International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 08 Issue: 07 | July 2021
p-ISSN: 2395-0072
www.irjet.net
Experimental studies on Micro Particles induced High Volume Fly Ash (HVFA) Slabs under Static Loading Keerthan S Reddy1, Dr P S Nagaraja2 1Student,
Department of Civil Engineering UVCE Bangalore, India Department of Civil Engineering UVCE Bangalore, India ---------------------------------------------------------------------***---------------------------------------------------------------------2Professor,
Abstract - This study aims to the effect of using micro
of Portland cement (particularly C-S-H) at the micro-scale. This makes possible the development of better concrete that can address specific durability and environmental issues. Developing these structures in concrete give results in higher compressive, split tensile and flexural strength; lower set time and permeability of water and higher resistance to chemical attacks.
particles as addition to cementitious materials on the properties of fly ash concrete. Binary combination of (micro CaCO3 + micro SiO2) different contents were applied to investigate their combined effect. Mechanical properties (compressive strength, split tensile strength and flexural strength) and Static loading tests on slabs were done after 28 days of water curing. Results of mechanical strength tests manifested that the mix with 8% Micro particles addition to 50% fly ash replaced concrete showed considerable results compared with the conventional mix of M40 grade concrete. Six slab specimens of 600mm*600mm*60mm consisting of a control mix, a mix with 50% fly ash replacement of cementitious materials and a mix with 50% fly ash replacement of cementitious with 8% micro particles addition were investigated with fixed ends and static loading conditions to obtain load-deflection curves and was found to be comparable with theoretical values for the same.
2 Experimental programme Cement concrete aimed to have 28 compressive strength of 40Mpa was used as a reference mix. In addition to reference mix, two other mixes were studied with incorporation of 50% fly ash replacement to cement and 50% fly ash replacement and 8% micro particles addition to cement respectively.
2.1 Materials used 2.1.1 Cement
Ordinary Portland cement of 53 grade [Birla super plus] confirming to IS: 12269-1987 has been used.
Key Words: High volume fly ash concrete, Micro calcium carbonate, micro silica, fixed end conditions, Load deflection behaviour
2.1.2 Fly Ash Locally available class F fly ash was used for the studies.
1. INTRODUCTION Use of fly ash as partial replacement of OPC in concrete is persistent for many decades. Fly ash acts as Pozzolanic material which reacts with Calcium Hydroxide (CH) of cement hydration due to the presence of amorphous SiO2 and Al2O3. However, the reaction of fly ash in the hydration reaction is slow and affects the early age properties of concrete. Moreover, its use in concrete is also limited to approximately 15-25% by mass (ACI 226.4R). In view of sustainability of concrete the maximisation of the use of fly ash or other SCMs in concrete is the key priority and also researched extensively specially on high volume fly ash (HVFA) concrete. The mechanical behaviour of concrete materials depends to a great extent on their structural constituents and phenomenon which are functional on a Nano - and micro scale. The capability to target material development at the primary structural level promises to gain the optimization of material behaviour and performance. Significant advancements have been made in the application of micro-technology in cement and concrete science. There have been lots of improvements in understanding the characteristics of the hydration products
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2.1.3 Fine aggregates M sand passing through IS sieve 4.75 mm was used .the specific gravity and fineness modulus was 2.60 and 4.31 2.1.4 Course aggregates Crushed angular aggregates passing through 20 mm and retained on 10 mm sieve was used the specific gravity was 2.65. 2.1.5 Superplasticizer The super plasticizer based on poly-carboxylic ether polymer with long lateral chains “AUR MIX” confining with BIS 9103-1999 was used 2.1.6 Micro silica Micro silica purchased from M L A Industries of 0.18(g/cc) bulk density was used. 2.1.7 Micro calcium carbonate Micro Calcium carbonate purchased from Yamuna calcium with 0.44(g/cc) bulk density was used.
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