废旧聚氨酯混凝土掺量对再生混合料路用性能的影响

Influence of Content of Reclaimed Polyurethane Concrete on Pavement Performance of Recycled Mixture

为了研究废旧聚氨酯混凝土(RPC)的再生技术,本文提出了RPC室内模拟制备方法,并以聚氨酯为胶结料配制了七种RPC掺量的聚氨酯再生混合料(PRM),研究了聚氨酯与RPC界面的黏结性能和RPC掺量对PRM路用性能及耐久性能的影响,建立了PRM路用性能及耐久性能随RPC掺量变化的预测模型。结果表明,RPC满足规范中对集料的相关技术要求,其洛杉矶磨耗损失、软石含量、砂当量与棱角性高于石灰岩,压碎值与表观密度低于石灰岩。聚氨酯与RPC界面的黏结性能优越,随着RPC掺量的增加,PRM的路用性能及耐久性能呈下降趋势;相同RPC掺量下,随着冻融循环次数和老化时间的增加,PRM的劈裂强度逐渐降低并趋于稳定;随着RPC掺量的增加,PRM的劈裂强度随着冻融循环次数和老化时间的增加而下降的幅度更大。

The recycling of reclaimed polyurethane concrete(RPC)has not been explored yet.Therefore,this paper proposes an indoor simulation preparation method of RPC.Polyurethane recycled mixture(PRM)with 7 kinds of RPC content was prepared with polyurethane as binder.The bonding properties of polyurethane and RPC interface and the influence of RPC content on the road performance and durability of PRM were studied,and the prediction model of PRM road performance and durability with RPC content was established.The results show that RPC meets the relevant technical requirements of the specification for aggregates.The los angeles wear loss,soft stone content,sand equivalent and angularity are higher than those of limestone,and the crushing value and apparent density are lower than those of limestone.The bonding performance of the interface between polyurethane and RPC is superior;with the increase of RPC content,the road performance and durability of PRM show a downward trend.Under the same RPC content,splitting strength of PRM gradually decreases and tends to be stable with the increase of freeze-thaw cycles and aging time.With the increase of RPC content,the splitting strength of PRM decreases more significantly with the increase of freeze-thaw cycles and aging time.