Utilization of crushed recycled glass and metakaolin for development of self-compacting concrete

Abstract

• Crushed recycled glass and metakaolin were used for developing self-compacting concrete. • Crushed recycled glass has capability to improve the flow-ability of SCC. • The use of metakaolin offers improved strength properties at all glass replacement levels. • A relation between compressive strength, glass replacement and metakaolin content was developed. • Microstructural investigation of SCC was done through SEM, EDS and XRD analysis. Hypothetically, all the glass is recyclable, despite of which, only a small fraction of it is recovered globally. Furthermore, decomposition rate of waste glass is lowest when compared to conventional waste such as paper, rubber and plastic. So a gainful utilisation of waste glass in production of self-compacting concrete (SCC) would be fascinating. To this goal, a greener SCC incorporating crushed recycled glass (CRG) has been developed in this study. Alongside, the influence of metakaolin (MK) on fresh, strength and microstructural properties of CRG incorporated SCC was studied. To achieve this purpose, a total of 24 different SCC mixtures were prepared in which MK was used as a cement substitute; cement was partially replaced with 0%, 4%, 8%, and 12% MK and CRG was used to replace fine aggregate at the level of 0, 10, 20, 30, 40 and 50 % by volume. Slump flow, V-funnel, l -box and U-box test relates to passing and flowing ability of SCC, were improved as the CRG content increased in the mix. However, mechanical properties were decreased with increase in CRG content. Incorporating MK in CRG incorporated SCC mixtures improved the strength properties corresponding to all the glass replacement levels. The results showed that a greener SCC can be made using crushed recycled glass as sand replacement material and metakaolin as cement substitute.