Freeze–Thaw-Induced Deterioration and Failure Mechanisms of Permeable Concrete in Cold Regions

Abstract

Highlights Freeze–thaw degradation of permeable concrete was quantified up to 120 cycles. Damage evolved from paste peeling and microcracks to pore-structure failure. BPN remained above 70 after freeze–thaw cycles, indicating high skid resistance. Higher porosity accelerated strength loss, permeability decay, and pore expansion. Numerical sensitivity analysis explored the influence of porosity on thermal response and phase-change duration under idealized conditions. What are the main findings? Freeze–thaw damage of permeable concrete develops progressively: starting from cement paste peeling and microcrack propagation, then evolving into pore structure degradation and local skeleton failure; higher initial porosity accelerates mass loss, porosity growth, compressive strength, and permeability attenuation after up to 120 freeze–thaw cycles. After 120 freeze–thaw cycles, all specimens have mass loss below 1%, compressive strength drops 5.5–12.9%; all groups retain BPN above 70 and maintain decent permeability, meeting basic pavement anti-slip and drainage requirements for cold-region roads. CFD simulations prove permeable concrete shows three-stage temperature responses in both freezing and thawing; rising porosity reduces effective thermal conductivity, extends phase-change duration, amplifies internal temperature gradients, and aggravates thermo–mechanical coupling frost damage. What are the implications of the main findings? Optimizing the pore structure (appropriately lowering design porosity) is the core measure to improve the long-term frost resistance and service durability of cold-region pervious pavement. Even after long-term freeze–thaw cycling, permeable concrete still satisfies standard anti-slip and drainage performance, verifying its basic applicability for cold-area sponge city walkways and light traffic pavements. Numerical sensitivity analysis can provide qualitative insights into the thermal response of porous pavement materials, but quantitative prediction requires experimental temperature validation. Abstract To investigate the performance degradation patterns and underlying damage mechanisms of permeable concrete under freeze–thaw cycles in cold regions, permeable concrete with varying porosities was selected as the research subject. A total of 120 rapid low-temperature freeze–thaw cycles were conducted. The evolution of porosity, mass loss, skid resistance, permeability, and compressive strength was systematically analyzed. Exploratory numerical simulations, conducted under idealized assumptions, suggest that rising porosity may reduce effective thermal conductivity, extend phase-change duration, and amplify internal temperature gradients—trends that are consistent with the observed porosity-dependent frost damage but require experimental temperature validation for quantitative confirmation. With the increase in freeze–thaw cycles, mass loss and porosity continuously increase, while compressive strength and permeability gradually decrease. After 120 cycles, the mass loss of all specimen groups was below 1%, with compressive strength decreasing by 5.5% to 12.9%. Despite this, the specimens maintained good permeability and skid resistance. Numerical simulations indicate that permeable concrete exhibits a three-stage temperature response during both freezing and thawing processes. An increase in porosity reduces the material’s effective thermal conductivity, prolongs the phase transition duration, and intensifies the internal temperature gradient, thereby amplifying the thermo–mechanical coupling damage effects. Therefore, optimizing the pore structure is crucial for improving the long-term service performance of permeable pavements in cold regions.