Relationship between compressive strength and pore structure of tailings ball concrete

Abstract

To study the relationship between compressive strength and pore structure of concrete under chloride and sulfate dry–wet cycles, chloride dry–wet cycle tests, sulfate dry–wet cycle tests and cube compressive strength tests were conducted for normal concrete (C) and tailings ball concrete (T) with erosion ages of 30, 60, 90, 120, 150 and 180 days. A Rapidair 457 concrete pore structure analyser was used to obtain pore structure characteristic parameters to calculate the fractal dimension and investigate the influence of erosion environment and materials on macroscopic properties and pore structure, the connection between compressive strength, pore structure and fractal dimension, and the most relevant pore structure parameters, based on the most sensitive pore size theory, to derive a multifactor compressive strength model. The results show a better compressive strength of C than T for late chloride erosion and a better compressive strength of T than C for late sulfate attack, as well as much higher correlation between the most relevant pore structure parameters and compressive strength than between a single pore structure parameter and compressive strength. The multifactor compressive strength model is consistent with the experimental results and well describes the quantitative relationship between compressive strength and pore structure under chloride and sulfate attack.