Introduction to Roadworks

ROAD WORKS NUR QIAM FARHANA ADNAN

SUBTOPIC

PAGE

Definition

3

History of Road Development

4

Pavement

5

Types of Pavement

6

- Flexible Pavement

7

- Rigid Pavement

8

Pavement Works

10

Flexible Pavement Structures

12

Construction of Road Shoulder

19

Road Furniture

20

Road Markings

29

Road Drainage System

41

References

48

DEFINITION A road is a thoroughfare, route, or way on land between two places that has been paved or otherwise improved to allow travel by foot or some form of conveyance, including a motor vehicle, cart, bicycle or horse.

Road consist of one or two roadways (carriageways), each with one or more lanes and any associated sidewalks (pavement) and road verges.

Other names for roads include parkways, avenues, freeways, tollways, interstates, highways or primary, secondary and tertiary local roads.

Laterite Road

Roman Road HISTORY OF ROAD DEVELOPMENT

Pierre Tresaguet Road John Metcalf Road Thomas Telford Road John Macadam Road

PAVEMENT means surfacing layer only. includes all the structural layers of road structure lying on subgrade of the road. durable surface material laid down on an area intended to sustain vehicular or foot traffic, such as road or walkway. in the past, cobblestones and granite setts were extensively used. nowadays, asphalts or concrete have mostly been replaced.

FLEXIBLE PAVEMENT

TYPES OF PAVEMENT RIGID PAVEMENT

FLEXIBLE PAVEMENT Any kind of pavement that is not constructed using concrete.

Commonly constructed by using flexible pavement. constructed from bituminous or unbound material. the stress is transmitted to the sub-grade through the lateral distribution of the applied load with depth.

RIGID PAVEMENT The stress is transmitted to the sub-grade through beam/slab effect. contain sufficient beam strength to be able to bridge over localize sub-grade failures and areas of inadequate support. in contrast with flexible pavements the depressions which occur beneath the rigid pavement are not reflected in their running surfaces.

PAVEMENT WORKS

Preparation of materials used in the sub-base and road base of flexible pavement.

Not constructed using concrete.

Very low flexural strength and flexible in their structural behavior when under a load.

Priming cover - prime coat, tack coat.

Pavement Purposes : Load support, Smoothness & Drainage.

CHARACTERISTIC OF FLEXIBLE PAVEMENT

Elastic Use bituminous Easy to do road maintenance Do not have any expansion joint

FLEXIBLE PAVEMENT STRUCTURE SUB-GRADE A layer of natural soil or filled soil prepared to receive the pavement materials over it.

Function : to transfer the entire load coming to it to the earth mass and provide a good support to the pavement structure.

The strength properties of the soil sub-grade is necessary to evaluate.

The following tests on soils are carried out to find out its strength CBR Test Triaxial Compaction Test Field Density Test

FLEXIBLE PAVEMENT STRUCTURE SUB-BASE COURSE One course that is constructed to prepare the drainage from rough materials and its absorbs forces from road base directly and spreads the forces to the sub grade.

Function : i) improves the bearing capacity of sub-grade ii) checks the capillary rise of sub soil water iii) prevents sub grade material from working up into the base course iv) eliminates frost heave in frost affect area

FLEXIBLE PAVEMENT STRUCTURE BASE COURSE Main course of the road pavement.

Absorbs force from surface directly and spreads the force to the sub base.

Most important component of pavement structure because it has to bear the impact of traffic transferred through the wearing course.

Function : i) acts as foundation for the road pavement and transfer the traffic load to the sub base course ii) withstands the high shearing stress imposed upon it due to impact of traffic on the wearing course

PRIME COAT An apply of a low viscosity asphalt to a granular base in preparation for an initial layer (or surface course layer) of asphalt.

Purpose of the prime coat; to coat and bond loose material particles on the surface of the base. to harden or toughen the base surface to provide a work platform for construction equipment. to plug capillary voids in the base course surface to prevent migration of moisture, and to provide adhesion between the base course and succeeding asphalt course.

TACK COAT Application of bituminous material over an existing pavement surface that is relatively impervious.

Purpose of the tack coat; very light application of asphalt, usually asphalt emulsion diluted with water. provides proper bonding between two layer of binder course and must be thin, uniformly cover the entire surface, and set very fast.

Binder does not penetrate into the layer & remains at the surface.

