who represent 70% of the population will require the government support too, to own their units.

The second study (Iraq National Housing Policy ) dealt with the government housing policy and application, and recommended to develop new criteria capable to facilitating access to decent housing for all Iraqis and monitoring the overall production of housing of various levels of quality and cost, that can increasingly meet housing demand. The study have not specified a methodology to assess dwelling sizes and percentages for various family sizes.

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Mohamed M. Saeed Almumar

2. Research Variables and Methodology: This research defines four variables that bedrooms number and size varies according to.

They are: family size, children age, children gender, and the family income level. As family size increases, there will be a need to increase bedrooms number or size or both. Bedrooms number may vary also due to children gender. As an example, allocating one bedroom of two beds for two children above 10 years old is sufficient if they are of the same gender, whereas two bedrooms should be allocated if the gender of children is opposite. Bedrooms number may vary also due to children age, as in the last example, allocating one bedroom for the two children is sufficient if they are less than ten years old. Bedrooms number may vary due to the family income, as an example, allocating one bedroom for three children for a low income family is sufficient, whereas two or three bedrooms may be allocated, if the family income is high.

To achieve settling of growing families and to reduce their movement, this research considers all children as if they are above ten years old. This action will not force growing families with children below ten to move when those children grow up.

Since bedrooms number and size varies positively to the family income level, therefore the need of low income families is the minimum bedroom requirements that can ensure decent housing. The minimum bedroom requirements do not contradict with the medium and high income families, because these requirements do not confine or restrict any higher limit of their demand. Therefore minimum need of bedrooms number and size is associated to two variables: The first is the Family size distribution according to the demographic census of the community under study, and second to the children gender which has two qualitative values; the masculine and feminine.

The following standards of dwelling occupancy that suggested by Almuar, M. (2013) are adopted for controlling allocation of bedrooms number and size: “1. Allocating a private bedroom for the parents. Separating the children of opposite gender and of ten years old or more so as not to sleep in the same room. Children under the age of ten of both genders can share the same room.

2. Overcrowding standard must not exceed three.

3. Number of persons occupying one room shall not exceed four.”

These standards match the privacy requirement of the developed world (Housing Act, UK, 1985), and to the overcrowding rates standards of the “Habitat” for developing countries (Habitat, Iraqi Bureau, 2011) and to the local economic level and traditions. *Corresponding author (Mohamed M. Saeed Almumar). Tel: 964 750 4120951. E-mail: mmsaid49@yahoo.com. 2015. International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. Volume 6 No.1 ISSN 2228-9860 eISSN 1906-9642. Online Available at http://TUENGR.COM/V06/001.pdf.

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The adopted methodology in this research is summarized by: classifying families of equal children number to subgroups by their gender. Assessing the percentages of these subgroups by applying the binomial distribution theorem. Transforming the percentages of these subgroups to percentages of the whole distribution of the community according to the demographic census. Bedrooms number and size are allocated to the subgroups, complying to the adopted standard. Finally, summarizing the types by merging percentages of dwellings of equal bedrooms number and size.

3. Assessment and Results By the first step, classifying families of equal children number to subgroups by gender. As an example and not restricted to, group of families having three children are classified to: families of three male or female children (3G), and families of two male children and a single female child, or two female children and a single male child (2G+g). This classification has the importance when allocating the required number and size of bedrooms. Families of three male or female children(3G) can be accommodated in a single bedroom of three persons size, whereas families of two male children and a single female child , or two female children and a single male child (2G+g) should be accommodated in two bedrooms, one of two- bed size and the other of a single- bed size. Table 2 represents the subgroups classified according to the number of children and their gender.

1 G

2 2G

3 3G

G+g

2G+g

Number of children in families 4 5 6 4G 5G 6G

7 7G

8 8G

9 9G

3G+g

4G+g

5G+g

6G+g

7G+g

8G+g

2G+2g

3G+2g

4G+2g

5G+2g

6G+2g

7G+2g

3G+3g

4G+3g

5G+3g

6G+3g

4G+4g

5G+4g

classification of children by number and gender

Table 2: Subgroups classified according to the number of children and their gender.

The second step, assessing the percentages of these subgroups by applying the Binomial Distribution Theorem (Robert J. Boik, 2002) in Equation 1, đ?‘?đ?‘?đ?‘‹đ?‘‹ = ďż˝

��!

đ?‘Ľđ?‘Ľ!(đ?‘›đ?‘›âˆ’đ?‘Ľđ?‘Ľ)

ďż˝ đ?‘?đ?‘?đ?‘Ľđ?‘Ľ (1 − đ?‘?đ?‘?) đ?‘›đ?‘›âˆ’đ?‘Ľđ?‘Ľ

(1),

The Iraqi population census indicates that the percentages of male and female are (49.9%) and (50.1%) respectively (UNDP & MOPDC, 2004). Therefore, in this research, the probability of gender (đ?‘?đ?‘?) is binomial and at the same time equals a value of (0.5).

Subsequently, Equation 1 is transformed to Equation 2 by substituting ( đ?‘?đ?‘?) by (0.5). By

Equation 2, the percentages of the subgroups is calculated and presented in Table 3.

6

đ?‘?đ?‘?đ?‘‹đ?‘‹ = ďż˝

��!

đ?‘Ľđ?‘Ľ!(đ?‘›đ?‘›âˆ’đ?‘Ľđ?‘Ľ)

� 0.5��

Mohamed M. Saeed Almumar

(2)

1 G 100%

2 2G 50% G+g 50%

3 3G 25% 2G+g 75%

Children number 5 6 5G 6G 6.2% 3.1 4G+g 5G+g 31.3% 18.7% 3G+2g 4G+2g 62.5% 46.9% 3G+3g 31.3%

4 4G 12.5% 3G+g 50% 2G+2g 37.5%

7 7G 1.6% 6G+g 10.9% 5G+2g 32.8% 4G+3g 54.7%

8 8G 0.8% 7G+g 6.2% 6G+2g 21.9% 5G+3g 43.7% 4G+4g 27.4%

9 9G 0.4% 8G+g 3.5% 7G+2g 14.1% 6G+3g 32.8% 5G+4g 49.2%

Percentages of children distribution by number and gender.

Table 3: Percentages of children distribution by number and gender.

The third step, assessing the percentages of the subgroups to the whole distribution of the community by depending on the distribution of family size. For this research, Erbil governorate of Kurdistan region is considered as a case study and its family size distribution for the year 2007 census shown in Table 4 (MOP, KRSO, 2007) is adopted for calculation.

Percentages of the subgroups to the whole distribution of the community are calculated, and the results are presented in Table 5.

Table 4: Distribution of family size in Erbil governorate of 2007 census. (MOP, KRSO, 2007).

Family size % of families

1 8.1

2 17.7

3 12.7

4 14.1

5 13.6

6 11.1

7 8.4

8 6.1

9 3.9

10 2.3

11+ 2

Total 100

1 G 12.7%

2 2G 7.1% G+g 7%

3 3G 3.4% 2G+g 10.2%

4 4G 1.4% 3G+g 5.5% 2G+2g 4.2%

Children number 5 6 5G 6G 0.5% 0.2% 4G+g 5G+g 2.6% 1.1% 3G+2g 4G+2g 5.3% 2.9% 3G+3g 1.9%

7 7G 0.1% 6G+g 0.4% 5G+2g 1.3% 4G+3g 2.1%

8 8G 0.02% 7G+g 0.2% 6G+2g 0.5% 5G+3g 1% 4G+4g 0.6%

9+ 9G 0.01% 8G+g 0.1% 7G+2g 0.3% 6G+3g 0.6% 5G+4g 1%

Percentages of children distribution by number and gender in Erbil governorate.

Table 5: Percentages of children distribution by number and gender in Erbil governorate.

In the fourth step, bedrooms are allocated to the children subgroups. In a later stage the parents’ bedroom will be added. Allocation is complying to the adopted standard in this research of minimum need which require reducing number of bedrooms in a dwelling to the minimum, reducing the use of single bedrooms and adopting diversity in bedrooms size in each dwelling. This standard is interpreted to recommendations and presented in Table 6 which includes examples indicating preferences. The recommendations in Table 6 are interpreted to allocation and presented in Table 7. Cells in Table 7 represent the number of children bedrooms in dwellings. Cells are distributed into new groups of different number of *Corresponding author (Mohamed M. Saeed Almumar). Tel: 964 750 4120951. E-mail: mmsaid49@yahoo.com. 2015. International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. Volume 6 No.1 ISSN 2228-9860 eISSN 1906-9642. Online Available at http://TUENGR.COM/V06/001.pdf.

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bedrooms. The cells of similar number of bedroom are distributed again into sub groups of one bed space difference and are shaded with different tones. This action is due to the procedure in the next step.

Table 6: Recommendations of bedrooms allocation for minimum needs.

Recommendations 1

Reducing number of bedrooms in a dwelling to the minimum.

