An Investigation of the Effects of Incorporation of Supplementary Cementitious Materials on Fresh State Properties of Grouts for Grouted Aggregate Concrete

Abstract

Grout flowabiity is the key parameter in the production of grouted aggregate concrete (GAC). High flowability due to high water to binder ratio (w/b) of GAC grout in its fresh state invites bleeding and segregation whereas, low flowability due to low w/b in fresh state greatly influences setting times, loss in flowability and the grout handling process. It is difficult and crucial to have a grout that will exhibit adequate flowability in its fresh state maintaining appropriate w/b ratio. Scanty research is available in this regard and needs investigation. Therefore, an experimental study was proposed to develop the grout for GAC, investigating the effects of supplementary cementitious materials (SCMs) incorporation in place of ordinary Portland cement (OPC), for repairing or retrofitting of the reinforced cement concrete (R.C.C) piles subjected to damage or deterioration. Binary and ternary binder grout compositions, at water/binder = 0.45 and sand-to-binder ratio 1:1, using optimized poly-corboxylic ether (PCE) based high range water reducer (HRWR) adhering to the efflux time of 35-40 ± 2s according to American concrete institute (ACI) 304.1-2005, were studied to investigate the effect incorporation of SCMs, viz., fly ash (FA), silica fume (SF), ground granulated blast furnace slag (GGBS) and metakaolin (MK), on fresh state properties of GAC grouts. Utilization of supplementary cementitious materials (SCMs) in grouts will serve them green and will lead to ecological and economical benefits with true sustainable development. Therefore, an attempt was made to investigate the effects of SCMs on GAC grout fresh state properties for their suitability in repairs and retrofitting of R.C.C piles based on setting times, bleeding, flowability, and its loss employing flow cone method. Results have shown that grouts produced incorporating SCMs partially replacing OPC can result in many synergic effects and can offer significant benefits in view of their fresh state properties to suit with the pile repair and retrofitting methodology. Moreover, it was observed that ternary grout compositions offer significant benefits over binary grout compositions when binary grout system performing well is combined to form ternary grout system.