再生砂和再生粉对干粉砂浆工作性和力学性能的影响  

Effect of Recycled Sand and Recycled Powder on Workability and Mechanical Properties of Dry Powder Mortar

作　　者：凌刚 徐智勇 胡亮 林希 LING Gang;XU Zhi-yong;HU Liang;LIN Xi(Wuhan Chu Tian Ming Yang Building Materials Co.,Ltd.,Wuhan 430000,China)

机构地区：[1]武汉楚天名扬建材有限公司,湖北武汉430000

出　　处：《混凝土与水泥制品》2023年第5期95-98,102,共5页China Concrete and Cement Products

摘　　要：将废弃混凝土破碎、筛分制成再生砂和再生粉,研究了再生砂、再生粉分别等质量替代机制砂、石粉对干粉砂浆工作性和力学性能的影响,并对微观结构和水化产物进行了分析。结果表明:再生砂的掺入会增大砂浆的需水量、稠度损失和保水率,降低砂浆的表观密度;再生粉掺入过多会导致砂浆的需水量、表观密度和保水率降低,稠度损失增大;随着再生砂替代率的增加,砂浆的3 d抗压强度降低,28 d抗压强度先增大后减小,这主要归因于再生砂的内养护作用;再生粉对砂浆的3 d和28 d抗压强度影响不大,这主要归因于再生粉的水化作用和晶核效应;综合考虑砂浆的工作性和力学性能,建议再生砂替代率不超过40%,再生粉替代率不超过60%。The effects of recycled sand and recycled powder on the workability and mechanical properties of dry powder mortar were studied,and the microstructure and hydration products were analyzed.The results show that the addition of recycled sand can increase the water demand,consistency loss,and water retention rate of mortar,and reduce the apparent density of mortar.Excessive addition of recycled powder will reduce the water demand,apparent density,and water retention ratio of mortar,and increase the consistency loss.With the increase of the replacement rate of recycled sand,the compressive strength of mortar at 3 days decreases,and the compressive strength at 28 days first increases and then decreases,which is mainly due to the internal curing effect of recycled sand.The influence of recycled powder on the compressive strength of mortar at 3 days and 28 days is not significant,which is mainly due to the hydration and nucleation effects of recycled powder.Considering comprehensively the workability and mechanical properties of mortar,it is recommended that the replacement rate of recycled sand should not exceed 40%,and the replacement rate of recycled powder should not exceed 60%.

关 键 词：再生砂 再生粉 混凝土 工作性 力学性能 微观分析 

分 类 号：TU528.041[建筑科学—建筑技术科学]