Influence of fly ash and basalt fibers on the properties of recycled pervious concrete

As an environmentally friendly building material, recycled pervious concrete can not only alleviate the increasingly severe urban flooding and heat island effect, but also realize the resource utilization of construction waste. However, the porous nature of recycled pervious concrete leads to its low strength, and there is an urgent need to develop recycled pervious concrete with good mechanical and permeability properties. This paper proposes to mix fly ash and basalt fibers in the waste brick aggregate pervious concrete, and investigate the effects of mixing fly ash and basalt fibers on the properties of recycled brick pervious concrete by comparing the mechanical properties, water permeability and frost resistance of recycled brick pervious concrete. The results show that: with the increase of fiber admixture, the mechanical properties and frost resistance of recycled brick-mixed permeable concrete are improved, and the water permeability is decreased; fly ash is more obvious to improve the late strength of recycled brick-mixed permeable concrete, with the increase of fly ash admixture, the mechanical properties and frost resistance of recycled permeable concrete are improved, and the water permeability is decreased, and the excessive admixture of fly ash will greatly reduce the water permeability of recycled brick-mixed permeable concrete. Excessive incorporation of fly ash will greatly reduce the water permeability of recycled pervious concrete. Under the premise of better water permeability and mechanical properties, the optimal mix combination of 10% fly ash and 0.05% basalt fiber was selected on the basis of 85% recycled concrete aggregate and 15% brick aggregate as the mixed coarse aggregate.