Effect of filler on bituminous base layer containing recycled concrete aggregates

Abstract

Abstract The use of different filler materials is one of the effective techniques adopted to improve pavement quality and performance. The main purpose of this study is to quantify the influence of filler type on the performance of dense graded bituminous mixes containing recycled concrete aggregate (RCA). This RCA is replacing the coarse portion of the conventional natural aggregates (NA). In this present experimental investigation, the dense bituminous macadam (DBM) mixes according to the relevant Indian specifications are compacted using four different types of fillers, such as cement, stone dust, fly ash and carbon black and conventional VG 30 as binder. Eight different sets of Marshall samples are prepared using RCA and NA representing the coarse aggregate fraction and either of the above four binders. Different mixes thus prepared are evaluated in terms of their Marshall parameters, indirect tensile strength, moisture susceptibility characteristics (tensile strength ratio and retained stability) and resilient modulus. From the experiment conducted in the laboratory, it is found that all the mixes, in general satisfy the requirements in terms of Marshall and moisture susceptibility characteristics. Considering all engineering properties studied the mixes with NA and carbon black (CB) as filler material offered higher results comparable with other mixes. However, the mixtures prepared with RCA also offered a promising result compared to mixtures made with NA.