【摘要】 为研究再生混凝土的基本性能,选用替代率分别为30%、50%、80%、100%,基本水灰质量分数比为0.40、0.50,砂率为30%等条件下的再生粗骨料混凝土为研究对象,通过试验观察和数据分析,得出以下结论:在水灰质量分数比和砂率相同的条件下,不同替代率的再生混凝土的流动性和抗压强度均比普通混凝土差,且除100%再生混凝土外,其他再生混凝土的强度随着再生骨料取代率的增加而逐渐降低;当再生骨料替代率≤50%时,再生混凝土的粘聚性和保水性都满足要求;而替代率>50%时,其流动性、保水性、粘聚性都较差;在替代率和水灰质量分数比都较高的条件下,提高砂率能有效改善再生混凝土的和易性.建议再生混凝土表观密度取值为(2 400±100)kg/m3.更多还原

【Abstract】 The basic property of recycled aggregate concrete was studied.Different substitution rates of recycled aggregate(30%,50%,80% and 100%) were adopted and basic water-cement ratio were 0.40 and 0.50 as well as sand coarse aggregate ratio was 30%.Experiment results and data analysis indicated that under the same water-cement ratio and sand coarse aggregate ratio,the mobility and compressive strength of recycled concrete with different substitution rate were inferior than this of normal concrete; apart from recycled concrete with 100% substitution rates,the compressive strength of recycled concrete decreased as recycled aggregate substitution rate increased.When substitution rate of recycled aggregate was below 50%,the cohesion and water retention of recycled concrete adhered to the requirement; whereas the substitution rate of recycled aggregate exceeded 50%,both the mobility,cohesion and water retention of recycled concrete were relatively poor; Thus,it was illustrated that when substitution rate of recycled aggregate and water-cement ratio were both high,the workability of recycled concrete could be improved by appropriate increasing of sand coarse aggregate ratio.Furthermore,it was suggested that the optimal value of apparent density of recycled concrete was(2 400±100)kg/m3.更多还原