Experimental validation of the tensile monotonic behaviour of novel dry-connections for precast composite concrete walls

The precast shear wall structure has outstanding features for green buildings due to its construction convenience, safety, high quality and low pollution. In general, precast concrete shear walls are connected by multiple joints. The joint between precast walls has very strong influence on the whole structure, which calls for more detailed investigation. A new kind of connection – the joint connecting beam – was developed to connect the vertical reinforcement in precast concrete shear wall structures. This innovative connecting method has the advantages of convenient operation and saving steel. To evaluate the performance and for better application of the joint connecting beam, an experiment on seven full‐scale specimens was conducted under cyclic loading, including two cast‐in‐situ walls and five precast walls with varying reinforcement and sectional heights of the joint connecting beam. A comparison was performed between cast‐in‐situ walls and precast walls with joint connecting beam, focusing on failure mode, hysteretic curve, skeleton curve, bearing capacity, ductility and energy‐dissipating capacity. The results show that the joint connecting beam can effectively transfer the load of precast walls, especially for squat precast walls. Moreover, finite element models were developed to simulate the performance of the specimens. The simulation results agree well with experimental results.

Evaluation of seismic performance of precast concrete walls with X-shaped steel plate bracings

Experimental comparisons of repairable precast concrete shear walls with a monolithic cast-in-place wall

To investigate the effect of opening on the lateral behaviour of precast concrete shear wall with unspliced vertical distribution bars, a series of nonlinear numerical analyses is carried out. Cohesive elements and nonlinear springs are adopted to simulate the joints around the precast wall panel and the steel bars across the joints, respectively. The numerical analysis model was verified based on test results of the lateral behaviour of precast shear wall with unspliced vertical distribution bars. Based on the verified model, parametric studies are carried out for the influence of the opening’s characteristic parameters and the length of the boundary element. The results show that the influence of the area ratio and location of the opening on the lateral behaviour of the precast shear wall is similar to that of cast-in-situ shear walls with openings. Compared with the cast-in-situ shear wall with opening, the load-carrying capacity and stiffness of the precast shear wall similarly decreased with the increasing opening area ratio; and the stiffness of the precast wall decreased up to 47.6%. The wall beneath the window opening can slightly compensate for the weakening effect of the unspliced vertical bars on cracking, but the vertical location of the opening had little effect on the lateral behaviour of the precast shear wall with unspliced vertical distribution bars. Finally, the length of the cast-in-situ boundary elements of the precast shear wall was more influential in the stiffness rather than the load-carrying capacity of the shear walls.

To study the cyclic performance of precast concrete shear walls with a mortar–sleeve connection for longitudinal steel bars, a quasistatic test on shear wall specimens with flexure failure modes was carried out. The longitudinal steel bars in the precast concrete walls were connected with a steel sleeve using mortar. Test results indicated that the mortar–sleeve splicing effectively transferred the stresses on the vertical steel bars. The failure mode of the precast shear wall specimens had similar behaviors to that of the cast-in-place shear wall specimen, including the tensile yielding of the longitudinal steel bars and the crushing of the concrete in the compressive zone. The stiffness and energy dissipation capacity of the precast wall specimens were less than those of the cast-in-place wall specimen. The ultimate drift ratio of the precast wall specimens ranged from 1.69 to 2.08 %. The integrity of the precast shear walls with a vertical rough interface was better than that of the precast shear walls with a vertical step groove.

Study of effects of sleeve grouting defects on the seismic performance of precast concrete shear walls

Seismic performance of a novel partial precast RC shear wall with reserved cast-in-place base and wall edges

The seismic behavior of precast concrete structure wall mainly depends on connection of the shear walls, and constrains at edge elements. The strength of concrete in embedded column area is also especially important. This paper explores a mothod of connection for prefabrication that was post-cast at the connection when the precast wall was assembling. To investigate the failure mechanism of this kind of precast shear walls, a precast concrete wall specimen is studied and tested in this paper. Test results indicate that this kind of connection may effectively improve the behavier of precast shear walls, and ensure that the seismic performance of the precast walls can be equated with cast-in-place specimen.

Seismic behavior of drift-hardening precast concrete walls reinforced with SBPDN rebars

Seismic performance of precast concrete walls with grouted sleeve connections using large-diameter bars

Development of a novel friction damped joint for damage-plasticity control of precast concrete walls

The purpose of this study is to propose a calculation procedure using a macro model to evaluate the shear strength of multi-story precast concrete structural walls with columns at both sides. Since the shear strength equations for the monolithic reinforced concrete are usually used in Japan even for precast concrete structural walls with horizontal joints, such multi-story precast walls are expected to slip at the horizontal joints of bedding mortar type under earthquake forces. At the moment, there are only a few studies that show a theoretical evaluation method for determining the shear strength of precast walls taking into account the slip. A new macro model is proposed and a comparison between the analytical and actual test results from 22 multi-story wall specimens with bedding mortar type horizontal joints is done.

High-rise modular buildings with innovative precast concrete shear walls as a lateral force resisting system

Large panel precast concrete structures are built in major seismic regions throughout the world. The seismic behaviour of such structures is strongly dependent upon the characteristics of both the horizontal and vertical connections. The limiting behaviour of precast systems, however, is basically dependent upon the horizontal connection. The influence of horizontal connections can be studied in terms of the behaviour of a simple wall—a vertical stack of panels having only horizontal connections.This paper reports on research into the seismic behaviour of simple precast concrete walls. The research was carried out through the development of computer‐based modelling techniques capable of including the typical behavioural characteristics associated with horizontal joints. The model assumes that all non‐linear, inelastic behaviour is concentrated in the connection regions and that the precast panels remain linear elastic. This assumption allows the precast panels to be modelled as statically condensed ‘super‐elements’ and the connection regions as interface elements. The above modelling technique allows for non‐linear‐inelastic seismic analysis that is capable of handling both rocking type motions throughout the height of the structure and slippage due to shear in the plane of the connection.A series of parametric studies are presented to illustrate the potential influence of rocking and slip on precast walls with both regular reinforcement and post‐tensioning. These studies demonstrate the period elongation associated with the nonlinear‐elastic rocking phenomenon. Shear slip is found to occur only when friction coefficients are extremely low or when the normal forces across the connections are low. This latter case occurs only in low buildings or in the upper floors of tall buildings.The paper concludes with a brief discussion of the design implications of these results. Particular attention is paid to the problems stemming from the force concentrations associated with rocking and shear slip.

This paper aims to show the application of site-specific response spectra in the analysis of buildings that are supported by lightly reinforced precast concrete walls. Previous surveys on load-bearing precast reinforced concrete walls in multi-storey buildings in low-to-moderate seismic regions have found that many existing precast walls are lightly reinforced with a connection reinforcement ratio less than the wall reinforcement ratio. When these precast walls are subjected to reversed cyclic loads, the lateral response is typically controlled by rocking and the ultimate performance is governed by the ruptures of connection dowels. This paper uses moment–curvature analyses in combination with plastic hinge analyses to evaluate the force–displacement capacity of planar lightly reinforced load-bearing precast walls. The seismic performance of a building supported by these lightly reinforced precast walls can then be assessed by superimposing the capacity curve and the inelastic site-specific response spectra developed for the building site. The proposed analytical approach is illustrated through a case study building. By comparing a lightly reinforced precast wall with a comparable limited ductile reinforced concrete wall, it is also found that, although these two walls exhibit similar force capacities, the ultimate displacement capacity of the lightly reinforced precast wall is significantly lower. This finding highlights the potential seismic vulnerability of lightly reinforced precast walls in some existing buildings.