Temperature and age effects on mechanical behaviour of phosphorus slag-based concrete

A novel phosphorus slag-based concrete is illustrated and provided in the paper with the aim of investigating experimentally the water temperature and age effects on its mechanical behaviour. The compressive and splitting tensile experiments of this concrete with different water temperatures (5, 10, 20, 30 and 40°C) and ages (7, 24, 72, 168, 336 and 672 h) are carried out to reveal the corresponding strength change laws and the relationship between strength and curing parameters. The failure modes and internal cracks evolution of the phosphorus slag-based concrete are depicted through strength tests and acoustic emission (AE) tests. The results show that water temperature and age effects on the development of compressive strength of the phosphorus slag-based concrete are very significant. The relationships between compressive strength and curing age of concrete under different water temperatures can be described by a logarithmic model based on the experimental data. Finally, the effectiveness of the test results has been confirmed by comparing the results from AE location with the macroscopic failure mode of concrete. The present results can provide a reference for engineering application in underwater buildings repair, such as discharge holes and spillways.