Effects of curing condition on properties and microstructure of latex-modified cement mortars

Abstract

Polybutadiene-graft-polystyrene (PB-g-PS) latex with a core-shell weight ratio of 50/50 was used to modify cement mortar. In the constant water-cement ratio of 0.5, and curing 24h at 20 °C, RH90% air followed using two curing methods (6d immersed in 20°C water followed by 21d at 20°C, RH 65%air or 27d at 20°Cwater). At the different polymer-cement weight ratios (P/C), polymer-modified mortars (PMMs) were prepared, and tested to flow, compressive and flexural strengths and water absorption rate. Scanning electric microscope (SEM) was used to investigate the microstructure of PMMs. On the basis of the test results, effect of the curing condition on the properties and microstructure of modified-mortars were discussed. It is concluded that PB-g-PS core-shell latex can be incorporated into cement as modifier.