桥梁中预制T梁体的施工技术探讨

钢管混凝土在国内外的桥梁工程建造中被广泛应用，管内混凝土泵管灌注过程中的匀质性控制是保证钢管混凝土组合构件具有良好力学性能的关键。混凝土中各组成原料在钢管的分布情况直接影响钢管混凝土的力学性能，为了探究泵送灌注时各组成原料在钢管中分布规律，将混凝土拌合物等效为气相（空气，主相）、液相（水介质，第2相）、固相（拟流体，第3相），用流体力学软件模拟了混凝土拌合物在钢管垂直布置和倾斜布置时各相流动行为和各相的体积分布规律。对于钢管道垂直布置，混凝土拌合物表现出来第2相和第3相以不同速度的整体顶升推移；对于钢管道倾斜布置，混凝土拌合物表现出来第2相和第3相以不同速度沿上升通道顶升推移和沿下降通道的沉降；两种布置方式均会导致近液面部分出现浮浆趋势，而在底部出现骨料下沉；泵送压力与高度成正比。以上结论可为钢管混凝土在工程上的应用提供参考。

Discussion on the construction technology of the precast T-beam body in the bridge

The concrete filled steel tube (CFST) is increasingly widely used in bridge construction at home and abroad. The homogeneity control of concrete during the pouring is the key to ensure the good mechanical properties of CFST members. The distribution of various raw materials in the main concrete pipe directly affects the mechanical properties. In order to explore the distribution of the raw material in the tube during the pumping, the concrete slurry is equivalent to three phase material: air (phase 1), water (phase 2: liquid phase) and particle (phase 3: fake fluid). Through fluid mechanics software, the flow behavior and the volume distribution law of each phase were simulated when the tube was vertical layout and tilt layout. The pumping pressure with the height was also obtained. For the vertical layout, the second and the third phases of the concrete slurry shows the overall jacking at different speeds. As for the tilt layout, the second and the third phases rise along the ascending channel and sediment along the descending channel. The both arrangements will lead to the stratification near liquid level, and the sedimentation at the bottom. And the pumping pressure is proportional to the height. The above conclusions can provide a reference for the application of CFST in engineering.