Reducing the use of bedrooms of single bed. preference of diversity in bedrooms size in a single dwelling.

2 3

Children number 5

Examples Rejected choice 2B2+B1

Preferred choice B3+B2

3

3B1

B3

6

3B2

B4+B2

1

2

3

4

B1 12.7%

B2 7.1%

B3 3.4%

B4 1.4%

2B1 7%

B2+ B1 10.2%

B3 + B1 5.5% 2B2 4.2%

Children number 5 6 B3 2B3 +B2 0.2% 0.5% B4 B3 +B2 + B1 + B1 2.6% 1.1% B3 B4 + B2 + B2 5.3% 2.9% 2B3 1.9%

7 B4 + B3 0.1% 2B3 + B1 0.4% B3 + 2B2 1.3% B4 + B3 2.1%

8 B4+B3 +B1 0.02% B4+B3 + B1 0.2% 2B3 + B2 0.5% 2B3 + B2 1% B4+B3 + B1 0.6%

9 B4+B+ B2 0.01% 2B4+ B1 0.1% B4 +B3 + B2 0.3% B4 +B3 + B2 0.6% B4 +B3 + B2 1%

Bedrooms number and size allocation for children

Table 7: Allocation of bedrooms number and size for children in low income families in Erbil governorate

Table 8: Finalized allocation for children of low income families in Erbil governorate 2 B2 19.8%

3

4 B4 4.8%

B2+ B1

17.2%

B3+ B2 15%

Children number 5 6 7 B3+B2 B4+ B3 0.5% 0.3% B4+B3 B+ 2B2 2.6% 2.8% B4+ B3 6.9%

8

9

B4+B3+B2 4.4%

Bedrooms number and size allocation for children

1

In the fifth step and in order to reduce types of dwellings to a practical limit without effecting need, a treatment has been taken to the types that have equal number of bedrooms but of one bed space less. One bed space is added to smaller bedrooms in some cases to have dwellings of equal bedrooms number and bed spaces. This procedure matches to all allocations except to the two dwelling types: (2B3+B1) and (2B4+B1) which belong to the category of families of children number of (7) and (9). These two cases comprise very low percentages, a total of 0.5% for both and therefore they are

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Mohamed M. Saeed Almumar

merged with the types (B3+ 2B2) and (B4+B3+B2) respectively. For large developments (bigger than 1000 dwellings) a specific type for these cases can be established.

Percentages of equal size dwellings are added to get the final Table of children bedrooms allocation by number and size.

Results are presented in Table 8.

Finally, Table 8 is

rearranged and tabulated according to bedrooms number, size and percentages. Master bedrooms are added to each allocation as presented in Table 9.

Table 9: Finalized allocation of bedrooms number and size in dwellings for low income families in Erbil governorate.

Number of bedrooms in the dwelling 1 2 3 4

Number and size of habitable rooms in the dwelling Bm Bm + B2 Bm +B4 Bm + B2+B1 Bm + B3+B2 Bm +B4+ B3 Bm +B3+2B2 Bm +B4+B3+B2 Total

% of dwellings size Relative to size and number Relative to number of of habitable rooms habitable rooms 25.8 25.8 19.7 24.5 4.8 17.2 15.5 42.5 9.8 2.8 7.2 4.4 100 100

For developments of less than (100) dwellings, results can be simplified by merging types of smaller percentages of dwellings with higher ones, to reduce types without effecting the need requirements. This action will facilitate the process of design, construction and distribution. Result are approximated to the nearest integer as shown in Table 10, which can be used for housing developments and satisfying family need.

Table 10: Finalized allocation of bedrooms number and size in dwellings for low income families in Erbil governorate for small developments Number of bedrooms in the dwelling 1 2 3 4

Number and size of habiTable rooms in the dwelling Bm Bm +B4 Bm + B2+B1 Bm +B4+ B3 Bm +B4+B3+B2 Total

% of dwellings size 26 25 17 25 7 100

4. Discussion Research results show the capability of the methodology to assess dwelling sizes and percentages that can satisfy families minimum need. When comparing the research results of dwelling sizes for Erbil governorate -which range from one bedroom up to four- with the majority of the current developments in Iraq, one can notice the lack of the latter to variety, *Corresponding author (Mohamed M. Saeed Almumar). Tel: 964 750 4120951. E-mail: mmsaid49@yahoo.com. 2015. International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. Volume 6 No.1 ISSN 2228-9860 eISSN 1906-9642. Online Available at http://TUENGR.COM/V06/001.pdf.

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sufficient bedrooms number and adequate percentages. These results support the research hypothesis.

It is worthy to mention that the range of dwelling sizes of the case study in this research, is relatively low due to low average family size of 4.6 in Erbil, compared to other local governorates of average family size of 8 or more. It is expected that for higher average family sizes, there will be more variety in dwelling sizes and different percentages which need exclusive assessment.

5. Conclusion This paper tackles the problem of the lack of a methodology necessary to determine the minimum need of dwelling types by bedroom number and size for low income families. In This paper, the need of dwellings-and not the demand- as a dependent variable is associated to the objective independent variables; the family distribution by size, family members distribution by age and gender and the criteria in the standard of decent housing of minimum need.

The methodology proposed in this paper can ensure the coinciding of supply and need of dwellings which will increase accessibility of families. In addition, this methodology can reduce resources consumption of construction and development total cost. Although the methodology is appropriate to societies of various average family sizes, it acquires more importance when applied to societies of large average family size due to the complexity of increasing range of dwelling types. When assessing size of dwellings for medium income families, developers and designers can benefit of the methodology results as a base information for comparison and avoid allocation of smaller size dwellings than that for low income families.

This research recommends extending studies to: • Assess the need for other local cities of higher average family size.

• Assess the future required bedrooms extension for originating and growing families to reduce movements.

• Develop mathematical methods necessary to determine demographical attributes not contained in census, such as family distribution during stages of originating, growing and dissolving.

• Achieve field researches for various types of dwellings, to detect level of “Residential Satisfaction” of families during their growth.

6. References AECOM, 2010, Ministry of Construction and Housing, Republic of Iraq, United Nations Human Settlements Program, International Development, Iraq National Housing Policy, PP. 8-11.

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Mohamed M. Saeed Almumar

Almumar, Mohamed,S. (2013). Proposed Standard for Dwelling Size in Iraq, the Minimum Need of Bed Rooms Number and Size, Journal of Pure and Applied Science, V. 25, No.1(Arabic) Zanco Press, Iraq. P.12.

County Durham, (2008), Strategic Housing Market Assessment, Final Report, PP 1-2. DTZ New Zealand, (2009), Centre for Housing Research, New Zealand Housing Market Assessments Manual, New Zealand, PP 9-10.

Habitat, Iraqi Bureau, 2011, National Committee for Population Policy, State of Iraqi Population, 2010, First National Report of Iraqi Population ,PP. 22-32.

Housing Act, UK, 1985, Overcrowding, Chapter 68, Part X, , PP. 1-2. Jennifer A. Rode, (2005), Appliances for Whom? Considering Place. University of California, Irvine, Informatics Department, USA. King & L. Anne, (2008), Housing Diversity and Accessibility, Sustainable Community Development Code, AICP, The Rocky Mountain Land Use Institute, P. 11.

MOCH & UN-HABITAT, 2006, Ministry of Construction and Housing, Iraq Housing Market Study, Main Report, P. 2.

MOCH & UN-HABITAT, 2010, Ministry of Construction and Housing, Iraq National Housing Policy, PP 8-11.

MOP, BRP,1977, Ministry of Planning, Board of Regional Planning, Standard and Basics of Urban Housing, P60.

MOPDC, COSIT, 2008, Ministry of Planning and Development Cooperation, Central Organization for Statistics and Information Technology, Number of Iraqi Population in Accordance to Governorates for the Year. (Tables).

MOPDC, COSIT, 2009, Ministry of planning and Development Cooperation, Central Organization for Statistics and Information Technology, Baseline Security in Iraq, PP 10-11.

MOPDC,COSIT, 2009, Ministry of Planning and Development Cooperation, Central Organization for Statistics and Information Technology, Poverty Line and Features Report in Iraq, pp.10-11.

MOPDC, 2011, Ministry of Planning and Development Cooperation, Iraq Knowledge Network Survey IKN, P8.

MOPDC,GBS, 2009, Ministry of Planning and Development Cooperation, General Board of Statistics, Summary of Buildings Statistic for the year 2011, P.6.

MOP, KRSO, 2007, Ministry of Planning, Kurdistan Regional Statistical Office, Household Size in Hawler Government.

P. Huiginn, (1959), Some Social and Economic Aspects of Housing—An International Comparison, (Bead at a joint meeting of the Society and the Institute of Public Administration.

Pole Service & MOHC, 1982, Ministry of Housing and Construction, State Organization for Housing, Housing Technical, Standard and Code of Practice for Iraq, PP. 143-169.

