UHPC薄壁盖梁设计、结构试验及施工技术研究

摘要:

预制桥梁中盖梁重量较大的问题一直困扰着施工，具有轻质高强特点的UHPC可为盖梁轻量化提供解决方案。设计三种采用UHPC的薄壁盖梁，对比断面形式、材料指标及预应力体系；分批次开展结构试验，测试不同缩尺比下的全过程受力状态，分析构件抗裂性、承载力及变形等；比较不同UHPC材料、模板、振捣及养护方法对试件质量的影响。经过研究，UHPC薄壁盖梁设计方案可减轻原结构重量40%以上；UHPC盖梁受力可靠、抗裂性好、变形能力强；UHPC构件生产需严控浇筑过程。

Abstract:

In precast bridges, weight of bent cap is a main problem, and it influences bridge construction. Ultra high performance concrete (UHPC) has features of light weight and high intensity, those could supply settlements for bent cap light-weighting. Designs three UHPC thin wall bent caps, compares sections, material indexes and prestressing systems. Carries out structural tests in three batches, tests whole loading processes with two scale ratios, analyzes crack resistances, bearing capacities and deformations. Compares qualities influences of different UHPC, templates, vibrating and maintenances. After research, UHPC thin wall bent cap could reduce weight 40% opposite original bent cap. UHPC bent cap is reliable, has fine crack resistances and deformability. In productions of UHPC members, casting processes must be controlled rigorously.