Effect of Rubber Aggregate and Binary Mineral Admixtures on Long-Term Properties of Structural Engineered Cementitious Composites

Siad H., Lachemi M., Ismail M. K., Sherir M. A. A., ŞAHMARAN M., Hassan A. A. A.

JOURNAL OF MATERIALS IN CIVIL ENGINEERING, vol.31, no.11, 2019 (SCI-Expanded) identifier identifier


This paper investigates the effect of replacing silica sand (SS) with waste rubber aggregates on the long-term mechanical and transport properties of structurally engineered cementitious composites (ECCs). ECC mixtures prepared with 0 to 30% crumb rubber sand (CRS) or 30% to 40% powder rubber sand (PRS) were tested for up to 360 days of curing. The addition of ground granulated blast-furnace slag (GGBS), metakaolin (MK), and silica fume (SF) in PRS-ECCs with incorporated binary mineral admixture-based fly ash (FA) was also investigated. The compressive and flexural strengths, midspan beam deflection capacity, chloride permeability, water sorptivity, and electrical resistivity of 17 ECC mixtures were studied at different ages. The diverse aggregate vicinities and their interfacial transition zone aspects were analyzed at 28 and 360 days using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The results indicate that, from 28 to 360 days of curing, ECC mixtures with CRS and PRS exhibited lower mechanical strengths and enhanced deflection capacities compared to the control mixture. However, ECCs with up to 40% PRS content showed better transport properties than the control ECC mixture, especially when incorporating a binary mineral admixture, including MK and FA. Microstructural investigations confirmed the presence of some gaps at the rubber aggregate interface, which healed partially or completely with long curing times.