Shake Table Tests of a Novel Low-rise Bolt-Assembled Precast Concrete Sandwich Wall Panel Structure

A novel low-rise bolt - assembled precast concrete sandwich wall panel structure for rural residential houses was proposed, in which the connections between wall and wall, and wall and floor were connected by high strength bolts and steel plates. The bolt joints can be easily installed and disassembled. They are replaceable to make the precast structure demountable and reassembled. All the components are connected together by the novel bolted connectors. This paper presents the shake-table tests of a full-scale two-story bolt-assembled precast concrete sandwich wall building. The results indicated that the proposed structural system had good seismic performance and remained in the elastic stage with no damage after 9-degree rare earthquake excitation for the Model-1. The Model-2 exhibited excellent capacity and performed satisfactorily under the excitation up to 0.8 g. Cracks were observed at the wall openings and the base of walls and columns, which was similar to that of a cast-in-situ structure. The damage statuses were mainly light damage and moderate damage. The bolt connection joints were not anti-seismic weak places and had good seismic performance. Equivalent base shear method is suitable for estimating the seismic demand of the proposed precast concrete sandwich wall panel structure.

Seismic Performance Test of Double-Row Reinforced Ceramsite Concrete Composite Wall Panels with Cores

The research objective of this study was the seismic performance of double-row reinforced ceramsite concrete sandwich wall panels. The feasibility of upgrading a new wall panel from a non-load-bearing partition wall to a load-bearing seismic wall was examined by conducting cyclic load tests on five wall panel specimens. The test piece was a sandwich thermal insulation structure that could achieve a good protection distance between the thermal insulation material and the fire source so that the fire prevention problem could be solved. At the same time, the problem of easy fall-off of the insulation system was also solved. The specimens were divided into three groups, including three double-row reinforced ceramsite concrete sandwich wall panels with different dosages of alkali-resistant glass fiber, a double-row reinforced ordinary concrete sandwich wall panel, and a solid concrete ceramic wallboard. The effects of different dosages of alkali-resistant glass fiber, construction forms, and bearing side plate materials on the seismic performance of the sandwich wall panels were investigated separately for the specimens. From the analysis of the specimen results (damage characteristics, hysteresis curves, energy dissipation capacity, bearing capacity, ductility, longitudinal reinforcement strain, and stiffness degradation), it could be seen that among the five types of wallboard, the double-row reinforced ceramsite concrete sandwich wall panel with 0.3% fiber content had the best ductility and energy dissipation capacity. Adding fiber could solve or improve the problem of the low ultimate bearing capacity of ceramsite concrete as the wallboard’s bearing material. Compared with the same size solid ordinary concrete wallboard, the bearing capacity of the double-row reinforced ceramic concrete sandwich panel was slightly reduced. However, the additional seismic performance indexes were relatively superior. Through the analysis of the test results, it was shown that, when considering the thermal performance and seismic capacity, the new wall panel had good prospects for engineering applications.

High Temperature Performance of a prefabricated concrete sandwich panel

The innovative sandwich wall panel studied in this paper can be used as the load-bearing member of the structure. In addition to the traditional sandwich panel structure, the new panel system also has the characteristics of spiral stirrups along the section of the core column, 650mm column spacing, foam concrete for insulation layer and self-compacting concrete for outer layer. In addition, in order to improve the overall strength and stiffness of the panel, a unique wire system consisting of two vertical wire mesh connected by a short horizontal steel bar is adopted in the concrete layer. In order to study the mechanical properties of the new panel system at high temperature, ABAQUS simulation was carried out. The simulation results show that the new precast concrete sandwich wall system has good resistance to high temperature and still has good bearing capacity after high temperature.

Thermal Insulating Concrete Wall Panel Design for Sustainable Built Environment

Air-conditioning system plays a significant role in providing users a thermally comfortable indoor environment, which is a necessity in modern buildings. In order to save the vast energy consumed by air-conditioning system, the building envelopes in envelope-load dominated buildings should be well designed such that the unwanted heat gain and loss with environment can be minimized. In this paper, a new design of concrete wall panel that enhances thermal insulation of buildings by adding a gypsum layer inside concrete is presented. Experiments have been conducted for monitoring the temperature variation in both proposed sandwich wall panel and conventional concrete wall panel under a heat radiation source. For further understanding the thermal effect of such sandwich wall panel design from building scale, two three-story building models adopting different wall panel designs are constructed for evaluating the temperature distribution of entire buildings using finite element method. Both the experimental and simulation results have shown that the gypsum layer improves the thermal insulation performance by retarding the heat transfer across the building envelopes.