微坍落度混凝土技术及其在碾压混凝土坝等工程中的应用

通过近年来从潘家口到玄庙观等碾压混凝土（RCC）筑坝的研究和创新，提出微坍落度混凝土（MSC），使原坍落度为零改为趋近于零且小于0．5cm．这样，保留了原零坍落度混凝土（ZSC）的各种优点，如与相邻的碾压混凝土的各种性质（包括力学和热学性能指标）相近，温度变形相近或相容，故抗裂性能好．此外，它还弥补了原来的缺点，即改善了混凝土的稠度，有利于平仓振捣，提高施工进度和质量，并改善靠近模板、地基、止水片及廊道孔洞部附近有钢筋部位的质量．在大坝等大体积工程、厚度不大的厂房、水闸、涵管等水工建筑物、工民建和桥梁等工程领域中，随着施工设施和工艺水平的提高，这种微坍落度混凝土具有良好的或潜在的发展前景．

Microslump Concrete Technology and Its Use in RCC Dam and Other Projects

From Panjiakou to Xuanmiaoguan, the microslump concrete （MSC） technology has been passed a long way, and a rather new and innovational concrete was brought about. MSC may be supplemented by vibrator compaction in some key areas as near the dam foundation, plate form, around the galleries and penstocks with steel reinforcement and areas near water stops. The viscosity of MSC is closely near zero slump concrete （ZSC）. Its slump value is less than 0.5 m, approaches to but does not equal zero. Not only the favorable characteristics of the former ZSC are preserved, but also the inferior points are remedied and improved. The superiorities of MSC include：（1）Compared with other concretes, its cementinous （gelatinous）content is the lowest,and only a little richer than that of ZSC,it is favorable for quick and economical construction;（2）Upgrade its quality including almost all the characteristics as compressive,tensile,cohesive strength and its ultimate tensile strain;（3）As its physical and heat mechanics properties approximately with the same magnitude of roller compacted concrete near by, its crack resistance is fine. In conclusion, it is pointed out that an innovational MSC provides practical and latent application foreground in massive dam and also some other hydraulic and civil structures with thinner thickness ,such as water locks, power houses, sluices culverts, bridges and so on.