Analysis of the physical-mechanical properties of coating mortars with the incorporation of polypropylene and nylon fibers

ABSTRACT

The search for new mixtures and materials that will improve the properties of coating mortars and consequently their performance in service is becoming more and more frequent, thus synthetic fibres appear as a possibility for a new material to be used in the composition of mixtures. The study aims at analyzing the behavior of coating mortars with the incorporation of different contents of polypropylene and nylon fibers. The experimental program was based on the incorporation of 500, 900 and 1300 g/m³ of polypropylene and nylon fibers in a reference mortar with a trace of 1:0.5:5 (cement:lime:sand). As a parameter, the amount of water used in all mortars produced was fixed and a plasticizer additive was added when necessary. Thus, this work aimed to analyze the influence of the incorporation of different contents of polypropylene and nylon fibers on the physical characteristics and mechanical properties of mortars in their hardened state. For this purpose, analyses of tensile strength in bending, compression strength, modulus of elasticity, dynamic and static, capillary water absorption and analysis of characteristics by scanning electron microscopy were performed. The results indicate that the mortars with incorporation of nylon fibers presented higher values of tensile strength in bending, axial compression and lower values of water absorption by capillarity. The analysis of the images obtained by the microscopy of the mortars showed that the mortars with polypropylene insertion showed greater porosity than the mortars with nylon addition. The mortars incorporating polypropylene fibers showed lower values of dynamic and static modulus of elasticity, which indicates that these mortars have a good capacity to suffer deformation.

Keywords
Coating Mortar; Synthetic Fibers; Polypropylene; Nylon; Performance