Effect of Micro-silica on the Fresh and Hardened Properties of Self-compacting Concrete Containing Pre-absorbed Superabsorbent Polymer

Abstract

This research work focuses on the effect of micro-silica (MS) and the performance of pre-soaked superabsorbent polymer (SAP) on the fresh and hardened properties of self-compacting concrete (SCC). In this work, the MS in different proportions of 5, 10 and 15% was used to replace the cement and the pre-absorbed SAP of 0.1, 0.2, 0.3 and 0.4% to the weight of cementitious material was added in concrete as an Internal Curing Agent (ICA). To assess the fresh properties like flowing, filling and passing abilities of SCC, the workability tests such as slump flow, V-funnel and L-box were carried out. Out of several trials, the mix with the addition of 0.3% SAP and replacement of 10% MS gave a positive response in all the examined properties of SCC. The durability tests on permeability properties like water absorption, sorptivity and rapid chloride penetration test (RCPT) of SCC at 28 days and 60 days were conducted. The shrinkage test and Scanning Electron Microscope (SEM) tests were also carried out on all the optimum mixes of SCC at 28 days and 60 days. Better development of calcium silicate gel was observed in the concrete mix that contains both MS and SAP. The results of all the experimental tests exhibit better performance of internally cured concrete containing MS in SCC even at later ages. This study suggests the potential use of pre-absorbed SAP in reducing the manual curing process and utilizing the waste materials effectively in concrete.