A water sorptivity test for martar and concrete

This paper describes a test rig to measure the uni-directional water absorption of mortar and concrete. The test data acquisition is controlled by purpose written software installed on a PC and the results are utilised directly to obtain the sorptivity measured in g/mm2/min1/2. As an example the apparatus was used to obtain the sorptivity of mortar in which the ordinary Portland cement was partially replaced by ground waste brick obtained from different sources. The results presented demonstrate the validity of the test, and the apparatus and the methodology are shown to be of sufficient sensitivity in detecting the differences between the sorptivities of the various mortars tested. The variation in the sorptivity with curing time and mixture composition was determined. The paper also gives the results of total water absorption test conducted on the sorptivity test specimens, after being reconditioned, and the results of compressive strength tests for all the mortars investigated.