Robert J. Boik, (2002), Probability, Lecture Notes Statistics, Department of Mathematical Sciences, Montana State University | Bozeman, Revised August 30, 2004.

UNDP, MOPDC, 2004, Ministry of Planning and Development Cooperation, Central Organization for Statistics and Information Technology, Iraq Living Conditions Survey 2004, Volume I: Tabulation Report,P.18.

UN, Institute for International Law & Human Rights, July 2009, Access to Housing for Vulnerable Populations in Iraq, PP. 7-10.

Warwick District Council, (2007), Development Control Guidance: Achieving a Mix of Housing, PP. 1-3. WFP/VAM-MPDC/CSP-MOH/NRI, 2004, Ministry of Planning and Development, Socio- Economic Factors, Baseline Security in Iraq, P. 99. *Corresponding author (Mohamed M. Saeed Almumar). Tel: 964 750 4120951. E-mail: mmsaid49@yahoo.com. 2015. International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. Volume 6 No.1 ISSN 2228-9860 eISSN 1906-9642. Online Available at http://TUENGR.COM/V06/001.pdf.

11

7. Appendix Table 1A: Bedroom number and size of dwellings in some housing developments in Iraq.

Housing Development Basmaya/Alnahrawan www.investpromo.gov.iqbas maya/ Noor Almurtada Almenathira Housing/ www.skyscrapercity.com Bayti Housing www.myhome-iq.com

Governorate

Dwellings Number

Bedrooms Number

%

Apartmt.

100 000

3 4

-

Apartmt.

Houses

272 134

Apartmt. & Houses

370 260 610 -

2 2 3 2 3 4 1 2 3

100 21 30 49 33 67 15 85 9 91 67 33 50 50 100 100

80 140 170 200 48 61 113 120 94 145 91, 99 145 150, 165 155

Baghdad

Najaf

Alzahrah Housing www.alzahrahousing.com

Alkhalis Complex Alaziziya Complex www.moch.gov.iq zirbatia Complex www.moch.gov.iq Ashti City www.ashticity.com Dashti Bahasht

Balad Complex www.skyscrapercity.com Mtarda/ Tikrit www.moch.gov.iq Alarmoshia/ Samarra www.moch.gov.iq Tel-Afar Complex www.aknews.com Haswat Alshamia Gbail Alkharab/ Alfalloga (Alsabah Aljadid, 2343 on 24/07/2011 Ana Housing Complex

Apartmt.

214 592

2 3 2 3 2 3 2 4 2 3 3 3

Apartmt.

512

3

100

155

Apartmt. Type A: 480 Type B: 320 Apartmt. Type A: 376 Type B: 188 Apartmt.

568 Apartmt. Type A: 392 Type B: 240

3 2 3 2 3 3 2

60 40 67 33 100 62 38

137 117 127 106 155 150 130

Apartmt. Type A: 224 Type B: 300

3 2

43 57

150 112

-

Apartmt.

369

Apartmt.

604

Apartmt.

544

Houses

1200

Apartmt. & Houses

2376

Dialah

Wasit

Salahhiddin

Naynawa

Al Anbar

Dwelling Area (M2)

1.5 4 4+3 4+4+3 1.5 2+3 3+4 2 7 2 4 4 -

Apartmt.

Erbil

Number of Children Bed Spaces 100, 120 5 140 9

Dwellings Type

Notes: 1. number of bed spaces in bedrooms are calculated by the author depending upon the standard of area adopted in this paper.

2. Apartmt.= Apartment.

3. The sign ( - ) indicate not available information.

Mohamed M. Saeed Almumar holds the M.Sc. in Architecture since 1988. He is a senior lecturer since 2006 for the subjects of Building Construction, Architectural Environment and Architectural Thesis at the Department of Architecture, Salahaddin University, Erbil, Iraq. He is a member of the curriculum committee of the Department. He is also a consulting architect and the founding member of Elrukn Alarabi center for architectural design in Baghdad city. He has designed and supervised buildings of more than 100 000 m2 area since 1972. He is a registered architect in the Iraqi engineers union (IEU) and Kurdistan engineers union (KEU). His researches are particularly addressed to residential studies and programming, and to building design that ensure environmental requirements.

12

Mohamed M. Saeed Almumar

2015International InternationalTransaction TransactionJournal Journalof ofEngineering, Engineering,Management, Management,&&Applied AppliedSciences Sciences&&Technologies.

Technologies.

2015

International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies http://TuEngr.com

Structural Strength Evaluation by NDE and Load Test of RC Slab Structure, Case Study: RC Deck Slab of Primary Hospital Building, Faculty of Medicine, Thammasat University, Thailand Saharat Buddhawanna a* , Boonsap Witchayangkoon a, and Songpol Panmekiat a a

Department of Civil Engineering, Faculty of Engineering, Thammasat University, THAILAND

ARTICLEINFO

Article history: Received 05 September 2014 Received in revised form 19 November 2014 Accepted 28 November 2014 Available online 09 December 2014

Keywords: Structural Evaluation; nondestructive evaluation; ACI 318.

A B S T RA C T

The primary hospital building of Faculty of Medicine, Thammasat University, Kukhot district, Pathumthani, Thailand is an RC building and serves the primary treatment for local patients. This building has been constructed in early 2011 and finished in 2014. This building is still not yet opened for used due to rather huge deflections of the deck slabs. Such huge deflections can be seen with the naked eye. Undrained rain-waterlog remaining on the roofslap causes corrosion to the reinforced steel as well. As a result, the physicians feel fear of the unsafe building and ask the engineer to perform both nondestructive evaluation (NDE) and load test in order to learn the strength of the problematic deck slabs. The load test results are analyzed both load and rebound portions. The graphs relationship between the loads and deflections and weights against times are plotted and analyzed. Furthermore, the slab deflections are compared with the allowable deflections that allowed by ACI 318/318R as well.

2015 INT TRANS J ENG MANAG SCI TECH.

1. Introduction This article evaluates and checks both the deflection and strength of a RC deck slab that is a structural member in the primary hospital building, Faculty of Medicine, Thammasat University, Lumlukka district, Pathumthani province, Thailand. This building has been constructed in early 2011 and finished in 2014. The building structure is a two-story reinforced concrete building and still not yet opened for use as it encounters a problem of rather huge deflections of the deck *Corresponding author (Saharat Buddhawanna).

Tel: 66-2-5643005 ext3248.

E-mail: bsaharat@engr.tu.ac.th.

2015. International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. Volume 6 No.1 ISSN 2228-9860 eISSN 1906-9642. Online Available at http://TUENGR.COM/V06/013.pdf.

13

slabs. First step, the visual inspection is applied for observation on building damages such as the cracks, deformations (deflections), water leaking, reinforcing steel corrosion, and etc. Then, the other suitable NDE methods and load test are done in order to get the damage causes, structural (slab) strength, and optimal repair method respectively.

There are many kinds of damages that occur in the deck slabs especially the slab deflections.

Some deck slab deflections are more than 8 cm. and rain-waterlog add more load on the slab and also causes the steel corrosion. For this investigation, the slab structure evaluation methods are comprised with the NDE methods, which are the visual inspection and Schmidt Hammer or Rebound Hammer methods, and structural load test.

2. Literature Review Masetti et al. (2006) studied the behavior of one-way reinforced concrete slab. The hydraulics jack was used for loading on the slab and the Linear Variable Displacement Transducers (LVDT) was used to collect the slab deformations. The results were obtained from the analysis of the graph relationship between load and deflection. The maximum deflection should be not more than the allowable deflection from ACI 318 and the rebound (residual) deflection should be not less than the standard residual deflection that has followed ACI 318 as well.

Casadei et al. (2005) studied the structure response of two way slab. The hydraulics jack was used for loading on the slab and the LVDT was used to collect the slab deformations. The results were obtained from the analysis of the graph relationship between statics load and deflection and between cyclic loading and deflection. The conclusion was shown that the statics load gave the clearly results (deflection) than the cyclic load.

Ramana (2013) studied the concrete strength of a two way slab by Schmidt Hammer. The results were obtained from the graph relationship between rebound number and concrete strength.

The dimensions of the tested deck slab is 7.32 x 4.74 m. (length x width) and its thickness is 15 cm. The nine dial gages are installed at the points G1 to G9 and the dial gage no.5 (G5) is located at the middle of the slab as shown in Figure 1.

3. Load Test Protocols From the American Concrete Institute (ACI) standard, two variables are considered for the principle evaluation and they are : 14

Saharat Buddhawanna, Boonsap Witchayangkoon, and Songpol Panmekiat

1) Dead load effect such as weight of slab and 2) Live load effect.

By this way, the total load (weight) that is applied on the tested deck slab can be calculated as suggested by ACI 318/318R

Figure 1: Location of Dial Gauges.

Total Load = 0.85*(1.4*Dead load + 1.7*Live load)

(1).

The ACI requirements and standards for the structural using condition must be considered and limited by two variables that are: 1) Maximum Deflection and 2) Rebound Deflection or Residual Deflection.

