Study on the change of adhesive strength between adhesive mortar and ceramic tile overtime in Vietnamese climate

Abstract

Material durability in climate and weather condition highly affect material longevity and usable time. Climate is temperature, humidity, and solar radiation. Durability of adhesive mortar in working condition decides mortar quality and longevity of ceramic tile. Vietnamese standard does not regulate specifications on choosing adhesive mortar for equivalent tiling process. In addition, the long-lasted practice of using slurry coat as adhesive material is still being used widely for construction projects. This practice causes difficulty for designers and constructors when choosing quality mortar and glue. This article focuses on studying the change of adhesiveness of adhesive mortar in changing environmental condition, specifically indoor and outdoor environment. Comparing four material groups: PCB30 slurry coat, PCB40 slurry coat, C1 grade adhesive mortar, C2 grade adhesive mortar (classified according to TCVN 7899:2008) are used in indoor and outdoor construction, and then are checked for changes in adhesiveness within 12 months by pulling method. Results: the slurry coat group had high initial adhesiveness - > 0.5MPa (C1 grade) and gradually reduced after 3, 6, 9, and 12 months – reducing by 97% compared to at 28 days old and did not maintain C1 grade; the mortar group had high initial adhesiveness and maintained adhesiveness after 3, 6, 9, and 12 months – fluctuation of 15% compared to at 28 days old and still maintained equivalent C1, C2 grade.