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- 混凝土与制品
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中热及低热水泥配制超高性能混凝土的研究
作者：郑丽1，2，陈露一1，2，石俊华2，龚玉杰2，李承福2
（1.桥梁结构健康与安全国家重点实验室，湖北 武汉 430034；2.中铁桥研科技有限公司，湖北 武汉 430034）
摘要：分别采用低热水泥、中热水泥、普硅水泥及大掺量矿物掺合料配制超高性能混凝土（UHPC），研究了UHPC力学性能、体积稳定性及热学性能的变化。结果表明：普硅水泥配制的UHPC力学性能最好，采用中热、低热水泥或增加矿物掺合料掺量均会使混凝土的抗压及劈裂抗拉强度降低；中热、低热水泥可以减小UHPC的自收缩，增大干燥收缩，但UHPC自收缩和干燥收缩的收缩总量减小，且低热水泥的降低效果优于中热水泥，相较于普硅水泥，低热水泥配制的UHPC总收缩量减小了33%；中热、低热水泥配制UHPC可以降低混凝土的水化速率，同时延缓到达最大水化速率的时间；单纯采用低热水泥降低UHPC绝热温升效果有限，混凝土中心温度与普硅水泥配制的UHPC相差不大。
关键词：低热水泥；中热水泥；超高性能混凝土；水化热；自收缩
中图分类号：TU528.31 文献标识码：A 文章编号：1001-702X（2023）01-0036-05
Study on the preparation of ultra-high performance concrete with medium and low heat cement
ZHENG Li1，2，CHEN Luyi1，2，SHI Junhua2，GONG Yujie2，LI Chengfu2
（1.State Key Laboratory of Bridge Structure Health and Safety，Wuhan 430034，China；
2.China Railway Britech Co. Ltd.，Wuhan 430034，China）
Abstract：The mechanical properties，volume stability and thermal properties of ultrahigh performance concrete（UHPC） were studied by using geothermal cement，medium heat cement，Portland cement and large amount of mineral admixtures. The results show that the mechanical properties of UHPC prepared with Portland cement are the best. The compressive strength and splitting tensile strength of concrete can be reduced by using medium and low heat cement or increasing mineral admixture. Medium and low heat cement can reduce UHPC self-shrinkage and increase dry shrinkage，but the total shrinkage of UHPC self-shrinkage and dry shrinkage decreased，and the reduction effect of low heat cement is better than that of medium heat cement. Compared with Portland cement，the total shrinkage of UHPC prepared by low heat cement is reduced by 33%. Mixing UHPC with medium and low heat cement can reduce the hydration rate of concrete and delay the time to reach the maximum hydration rate. The effect of simple use of low heat cement to reduce the adiabatic temperature rise of UHPC is limited，and the central temperature of concrete is not much different from that of UHPC made of Portland cement.
Key words：low-heat cement，medium-heat cement，ultra-high performance concrete，heat of hydration，self-shrinking