活性粉末混凝土简支箱梁模型试验研究

Model Test Study on Simply Supported Box Girder of Reactive Powder Concrete

为了研究活性粉末混凝土在铁路箱梁中的结构性能和破坏状态,试验设计了1孔斜腹板薄壁活性粉末混凝土简支箱梁模型。该箱梁模型采用节段拼装制梁成孔,短线法预制,采用胶接缝。本试验完成了跨度24 m活性粉末混凝土简支箱梁的预制和拼装施工,研发了适应活性粉末混凝土箱形梁预制的钢模板系统,探索了合理的拆模、搅拌、浇筑、养护、预应力张拉工艺。通过活性粉末混凝土简支箱梁静载试验,对设计参数的选取和计算方法进行了验证。试验结果表明:梁体刚度和抗裂安全系数满足设计要求;跨中截面和1/4跨截面中性轴高度实测值均与设计值基本一致;胶接缝的抗拉弹性模量满足设计要求。

In order to study the structural performance and failure state of reactive powder concrete in railway box girder,a simple supported box girder model of thin-walled reactive powder concrete with an inclined web was designed.The box girder model segments were assembled to form holes and prefabricated by short-line method,and the epoxy joints were used.In this experiment,the prefabrication and assembly of a simple supported box girders of reactive powder concrete with a span of 24m were completed.A steel formwork system suitable for prefabrication of reactive powder concrete box girders was developed.The reasonable technologies of dismantling,stirring,pouring,curing and tensioning were explored.The selection of design parameters and the theory of calculation method were verif ied by the static load test of a reactive powder concrete simply supported girder.The test results show that the stiffness and safety factor of crack resistance of the girder meet the design requirements.The measured values of the neutral axis height of the mid-span section and 1/4 span cross-section are consistent with the design values.The tensile elastic modulus of the epoxy joint meets the design requirements.