Flexural behavior of precast concrete box beams posttensioned with unbonded, carbon-fibercomposite cables

PCI Journal ◽  
2008 ◽  
Vol 53 (4) ◽  
pp. 62-82 ◽  
Author(s):  
Nabil Grace ◽  
Tsuyoshi Enomoto ◽  
Ahmed Abdel-Mohti ◽  
Yahia Tokal ◽  
Sreejith Puravankara
2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Shun Chai ◽  
Tong Guo ◽  
Zheheng Chen ◽  
Jun Yang

Precast concrete segmental (PCS) box-girders are widely used in bridge construction, while studies on flexural behaviors of PSC box-girders with dry joints are insufficient. Six large-scale PCS box-girders with dry joints were tested to failure under two-point loading in this study. Strain increments, tendon forces, deflections at mid-span, and cracks were recorded during the tests. Multiple factors were investigated with regards to their influence on flexural performance of girders. It is found that most specimens failed due to the excessive force in tendons, while the specimen with external tendons failed due to concrete compressive crushing. Larger shear span ratio resulted in greater increase in tendon force and concrete strain during loading and, accordingly, the lowest ultimate flexural capacity. Lower concrete strength resulted in larger increase in concrete strain and tendon force during loading and relatively smaller deflection at failure. For the specimen with four segments, a significant increase in tendon force and smaller deflections at failure was observed as compared with specimen 1, though the failure load was similar. Numerical simulation is further conducted, where it is found that the area of prestressed tendon and the number of joints have a significant influence on ultimate flexural bearing capacity and deflection; besides, deflection control standard of PCS girders should be stricter than that of the integral cast girder. The corbel joints, in general, show better ultimate performance than the castle-shaped joints.


2010 ◽  
Vol 32 (9) ◽  
pp. 2940-2949 ◽  
Author(s):  
Keun-Hyeok Yang ◽  
Myoung-Ho Oh ◽  
Myeong-Han Kim ◽  
Ho-Chan Lee

2019 ◽  
Vol 9 (22) ◽  
pp. 4946 ◽  
Author(s):  
Sun-Jin Han ◽  
Jae-Hoon Jeong ◽  
Hyo-Eun Joo ◽  
Seung-Ho Choi ◽  
Seokdong Choi ◽  
...  

Half precast concrete slabs with inverted multi-ribs (Joint Advanced Slab, JAS), which enhance composite performance between slabs by introducing shear keys at connections between the slabs and improve structural performance by placing prestressing tendons and truss-type shear reinforcements, have recently been developed and applied in many construction fields. In this study, flexural and shear tests were performed to verify the structural performance of JAS members. Towards this end, two flexural specimens and four shear specimens were fabricated, and the presence of cast-in-place concrete and the location of the critical section were set as the main test variables. In addition, the flexural and shear performance of the JAS was quantitatively evaluated using a non-linear flexural analysis model and current structural design codes. Evaluation results confirmed that the flexural behavior of the JAS was almost similar to the behavior simulated through the non-linear flexural analysis model, and the shear performance of the JAS can also be estimated appropriately by using the shear strength equations presented in the current design codes. For the JAS with cast-in-place concrete, however, the shear strength estimation results differed significantly depending on the way that the shear contributions of the precast concrete unit and cast-in-place concrete were calculated. Based on the analysis results, this study proposed a design method that can reasonably estimate the shear strength of the composite JAS.


2010 ◽  
Vol 163-167 ◽  
pp. 1980-1986
Author(s):  
Yi Min Dai ◽  
Can Li ◽  
Jian Xiang Ouyang

Based on twelve push-out specimens with different holes filling different materials,the paper compared and analyzed the capacity and the corresponding slip value of the stud shear connector.Meanwhile, tests were also conducted on three composite steel-FDPCP(Full-Depth Precast Concrete Panel) beams with different holes shape and degree of shear connection to investigate the characteistics of load-displacement,load-deflection,load-strain of the total cross section and monolithic action of the entire cross section in the paper. The results show that, as to the two different kinds of holes shape ,the strength of the stud shear connectors of square push-out specimens was huger than that of circular specimens with the same condition; the strength of stud shear connectors in steel-concrete composite structure was decided by the strength of concrete surrounding the shear in the holes, with increasing concrete strength, the strength of stud shear connectors improved greatly; the composite steel-FDPCP beams failed in bending,plane section was maintained in composite beams throughout the testing process.the composite steel-FDPCP beams have some merits :good bearing capacity, good anti-bend capability, fast pile-driving pace and perfect work behaviors as a whole;the ultimate flexural capacity of the composite steel-FDPCP beams with a full shear connection is close to that of a partial shear connection. The outputs of this study are very useful for further understanding of the characteristics of the composite steel-FDPCP beams,it is also expected that the results presented in this paper should be valuable for the design of the composite steel-FDPCP beams.


Author(s):  
Jang-Woon Baek ◽  
Su-Min Kang ◽  
Tae-Ho Kim ◽  
Jin-Yong Kim

AbstractRecently, as a new precast concrete (PC) construction method for increasing economy and constructability, the PC double-beam system has been developed for factories or logistic centers, where construction duration is particularly important. In this study, half-scaled PC double beam–column connection was tested under gravity loading and cyclic lateral loading. The major test parameters included the use of the spliced PC column and the addition of reinforcement at the beam–column joint. In the gravity loading test, the flexural behavior of the PC double beam was investigated. The test results showed satisfactory flexural capacity at the PC double-beam section, validating the composite action between the PC and RC members. In the cyclic lateral loading test, the seismic performance of the PC double beam–column connection was investigated. Based on the test results, the failure mode, load-carrying capacity, deformation capacity, energy dissipation capacity, secant stiffness, and shear strength of the PC double-beam system were evaluated and compared with those of a conventional RC double beam–column connection. According to the test results, the structural performance of the PC double beam–column connection was comparable to that of the RC double beam–column connection and satisfied the acceptance criteria of moment frame in the ACI 374.1-05 provision.


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