Effect of Metakaolin on the Durability Property of Superabsorbent Polymer Blended Self-Compacting Concrete

This study investigated the effect of metakaolin (MK) and the performance of pre-absorbed superabsorbent polymer (SAP) on the durability properties of self-compacting concrete (SCC). MK in different proportions varying from 5 to 25% with and without SAP in SCC was adopted. The SAP of 0.3% to the weight of cementitious material was fixed after several trials. The naphthalene-based superplasticizer ranging from 0.8 to 1% was used based on the flow condition of SCC. To achieve the target strength of M40, twelve mixes were prepared and the fresh properties like flowing, filling and passing abilities were assessed through slump flow, V funnel and L box tests. The results of the mechanical property of SCC showed that the addition of MK up to 10% in SCC containing SAP has no significant development in strength; still, upon 15% replacement the strength was improved to 2% when compared to reference concrete and 14.86% with the concrete containing SAP at 28 days. The widely accepted test methods for durability assessments such as chloride diffusion, Rapid Chloride Penetration Test (RCPT), water absorption, sorptivity and drying shrinkage test were conducted on MK and SAP added to concrete for 28 and 60 days. The mix containing SAP exhibited a reduction in shrinkage of about 20% at 28 days and 26.47% at 60 days. As compared to reference concrete, the MK and SAP added concrete has improved the significant resistance to chloride attack and the amount of capillary water absorbed was reduced to 38.5% at 60 days.