Effect of freeze-thaw cycles on mechanical and porosity properties of recycled construction waste mixtures.

Highlights • The strain presents a parabolic or linear increase with the times of freeze-thaw cycles. • Proportion of 2:5:3 of recycled construction waste mixtures has better mechanical properties. • Maximum porosity occurs after 10 freeze-thaw cycles. • Fractal dimension of construction waste increases gradually with the increased freeze-thaw cycles. • Order between particles of construction waste decreases with the increased freeze-thaw cycles. Abstract To investigate the effect of freeze-thaw cycle on the mechanical and porosity properties of the recycled construction waste mixtures, a series of freeze-thaw cycles, cyclic loading and unloading and CT scan tests were carried out on four proportions of samples, including the brick, concrete and mortar slag. The testing results reveal that the strain presents a parabolic or linear increase with the increasing freeze-thaw cycles. Hence, the cumulative plastic strain and resilience modulus show a linear relation to freeze-thaw cycles. Reducing the brick slag content and increasing the concrete slag content can increase the modulus of resilience. In addition, the maximum porosity occurs after 10 freeze-thaw cycles. The minimum porosity within and between layers appears in 0 and 20 freeze-thaw cycles, respectively. The fractal dimension of the construction waste mixture increases gradually and the order between the particles decreases with the increase of freeze-thaw cycles. The proportion of 2:5:3 of recycled construction waste mixtures has the better mechanical properties under freeze-thaw cycles and can be used as subgrade filling. Moreover, effective utilization of construction waste can reduce the environmental pollution and promote sustainable infrastructure. [ABSTRACT FROM AUTHOR]