新拌低水胶比水泥浆体流变性能影响因素及流变参数预测方法  

Influencing factors of rheological properties and prediction of rheological behavior of fresh low water-to-cement ratio cement pastes

作　　者：王鹏刚[1] 高义志 陈际洲 左文强 冯家润 郑瑞剑 WANG Penggang;GAO Yizhi;CHEN Jizhou;ZUO Wenqiang;FENG Jiarun;ZHENG Ruijian(School of Civil Engineering,Qingdao University of Technology,Qingdao 266525,China;Qingdao Municipal Construction Group Co.,Ltd.,Qingdao 266000,China;School of Materials Science and Engineering,Southeast University,Nanjing 211189,China)

机构地区：[1]青岛理工大学土木工程学院,青岛266525 [2]青岛市政空间开发集团有限责任公司,青岛266000 [3]东南大学材料科学与工程学院,南京211189

出　　处：《复合材料学报》2024年第12期6681-6690,共10页Acta Materiae Compositae Sinica

基　　金：十四五国家重点研发计划(2023 YFB3711400);江苏省青年科技基金(BK20230865);山东省自然科学面上项目(ZR202103020358);泰山学者青年专家(tsqn202306231)。

摘　　要：高性能混凝土流变性能较差的稳定性以及较为复杂的调控方法,是影响其在土木工程建设中推广应用的重要因素之一。基于堆积密度试验、流变试验和总有机碳吸附试验,研究了矿粉和粉煤灰掺量对低水胶比水泥浆体流变参数的影响规律。结果表明:当矿粉和粉煤灰体积掺量在0%~15%之间时,随着掺量的增加,复合胶凝材料体系的堆积密度提高,水泥浆体的屈服应力和塑性黏度降低,并且上述规律随着减水剂掺量和矿物掺合料取代量的增加更加明显。胶凝材料表面的吸附-脱附平衡速率常数只与减水剂性质有关,对于本试验所用的减水剂拟合值为12。通过颗粒堆积理论和经典流变模型分析得到,矿粉和粉煤灰主要通过影响复合胶凝材料体系的凝胶作用力和相对堆积密实度,影响水泥浆体的流变性能。基于此提出了适用于水泥-矿粉和水泥-粉煤灰体系的低水胶比水泥浆体流变性能预测及优化方法。The poor stability and complex control methods of rheological properties of high performance concrete are one of the important factors that affect its popularization and application in civil engineering construction.Based on the measurements of packing density,rheological properties,and total organic carbon adsorption,the influence and mechanism of the content of mineral additives on the rheological properties of cement paste with low water-to-cement ratio were investigated.The results show that,when the volume content of mineral powder and fly ash is between 0% and 15%,with the increase of the volume,the packing density of the composite cementing material system will be increased,and the yield stress and plastic viscosity of the cement slurry will be reduced.Moreover,the above rheological parameters increase with the increase in polycarboxylate superplasticizer(PCE)dosage and the replacement ratio of mineral additives.Through adopting the particle packing model and recently developed rheological models,the adsorption-desorption equilibrium rate constant on the surface of the cementitious material is only related to the nature of the water reducing agent,and the fitted value is 12 for the water reducing agent used in this test.It is concluded that the change in rheological properties by blending mineral additives is mainly due to the changes in the colloidal interactions and relative packing density of the cementitious particles.Based on the above findings,an approach for predicting and optimizing the rheological properties of low water-tocement ratio cement paste applicable to the cement-slag and the cement-fly ash microbeads system is proposed.

关 键 词：等温吸附 堆积密度 屈服应力 塑性黏度 流变模型 

分 类 号：TB332[一般工业技术—材料科学与工程]