The Strength and Elastic Modulus of Pervious Concrete Considering Pore and Fiber during Freeze–Thaw Cycles

Abstract

The interface between aggregate and cement matrix and the strength of the cementation layer between aggregates are the key factors affecting the strength of pervious concrete. The purpose of this paper is to evaluate the effects of porosity, compressive strength and elastic modulus of pervious concrete before and after freeze–thaw cycles. The effective porosity and total porosity were obtained by the underwater weighing and CT (computed tomography) image analysis methods. Uniaxial and triaxle compression tests were carried out to obtain the strength and elastic modulus of pervious concrete considering pore and fiber. The results indicated that the effective modulus and effective stress were closely related to the porosity, and the continuous fracture of cementation points between aggregates caused damage to pervious concrete. Inclined shear failure of pervious concrete occurred under uniaxial pressure, and the strength and elastic modulus increased with increases in confining pressure. With the increase in freeze–thaw cycles, the porosity increased linearly, the strength and elastic modulus decreased and a mutational point appeared between 40 and 50 times during the freeze–thaw cycles. The fiber enhanced the strength of the cementation layer and increased the connection between aggregates, thus improving the strength and integrity of pervious concrete. This work is needed to serve as a reference for the fracture mechanism of pervious concrete and the effect of freeze–thaw cycles considering pore and fiber.