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

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 GFRPconcrete 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.