FLEXURAL PERFORMANCE OF COLD-FORMED THIN-WALLED STEEL-PAPER STRAW BOARD COMPOSITE SLAB

A new type of composite slab was proposed by connecting paper straw board and coldformed thin-walled steel with self-tapping screws. In order to investigate the failure process and failure mode of the composite slab, the tests on the flexural capacity of three composite slabs with different factors such as steel beam section size, beam spacing and the number of screws were carried out. The strain of the cold-formed thin-walled C-shaped steel and the paper straw board, and the deflection of the composite slab were observed, respectively. Moreover, the flexural behaviour and the composite action of the composite slab were investigated and the flexural capacity of the composite slab was obtained. It was found that the final failure mode of composite slab was the local buckling mode of cold-formed thin-walled C-shaped steel beam due to the adequate restraint of the straw board, and the reducing of the screw spacing had beneficial influence on the flexural yield capacity. The calculation method of midspan deflection and flexural capacity of composite slab were proposed, and the calculated values of deflection and flexural capacity agreed well with the test results. Therefore, the new composite slabs were of good working performance and high flexural capacity.