According to ACI 318/318R, the maximum deflection and the rebound deflection are Δ max ≤ L2/20000h Δ rebound ≤ Δ max /4 where Δ max is the maximum deflection Δ rebound is the Rebound deflection or Residual Deflection L is length of slab on the short side, and h is thickness of slab.

(2) (3)

3.1 Load Testing Procedure Procedure for load testing 1. Test the concrete strength by Schmidt Hammer (Rebound Hammer) that is an NDE testing-before Load Test 2. Install the dial gauges no.1 to 9 (G1- G9) onto the deck slab structure for nine points that are located as shown in Figure 1 and the dial gage no.5 (G5) is installed at the middle of the *Corresponding author (Saharat Buddhawanna).

Tel: 66-2-5643005 ext3248.

E-mail: bsaharat@engr.tu.ac.th.

2015. International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. Volume 6 No.1 ISSN 2228-9860 eISSN 1906-9642. Online Available at http://TUENGR.COM/V06/013.pdf.

15

slab. The dial gage installation is used the magnetic base (shown in Figures 2) and shown in Figure 3 as well.

3. Record all initial deflections and the temperature prior the testing 4. Increase the load (water weight) step by step from 0%, 25%, 50%, 75%, and 100% of the maximum test load and each load step is held for 1 hour (for this deck slab structure, the design maximum live load equals 200 kg/m2) 5. Except the maximum test load (100%) that has to maintain 24 hours (shown in Figure 4) 6. After 24 hours, the test load is decreased step by step from 0%, 50%, and 100% of the maximum test and each released load step is held for 1 hour.

7. After release all test load, it is maintained for 24 hours.

Figure 2: Dial Gauge and Magnetic Holder.

Figure 3: Dial Gauges installation.

Figure 4: Loading by Water.

16

Saharat Buddhawanna, Boonsap Witchayangkoon, and Songpol Panmekiat

4. Testing Results The testing results from Schmidt Hammer (NDE) are reported in Table 1 and the results from the load test are shown by the table and graph as Table 2 and Figure 5 respectively.

5. Analysis of Load Test Results The results from the testing (both the maximum and rebound deflections) must be compared with the allowable maximum and rebound deflections (that are calculate from Equation (2) and (3) respectively as shown in Table 3.

Table 1: Schmidt Hammer Testing Results.

(The average concrete strength from Schmidt hammer is 214 ksc.)

Rebound No. f'c (ksc) Rebound No. f'c (ksc) Rebound No. f'c (ksc) 32 194 32 194 36 261 33 211 36 261 38 296 33 183 35 246 35 246 31 183 33 211 35 246 29 155 31 183 34 225 32 194 32 194 33 211 33 211 36 261 32 194 30 158 33 211 38 296 32 194 33 211 36 261 32 194 30 158 36 261 31 183 30 158 35 246 34 225 36 261 38 296 32 194 36 261 33 211 33 211 32 194 32 194 31 183 31 183 36 261 31 183 31 183 32 194 29 155 32 194 35 246 33 211 33 211 32 194 33 211 36 261 38 296 32 194 34 225 36 261 32 194 36 261 35 246 32 194 30 158 33 211 33 211 30 158 32 194 33 211 31 183 32 194 Table 2: Dial Gauges Readings.

Dial Gauge Reading (mm) Load 0% Load 25% (Step 1) Load 50% (Step 2) Load 75% (Step 3) Load 100% (Step 4) Load 100% held for 24 hours Released Load 50% Released Load 100% Released Load 100% held for 24 hours

G1 0.00 1.25 1.86 2.57 3.05

G2 0.00 1.25 1.85 2.6 3.07

G3 0.00 0.55 1.05 1.72 2.11

G4 0.00 1.25 1.96 3.83 4.29

G5 0.00 1.13 2.60 3.62 4.11

G6 0.00 1.14 2.70 3.44 3.94

G7 0.00 1 1.48 2.12 2.48

G8 0.00 2.96 3.41 4.03 4.35

G9 0.00 0.89 1.27 1.83 2.12

3.26 3.31 2.25 4.57

4.4

4.13 2.63 4.53

2.4

2.36 2.39 1.48 3.52 3.35 3.22 1.91 3.81 0.72 0.71 0.07 0.68 1.47 1.68 0.59 2.57

2.36 2.33

0.65 1.64 0.01 0.60 0.94 1.57 0.49 2.47

2.17

*Corresponding author (Saharat Buddhawanna).

Tel: 66-2-5643005 ext3248.

E-mail: bsaharat@engr.tu.ac.th.

2015. International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. Volume 6 No.1 ISSN 2228-9860 eISSN 1906-9642. Online Available at http://TUENGR.COM/V06/013.pdf.

17

Figure 5: Graph Relationship between Time and Loading Percentage.

Table 3: Testing Deflection (Δ max and Δ rebound) and Allowable Rebound Deflections from ACI 318 Dial Gauge No. Δ max (mm.) Δ rebound (mm.) (Δmax )/4 (mm.)

3.26 0.65 G1 0.81 3.31 1.64 G2 0.82 2.25 0.01 G3 0.56 4.57 0.60 G4 1.14 4.40 0.94 G5 1.10 4.13 1.57 G6 1.03 2.63 0.49 G7 0.65 4.53 2.47 G8 1.13 2.40 2.17 G9 0.60 1. All maximum deflections (Δ max ) from testing must be less than the calculated deflection that equals 8.33 mm. (calculated from Equation (2)).

2. The rebound deflections must be less than the calculated rebound deflections that are shown in the last column of Table 3.

Note

Figure 6: Relationships between Deflection and Maximum Load Percentage for Dial Gage No.4.

For the Rebound Hammer test results, the concrete strength average is 214 ksc as shown in Table 2 that means the slab concrete strength is rather common for the building construction.

18

Saharat Buddhawanna, Boonsap Witchayangkoon, and Songpol Panmekiat

The graph, that is shown in Figure 6, show the relationships between the deflection of the maximum slab deflection for the dial gage no.4 (G4) is 4.57 mm and the rebound deflection is to 0.6 mm. For the dial gage no.9 (G9), the maximum slab deflection is 2.4 mm and the rebound deflection is 2.17 mm as shown in Figure 7. From the load test results, all maximum deflections (Δ max ) from the testing must be less than the calculated deflection that is 8.33 mm. (calculated from Equation (2)) and the rebound deflections must be less than the calculated rebound deflections that are shown in the last column of Table 3 as well. This building has been suggested for repair because some rebound deflections still exist in the slab structure as shown in Table 3.

Figure 7: Relationships between Deflection and Maximum Load Percentage for Dial Gage No.9

6. Conclusions This work investigates structural strength by NDE and load test of RC slab structure of primary hospital building, Faculty of Medicine, Thammasat University, Thailand. After the construction in 2014, the building is still not yet opened for used as rather huge deflections of the deck slabs have been observed with the naked eye. The undrained rain-waterlog remaining on the roof slap causes more load and corrosion to the reinforced steels. This work performs both nondestructive evaluation (NDE) and load test in order to learn the strength of the problematic deck slabs. The load test results are analyzed both load and rebound portions. The plot of relationship between the loads and deflections and weights against times are analyzed. From test observation, greatest deflections do not beyond maximum allowable defection, according to ACI 318. However, the rebounds at some points are fully recovered while at some points are not.

Thus, for long term use, it is suggested for proper repair.

7. References American Concrete Institute, (1995). “Building Code Requirements for Structural Concrete and Commentary.” ACI 318R-95, Washington,D.C. *Corresponding author (Saharat Buddhawanna).

Tel: 66-2-5643005 ext3248.

E-mail: bsaharat@engr.tu.ac.th.

2015. International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. Volume 6 No.1 ISSN 2228-9860 eISSN 1906-9642. Online Available at http://TUENGR.COM/V06/013.pdf.

19

American Society for Testing and Materials, “Test for Rebound Number of Hardened Concrete.” ASTM C805, USA. Casadei, P., Parretti, R., Nanni, A., and Heinze, T. (2005) “In situ load testing of parking garage reinforced concrete slabs: comparison between 24 h and cyclic load Testing” Practice Periodical on Structural Design and Construction, 40-48.

Department of Public Works and Town & Country Planning, (2008). “Standards check reinforced concrete structures by means of non-destructive testing.”

Masetti, F., Galati, N., Nehil, T.,and Nanni, A. (2006). “In-situ load test: a case Study.” Fédération Internationale du Béton Proceedings of the 2nd International Congress, Naples, Italy Ramana Reddy, K.V., (2013). “Non- destructive evaluation of in-situ strength of high strength concrete structures.” International Journal of Civil Engineer and Technology, 21-28.

