中文摘要：

采用双层箍筋约束高强混凝土提高框架柱的承载力和抗震性能，具有重要的应用前景。相较于普通的钢筋混凝土结构，采用双层箍筋，增加了钢筋的密度，对约束混凝土的施工性能提出了严格的要求。配制的混凝土不仅要满足强度要求，而且还要流动性大，黏聚性好，匀质性高，石子的粒径小，才能使混凝土均匀地穿过双层箍筋，达到外层的保护层，形成致密的混凝土结构。选用粉煤灰、硅灰、偏高岭土作为混凝土掺合料，进行细石高强混凝土配合比设计，讨论不同掺合料高强混凝土的强度发展规律以及它们的对比分析。试验结果表明：同等条件下，硅灰和偏高岭土的掺量均以12％为宜；粉煤灰的适宜掺量为20％；硅灰对混凝土的增强效果高于偏高岭土。上述结果对配制双层箍筋约束的高强混凝土，具有重要的指导意义。

英文摘要：

It has important application foreground to constrain high-strength concrete by using double-stirrup.This kind of structure helps improve the carrying capacity and seismic capability of frame columns.Compared with ordinary reinforced concrete,the structure＇s density of the reinforced concrete has been increased.So strict requirements had been raised on workability of the concrete.The concrete mix should not only satisfy the strength requirement,but also possess great fluidity,good cohesiveness,high homogeneity and smaller stone sizes to make concrete evenly go through the double-stirrup to form dense concrete cover.Fly ash, silica fume and metakaolin had been selected as concrete admixture.Discussion was made on the fine aggregate,high-strength concrete especially in collocation ratio, de- velopment of strength of it with different admixture and comparative analysis of different admixture.The results of tests indicated that, on the same conditions, suitable adding volume of silica fume and metakaolin both have been determined as 12%, and appropriate quantity of additive fly ash was 20%.And concrete with silica fume has a better performance than that with metakaolin.The above results had important guiding significance to compound double-stirrup reinforced high-strength concrete.