Review of Characterization and Testing Methods for the Mechanical, Microstructure, Pore, Permeability and Freeze-Thaw Properties of Porous Concrete

Porous concrete, with its unique pore structure and excellent permeability, is widely used in modern engineering, particularly in urban drainage, environmental protection, and transportation. This paper systematically introduces the testing methods for the mechanical properties, microstructure, pore characteristics, permeability, and freeze-thaw durability of porous concrete, and explores the intrinsic relationships between these properties. Through experiments on compressive strength, flexural strength, porosity, permeability coefficient, and freeze-thaw cycles, the study reveals the influence mechanisms of pore characteristics on the mechanical and permeability properties of porous concrete. The results indicate that the porosity, pore size, and pore coordination number of porous concrete significantly affect its permeability and durability, while its mechanical properties are closely related to the uniformity of the microstructure and pore distribution. Specifically, the porosity of the tested specimens ranged from 15% to 30%, with pore sizes varying between 0.1 mm and 2.0 mm. The permeability coefficient was found to increase with higher porosity and larger pore sizes, while the compressive strength decreased. This paper provides theoretical support for the engineering applications of porous concrete and points out directions for future research.