建筑废料粉煤灰混凝土冻融作用下耐久性分析

Analysis on Durability of Construction Waste Fly Ash Concrete under Freeze-thaw

为探究建筑废料粉煤灰混凝土在冻融循环作用下的耐久性,对0%、40%、50%、60%4种不同建筑废料取代率和0%、10%、20%、30%4种粉煤灰掺入量的混凝土进行了抗冻融循环试验。结果表明:建筑废料的掺入,会增大混凝土的孔隙率,使混凝土的耐久性降低;粉煤灰的掺入,可改善混凝土和易性,提升新砂浆与旧骨料以及旧骨料结合面的胶结力,使混凝土的耐久特性得到明显改善;当建筑废料取代率为40%、粉煤灰掺量为20%时,混凝土的耐久性最好,且此时的抗冻融等级能达到D100。

In order to explore durability of fly ash concrete under the action of freeze-thaw cycle,the freeze-thaw cycle test was carried out for four kinds of concrete with different replacement rates of 0%,40%,50%and 60%and four kinds of fly ash content of 0%,10%,20%and 30%.The results show that:incorporation of construction waste will increase porosity of concrete and reduce durability of concrete;incorporation of fly ash can improve workability of concrete,enhance cementation of the interface between new mortar and old aggregate and between old aggregates,and improve the durability of concrete significantly;when the replacement rate of construction waste is 40%and the content of fly ash is 20%,the durability of concrete is the best,and the freeze-thaw resistance level can reach D100 at this time.