A Novel Pervious Concrete Improved by Hexagonal Boron Nitride and Basalt Fiber in Mechanical Properties, Permeability, and Micro-Mechanisms

In order to overcome the limitations of traditional pervious concrete, which is difficult to balance in terms of both mechanical properties and permeability, this study proposed a novel and effective approach to improve the performances of pervious concrete (PC) based on hexagonal boron nitride (h-BN) and basalt fibers (BF). The mechanical properties and permeability tests of PC with single-doped or double-doped h-BN and BF were conducted first. Then the influence laws of h-BN and BF content on the compressive strength, flexural strength, porosity, and permeability coefficient for PC were revealed. Finally, the micro-mechanism effects of h-BN and BF on the performances of PC were explored by using a scanning electron microscope and an energy dispersive spectrometer. The results showed that the compressive strength of PC was increased with the increase in the h-BN content, and the flexural strength, porosity, and permeability coefficient increased first and then decreased. Meanwhile, with the increase in the BF content, the compressive strength and flexural strength of PC increased first and then decreased. Moreover, the compressive strength, flexural strength, porosity, and permeability coefficient of the proposed pervious concrete were 22.8 MPa, 5.17 MPa, 18.5%, and 5.09 mm/s, respectively, which were increases of 21.9%, 19.7%, 60.9%, and 42.2%, respectively, compared with ordinary permeable concrete when the optimal admixture combination was 15% fly ash, 0.08% h-BN, and 2.25% BF. This study can avoid the limitations of traditional pervious concrete and provide an efficient alternative way for improving the mechanical and permeability properties of pervious concrete.