Durability of self-compacting concrete with addition of residue of masonry when exposed to carbonation and chlorides mediums

Abstract

This research studies the durability of self compacting concrete (SCC) with residue of masonry (RM) taken from construction and demolition waste (CDW) as partial replacement of Ordinary Portland Cement (OPC). For this purpose, three concrete mixes each with a different percentage of RM (0, 25% and 50% by volume). A control mixture with 100% OPC content was used as reference specimen to compare other two mixes. The fresh properties of SCC mixtures were performed using tests for slump flow, T50 cm slump flow, V-Funnel flow time, and L Box. The strength and durability properties were evaluated using a compressive strength test, water absorption, porosity, sorptivity, accelerated and natural carbonation test, and rapid chloride penetration test (RCPT). Further Scanning electron microscope (SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TG-DTG) tests were also conducted for microstructure analysis. The results showed that the use of RM in SCC mixtures does not affect the properties in the fresh state. In the hardened state, the compressive strength of SCC with 25% RM showed an improvement of 3.6% and 9.1% after 180 and 720 days of curing respectively compared to reference mixture. However, the durability properties such as resistance to carbonation, the use of RM in SCC mixtures resulted in increased carbonation in both the accelerated and natural carbonation tests. On the other hand, the SCC with RM showed a better behavior to chloride penetration, locating in the low permeability zone at 180 and 360 days according to ASTM C1202.