مشخصات مکانیکی و جمع شدگی ملاتهای سیمانی اصلاح شده با لاتکس استایرن – اکریلیک و پلی وینیل الکل

The brittle nature of cementitious materials leads to the formation of cracks and damage in concrete structures, highlighting the necessity of using materials that can prevent the initiation and propagation of shrinkage-induced cracks while enhancing the mechanical properties of cement mortars. This study examines the shrinkage and mechanical properties of cement mortars modified with polyvinyl alcohol (PVA) and styrene-acrylic latex (LSA). Therefore, a standard cement-based mortar was prepared using 400 kilograms of cement with a sand-to-cement weight ratio of 3. The cement-based mortar was modified by incorporating LSA at dosages of 5%, 10%, 15%, and 20%, in two groups: one with and one without the addition of 2% PVA. Following this, tests for compressive strength, flexural strength, abrasion resistance, and shrinkage were conducted on the samples. To assess the surface adhesion of the mortars, a surface tensile test was performed. The results indicated that the addition of 10% LSA resulted in a 25% increase in the compressive strength of the mortars without PVA compared to the base mortar. The inclusion of PVA in all mortars containing LSA led to a reduction in compressive strength. The flexural strength of the mortars with 2% PVA and 10% LSA increased by 29% compared to the base mortar. Abrasion resistance decreased by 11% with the addition of 10% LSA to the base mortar, and by 5% in the samples containing 10% LSA when 2% PVA was added. In summary, the addition of LSA reduced shrinkage, while the inclusion of PVA increased it. Adding LSA up to 10% improved surface tensile strength, whereas the addition of PVA resulted in a decrease in this property.