低压对水泥净浆力学特性的影响  

Effect of low pressure on mechanical properties of cement paste

作　　者：李玉成 王起才[1,2] 代金鹏[1,2] 楚昊 杨展湖 胡飞扬 LI Yucheng;WANG Qicai;DAI Jinpeng;CHU Hao;YANG Zhanhu;HU Feiyang(Bridge Engineering National Local Joint Engineering Laboratory of Disaster Prevention and Control Technology,Lanzhou Jiaotong University,Lanzhou 730070,China;Key Laboratory of Road and Bridge and Underground Engineering of Gansu Province,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学甘肃省道路桥梁与地下工程重点实验室,甘肃兰州730070 [2]兰州交通大学道桥工程灾害防治技术国家地方联合工程实验室,甘肃兰州730070

出　　处：《混凝土》2023年第10期87-90,共4页Concrete

基　　金：国家自然科学基金(51768033,51808272);甘肃省青年科技基金(21JR7RA330);甘肃省青年科技人才托举工程项目(GXH20210611-10);兰州交通大学“天佑青年托举人才计划”基金;长江学者和创新团队发展计划滚动资助项目(IRT_15R29);甘肃省引导科技创新发展专项-重点研发能力提升项目(2019ZX-09)。

摘　　要：水泥净浆是利用水泥和水拌和均匀后而成具有流动度好,不泌水,收缩率小,且具有一定的可塑性,硬化后强度稳定的混合物。通过在温度5℃的不同气压下(38.7、47、57.6、70.7、95 kPa),以及水灰比为0.31的情况下在1、3、7、14、21、28 d的抗压强度测试,将试块放进低温低压养护箱并在恒温下控制气压来研究水泥的抗压强度。结果表明:在恒温和水灰比不变的条件下,水泥净浆抗压强度养护的气压强度越高,其抗压强度也随之升高并趋向于定值。其孔隙率和含水率受到随气压的影响,随气压的升高加速了水化速率,使得含水率和孔隙率降低。Cement paste is a mixture made by mixing cement and water evenly.It has good fluidity,no bleeding,small shrinkage,certain plasticity and stable strength after hardening.The compressive strength of cement is studied by testing the compressive strength of cement at different air pressures(38.7,47,57.6,70.7,95 kPa)at the temperature of 5℃and at the water cement ratio of 0.31 for 1,3,7,14,21,28 d.The test block is put into the low-temperature and low-pressure curing box and the air pressure is controlled at a constant temperature.The results show that under the condition of constant temperature and constant water cement ratio,the higher the air pressure strength of cement paste curing,the compressive strength also increases and tends to a fixed value.The porosity and water content are affected by air pressure.With the increase of air pressure,the hydration rate is accelerated and the water content and porosity are reduced.

关 键 词：水泥净浆 低压 含水率 孔隙率 抗压强度 

分 类 号：TU528.041[建筑科学—建筑技术科学]