Influence of crumb rubber on mechanical properties of self-consolidating concrete

The use of worn-out vehicle tires particles know as Rubber aggregate and Crumb Rubber (CR) in Concrete (CRC) has gained significance in the recent past to manage this waste product from an Environment Sustainability perspective. In this study, the authors used the crumb rubber partially in high strength self-consolidating concrete with steel fibers (SCFRC) to evaluate its suitability. Steel fibers were added to the self-consolidating concrete containing untreated crumb rubber used as a limited replacement of fine aggregate to enhance its properties. The properties both in the plastic and hard state properties of Self-consolidating Fiber Reinforced Crumb Rubber Concrete (SCFRCRC) were studied. The SCFRCRC was prepared bypartially replacing fine aggregate with untreated crumb rubber at 10%, 20% by weight and a constant ratio of steel fibers at 1.0% was used in all the specimen. The SCFRC and SCFRCRC samples were thus prepared and studied. The EFNARC limitswere used for the fresh properties’ tests. The results showed that the fresh properties are affected by the crumb rubber and theoptimal dosage of super-plasticizer is essential to meet the acceptable limits. Regarding the mechanical properties, the compressive and splitting tensile strength was reduced in SCFRCRC sample with increased crumb rubber content when compared with the controlled samples of SCFRC. The Flexural strength improved significantly with both 10% and 20% crumb rubber samples. However, the 20% samples demonstrated lower flexural strength when compared with 10% crumb rubber replacement. In summary, the proposed SCFRCRC can meet fresh properties with a suitable proportion of super-plasticizer and an acceptable hardened state results. This study presents the laboratory test results for the usage of recycled waste tire crumb rubber aggregates in high strength SCC.