Dr. Saharat Buddhawanna is an Assistant Professor of Structural Engineering at Thammasat University in Thailand. He received a Bachelor Degree in Agricultural and Civil Engineering and Master Degree in Structural Engineering from Khonkaen University (KKU), Khonkaen, Thailand. Dr Buddhawanna earned Master and Ph.D. degrees in Civil Engineering concentrated on Structural Engineering field from University of Colorado (UCD), Denver, and Colorado State University (CSU), Fort Collins, Colorado, USA. His research involves nondestructive testing of structures.

Dr. B. Witchayangkoon is an Associate Professor of Department of Civil Engineering at Thammasat University.

He received his B.Eng. from King Mongkut’s University of Technology Thonburi with Honors. He continued his study at University of Maine, USA, where he obtained his PhD in Spatial Information Science & Engineering.

Dr. Witchayangkoon current interests involve applications of emerging technologies to engineering.

Songpol Panmekiat is a Master Candidate in Department of Civil Engineering, Faculty of Engineering, Thammasat University, Thailand. He obtained a Bachelor of Engineering from Engineering and Business Management (EBM) Program, Thammasat University. Panmekiat research interests encompass investigations of structures via nondestructive evaluation (NDE).

20

Saharat Buddhawanna, Boonsap Witchayangkoon, and Songpol Panmekiat

2015International International Transaction TransactionJournal Journalof of Engineering, Engineering,Management, Management, &&Applied Applied Sciences Sciences &&Technologies.

Technologies.

2015

International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies http://TuEngr.com

Effect of Exchangeable Cations on Bentonite Swelling Characteristics of Geosynthetic Clay Liners Anekpong Thammathiwat a, and Weeraya Chimoye a* a

Department of Civil Engineering, Faculty of Engineering, Thammasat University, THAILAND

ARTICLEINFO

Article history: Received 08 October 2014 Received in revised form 15 December 2014 Accepted 19 December 2014 Available online 24 December 2014

Keywords: X-ray diffraction test; Scanning electron microscopy; Bentonite; Montmorillonite; GCL;

A B S T RA C T

Geosynthetic clay liners (GCLs) are thin hydraulic barriers which contain the bentonite sandwiched between geotextiles or geomembrane. Bentonite swelling is a very common phenomenon observed in GCLs. It is one of the major causes for permeability reduction in hydraulic barriers. The aim of this study is to characterize the swelling behavior of bentonite in GCLs by exchangeable cations.

X-ray diffraction test and scanning electron microscopy were used to quantify the swelling characteristics of this bentonite under contact with salt solutions, as in the hydraulic barriers. The results from X-ray diffraction test showed that the presence of clay minerals was swelling montmorillonite. The swell volume of bentonite decreases with increasing valence of cations. In the case of the same valence the free swell volume of bentonite increased with decreasing concentration of permeant liquids. From another test, the scanning electron microscopy, it can be seen that the bentonite appears as corn flake like crystals for air-dried bentonite. However, specimen permeated with salt solutions, the clay has become more porous and fluffy and porous size seemed to be diminished.

2015 INT TRANS J ENG MANAG SCI TECH.

1. Introduction Geosynthetic clay liners (GCLs) are thin hydraulic barriers containing approximately 1 lb/ft2 (5 kg/m2) of bentonite, sandwiched between two geotextiles or attached with an adhesive to a geomembrane. Due to surrounding environmental conditions and applied superimposed loads, conventional compacted clay liners (CCLs) develop internal cracks and shrinkage that lead to significant increase in seepage and leakage of contaminant liquid into the soil and ground water. *Corresponding author (A.Thammathiwat). Tel/Fax: +66-8-4820-5674. E-mail address: 2015. International Transaction Journal of Engineering, Management, anekpong_l@hotmail.com. & Applied Sciences & Technologies. Volume 6 No.1 ISSN 2228-9860 eISSN 1906-9642. Online Available at http://TUENGR.COM/V06/021.pdf.

21

Bentonite used in GCLs is commonly a sodium bentonite, where sodium ions are located in the interstitial water, between clay platelets, in an adsorptive layer that results in the bentonite swelling characteristics. This swelling allows the bentonite to seal around penetrations, giving the GCL self-sealing characteristics (Bouazza, 2002).

The primary mineral in bentonites is montmorillonite (Moore and Reynolds, 1997) that is the most commonly found mineral in the dioctahedral smectite subgroup, where substitution of one Mg2+ occurs in every sixth Al3+ in octahedral sheets and no substitution takes place in tetrahedral sheets (Grim, 1968, Faure, 1998). Because the adsorbed layer plays in controlling the hydraulic conductivity of clay minerals and, in particular, bentonite is reported by Mesri and Olson (1971). They permeated sedimented specimens of kaolinite, illite, and montmorillonite with nonpolar liquids, salt solutions (NaCl and CaCl2), and deionized water. At a given void ratio, the kaolinite, illite, and montmorillonite had identical hydraulic conductivity when permeated with nonpolar liquids. In contrast, the three minerals had very different hydraulic conductivities when permeated with the salt solutions and deionized water.

Because replacement of sodium in the exchange complex with other ions should affect the thickness of the adsorbed layer and, thus, swelling and hydraulic conductivity of the bentonite in GCLs. X-ray diffraction is a routine method in mineralogy, particularly for fine-grained material study. It is one of the primary techniques used by mineralogists and solid state chemists to examine the physicochemical composition of unknown solids. Then, this study aims to study the effect of exchangeable cations on bentonite swelling characteristics of geosynthetic clay liners

by X-ray diffraction test in term of distance of clay particle (interlayer) and scanning electron microscopy. The influence of valence and concentration of solution on bentonite swelling characteristics by X-ray diffraction test and scanning electron microscopy was investigated to characterization of crystalline materials and the determination of atomic packing in the crystalline state and interatomic distances and angles.

2. Materials and methods 2.1 Materials In this study bentonite was prepared from the high strength type of GCLs, namely: Enviromat. The GCLs, Enviromat, contained sodium bentonite placed between high strength non-woven geotextile and high-density polyethylene geomembrane. The geotextile were bonded together by needle punching. The initial air-dried thickness of the bentonite layer was approximately 3.5 mm and the initial water content of the bentonite was 12%. The total thickness 22

Anekpong Thammathiwat, and Weeraya Chimoye

of the GCLs was about 4.0 mm. For the physical properties of the bentonitein the GCLs, liquid limit was 540 %, plastic limit was 62% and plasticity index was 472%, which were very much higher than those of general clays because its primary mineral was montmorilonite.

2.2 X-Ray Diffraction Test The X-ray diffraction data were performed using a Bruker AXS Model D8 Discover. X-rays are generated within a sealed tube under vacuum. A current is applied that heats a filament within the tube; the higher the current the greater the number of electrons emitted from the filament. This generation of electrons is analogous to the production of electrons in a television picture tube. A high voltage, typically 15-60 kilovolts, is applied within the tube. This high voltage accelerates the electrons, which then hit a target, commonly made of copper. When these electrons hit the target, X-rays are produced.

The wavelength of these X-rays is

characteristic of that target. These X-rays are collimated and directed onto the sample, which is a fine powder of particle size of less than 10 microns.

2.3 Scanning Electron Microscopy In this study, microstructure of the received bentonite was conducted by Scanning Electron Microscopy (SEM). Energy dispersive X-ray microanalysis uses detection equipment to measure the energy values of the characteristic X-rays generated within the electron microscope. An Xray micro-analyzer system converts X-ray energy into an electronic count by using semiconductor materials that can detect the X-rays. The accumulation of these energy counts creates a spectrum, which is then plotted against relative counts of the detected X-rays and evaluated for qualitative and quantitative determination of the elements present in the specimen.

3. Results and Discussion 3.1 X-ray Diffraction Test X-ray powder diffraction (XRD) patterns of the clay fraction were obtained using a Bruker AXS Model D8 Discover. The dispersed clay fraction separated by sedimentation under gravity was centrifuged on a glass slide in a high speed centrifuge and the XRD patterns were recorded as shown in Figure 1 and 2. Figure 1 shows the XRD patterns of air-dried bentonite specimen and bentonite permeated with DW, 0.1M NaCl and 0.1M CaCl2. When the XRD patterns of bentonite permeated with DW (Figure 1(b)) was examined, firstly a sharp peak whose d(001) distance (approximately 7.107(2θ)) was 12.43 Å was seen. The fact that the 10.20 Å d(001) distance (7.088(2θ)) for air-dried went up to 12.43 Å proves that the DW molecule went into between the bentonite layer and was bound to them. It can be concluded that when DW molecule *Corresponding author (A.Thammathiwat). Tel/Fax: +66-8-4820-5674. E-mail address: 2015. International Transaction Journal of Engineering, Management, anekpong_l@hotmail.com. & Applied Sciences & Technologies. Volume 6 No.1 ISSN 2228-9860 eISSN 1906-9642. Online Available at http://TUENGR.COM/V06/021.pdf.

