Effect of Different Mineral Admixtures on the Properties of Pervious Concrete

Abstract

Taking pervious concrete with a target porosity of 15% as the research object, the influence of three factors, including the contents of silica fume (mass fraction3%, 5%, 7%), metakaolin (mass fraction8%, 10%, 12%) and Polypropylene fiber content (volume fraction1%, 2%, 3%), on the mechanical properties, permeability and frost durability of pervious concrete were investigated by utilizing the orthogonal testing method. Through the range analysis of the test results, the significant influence degree of the three factors were obtained, and the freeze-thaw cycle test was carried out with the optimal mix ratio. The results indicated that the content of silica fume and metakaolin has the most significant influence on the mechanical properties of pervious concrete, the fiber has the most significant influence on the continuous porosity, but the influence on the compressive strength is small. The best mix proportion was obtained, and the silica fume content is 7%, metakaolin content is 10%, and fiber content is 2%. The results of freeze-thaw cycle test of pervious concrete with optimal mix ratio show that the relative dynamic modulus and compressive strength of pervious concrete decrease gradually with the increase of freezing-thawing cycles, and the change rate of mass loss, continuous porosity increases gradually with the increase of freeze-thaw cycles. The relative residual compressive strength and dynamic elastic modulus of pervious concrete show a parabolic decline trend subjected to freeze-thaw cycles. The results also can provide technical reference for the engineering application of pervious concrete in cold regions.