Effects on the Properties of Concrete by Partial Replacement of Cement with Carbon Black and Natural Fine Aggregate with Robo Sand

Abstract

The sustainability, strength and durability of any of the constituent material of concrete plays an important role in studying and determining the effects on the properties of concrete. Pores in concrete seem to be an immense problem ever since concrete was discovered. Pores attract water that leads to the ill effects such as acid intrusion, freezing and thawing, decrease in resistance to chloride ion, reduced compressive strength etc. Less permeability of concrete plays an important role in gaining the strength and reducing the corrosion of reinforcement in concrete. This paper reviews in studying the properties of concrete using quarry dust (robo sand) as a partial replacement of natural fine aggregate and carbon black as a partial replacement of cement in concrete by using different percentages of both the materials. Experiments have been conducted by introducing carbon black in concrete which is a waste of rubber industry to act as filler and which imparts the enhanced properties of concrete. In this present experimental study, various properties of concrete have been studied using quarry dust (robo sand, artificial sand, stone dust) as a replacement of natural fine aggregate and carbon black as a replacement of cement in concrete by using different percentages of both the materials. Based on the review of previous studies, it can be concluded that the improvement in the strength of concrete is attributed the hydration acceleration at the early ages due to the effect of the stone dust as microfillers. It was also found that the concrete porosity was lower than that of the corresponding concrete without robo sand at the same water/cement ratio. It was also found that at the percentage replacement of cement by carbon black (CB) (5%) and robo sand (RS) by natural sand (50%), the concrete becomes denser as both carbon black and stone dust act as micro fillers in the concrete due to their sizes with respect to cement and natural sand. Hence a study has been carried out using both the materials carbon black and robo sand simultaneously in the concrete. Moreover, the permeability of the concrete decreases which in turn would reduce the corrosion rate and in turn increase the durability and sustainability of concrete. Replacing a portion of cement with non-reactive waste material carbon black and natural sand with quarry dust and getting the increase in strength and durability at same w/c ratio is of utmost importance regarding the economy (sustainability).