Influence of superplasticiser and mixing procedure on properties of styrene-acrylic ester latex modified mortars

摘要

The influence of different superplasticisers and mixing procedures of latex on the properties of styrene-acrylic ester latex-modified mortars (LMM) was studied. The results indicate that the water-reducing effect of latex in LMM with naphthalene formaldehyde condensate superplasticiser (NF) is 27% higher than that in LMM with polycarboxylic superplasticiser, which demonstrates that more polymer particles are free in pores (not adsorbed by cement grains) and act as ball bearing in LMM with NF. The mixing procedure of latex influences the microstructure and mechanical properties of LMM. LMM added latex and water simultaneously (LMM-S) show higher compressive, flexural and adhesive strength at later stage than LMM added latex later than water (LMM-L). The scanning electronic microscopy observation results also illustrate that more polymer particles are adsorbed by cement grains in LMM-S than in LMM-L.