Resumen El objetivo de este estudio fue proponer una correlación para los parámetros hidráulicos del concreto permeable (CoPe). Para esto, se utilizaron 3 agregados de residuos de construcción civil y 1 agregado de basalto como referencia para producir CoPe. La relación 1: 3.26 (cemento: agregado) se trabajó en todas las mezclas, una relación a/c de 0.34. Se realizaron pruebas de resistencia a la compresión y resistencia a la flexión para caracterizar mecánicamente el concreto producido y verificar el cumplimiento con los estándares ACI 522R-10, NBR 16416 (2015) y VTT-R-080225-13. También se llevaron a cabo pruebas de porosidad y permeabilidad a carga constante para estudiar las propiedades hidráulicas del material. Los resultados indican que es factible producir concreto permeable con agregados sostenibles que cumplan con los estándares y que se podría usar en la construcción de calzadas. Por otro lado, se propone una correlación de permeabilidad y porosidad que involucra las leyes de Bernoulli y Darcy y establece las condiciones de contorno en las que funcionan estas dos propiedades, teniendo como conclusión una ecuación exponencial que caracteriza la eficiencia hidráulica de los canales internos del material relacionado. A la interconexión de poros. Al realizar la regresión no lineal, la ecuación se ajusta a los resultados encontrados y se ajusta a lo que se encuentra en la literatura, siendo una herramienta excelente para identificar la eficiencia hidráulica del material.

Abstract The aim of this study was to propose a correlation for the hydraulic parameters of pervious concrete (PC). Thus, three aggregates from civil construction waste and one basalt aggregate (reference) were used to produce PC. The ratio c/a (cement: aggregate) 1:3.26 and a w/c ratio of 0.34 were used in all mixtures. Compressive and flexure tensile strength tests were performed to mechanically characterize the mixtures produced, whereas porosity and constant head permeability tests were also carried out to assess the material hydraulic properties. Firstly, the experimental results were compared with the requirements established in international guidelines (ACI 522R-10, NBR 16416 (2015) and VTT-R-080225-13). The results complied with the guidelines indicating it is feasible to produce pervious concretes with the sustainable aggregates used in the study in low structural applications such as walkways. On the other hand, a correlation between permeability and porosity was proposed based on Darcy’s and Bernoulli’s laws. The proposed equation, obtained by means of a non-linear regression, is an exponential equation that characterizes the hydraulic efficiency of the internal channels of the material considering the pores interconnection. The correlation between porosity and permeability was finally validated using results from the literature showing the same trend found in laboratory, and therefore it was demonstrated that the proposed correlation in an efficient tool to predict the hydraulic efficiency of pervious concrete.

The present study proposes a methodology to characterize the mechanical properties of synthetic macrofibres, which are used as a reinforcement of new composites applied in civil construction industry. Some standards suggest that this characterization should be performed on original filaments and others propose using the current methodology used to characterise metallic fibres. These recommendations turn difficult the quality control procedure, so it was developed a methodology to characterize the mechanical properties of the macrofibres as they are supplied in the construction site, using the tensile test. In that sense, two types of macrofibres were evaluated obtaining their tensile strength and elastic modulus. Additionally, the macrofibres were mixed with aggregates in order to study how the abrasion affects their mechanical properties. Summing up, the proposed methodology is feasible, especially to estimate the tensile strength allowing its application in ordinary laboratories. Regarding the elastic modulus results, they may be underestimated using this method. Finally, it was observed that the abrasion between the macrofibre and the aggregates during the mixing process compromises the mechanical properties decreasing both the tensile strength and the elastic modulus.