Investigation on the interfacial behaviour between the rubber-cement matrix of the rubberized concrete

Abstract

Rubberized concrete is an innovative clean production material. In this study, the interfacial behaviour of the rubber-cement matrix (R-CM) of rubberized concrete was improved by selecting better rubber types, surface modifiers, mixing methods, supplementary cementing materials (SCMs), water-binder ratio (W/B ratio), and mixing time. The slump, apparent density, compressive strength, impact strength, and R-CM interfacial bonding property of the rubberized concrete were determined. The results showed that the following combination delivered an improved rubberized concrete (IRC) with the best R-CM interfacial bond strength – acrylonitrile-butadiene rubber (NBR), W/B ratio of 0.42, mixing time of 150 s, styrene-butadiene latex (SBL) as a surface modifier and a SCM, premixing rubber and binder paste. The main factors affecting the R-CM interfacial bonding properties were the rubber type, surface modifier, mixing method, and W/B ratio. Compared to the reference rubberized concrete, the R-CM interfacial tensile bond strength, shear bond strength, compressive strength, and impact strength of IRC increased by 756%, 151%, 48.1%, and 17%, respectively. As a surface modifier, SBL provided a connection between NBR and the binder paste, while as a SCM, it created an environment for reducing the W/B ratio of rubberized concrete. The R-CM interface was found to play a major role in controlling the macro mechanical properties of rubberized concrete.