23

5000 M: Montmorillonite

4000

C: Cristobalite Q: Quartz

3000 2000 1000

(a) Air-dried

5000 4000 3000 2000 1000

(b) DW

5000 4000 3000 2000 1000

(c) 0.1 M NaCl

5000 4000 3000 2000 1000

(d) 0.1 M CaCl2

Figure 1: Effect of cation on microstructure swelling characteristics (a) air-dried, (b) DW, (c) 0.1M NaCl and (d) 0.1M CaCl2 specimen.

24

Anekpong Thammathiwat, and Weeraya Chimoye

5000 M: Montmorillonite

4000

C: Cristobalite Q: Quartz

3000 2000

(a) DW

1000 5000 4000 3000 2000 1000

(b)0.025 M CaCl2

5000 4000 3000 2000 1000

(c) 0.1 M CaCl2

5000 4000 3000 2000 1000

(d) 1.0 M CaCl2

Figure 2: Effect of concentration on microstructure swelling characteristics (a) DW, (b) 0.025M, (c) 0.1M and (d) 1.0M CaCl2 specimen.

*Corresponding author (A.Thammathiwat). Tel/Fax: +66-8-4820-5674. E-mail address: 2015. International Transaction Journal of Engineering, Management, anekpong_l@hotmail.com. & Applied Sciences & Technologies. Volume 6 No.1 ISSN 2228-9860 eISSN 1906-9642. Online Available at http://TUENGR.COM/V06/021.pdf.

25

14

d(001), Å

DW 12

Air-dried 10

8

0

1

2

3

Valence

Figure 3: Valence dependence of the d-value for X-ray diffraction test

14

d(001), Å

DW 12

10

8

0

0.2

0.4

0.6 0.8 Concentration, M

1

1.2

Figure 4: Concentration dependence of the d-value for X-ray diffraction test was bound between the bentonite layers, it created an inner layer space of 2.23 Å. On the other hand, in Figure 1(c) and (d) it can be seen that d(001) distance for bentonite permeated with 0.1M NaCl went up to 12.27 Å (7.200(2θ)) and 11.26 Å (5.787(2θ)) for bentonite permeated with 0.1M CaCl2. Then Na+ and Ca2+ cations created and inner double layer of bentonite 2.07 Å and 1.06 Å, respectively. Since the diffuse double layer of divalent cations (Ca2+) in thinnest compare with monovalent cation (Na+). In addition, in the XRD patterns of air-dried bentonite 26

Anekpong Thammathiwat, and Weeraya Chimoye

specimen in Figure 1(a), the peak with 4.48 Å distance (19.770(2θ)), 3.13 Å distance (28.446(2θ)), 3.34 Å distance (26.622(2θ)) and the one with a 1.50 Å distance (61.940(2θ)) belong to the major montmorillonite component. Also, a quartz non-clay component with 26.62(2θ) was seen in the same XRD pattern.

Figure 2 shows the XRD pattern of the bentonite permeated with DW, CaCl2 solutions at 0.025M, 0.1M and 1.0M concentrations. There is a considerable increase in the d(001) spacing of the montmorilonite for values of CaCl2 solutions concentration under 1.0 M and the swelling increased dramatically from 11.21 Å (5.804(2θ)) for 1.0 M to 11.26 Å (5.787(2θ)) for 0.1M CaCl2 and 11.82 Å (5.958(2θ)) for 0.025 M CaCl2, respectively.

It shows that double layer of

montmorillonite decreased with the increasing of concentration of solution.

Since when the

concentration of cations in the solution increases, water moves out of the interlayer and causes the reduction in swell. In addition, valence and concentration dependence of the d-value for X-ray diffraction test are ploted in Figure 3 and Figure 4. In these figure, the d-value of bentonite decreased with increasing valence and concentration of solution.

3.2 Scanning Electron Microscopy In this study, scanning electron microscopy (SEM) was used to proof the change in morphological features of air-dried bentonite in GCLs and after permeated with DW, NaCl and CaCl2 solutions (Figure 5).

Surface morphological analyses were made in a SEM (JSM-

5800LV), working at 15 kV of electron accelerating voltage and with a beam current of about 1 nA at the specimen level. Sample were gold-coated with a layer about 10 nm thick by using a vacuum of 0.15 Pa (10-5 Torr) metal-coating process.

The surface morphology of air-dried bentonite in Figure 5(a) is different from that after permeated with DW, NaCl and CaCl2 solutions in Figure 5(b)-(d). The air-dried bentonite appears as corn flake like crystals with fluffy appearance revealing its extremely fine platy structure. This is consistent with the reported SEM micrographs for bentonite (Nguetnkam et al., 2005 and Reinholdt et al., 2001). However, after permeated with DW as shown in Figure 5(b), clay has become more porous and fluffy. This porous and fluffy appearance probably occurs due to the change in the surface charge of the particle as a result of permeated process and the reduction in certain amorphous phase originally associated with the air-dried bentonite.

SEM picture for specimen permeated with DW, 0.1M NaCl, 0.025M CaCl2, 0.1M CaCl2 and 1.0M CaCl2 were represented in Figure 6(a)-(d). It can be seen that the porous size seemed to be *Corresponding author (A.Thammathiwat). Tel/Fax: +66-8-4820-5674. E-mail address: 2015. International Transaction Journal of Engineering, Management, anekpong_l@hotmail.com. & Applied Sciences & Technologies. Volume 6 No.1 ISSN 2228-9860 eISSN 1906-9642. Online Available at http://TUENGR.COM/V06/021.pdf.

27

diminished from bentonite specimen permeated with DW specimen in Figure 6(a) due to the large specific surface of montmorillonite adsorb a large number of hydrated cations during hydration that can comprise a significant fraction of pore space, and are essentially immobile.

However, the porous and fluffy decreased with increase in concentration of CaCl2 solution as shown in Figure 6(b)-(d).

Similar with free swell results of montmorillonite, at similar

concentration, swell volume was larger with monovalent cation solutions than with divalent and trivalent cation solution (Anekpong and Weeraya, 2010).

(a)

(b)

(c)

(d)

Figure 5: SME micrographs of (a) air-dried specimen (b) distilled water (c) 0.1M NaCl solution (d) 0.1M CaCl2 solution (1,500x).

28

Anekpong Thammathiwat, and Weeraya Chimoye

(a)

(b)

(c)

(d)

Figure 6: SME micrographs of (a) distilled water (b) 0.025 M CaCl2 solution (c) 0.1M CaCl2 solution and (d) 1.0M CaCl2 solution (1,500x).

4. Conclusion The results from X-ray diffraction test showed that the presence of clay minerals was swelling montmorillonite. The swell volume of bentonite decreases with increasing valence of cations. In the case of the same valence, the free swell volume of bentonite increased with decreasing concentration of permeant liquids. Since the diffuse double layer of trivalent cations in thinnest compare with monovalent and divalent cation. From the scanning electron microscopy, it can be seen that the bentonite appears as corn flake like crystals for air-dried bentonite.

However, specimen permeated with salt solutions, the clay has become more porous and fluffy *Corresponding author (A.Thammathiwat). Tel/Fax: +66-8-4820-5674. E-mail address: 2015. International Transaction Journal of Engineering, Management, anekpong_l@hotmail.com. & Applied Sciences & Technologies. Volume 6 No.1 ISSN 2228-9860 eISSN 1906-9642. Online Available at http://TUENGR.COM/V06/021.pdf.

29

and porous size seemed to be diminished due to the large specific surface of montmorillonite adsorb a large number of hydrated cations during hydration that can comprise a significant fraction of pore space, and are essentially immobile.

5. Acknowledgements The authors express their deep gratitude and sincere appreciation to Associate Professor Dr. Burachat Chatveera, Assistant Professor Dr. Winai Raksuntorn, Assistant Professor Dr. Sunisa Smittakorn, and Dr.Parames Kamhangrittirong for their interest, useful suggestions and constant support in this study.

6. References Anekpong, T. and Weeraya, C. (2010). Effect of permeant liquid on the swell volume and permeability of Geosynthetic Clay Liners. The Electronic Journal of Geotechnical Engineering, 15L, 1183-1197.

Bouazza, A.(2002). Geosynthetic clay liners. Geotextiles and Geomembranes, 20 (1), 3-17.

Faure, G. (1998). Principles and Applications of Geochemistry, 2nd edition, Prentice-Hall, Inc., New Jersey.

Grim, R.E. (1968). Clay Mineralogy, 2nd edition, McGraw-Hill Book Company.

Mesri, G. and Olson, R..E. (1971). Mechanisms Controlling the Permeability of Clays.Clays and Clay Minerals, 19(3), 151-158.

Moore, D.M., and R.C. Reynolds, Jr. (1997). X-ray diffraction and the identification and analysis of clay minerals. 2nd ed. Oxford Univ. Press, New York.

Nguetnkam J.P., Kamga R., VilliĂŠras F., Ekodeck G.E., Razafitianamaharavo A., Yvon J. (2005). Assessment of the surface areas of silica and clay in acid-leached clay materials using concepts of adsorption on heterogeneous surfaces, Journal of Colloid and Interface Science, 289, 104 - 115.

