Effects of shrinkage-reducing additives o nthe curing shrinkage and strengths of unaturated polyester mortar

摘要

The objective of ths study is to evalaute the effects of shrinkae-reducign additives (SRA) such as expanded polystyrene (EPS), poly methyl methacrylate (PMMA) and poly vinyl acetate (PVAc) on the curing shrinkage and strengths of unsaturated polyester resin (UP) mortar. Research is carried out to determine the curing shrinkage and strengths properties as a function of SRA-based resin content melted by styrene momoer (SM), (SRA/SRA+SM), total SRA solution content to weight of UP resin (SRA solution/SRA Solution+UP), SRA type and curing temperature. It is tested for compressive and flexural strengths, and curing shrinkage. From the test results, the compressive strength tends to decrease with increasing SRA content, regardless of SRA types, but lexural strength shwos the difference according to SRA content to UP and SRA type. The difference of the curing shrinkage of UP mortar using PVAc as a SRA with increase in PVAc content to UP is not recognized. We can be recommended for optimum mix proportions of a balance between the curing shrinkage and strengths.