The Embedded Steel Connection in Concrete Subjected to Coupled Cyclic Pull-out Force and Water
摘要
Steel-concrete connection employed in hybrid structure is often exposed to water ingress and cyclic loading. Moreover, various types of concrete have been developed as an alternative to conventional cement concrete in response to the need for a smaller environmental footprint. This study investigates three types of concrete as the base material for the embedded connection: geopolymer concrete (GPC), prepacked concrete (PPC), and ordinary Portland cement concrete (OPCC). A cutout steel with an effective embedment depth of 134 mm, was embedded in reinforced concrete. Pull-out test under monotonic condition and cyclic condition was conducted to determine the ultimate tensile capacity and cyclic behavior coupled with water ingress. The tensile capacity was compared with design formula in (JSCE 2022) and finite element analysis (FE analysis) result. The design formula shows good agreement with OPCC capacity, while FE analysis overestimate the capacity. In the case of GPC and PPC, both design formula and FE analysis underestimate the capacity. The angle of inner crack observed after the failure and principal strain in FE analysis ranging from 20° to 30° were consistent despite the conflict with the assumption in the code. The loading amplitude of the cyclic loading procedure was set as 70% to 80% of the tensile capacity. Water addition during the cyclic procedure did not accelerate residual displacement where the fine pore structure and low loading frequency are the possible causes.