再生混凝土粉对湿拌砂浆物理力学性能的影响  

Effects of recycled concrete powder on the physical mechanical properties of wet-mixed mortar

作　　者：丁向群[1] 邢伟 李贺[1] DING Xiangqun;XIN Wei;LI He(School of Materials Science and Engineering,Shenyang Jianzhu University,Shenyang 100168,China)

机构地区：[1]沈阳建筑大学材料科学与工程学院,辽宁沈阳110168

出　　处：《混凝土》2018年第11期94-97,共4页Concrete

摘　　要：研究了再生混凝土粉和粉煤灰作为矿物掺合料,在不同掺量下,对湿拌砂浆的和易性、稠度、保水性、收缩率、以及抗压强度的影响。并利用扫描电子显微镜观察了该湿拌砂浆的微观结构。研究表明:随着再生混凝土粉的掺量增加,湿拌砂浆的保水性提高,收缩率降低,但再生混凝土粉会降低湿拌砂浆稠度,粉煤灰的加入可以提升水泥-再生混凝土细粉-粉煤灰湿拌砂浆体的稠度,因此,两者同时掺入能明显改善湿拌砂浆和易性。再生混凝土粉对湿拌砂浆抗压强度影响大,掺入10%以上的再生混凝土粉后胶砂强度较基准大幅降低,仅当再生混凝土细粉掺量小于10%时,稍有利于早期强度。微观结构观察表明:再生混凝土粉掺量为10%时,体系中产生钙矾石较多,可以提升湿拌砂浆前期强度,掺量进一步增加时,水化产物明显减少,结构松散是强度大幅降低的原因。Study on the effect of recycled concrete powder and fly ash,as mineral admixture,on workability,consistency,water retention,shrinkage and compressive strength of wet-mixed mortar.and he micro structure of the wet-mixed mortar were observed by using scanning electron microscopy.Research shows that with the content of recycled concrete powder increases,the water retention of wet-mixed mortar increases,the shrinkage rate decreases recycled concrete powder will reduce the consistency of wet mortar,the addition of fly ash can enhance the consistency of cement-recycled concrete powder-fly ash wet-mixed mortar system,so both work together to improve the wet mix mortar workability.Recycled concrete powder wet compressive strength of mortar,when more than10%of the strength of recycled concrete powder significantly lower than the blank group,only when the recycled concrete fine powder content is less than10%,slightly conducive to the early strength.microstructure observation showed that:when the amount of recycled concrete powder is10%,more ettringite is produced in the system,which can enhance the early strength of wet-mixed mortar.When the content of recycled concrete powder increases,the hydration products decrease obviously.The loose structure is the reason of the sharp decrease of strength.

关 键 词：再生混凝土粉 湿拌砂浆 稠度 保水性 收缩率 抗压强度 

分 类 号：TU528.01[建筑科学—建筑技术科学]