Experimental investigation on the effect of local debonding of longitudinal reinforcement on seismic performance of precast concrete columns

2022 ◽  
Vol 46 ◽  
pp. 103131
Author(s):  
Xuhua Deng ◽  
Shaoxian Wang ◽  
Jun Chen ◽  
Fa-xing Ding ◽  
Qing Zhang ◽  
...  
2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Qiong Yu ◽  
Liang Zhang ◽  
Shaohua Bai ◽  
Baoxiu Fan ◽  
Zhenhai Chen ◽  
...  

Grouted splice connector is widely employed in precast concrete structures, but its utilization is still limited by shortcomings such as high construction cost, inconvenience in assemblage, and uncompacted grout caused by its small sleeve diameter. The grouted sleeve lapping connectors proposed by the authors can not only provide reasonable force transfer and convenient construction processing but also have the characteristics of low price and easy grouting. In this paper, the seismic performance of two full-scale precast concrete columns with two types of grouted sleeve lapping connectors was investigated, where type-I connector connected two lapped rebars and type-II connector connected four lapped rebars by a steel sleeve, respectively. A cast-in-situ column was also tested as a reference. All the specimens were tested under reversed cyclic horizontal load with a constant axial force. The distribution of cracks, failure modes, loading capacities, deformation abilities, stiffness, ductility, hysteresis loops, and energy dissipation of the specimens were studied. The type-I and type-II grouted sleeve lapping connectors satisfactorily transferred the stress of rebars when the columns reached their ultimate loads, and the seismic performance of the precast concrete columns was found to be comparable to that of the cast-in-situ column. Thus, the grouted sleeve lapping connector has a potential to replace the grouted splice connector in cast-in-situ connection.


2021 ◽  
pp. 136943322110159
Author(s):  
Bo Wu ◽  
Zhikai Wei

Recycled lump concrete (RLC) made with demolished concrete lumps (DCLs) and fresh concrete (FC) provides a solution for effective waste concrete recycling. To promote the development of precast RLC structures, this study tested a new type of connection for precast concrete columns: connecting the upper and the lower halves of columns with bent longitudinal reinforcements and structural adhesive. In this work the behavior of precast RLC columns with the new connection was studied under axial compression. The axial compressive strength of nine two-part columns was tested. The effects of the degree of bending in the longitudinal reinforcement, the replacement ratio of DCLs and the stirrup spacing were investigated. Tests showed that: (1) the failure mode of precast concrete columns is different from that of cast-in-place columns; (2) when the strength of the waste concrete is close to that of the fresh material, there is no significant difference in the axial compression performance of either precast or cast-in-place columns; (3) the bent longitudinal reinforcement causes the axial load bearing capacity of precast concrete columns to be 4.2%–12.3% lower than that of a similar cast-in-place column; (4) reducing the stirrup spacing has little effect on a precast column’s axial load bearing capacity and ductility; (5) when using Chinese and American codes to predict the axial load bearing capacity of the column, the predicted value should be multiplied by a reduction factor.


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