BINDER COURSE Providing a flat base layer to wearing course. to spread the traffic force to base course.

WEARING COURSE Final layer of the pavement structure.

Provide smooth and dense riding surface.

Resists pressure exerted by tires.

PAVEMENT WORKS

A. Presentation sub-grade layer B. Laid the sub-base course C. Laid the base course/road base D. Spray the priming coat E. Laid the premix (pavement concrete asphalt orbituminous pavement)

CONSTRUCTION OF ROAD SHOULDERS ROAD SHOULDER IS THE RESERVED AREA ALONGSIDE THE ROADWAY TO BE USED IN THE EVENT OF AN EMERGENCY OR BREAKDOWN.

ROAD FURNITURE

Encompasses all roadside objects used for safety and control of traffic in addition to those for assisting the driver.

Provide drivers with the necessary warnings, rules, distance and directional information in order to travel roads and thoroughfares safely.

Certain types of road furniture include non-essential road elements, such as telephone booths, mailboxes, tourist information signs and trash receptacles.

Traffic control devices include all traffic signs, traffic lights, road signs and other devices placed on or sight of a street or highway by the public authorities.

THE FUNCTIONS ROAD FURNITURE

To provide convenience to the user to reach the destination To provide security for the traffic user To give warning on the dangerous condition along the road way or highway

To avoid traffic conflict at complex or congested areas To smoothen traffic flow or to manage the traffic flow efficiently

ROAD SIGN Traffic signs or road sign warn you of possible dangers and provide information.

The rules and the road conditions.

ROAD FURNITURE For controlling, warning, guiding and informing the users.

Define as lines, patterns, words or other devices, except signs, set into applied or attached to the carriageway or kerbs.

The essential purpose of road markings is to guide and control traffic on a highway.

ROAD MARKING

ROAD SIGN TYPES REGULATION

MANDATORY

ROAD SIGN TYPES REGULATORY & WARNING

ROAD SIGN TYPES INFORMATION

ROAD SIGN TYPES GUIDE & TEMPORARY

ROAD SIGN TYPES GUIDE

ROAD MARKINGS

TYPES OF ROAD MARKINGS

PURPOSE OF ROAD MARKINGS To mark the class path.

To give the user access to the user.

To be a reference to the road authorities.

BASIC PRINCIPLE OF ROAD MARKINGS Street sign can be used to guide and control the position of the vehicle and complete a number of traffic signs.

To channel traffic into the correct position on the route.

To separate opposing traffic flows.

To determine the boundaries of the prohibition zone, overtake and turning lanes at intersections.

THERMOPLASTIC

PAINTS

TYPES OF MATERIAL OF ROAD MARKINGS EPOXY PREFORMED POLYMER PLASTIC TAPES

POWDER LANES, GLASS BEADS ETC

PAINTS reflectorized and non-reflectorized

Paint, sometimes with additives such as retroreflective glass beads, is generally used to mark travel lanes.

It is used to mark spaces in parking lots or special purpose spaces for disabled parking, loading zones, or time-restricted parking areas.

Paint consists of three main components: pigments, resins or binderst is usually applied, an water or solvents.

Painted symbols such as turn-lane arrows are applied manually using stencils.

Painted markings usually last 9 to 36 months.

THERMOPLASTIC The most common types of road marking based on its balance between cost and performance longevity.

Thermoplastic binder systems are generally based on one of three core chemistries : hydrocarbons, rosin esters or maleic modified rosin esters (MMRE).

Applied using specially designed vehicles called road marking machine to coating traffic lines, and the road paint needs preheating by a device commonly called a preheater.

PREFORMED POLYMER PLASTIC TAPES

Commonly referred to as tape or cold plastic, this product is heavy-grade material with reflective beads embedded in the plastic.

It is commonly used to mark crosswalk, stop bars, and traffic guidance such as turn lanes, train crossing, pedestrian crossing, taxi lanes, bus lanes, and bike lanes.

Two types of application: a) Overlay : The application being laid over the surface of the pavement. b) Inlay : The tape physically becomes part of the asphalt.

EPOXY Contains two parts which are pigmented resin base and catalyst.

The two parts are mixed in a specialized truck for epoxy marking application.

The epoxy is then heated prior to spraying onto road surface.

Retroreflective glass beads are applied using a separate bead gun behind the epoxy spray gun.

