Estimation of the impacts of adding recycled demolition waste and steel fibers on different mechanical properties of self-compacting concrete

Abstract

Replacement of natural aggregates (NAs) with recycled aggregates has been identified as a promising way of managing the waste associated with civil engineering. Therefore, the objectives of this study are also oriented towards managing the demolition waste in self compacting concrete (SCC). Efforts were made to estimate the impacts of replacing the NAs with the recycled-demolition waste aggregates (rDWAs) and addition of steel fibers (SFs) on the compressive strength (CS), split tensile strength (STS) and flexural strength (FS) of M30 grade fiber reinforced self-compacting concrete (FRSCC). A novel approach of central composite design (CCD) and response surface methodology (RSM) was adopted to design the experiments. The three levels of process parameters i.e., % replacement of NAs with rDWAs (X1: %) and volumetric proportion of SFs (X2: %) were 25, 50 and 75 and, 0.35, 0.70 and 1.05, respectively. The findings of this study revealed that at optimized conditions i.e., X1 = 0.92 and X2 = 0.89, the values of CS, STS and FS of FRSCC improved and were observed to be 35.67 MPa, 2.56 MPa and 4.96 MPa, respectively. From the findings of this study it was made evident that the replacement of NAs with rDWAs, in FRSCC-based structures, can prove efficient in the management of construction-associated waste.