Flexural Behavior of a 30-Meter Full-Scale Simply Supported Prestressed Concrete Box Girder

Abstract

Compared with scaled-model testing, full-scale destructive testing is more reliable since the test has no size effect and can truly record the mechanical performance of the structure. However, due to the high cost, only very few full-scale destructive tests have been conducted on the flexural behavior of prestressed concrete (PC) box girders with girders removed from decommissioned bridges. Moreover, related destructive testing on the flexural behavior of a new precast box girder has been rarely reported. To investigate the flexural behavior and optimize the design, destructive testing of a 30-meter full-scale simply supported prestressed box girder was conducted at the construction site. It is illustrated that the failure mode of the tested girder was fracture of the prestressing tendon, and the corresponding maximum compressive strain in the top flange was only 1456 μ ε , which is far less than the ultimate compressive strain (3300 μ ε ). Therefore, the concrete in the top flange was not fully utilized. A nonlinear analysis procedure was performed using the finite strip method (FSM). The validity of the analysis was demonstrated by comparing the analytical results with those of the full-scale test in the field and a scaled model test in a laboratory. Using the developed numerical method, parametric analyses of the ratio of reinforcement were carried out. The prestressing tendon of the tested girder was increased from four strands to six strands in each duct. After the optimization of the prestressed reinforcement, the girder was ductile and the bearing capacity could be increased by 44.3%.

Sustainable Applications for Utilizing Antimony Tailing Coarse Aggregate (ATCA) in Concrete: Characteristic of ATCA and Toxicity Risks of Concrete

“…To ensure the mechanical property [ 45 ] and durability [ 46 ] of the bridge structure, the quality of concrete materials should be guaranteed. Since the performance of concrete is directly affected by CA, the material quality of ATCA should meet the specification requirements.…”

Blasting‐Induced Vibration Response of the Transition Section in a Branching‐Out Tunnel and Vibration Control Measures

“…e branching-out tunnel is composed of three parts, namely, the large-span, multiarch, and small net span sections. e branching-out tunnel has promising application prospects in difficult highway construction and in transition project of bridges and tunnels because it exhibits the engineering characteristics of large-span multiarch tunnel and neighborhood tunnel [4][5][6]. However, the distance between the two holes changes continuously, and the stress structures in the transition section become complicated because the blasting excavation of the posterior tunnel in the transition section of the branching-out tunnel can influence the stability of the supporting structure of the anterior tunnel, thereby further changing the stress state and mechanical behavior of the supporting structure in the tunnel, and even local collapse or overall instability of the supporting structure [7,8].…”

“…surrounding rocks (III, IV, and V), 6 buried depths(5,10,20,30, 40, 50, and 100 m), 6 net spans (1, 2, 3, 4, 5, and 6 m), and 9 different distances from explosive source (−20, −15, −10, −5, 0, 5, 10, 15, and 20 m). e blasting-induced vibration velocity peaks under different calculation conditions were calculated.…”

Detecting of the Crack and Leakage in the Joint of Precast Concrete Segmental Bridge Using Piezoceramic Based Smart Aggregate

“…The precast segmental construction (PSC) method is very suitable for medium- and long-span bridge projects due to its efficiency and economy [ 1 , 2 , 3 ]. By precasting the segmental units in the strictly controlled factory environment, high-quality structures with precise dimensions, desired strengths and reduced shrinkage and creep effects can be fabricated [ 4 , 5 , 6 ].…”