Effect of high ratio fly ash on roller compacted concrete for dam construction

One of the biggest advantages of Roller Compacted Concrete is faster and economic construction along with lesser heat generation. It is primarily used in mass concrete work like in Pavements, Ports and Dams. In this study the properties of Roller Compacted Concrete such as Vee-Bee density, Vee-Bee time, initial setting time, final setting time and compressive strength are studied for twelve mixes prepared using two types of fly ash sources, three cement sources and three admixture types. Furthermore, on one of the mixes with the least cement to fly ash ratio mechanical and thermal property related tests were performed. These tests include split tensile strength, direct tensile strength, modulus of elasticity, Poisson's ratio, apparent cohesion, angle of internal friction, specific heat of concrete by Transient Plane Source (TPS) method and Coefficient of Thermal expansion of Concrete. From the study it was found that compressive strength at 365 days is nearly two times that of 28 days. Also, there is negligible effect of adding admixture on compressive strength of roller compacted concrete. Current study shows that finer the fly ash, higher the compressive strength at later stage. The study on mechanical and thermal properties of Roller Compacted Concrete indicates that results are in line with Indian Standard Specification and Internationally reported values.