Deformation of reinforcement in precast reinforced concrete, due to electrical welding

Abstract

1. With the usual technology, welding of joints between reinforcement projections, with two straps with two side welds for joining two reinforced-concrete elements, produces stresses in the reinforcement, which do not reduce the strength of the flexed elements (μ=0.37%). 2. According to the construction of the bearing pads in the seam between component reinforced-concrete elements, the weld stresses in the reinforcement rods may be of like or opposite signs. If the stresses in the reinforcement are of like sign (tensile), the rigidity of the seam between the two reinforced-concrete elements is greater than that of a similar monolithic specimen; if the signs are opposite (both tensile and compressive), the rigidity is less than that of a similar monolithic specimen. 3. The main cause of weld stresses in the reinforcement of composite specimens is thermal elongation of the reinforcement projections during welding of their joints. 4. Welding of the joints of the reinforcement projections did not affect the value of the restraining force in the reinforcement rods anchored in the concrete to a length of 30d. 5. The crack resistance of the abutment zone of the composite reinforced-concrete elements was higher when only tensile stresses arose in the welded reinforcement rods, and lower when both tensile and compressive stresses arose.