Multifunctional all-GFRP joint for concrete slab structures
An existing hybrid-GFRP/steel joint for load transfer and thermal insulation in concrete slab structures was developed into an all-GFRP joint. The new joint consists of a pultruded GFRP tensile/shear element anchored through adhesively bonded ribs in the concrete and a compression/shear element with contacting cap-plates. The new joint improves considerably the energy savings of buildings due to the low thermal conductivity of GFRP composites. The quasi-static performance of the new joint was investigated through full-scale experiments on cantilever beam elements and analytical modeling. The all- GFRP joint provides ductile performance similar to the hybrid-GFRP/steel joint. The transfer of bending moments occurs through tensile forces in the upper flange of the tensile/shear element and compression forces in the lower flange of the compression/shear element. The shear force transfer is shared between both GFRP elements. The tensile/shear element attracts 50% more shear force due to the fixed end supports. Simple analytical models can be used to describe the joint behavior and compare well with measurements. (c) 2006 Elsevier Ltd. All rights reserved.