Typically, epoxy markings last about 4 years.

Mechanical devices may be raised or recessed into the road surface and either reflective or non-reflective.

Most are permanent; some are movable.

Cat's Eye (Road Studs)

Bott's Dots

Rumble Strips

Reflective Markers

TYPES OF ROAD STUDS When road condition is wet, reflectorized road lines with reflectorized road studs is much needed.

3 types of road studs: Cat's eye Corner cube Ceramic

COLOURS USED IN ROAD MARKINGS

All road pavement markings shall be in white colour.

YELLOW paint may be used at : Yellow boxes in the urban areas.

Curb markings showing parking prohibitions covered by signs or ordinance.

Parking bays for taxis, buses and pedestrian crossings.

Yellow bars at approaches to roundabouts and crosswalks.

ROAD DRAINAGE SYSTEM

Road drainage includes the removal or control of surface water and subsurface water away from the road surface and the subgrade that support it, one part of the rainwater flows to the ground or road surface, while the other part flows into the ground and reaches the groundwater table, raising its level.

It includes interception and diversion of water from the road surface and sub grade.

Purpose of road drainage: Road drainage maintains the surface of the road and its foundation as dry as possible with water.

It maintain the stability and durability of the road.

A good drainage system is required to maintain highway transportation at a minimal cost.

TYPES OF ROAD DRAINAGE:

1.SURFACE DRAINAGE: A system in which road surface water is collected and disposed within the roadway, it is called surface drainage.

This system prevents surface water flowing from the surface of the pavement to the shoulders into the subgrade of the road pavement or any other layer.

Functions of surface drainage: To stop the drainage of water from the road surface.

To keep the road surface dry with water.

The flow of water collected by gravity to a nearby natural stream or river.

To increase the stability of all types of pavement.

Types of surface drainage: 1.Side gutter: The drain provides a parallel to the roadway so that collecting and disposing of surface water is called a side gutter.

Surface drainage is efficiently done by providing a side gutter or side drain in the embankment and cuttings.

The section of the side gutter is normally trapezoidal or triangular in cutting.

Side drains are usually provided parallel to roads, the design depth of side drains is low and the road is subjected to light traffic.

Function of side gutter: The main function of the side gutters is to collect surface water.

These drains eventually connect with the natural stream i.e. river.

This side gutter can be cheap, easily constructed, and maintained but it gives an unpleasant look due to the deep ditch, so is undesirable where traffic is heavy.

2.Catch water drains: Additional gutters or road drainage are provided parallel to the road at high levels for the collection and disposal of surface water are known as water drains.

Since the sloping land has a higher water content, it acquires a higher velocity as it approaches the gutter.

This can cause the ground to sink and the drain can also be damaged, therefore water drains are provided exclusively on sloping ground which goes near the roadside drain.

Functions of catch water drains: The catchwater drain accepts a large amount of surface water flow and also breaks the continuity.

In this way, the flow reduces the velocity of the water thus prevents erosion, landslides and thereby protecting the side gutter.

It also helps to reduce the size.

If surface water flowing from high-level land to the road is large, it is desirable to take this water at regular intervals then this water flow through the embankment of the road through a pipe drain.

TYPES OF ROAD DRAINAGE:

2.SUB-SURFACE DRAINAGE: When the system drains water from the pavement under which it is collected and removed, it is called subsurface drainage.

Sub-surface drainage is used exclusively to control the moisture of all types of roads sub-grades.

If the moisture that accumulates in the sub-soil is excessive, the road structure weakens therefore it is more necessary to control the moisture of the road sub-grade.

Functions of sub-surface drainage: To control the moisture of road sub-grades.

Also maintains the carrying capacity of subgrade soil by preventing water ingress into it.

To reduce capillary growth, water sometimes rises to a sub-grade from groundwater due to capillary action.

This can be controlled by introducing a cut-off layer of granular material or impermeable bituminous layer.

ADVANTAGES OF ROAD DRAINAGE: 1. Excess water that accumulation above the ground can create an environment that encourages mosquitoes to breed.

2. Stationary water can make the soil dirty that cause corrosion.

3. A drainage system can solve this problem by removing toxins from your yard.

DISADVANTAGES OF ROAD DRAINAGE: 1. A higher initial cost is required.

2. Repair works are costly and inconvenient.

REFERENCES

All images are from google image.