Strength and durability characteristics of self compacting recycled aggregate concrete incorporating crumb rubber, fly ash and silica fume

Abstract

This study deals with the development of an environmentally sustainable Self-compacting recycled aggregate concrete (SCRAC) incorporating crumb rubber (CR), fly ash (FA) and silica fume (SF). The study gains significance due to increased popularity of environmental-friendly building materials. M50 grade self compacting concrete (SCC) was designed as per EFNARC 2005 specifications and the influence of recycled aggregate (CRA) (as coarse aggregate replacement), CR (as fine aggregate replacement), and FA & SF (as supplementary cementitious materials) on the workability, strength, and durability characteristics of SCC. Slump flow, T500, L-box, and V-funnel, U-Box tests were used to evaluate the workability in accordance with the standards set by EFNARC 2005. The compressive, and flexural strengths were measured after 7 and 28 days of curing to evaluate the strength properties of SCC. Sorptivity and Water absorption were used to understand the durability characteristics of the SCC mixes. Test results indicate that use of CRA and CR impair SCC’s workability, while use of SCMs improved the workability. It can be noted that all mixes fulfilled EFNARC criteria for fresh properties. A decrease in strength was seen when NA was replaced with CRA and CR. The 28-day compressive strength and flexural strength of SCC were reduced by about 21.78% and 19.51%, respectively, when 100% CRA was used instead of NCA and 10% CR was used instead of NFA. To over come this loss in strength SCMs could be effectively used and it based on the study, RA100CR10F20S10 combination had strength properties similar to those of CM. Similar trend was observed in durability properties as well. Therefore, it can be concluded that CR, FA and SF has a positive impact on the strength and durability of SCRAC and can be a sustainable alternative.