Durability studies and microstructure analysis on roller compacted concrete with sodium bentonite as special admixture and crusher dust as fine aggregate

Roller Compacted Concrete (RCC) is experiencing rapid growth in its usage all over the world. Thus, it is crucial to examine the characteristics of RCC. This research work investigates the durability studies of RCC with sodium bentonite as a special admixture and fine aggregate as crusher dust. Three different groups of concrete mixes are considered in this study. Each group has three mixes where sodium bentonite was used at 1%, 1.5%, 2% by weight of cement and fine aggregate is replaced with crusher dust completely. The water content required for each mix was determined by Modified Proctor test. The compressive strength of RCC mixtures was evaluated at 28 days. The compressive strength is found to decrease at 20% of cement. Durability characteristics such as acid attack test, rapid chloride penetration test (RCPT) are studied to understand the resistance and permeability characteristic of the RCC mixes. Moreover, microstructural analysis of RCC were also performed. From XRD analysis it was observed that each mix has high percentage of silicon oxide, calcite, aluminum silicate and strength is achieved because of adding sodium bentonite due to presence of kaolinite, montmorillonite. The microstructural analysis shows that the formation of CSH gel is appreciable in the RCC mixes with 1.5% of admixture.