Effects of Fiber Inclusion on Pervious Concrete: A Multiscale Experimental and Imaging Study

As is known, pervious concrete is commonly used in low-traffic-load applications. Therefore, pervious concrete is exposed to flexural loads throughout its economic life. To improve the flexural behavior of pervious concretes, fibers are the most common solution used by researchers. Hence, fiber dosages of 0.1%, 0.2%, and 0.3% (by volume of concrete) are selected for this study. The influence of increased cement content is also discussed. Single-sized limestone aggregates without any mineral admixture were used to produce pervious concretes. The mechanical and hydraulic properties of the pervious specimens were examined. Additionally, image analyses using both CT (Computed Tomography) and scanned sliced samples were conducted. In this study, the samples containing 0.3% polypropylene fiber by volume yielded the highest splitting tensile and flexural strength. Adding fiber reduced the porosity of the pervious concrete. Mixtures with the highest fiber content exhibited the lowest porosity and permeability coefficients. Also, the porosity obtained from image analyses correlates well with volumetric porosity results. The impact of fiber additives on the strength and permeability of pervious concrete has been explored only to a limited extent in existing literature. This study contributes original insights by assessing this impact through a comprehensive approach that examines mechanical, hydraulic, and microstructural aspects, utilizing both experimental methods and image analysis.