Mechanical and durability properties of self-compacting concrete made with processed waste rubber granules

The study presented herein was carried out to investigate the mechanical and durability characteristics of self-compacting concrete containing waste coarse rubber aggregates (WRA). Two different series of self-compacting rubberized concrete (SCRC) mixtures were designed with a constant water–cementitious material (w/cm) ratio of 0.32 and total cementitious materials content of 550 kg/m3. The first group of mixtures was incorporated binary cementitious blends of 20% flyash (FA) and 80% Portland cement. However, the second series of the mixtures incorporated Ternary cementitious blends of 20% FA with 10% silica fume (SF) and 70% Portland cement. To develop the RSCCs, medium aggregate was substituted by WRA at five designated contents of 0%, 10%, 20%, 30% and 40% by volume in both series of concretes. Totally, 10 concrete mixtures were cast and tested for mechanical and durability related properties such as compressive strength, splitting tensile strength, modulus of elasticity, sorptivity, chloride ion permeability, gas permeability and fracture energy. The tests were conducted at 28 and 90 days after casting. Test results demonstrated that using the rubber particles improved the fracture and ductile properties, whereas aggravated all other measured properties of self-compacting rubberized concretes (SCRCs). However, with the addition of silica fume in to the mixes all mechanical and durability properties enhanced, depending mainly upon rubber content.