关键词: 桥梁工程；结构工程；地聚物混凝土；T形梁；翼缘宽度；翼缘厚度；抗弯性能

Abstract: The influence of flange width and thickness on the flexural behavior of geopolymer concrete T-beams was investigated by the four-point bending test of five geopolymer concrete T-beams with different flange sizes and one ordinary concrete T-beam. Meanwhile, the difference between geopolymer concrete and ordinary concrete T-beam were evaluated. The results show that the flexural ultimate load, yield load, crack behavior and failure mode of geopolymer concrete T-beams are similar to those of ordinary concrete T-beams. The ductility of geopolymer concrete T-beam is better than that of ordinary concrete T-beam. However, the strain of the longitudinal reinforcement in mid span tension is relatively larger, and the stiffness, crack loading, and bearing capacity of geopolymer concrete T-beam under the maximum crack width limit are relatively lower. As the flange width increases from 200 mm to 500 mm, the stiffness, yield load, flexural ultimate load, ductility, and bearing capacity under the maximum crack width limit of the geopolymer concrete T-beam all increase. The strain of the tensile longitudinal reinforcement at the mid span decreases, and there is no significant change in cracking load. However, the wider the flange width, only a part of the width close to the web can effectively bear the load. The effect of increasing flange thickness on the flexural behavior of geopolymer concrete T-beams is basically the same as that of increasing flange width. However, its effect on improving the bearing capacity under the maximum crack width limit is significant. The design formulas for the normal section flexural bearing capacity of GB 50010—2010 and ACI 318—19 are applicable to geopolymer concrete T-beams. The prediction of GB 50010—2010 is more accurate, and the safety reserve of ACI 318—19 is higher.

Key words: bridge engineering; structural engineering; geopolymer concrete; T-beams; flange width; flange thickness; flexural behavior