Sorptivity as a Durability Index for Service Life Prediction of Self-compacting Concrete

Abstract

Durability of concrete is assessed by its permeation. Water ingress is the major factor for deterioration of concrete, and there is always an urge to find a simple and reliable way to measure the material properties of concrete which can be related to durability. Water sorptivity is a useful single material property which is useful in service life planning and prediction. This paper presents the results of sorptivity of self-compacting concrete (SCC) and comparable normal concrete (CNC). SCC mixes were developed for different paste contents of 0.38, 0.41 and 0.43 with filler fly ash and cement contents ranging from 300 to 450 kg/m³. SCC has its own unique advantage over CNC due to its characteristics of higher powder per se paste with higher flow and better lubrication of the aggregate with reduced interparticle friction and superior densification of microstructure. The results show better performance of SCC in terms of capillary absorption compared to CNC. The sorptivity value decreased as the volume of paste (Vp) increased and higher paste content generally makes the mix robust with better densification of the microstructure, thereby improving the durability and making the concrete more sustainable with improved long-term performance. The sorptivity based on secondary absorption can be effectively used as a durability index to predict the time duration required for the ingress of water to penetrate the concrete, which has practical significance.