Reinholdt, M., Miehe-Brendle, J., Delmotte, L., Tuilier, M.-H.,Le Dred, R., Cortes, R., Flank, A.-M. (2001). Fluorine route synthesis of montmorillonites containing Mg or Zn and character-ionzation by XRD, thermal analysis, MAS NMR, and EXAFS spectroscopy.

European Journal of Inorganic Chemistry, 2831-2841.

Anekpong Thammathiwat received his Bachelor in Civil Engineering from Thammasat University in 2000.

He received his Master of Engineering in Structural Engineering from Thammasat University in 2003. Now he is a PhD candidate at Faculty of Engineering, Thammasat University. He is currently working at the Phetchabun Rajabhat University. His research is related to permeability and swelling characteristics of GCLs permeated with chemical solution and leachates.

Dr. Weeraya Chimoye is an Associate Professor of Department of Civil Engineering at Thammasat University. She received her B.Eng. from Kasetsart University in 1987. She continued her Ph.D. study at Hiroshima University, Japan, where she obtained her PhD in Geotechnical Engineering. Her research encompasses geotechnical and geoenvironmental engineering.

30

Anekpong Thammathiwat, and Weeraya Chimoye

2015 2015 International InternationalTransaction Transaction Journal Journalof of Engineering, Engineering, Management, Management, && Applied Applied Sciences Sciences&& Technologies.

Technologies.

International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies http://TuEngr.com

Roles of Bangkok Vanpool Commuter Services Towards Livable City Boonsap Witchayangkoon a*, Sayan Sirimontree a, Saharat Buddhawanna a, and Krittiya Lertpocasombut a a

Department of Civil Engineering, Faculty of Engineering, Thammasat University, THAILAND

ARTICLEINFO

A B S T RA C T

Article history: Received 29 September 2014 Accepted 24 December 2014 Available online 24 December 2014

This work reports an observation on vanpool commuter services in Bangkok. Vanpool commuter services, a unique service in Thailand, are offered by a join of van owners. Vanpools are similar to carpools in that all passengers share the ride. As an element of the transit system, vanpools offer reduced travel costs as it can save fuels and tolls. Each vanpool service conveys hundreds of thousand passengers with specific route of origin and destination, as riders can also get off at a station along its route. This study uses questionnaire as a study tool, to ask 100 passengers about their satisfactions in term of safety, convenience, and reasonable fares. The questionnaire has 5 Likert scales, with 5 being the highest satisfaction level and 1 the lowest satisfaction level. From the study, passengers have moderate satisfaction with the services, with 3.4 score. With hundreds of thousand users, vanpool commuter services make Bangkok a livable city in aspects of public transportation, and environmental issues.

Keywords: questionnaire survey; satisfaction survey; minibus; Likert scales; vanpool transport.

2015 INT TRANS J ENG MANAG SCI TECH.

1. Introduction Vanpools are similar to carpools in that all passengers share the ride.

Each vanpool

commuter service takes off from its station. Most of the passengers are collected at its take-off station; some passengers possible get in at the following stations along the route. As an element of the transit system, vanpools offer reduced travel costs of fuels and tolls. Stress of driving is also avoided (worry-free). In fact, vanpool services help decrease traffic volume and congestion.

By this, vanpool can help reduce amount of emitted gases, thus less pollution. Also, it is no need *Corresponding author (Boonsap Witchayangkoon). Tel/Fax: +66-2-5643005 E-mail address: drboonsap@gmail.com.

2015. International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. Volume 6 No.1 ISSN 2228-9860 eISSN 1906-9642. Online Available at http://TUENGR.COM/V06/031.pdf.

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of finding parking spaces. In Thailand, most of vanpool commuter services are in Bangkok and its outskirt provinces areas. With more than a hundred routes, vanpool commuter services make Bangkok a livable city in aspects of public transportation, and saving environmental issues.

2. Review of Literature In USA, there are companies and government agencies offering vanpool and school-bus services sending students to school and people to work. For example, the State of Wisconsin provides alternate vanpool transportation for state and non-state employees commuting to Madison from outside communities. The State of Wisconsin Vanpools are groups of 7-15 commuters sharing their ride to work in a passenger van that is owned, insured and serviced by the Wisconsin State Vanpool Program. Passengers share the van operating cost by paying a fare based on fixed and variable costs, the number of riders, and the number of miles driven. The fare covers all costs including gas, insurance and van maintenance (self-supporting operation).

Participants can join a group that is already established or, if there are enough interested people, they can form a new vanpool. Participants who like to drive could commute for free. Riders enjoy low rates (allowed up to 100% deduction for their services), comfortable vans, and the benefit of convenient pick-up and drop-off locations (UWM, 2010).

For international travels, there are companies offer daily minibuses (vanpools) for more than 10 years, for example, for trips between HadYai (South of Thailand) and Malaysia (e.g. Penang and Kuala Lumpur) (KST, 2010). Many travellers have used the minibuses services for many years and some seem happy with the services (Pantip, 2013).

Transport Studies Group of the Polytechnic of Central London studied on minibus development in Britain in term of cost-benefit analysis (White, 1992). Unit operating cost savings and passenger benefits were taken into account. Factors of passenger benefits primarily comprised reduced waiting time at the stop, reduced in-vehicle traveling time, and reduced walking time particularly permit minibus operation for better penetration to housing estates and town centers.

A survey of Sydney Metropolitan bus users 2010 was performed after a Sydney Metropolitan bus customer satisfaction survey in 2009 (TNSW, 2010). For each bus route, respondents were taken from different ages and genders. For quality rating, the study used fivescale rating with score 5 referring to very good, 4 good, 3 acceptable, 2 poor, and 1 very poor.

For important rating for aspect of service, score 5 means very important, 4 important, 3 desirable, 2 somewhat unimportant, 1 not at all important. Even though, there are many bus customer satisfaction surveys, but there are never any vanpool customer satisfaction survey.

This work is thus aim at studying vanpool services via satisfaction survey.

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B. Witchayangkoon, S. Sirimontree, S. Buddhawanna, and K. Lertpocasombut

Figure 1: Standard Vanpool Commuter in Thailand.

3. Characteristics of Public Vanpool Commuter in Thailand In Thailand, a vanpool commuter carries a group passenger of up to 15 people who commute together from the same origin to the same destination, with fixed route. The van is owned, maintained, and insured by its driver or a co-op. The van station collects passengers until the schedule time or immediately hit the road when passengers are full. Each seat is equipped with a seat belt. Passengers are normally sitting in the upright posture, as there is limited legroom. The van is installed mostly with either two steel cylinder NGV tanks or one LPG tank. Each public vanpool has yellow plate. The vanpools are run for many routes with different providers. Each vanpool vehicle normally runs multiple rounds each day. Vanpool is an economic way of sharing commute platform to get from specific place to place along its route.

Normally, vanpools in Thailand share bus stations for pickup (additional passengers in case of available seat) and drop-off passengers. Some vanpool routes also use toll-ways, in order for passenger to travel faster, while the toll cost is included in the vanpool fare. Vanpool commuter services gain popularity among Thai due mainly to convenience and cheap commute cost. Most of passengers are students, and working people. Figure 1 shows a standard vanpool commuter in Thailand.

4. Vanpool Fares and Daily Service Hours In Thailand, fares of vanpool commuter are fix prices, depending on route. Driving distance for each vanpool route is varied, approximately 10-40km for local travel or longer distance for traveling to/from upcountry provinces. Current fares are from 15Baht (about US$0.50), 30Baht (about US$1.00), 40Baht (about US$1.30) and more. Travel fares of each vanpool commuter route are posted at its take-off station. Vanpool commuter daily service hours vary on the route, mostly start about or before 6AM until about 9PM or later.

*Corresponding author (Boonsap Witchayangkoon). Tel/Fax: +66-2-5643005 E-mail address: drboonsap@gmail.com.

2015. International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. Volume 6 No.1 ISSN 2228-9860 eISSN 1906-9642. Online Available at http://TUENGR.COM/V06/031.pdf.

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5. Methodology 5.1 Passenger Satisfaction With vanpool services, passenger satisfaction indicates how products and services meet or exceed passenger expectation or specified satisfaction goals. This work uses questionnaire as a study tool to survey passengers’ perceptions regarding their satisfactions of the uses of vanpool services.

5.2 Questionnaire Survey A questionnaire asks a series of questions about respondents’ experience and perceptions of their vanpool travel in the previous six months. The pilot test questionnaire is conducted for ten respondents to obtain feedbacks for improvements. After the pilot test, the questionnaires are revised such that each question can be more clearly understood. The questionnaire asked for the main reason of why respondents have been using vanpool commuter services.

The questionnaire surveyed for passengers’ satisfaction levels of using vanpool commuter services. The satisfactions are derived from the five Likert scale questionnaire with 5: High Satisfaction.

