Correlating frost durability and liquid transport properties of concrete with a modified penetration depth model: Effect of aggregate, water/cementitious ratio, and supplementary cementitious materials

Frost resistance of concrete is highly related to air void system quality and moisture transport behavior in concrete, which are affected by multiple factors. In this study, different lightweight aggregate contents, water/binder ratios, and three types of supplementary cementitious materials were adopted to investigate the effects on frost resistance of concrete, along with mechanical properties, air void system, and transport properties. It was found that lightweight aggregate reduced compressive strength at an early age and increased air content and total moisture uptake due to its porous characteristics. However, the internal curing compensated for strength loss and lowered the chloride permeability. A lower water/binder ratio and incorporation of supplementary cementitious materials improved compressive strength and air void system quality, resulting in a lower total moisture uptake and chloride permeability due to the refined microstructure and reduced capillary connectivity. A modified penetration depth model was proposed to assess the frost resistance. When the calculated penetration depth surpassed the specimen thickness, the filling of water in the pore system caused severe frost scaling and degradation of the relative dynamic modulus. Freeze-thaw cycles also influenced the pore system of concrete in turn by increasing the size and continuity of capillary pores. • The frost resistance of concrete, mechanical properties, air void system, and transport properties were investigated. • A modified penetration depth model was proposed to quantify the relationship between capillary suction and salt scaling. • Freeze-thaw cycles influenced the pore system of concrete in turn by increasing the size and capillary pores continuity.