Análisis del comportamiento a compresión y corte puro de hormigón permeable para distintas relaciones agua/cemento con adición de fibras de polipropileno

Abstract

Pervious concrete is a material widely used as pavement in surface layers; however, its use is limited to lower load conditions due to its porous structure. Its application contributes to reduce problems generated by surface runoff such as flooding, soil erosion, and reduction of groundwater resources. Despite the existence of multiple investigations on their design and properties, a limitation has been identified in the analysis of their behavior under shear stresses. This property is crucial due to the fragility of concrete under such conditions, which can cause sudden failures in its structure. The research focused on analyzing the pure compressive and shear strength of permeable concrete for water/cement ratios of 0.30 and 0.35, and the addition of polypropylene macrofibers at 2.50 and 4.00 kilograms per cubic meter. The dosage was carried out in accordance with the recommendations of the ACI Committee PRC-522-23, using 1/2 inch gravel and 10 percent sand. Prior to obtaining the mechanical properties, physical properties such as density, porosity and permeability were determined. Subsequently, compressive strength was determined based on the NTE INEN 1573/ASTM C39 standard, while shear strength was obtained through an experimental procedure based on Push-Off tests, for which three beam configurations with different dimensions and reinforcements were evaluated in order to identify the fracture mechanisms involved. The results showed that a change in the water/cement ratio had a greater influence on the mechanical properties of the permeable concrete, increasing the compressive and shear strength by approximately 31 and 70 percent, respectively. On the other hand, the addition of polypropylene macrofibers showed a greater impact on shear strength, improving it by up to 55 percent. To carry out the shear analysis, a beam model was selected, reinforced internally with 6 mm rods and externally with glass fiber adhered to the lateral faces by means of a layer of mortar.