Search Results (5)

Precast concrete (PC) shear wall members are essential components of the precast concrete shear wall structural system. Therefore, it is crucial to research their materials, and seismic performance is an important and vital indicator to promote the development of prefabricated buildings. This study introduced a new type of precast concrete sandwich shear wall, the precast high-titanium heavy slag concrete sandwich panel wall (PHCSPW), by replacing ordinary concrete coarse and fine aggregates with high-titanium heavy slag and adding insulation boards. This study constructed a cast-in-place high-titanium heavy slag concrete wall (CHCW) for comparative pseudo-static tests to validate its seismic performance. Finite element simulation analysis was conducted to compare and validate the reliability of the test. Considering the limitations of the test conditions, it also researched the seismic performance of PHCSPW by simulating different parameters such as reinforcement ratio, concrete strength, and axial compression ratio. It concludes the following: (1) The failure mode, stress-strain distribution, and ultimate bearing capacity values of PHCSPW and CHCW were consistent with theoretical and experimental analysis results. (2) PHCSPW exhibited high stiffness before cracking but experienced a rapid stiffness degradation rate after cracking. (3) The development trend of the PHCSPW and CHCW hysteresis curve is the same as the skeleton curve. There is little difference between the bearing capacity and deformation capacity after cracking. Comparing the hysteresis loops of CHCW and PHCSPW, it is found that PHCSPW has a larger hysteresis loop area, which indicates that PHCSPW has better energy dissipation capacity. The value of the yield load of the specimen compared with the peak load is between 0.636 and 0.888; that is, the difference inthe early-stage stiffness of the specimen is small. The yield load of PHCSPW is slightly larger than that of CHCW. The maximum carrying capacity of CHCW is about 68.31% of that of PHCSPW. (4) The simulation of different parameters revealed that the energy dissipation capacity of the members increased within a specific range with an increasing reinforcement ratio. PHCSPW demonstrated superior energy dissipation capacity. The influence of concrete strength on the energy dissipation capacity of the members was relatively small. The energy dissipation capacity of the members decreased with increasing axial compression ratio. Full article

Prefabricated concrete shear-wall structures are a primary form of prefabricated concrete construction. In this paper, the seismic performance of precast shear walls with frames is studied by experimental methods. The failure characteristics, hysteretic performance, energy dissipation capacity, stiffness degradation, and ductility of the shear wall are mainly analyzed. The results indicate that incorporating various frames into concrete shear walls can significantly enhance the traditional single seismic defense line. The maximum differences between the positive and negative initial stiffnesses of the framed shear wall are 32.6% and 29.7%, respectively. The maximum differences between the positive and negative ductility coefficients compared to the ordinary reinforced concrete shear wall are 15.7% and 20.7%, respectively. The maximum difference in equivalent viscous damping compared to the ordinary reinforced concrete shear wall is 26.5%. Full article

This study presents the performance-based seismic assessment of low-rise reinforced concrete archetype buildings, considering repair costs for ordinary moment-resistant frames (OMF) and dual systems consisting of OMF plus special shear walls (SSW). Historically, the OMF systems, conceived for residential purposes in Ecuador resulting from informal construction, have reported poor responses under seismic forces. This study analyzes damage levels through fragility curves as a function of the maximum global drift reached through incremental dynamic analysis. For this, two archetypes with OMF and two with a similar configuration, including structural walls, are modeled to define a loss function and annual collapse probabilities. As a result, it is noted that systems with structural walls significantly reduce repair costs by between 75 and 90% of the total cost of the building, and prevent collapse. Systems with ordinary moment frames report total losses, implying their use should be limited in areas of high seismicity. Full article

The seismic performance of ordinary reinforced concrete shear walls, that are commonly used in high-rise residential buildings in Korea (h < 60 m), but are prohibited for tall buildings (h ≥ 60 m), is evaluated in this research project within the framework of collapse probability. Three bidimensional analytical models comprised of both coupled and uncoupled shear walls exceeding 60 m in height were designed using nonlinear dynamic analysis in accordance with Korean performance-based seismic design guidelines. Seismic design based on nonlinear dynamic analysis was performed using different shear force amplification factors in order to determine an appropriate factor. Then, an incremental dynamic analysis was performed to evaluate collapse fragility in accordance with the (Federal Emergency Management Agency) FEMA P695 procedure. Four engineering demand parameters including inter-story drift, plastic hinge rotation angle, concrete compressive strain and shear force were introduced to investigate the collapse probability of the designed analytical models. For all analytical models, flexural failure was the primary failure mode but shear force amplification factors played an important role in order to meet the requirement on collapse probability. High-rise ordinary reinforced concrete shear walls designed using seven pairs of ground motion components and a shear force amplification factor ≥ 1.2 were adequate to satisfy the criteria on collapse probability and the collapse margin ratio prescribed in FEMA P695. Full article

This study aimed to investigate the inelastic behavior of a newly-developed type of self-insulating concrete masonry shear wall (SCMSW) under in-plane cyclic loading. The new masonry system was made from concrete blocks with special configurations to provide a stronger bond between units than ordinary concrete masonry units. A total of six fully-grouted SCMSWs were prepared with different heights (1.59 to 5.78 m) and different vertical steel configurations. The developed masonry walls were tested under in-plane cyclic loading and different constant axial load ratios. In addition, the relationship between the amount of axial loading, the amount of the flexural reinforcement and the wall aspect ratios and the nonlinear hysteretic response of the SCMSW was evaluated. The results showed that the lateral load capacity of SCMSW increases with the amount of applied axial load and the amount of vertical reinforcement. However, the lateral load capacity decreases as the wall aspect ratio increases. The existence of the boundary elements at the SCMSW ends increases the ductility and the lateral load capacity. Generally, the SCMSW exhibited predominantly flexural behavior. These results agreed with those reported in previous research for walls constructed with ordinary units. Full article