SORPTIVITY LIMITS FOR SPECIFICATION OF DURABLE CONCRETES

Sorptivity is a measure of the rate of water penetration into concrete due to capillary action. This property is related to the pore structure of the concrete. Sorptivity has been used by concrete specifiers to evaluate mix designs and curing regimes, which are two main factors determining the pore structure and hence the durability of concrete. The sorptivity concept was adopted by the Roads and Traffic Authority of NSW for its specification B80 - Concrete Work for Bridges. The test method used to determine sorptivity was developed by the CSIRO and modified by the RTA's Bridge Branch over a number of years to its present form. This paper presents sorptivity data for various concretes with and without supplementary cementitious materials and using various curing regimes. Over 190 concrete mixes and curing combinations are analysed and reported. Subject to some improvements to the test procedure, the data and the analysis in this paper confirm that the sorptivity test is of value in evaluating the physical quality of concrete and the effectiveness of applied curing. (a) For the covering entry of this conference, please see IRRD abstract no. 895164.