中文摘要：

钢管混凝土桁梁是一种新型组合结构,管内混凝土应变状态是定义这种结构的关键指标之一,但其弦杆管径较小而长细比较大,很难准确测得弦杆管内混凝土应变.本文结合钢管混凝土桁梁受力性能试验研究,开发了内埋式混凝土应变计及其定位构造,并设计了配套的普通强度等级自密实混凝土的配合比和浇筑工艺.应用结果表明,本文开发的小管径、大长细比的钢管混凝土构件管内混凝土应变测试技术,可以减少结构损伤,造价低廉,而且设计和施工简便,可推广应用于钢管混凝土桁梁等新型组合结构的室内小比例模型.

英文摘要：

Concrete filled steel tubular （CFST） truss girder is a new composite structure, for which the concrete strain status is defined as a key index of structural behavior. However, the member slen- derness and the tube diameter of chord are so small that it is rather difficult to measure concrete strain. Based on experimental study on structural behavior of CFST truss girder, a kind of embedded concrete strain gauge with accessory location adjustment configuration are developed, and the special mix method for self- compacting concrete with normal strength grade and concrete pouring technique are also designed. It is verified by the experimental test that, the concrete strain measuring technology developed for infilled concrete of small - diameter but slender CFST members can help to minimize structural injure, cut cost and is convenient for engineering design and construction. The technology can be further applied for experiment of laboratory small scale model and in - situ construction of newcomposite structures like CFST truss girders.