掺活性掺合料的缓凝大流动性C80混凝土的性能研究

利用磨细矿渣粉、粉煤灰及二者复掺取代 30 %的水泥配制缓凝大流动性C80混凝土 ,测试了混凝土的力学性能以及干燥收缩、抗冻性、抗硫酸盐侵蚀性能、干热 -水浸泡循环作用下的性能等。研究表明 ,磨细矿渣粉单独掺入混凝土中仅有微弱的减水效应 ,但与高效减水剂共同使用时显示了显著的辅助减水效应。以掺合料与缓凝保塑高效减水剂共同配制的C80混凝土不仅流动性好 ,4h坍落度经时损失小 ,而且具有优异的力学性能 ,特别是掺磨细矿渣粉的混凝土早期力学性能与对比组接近。同时 ,掺磨细矿渣粉、粉煤灰或二者复掺的C80混凝土具有比对比混凝土更优越的抗干燥收缩性能、抗冻性、抗硫酸盐侵蚀性能及抗干热-水浸泡循环作用的性能

PROPERTIES OF FLOWABLE AND RETARDING C80 CONCRETE MADE WITH REACTIVE POZZOLANS

C80 concrete of high fluidity and long time high slump was prepared with 30%(by weight)of pulverized slag,class F fly ash or the combination of the two for replacement of cement.The mechanical properties,dry shrinkage,frost resistance,sulfate resistance and the performance under hot dry water cycling were examined.The investigation showed that the incorporation of pulverized slag together with superplasticizer in concrete could improve the flowability of fresh concrete while no improvement was observed if slag was used alone.C80 concrete with pulverized slag or fly ash showed excellent mechanical properties and superior durability,such as low dry shrinkage,good frost resistance and sulfate resistance and excellent performance under hot dry wet cycling.