自密实混凝土在钢管混凝土拱桥中的应用

Applications of self-compacting concrete in concrete-filled steel tubular arch bridges

通过优选原材料、复合外加剂 ,采用高掺量粉煤灰和微膨胀技术配制的自密实高性能混凝土 ,不仅具有优良的工作性且坍落度损失小、可泵性好 ,同时还具有优良的力学性能和耐久性能。自密实钢管混凝土与普通泵送钢管混凝土的轴心受压对比试验表明 ,两者的力学性能相近。将自密实混凝土作为钢管内填混凝土应用在钢管混凝土拱桥中 ,不仅能满足设计所要求的强度、弹性模量等力学指标 ,具有良好的填充性、抗离析性及混凝土与钢管壁的粘结力 ,同时满足了施工中采用泵送顶升法浇筑混凝土的技术要求 ,大大加快了施工进度、确保了工程质量。从材料成本、施工进度及工程质量等方面综合比较来看 。

With the use of selected materials, composite admixtures, high-volume fly ash and expansive agent, the SCC mixture with desirable workability, low slump lose and good segregation resistance is obtained. The mechanical properties and durability of SCC are excellent. The experimental results of short concrete-filled steel tubular under axis-compression load show that the mechanical properties of SCC-filled steel tubular are similar to the normal concrete (NC). The application of SCC in a concrete-filled steel tubular arch bridge is carried out, the results show that SCC not only meets the requirements of the designed mechanical properties such as compressive strength, elastic modulus, but also ensures the filling effect and bond strength between steel tube and concrete. Compared to normal pumping concrete, the SCC has speeded up the construction progress, guaranteed the construction quality and reduced the construction cost effectively. So the applications of self-compacting concrete in concrete-filled steel tubular arch bridges have good technology benefit and good economic benefit.