4: Good Satisfaction, 3: Satisfaction, 2: Fair satisfaction, and 1: No satisfaction.

Respondents are asked to answer with their perceptions and experiences they have with the vanpool commuter service within the past six months. Total three main criteria are asked, in terms of physical landscape of vanpool station, aspects of service, and conditions of vehicle. For physical landscape, the questionnaire involves satisfaction on vanpool take-off station, cleanliness of vanpool take-off station, access to vanpool commuter service, and number of vanpool commuter. For aspects of service, the questionnaire involves satisfaction on taking off follow posted schedule, willingness and eagerness to serve of staff, driving follow posted speed, having confidence in vanpool driver, and fare rates. For conditions of vehicle, the questionnaire asks satisfaction on Cleanliness inside the vanpool commute vehicle, Air condition system, Seat comfortability, and Seat belt. A privacy statement is noted that the identity of interviewers is not collected.

In this study, there are total 100 respondents (56 males and 44 females) are randomly selected from a wide range of respondents and different age groups of males and females. The survey is conducted during April 2014.

34

B. Witchayangkoon, S. Sirimontree, S. Buddhawanna, and K. Lertpocasombut

6. Study Result 6.1 Reasons of Using Vanpool Commuter Services All respondents are asked for the main reason of using vanpool commuter service. The reasons of using vanpool commuter are mostly from convenience, cheap cost, and being a fast commute, as shown in Table 1.

Table 1: Main Reason of Using Vanpool Transport.

Main Reason of Using Vanpool Frequencies Convenience 35 Cheap Cost 23 Being a Fast Commute 29 Punctuality 4 No other type of commute 9 available for the route Other reasons Sum 100

6.2 Respondents’ Expense for Vanpool Transport Expense of each respondent is surveyed, as shown in Table 2. A few of respondents spend for vanpool commuter services more than 200Baht/week (US$6.24), as most respondents pay less than 100Baht/week (US$3.12).

Table 2: Respondents’ weekly expenses for vanpool transport.

Expense for Vanpool Transport Frequency (per week) < 50 Baht (< US$1.56) 49 50-100 Baht (US$1.56 – US$3.12) 29 101-200 Baht (US$3.13 – US$6.24) 14 > 200 Baht (> US$6.24) 8 Total 100

7. Satisfaction Criteria Having vanpooling experiences, respondents’ perceptions on various criteria are reported in Table 3. Even though average of each criterion is above 3.0, criteria for physical landscape of vanpool station seem to be higher than criteria for service and criteria for condition of vanpool vehicle. Condition of vanpool vehicle seems to produce least satisfaction level, compared to other main criteria. This indicates that vanpool owner should improve and maintain good vehicle conditions. The highest satisfaction is criterion on suitability of vanpool take-off station.

It is also learn that passengers are quit very happy with the fair rates of vanpooling services.

This may that even the fuel prices are high, but the fairs are cheap because the vanpools are using LPG or NGV. *Corresponding author (Boonsap Witchayangkoon). Tel/Fax: +66-2-5643005 E-mail address: drboonsap@gmail.com.

2015. International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. Volume 6 No.1 ISSN 2228-9860 eISSN 1906-9642. Online Available at http://TUENGR.COM/V06/031.pdf.

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Table 3: Satisfaction Criteria in Using Vanpool Commuter Services.

Frequencies Satisfaction Criteria Satisfaction Level 5 4 3 2 1 Physical Landscape of Vanpool Station Suitability of vanpool take-off station 16 25 5 2 52 Cleanliness of vanpool take-off station 12 41 3 1 43 Access to vanpool commuter service 15 38 5 3 39 Number of vanpool commuter 13 10 1 38 38 Services Taking off follow posted schedule 5 33 15 2 45 Willingness and eagerness to serve of staff 5 42 7 0 46 Driving follow posted speed 4 38 12 0 46 Having confidence in vanpool driver 5 23 11 3 58 Fare rates 10 33 4 0 53 Condition of vehicle Cleanliness inside the vanpool commute vehicle 8 38 7 0 47 Air condition system 3 23 15 7 52 Seat comfortability 4 32 13 7 44 Seat belt 8 30 21 7 34 Overall satisfaction

Avg 3.75 3.60 3.58 3.52 3.24 3.45 3.42 3.16 3.69 3.56 3.00 3.13 3.11 3.40

8. Conclusion This work presents an observation on vanpool commuter services in Thailand. Similar to carpools, all vanpools passengers share the ride for the same specific route of origin and destination as riders can hop in and get off at any station along its route. Being an element of the transit system, vanpools give worry-free and cost-effective commute as it save fuels and tolls.

This study uses questionnaire as a study tool, asks 100 passengers about their satisfactions in three main criteria: physical landscape of vanpool station, aspects of service, and conditions of vehicle.

With five Likert scales questionnaire, it is found that passengers have moderate

satisfaction with the vanpool services, with 3.4 score at average. Vanpooling is an important environmentally friendly, sustainable, and faster way to commute. With vanpooling, sharing journeys reduce traveling cost and toll, driving stress, traffic congestion, and carbon emissions on the roads. In Bangkok alone, hundreds of thousand people traveled with vanpool commuter services truly make Bangkok a livable city.

9. Acknowledgment The authors would like to thank Mr.Pittawas Thoenburin and Mr.Voraphan Jitarjhan for helping collect the data of this study.

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B. Witchayangkoon, S. Sirimontree, S. Buddhawanna, and K. Lertpocasombut

10. References KST. (2010). Van-Bus-Boat Service. http://www.ksttravelthailand.com/index.php?lay=show&ac=article&Id=538990053 Accessed October 2014.

Pantip. (2013). What is the best vanpool service for traveling to George Town Penang Malaysia from HatYai Thailand. Pantip Discussion Board. http://pantip.com/topic/30699231 Accessed October 2014.

TNSW. (2010). Survey of Sydney Metropolitan Bus Users 2010. Transport New South Wales. http://www.transport.nsw.gov.au/sites/default/files/b2b/publications/bus_survey_2010.pdf Accessed October 2014.

UWM. (2010). Vanpooling Information. Transportation Services of the University of WisconsinMadison. http://transportation.wisc.edu/transportation/vanpool.aspx Accessed October 2014.

White, P. R., Turner, R. P., & Mbara, T. C. (1992). Cost benefit analysis of urban minibus operations.

Transportation, 19(1), 59-74.

Dr. Boonsap Witchayangkoon is an Associate Professor of Department of Civil Engineering at Thammasat University. He received his B.Eng. from King Mongkutâ&#x20AC;&#x2122;s University of Technology Thonburi with Honors in 1991. He earned his PhD from University of Maine, USA in Spatial Information Science & Engineering. Dr. Witchayangkoon current interests involve applications of emerging technologies to engineering.

Dr. Sayan Sirimontree earned his bachelor degree from Khonkaen University Thailand, master degree in Structural Engineering from Chulalongkorn University Thailand and PhD in Structural Engineering from Khonkaen University Thailand. He is an Associate Professor at Thammasat University Thailand. He is interested in durability of concrete, repair and strengthening of reinforced and prestressed concrete structures.

Dr. Saharat Buddhawanna is an Assistant Professor of Structural Engineering at Thammasat University in Thailand. He received a Bachelor Degree in Agricultural and Civil Engineering and Master Degree in Structural Engineering from Khonkaen University (KKU), Khonkaen, Thailand. Dr Buddhawanna earned Master and Ph.D. degrees in Civil Engineering concentrated on Structural Engineering field from University of Colorado (UCD), Denver, and Colorado State University (CSU), Fort Collins, Colorado, USA. His research involves nondestructive testing of structures.

Dr. Krittiya Lertpocasombut is an Associate Professor in the Department of Civil Engineering, Faculty of Engineering, Thammasat University, Thailand. She received a B.Sc. from Chulalongkorn University, Thailand, an M.Sc. from Asian Institute of Technology, D.E.A. Diplome dâ&#x20AC;&#x2122;Etudes Approfondies in Water Purification and Treatment Engineering from INSA de Toulouse, France, and a PhD in Water Purification and Treatment Engineering, Institut National des Sciences Appliquees (INSA), Toulouse, France. Dr. Lertpocasombut is interested in water and wastewater treatment; wastewater recycled by membrane technology; water supply sludge treatment and its reuse/recycle.

Note: The original of this article was presented as a keynote paper at the 2nd International Workshop on Livable City 2014 (IWLC2014), a Joint Conference with International Conference on Engineering, Innovation, and Technology (EIT), held at Tabung Haji Hotel, Alor Star, Malaysia, during December 9-11, 2014.

*Corresponding author (Boonsap Witchayangkoon). Tel/Fax: +66-2-5643005 E-mail address: drboonsap@gmail.com.

2015. International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies. Volume 6 No.1 ISSN 2228-9860 eISSN 1906-9642. Online Available at http://TUENGR.COM/V06/031.pdf.

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