Análise de propriedades mecânicas de argamassas com incorporação de fibras de polipropileno

Abstract

This Final Paper presents an experimental study on the influence of adding polypropylene microfibers to rendering mortars applied manually on ceramic substrates. The main objective was to evaluate how different fiber dosages (0, 1, and 2 kg/m³) affect the coating performance, especially regarding tensile bond strength, internal cohesion, and crack behavior. The methodology was divided into four stages: wall preparation, mortar production, manual application, and the tensile bond strength test. An additional test was also performed to analyze internal cohesion. The mortars reinforced with microfibers showed significant changes in their properties and confirmed one of the expected benefits: better microcrack control and increased toughness, although with a reduction of up to 29.9% in average bond strength compared to the reference mortar. The results demonstrated that the addition of fibers modifies the system behavior, making the mortar more cohesive but transferring failures to the scratch coat/mortar interface, identified as the weakest point of the system. It was also observed that, during application, human factors such as the manual throwing energy and the control of workability through the addition of water may have influenced the final performance. Despite the reduction in bond strength, the study highlights the potential of microfibers as allies in mitigating visual pathologies, such as cracks, thereby improving the surface integrity of coatings.