建筑垃圾细料生产流动化回填材料的性能

Properties of flowable backfill materials using recycled fine aggregates of brick and concrete waste

以灰砂比0.03、0.05和0.08,粉砂比0、0.05、0.1、0.15和0.2为设计参数,对建筑垃圾回填材料进行设计。通过试验对回填材料的流动性（流动度、泌水率）、无侧限抗压强度以及应力应变曲线、本构关系模型和弹性模量等进行研究。研究结果表明：回填材料的流动度受水固比影响较大,两者接近线性关系;流动度在200-250mm范围,泌水率在4%-8%之间;回填材料抗压强度与灰砂比和水固比之间存在很好的幂指数关系;回填材料应力应变曲线形状与普通混凝土的相似,在此基础上提出回填材料的本构关系模型;回填材料无侧限抗压强度与弹性模量之间存在很好的指数关系。

A new type of backfill materials using recycled brick and concrete waste as fine aggregates was designed with three cement-to-sand ratios（C/Sa）and five fly ash-to-sand ratios（FA/Sa）.A series of measurements were conducted to investigate the fluidity and bleeding and mechanical properties including uniaxial compressive strength,stress-strain relationship,constitutive relation model and elastic modulus.The results showed fluidity had linear correlation on water-to-solid ratios（W/So）;the range of the bleeding rates was in 4% -8% when the fluidity was within 200-250 mm.The compressive strengths had an exponential relationship to the cement-to-sand ratios and water-to-solid ratios.A constitutive relation model was put forward to describe the stress-strain relationship curve of backfill material on the base of themodel of the concrete.The relationship between the unconfined compressive strength and elastic modulus was established,which could be used to calculate the modulus of backfill materials by the compressive strength directly.