Experimental study on structural performance of two-span continuous GFRP-concrete composite hollow slabs

Abstract

为研究两跨连续GFRP-混凝土空心组合板的受力性能,进行了2个连续组合板试件的静力加载试验。组合板分别采用环氧树脂胶及栓钉与下部工字钢支座进行连接。试验结果表明,试件最终破坏形态均为跨中截面处受压区混凝土压碎后,下部GFRP型材下翼缘断裂或侧壁屈曲破坏。采用环氧树脂胶连接的试件,边支座可以视为简支支座;采用栓钉连接的试件,边支座可以视为固定支座。随着负弯矩区混凝土的开裂及受拉钢筋的屈服,组合板均出现了明显的内力重分布现象。基于截面分析方法和等效刚度,提出了连续组合板受力全过程计算方法。计算结果表明,组合板的支座反力和截面弯矩试验值与理论值吻合较好,提出的方法可以有效地用于组合板的全过程受力分析。 Static tests on two-span continuous GFRP-concrete composite hollow slabs supported on steel girders were conducted to investigate their structural performance. The connections between the steel girders and the GFRP-concrete composite slabs were realized by adhesive connection and mechanical connection, respectively. The observed failure modes for the two specimens were both concrete crushing followed by the bottom flange rupture or side wall buckling of GFRP profiles at the mid-span section. Two external supports for the specimen connected with adhesive connection can be considered as the simply support constraints. However, the fixed support constraints can be approximated for the specimen mechanically connected with shear studs. During the tests, the internal force redistributions were observed after concrete cracking and tensile steel reinforcement yielding at the negative moment regions. Based on the sectional analysis method and sectional equivalent stiffness, a full-process calculation method for the two-span continuous GFRP-concrete composite hollow slabs was proposed. The analytical results show that there is a good agreement between the tested and calculated values of the support reaction and the sectional bending moment, respectively. The proposed method can predict the full-process mechanics of the continuous composite slabs effectively.