Qian Gu

Analysis of Thermal Performance of a New Regenerated Glass Pumice External Wall Insulation System in Hot Summer and Cold Winter Zone

The thermal performance of a new regenerated glass pumice board as external wall thermal insulation material was analyzed in this paper. Considering the roles of solar radiation and air convection, and selecting Wuhan city as an example of the hot summer and cold winter zones, the temperature field distributions of the external building walls in different orientations in summer and winter seasons were numerically simulated by using the finite element software ANSYS. The thermal performance of regenerated glass pumice exterior wall external insulation system including the heat transfer coefficient and the temperature distribution was evaluated. The simulation results demonstrate the good thermal insulation performance of the regenerated glass pumice as a new kind of external wall materials, and the feasibility of the application of this environmentally friendly material to the wall insulation system in energy conservation building is also promoted.

Experimental Research on Seismic Performance of Pre-Damaged RC Frame T-Beam Strengthened with Sprayed BFRP

This experimental program was designed for investigating the seismic performance and reinforcement effect of pre-damaged RC frame T-beams reinforced with sprayed basalt fiber reinforced polymer (BFRP). Four RC frame T-shape beams specimens, among which one was unstrengthened , one was undamaged and strengthened , and the other two were pre-damaged and strengthened, were tested under an incremental loading procedure of the pseudo-static, cyclic shear loads. The test results including the failure mode, ultimate bearing capacity, load-displacement hysteresis curves and ductility of specimens were obtained and analyzed. It indicates that spraying BFRP reinforcement can effectively increase the peak load and energy dissipation performance of damaged RC frame T-beams, ultimate lateral deformation and ductility of damaged RC frame T-beams can be improved obviously. Increasing the reinforcement thickness of sprayed BFRP can effectively improve the seismic reinforcement effect of T-shaped beams damaged by the earthquake.

Experimental Research on Seismic Behavior of Seismically Damaged RC Frame Column Strengthened with Sprayed Hybrid BF/CFRP

This experimental program was designed for investigating the seismic behaviors and strengthening effect of pre-damaged RC frame columns retrofitted with sprayed BFRP and hybrid BF/CFRP. Four RC frame column specimens, among which one was unstrengthened and three was pre-damaged and strengthened with sprayed FRP, were tested under an incremental loading procedure of the pseudo-static, cyclic shear loads combined with constant gravity loads. The test results including the failure mode, ultimate bearing load capacity, load-displacement hysteresis curves and ductility of specimens were obtained and analyzed. It indicates that spraying hybrid BF/CFRP strengthening scheme can effectively improve the ductility and energy dissipation ability of pre-damaged concrete frame columns. Although the improvement of the peak loads and ultimate lateral deformation of damaged frame columns were not obvious compared with those of the reference column, but it should be pointed out that the strengthened columns were pre-damaged seriously with yielded steel bars and the recover of load bearing ability resulted from spraying FRP retrofit can not be neglected. It also shows that increasing the thickness of spraying overcoat can effectively improve the energy dissipation ability of damaged frame columns.

Experimental Study on Earthquake-Damaged RC Frame Columns Repaired with Sprayed Basalt FRP

Repairing of past earthquake-damaged members that are highly susceptible to future attack is necessary to prevent civil infrastructure destruction and consequent lives lose.Sprayed basalt FRP composite was tested and presented here as a promising solution.In this study, three 1/2 scaled reinforced concrete frame columns were used to investigate the effectiveness and feasibility.One column was damaged to failure and used as a reference specimen.The other two columns were damaged up to the yielding of main bars simulating deterioration of the structure due to seismic action to a control level.These two columns were repaired with sprayed basalt fiber reinforced polymer (BFPR) composite.Different thicknesses of sprayed BFRP composite were applied.Each specimen was subjected to lateral low-frequency cyclic loading and simultaneous constant axial load to simulate seismic action and dead load respectively.The test result analysis showed that sprayed BFRP can increase the load carrying capacity, enhance the energy absorption capacity, and can effectively restore the strength of past earthquakedamaged RC column.

Experimental Study on Seismic Behavior of Masonry Walls with Window Openings Strengthened with Sprayed GFRP

A contrast investigation of the seismic behavior of unreinforced masonry walls with window openings strengthened with Carbon Fibre Reinforced Polymer (CFRP) sheets and sprayed Glass Fibre Reinforced Polymer (GFRP) is presented. Three wall specimens in the scale of 1/2 were tested by the horizontal cyclic loading combined with constant gravity loads. The seismic strengthening effects by two different FRP retrofitting schemes are compared in aspect of the hysteresis response, deterioration of rigidity and ability of energy dissipation. The experimental results indicate that the increasing degree of the improvement of seismic behavior of the SGFRP-strengthened wall are significantly superior to that of the wall strengthened with epoxy-based CFRP; and the overcoat of sprayed GFRP can bond tightly and work well together with the masonry to play a critical role in earthquake resistance.

Experimental Study on Cracking Load and Ultimate Load of Masonry Walls with Window Openings Strengthened with Sprayed GFRP

A contrast investigation of the seismic behavior of unreinforced masonry walls with window openings strengthened with Carbon Fiber Reinforced Polymer (CFRP) sheets and sprayed Glass Fiber Reinforced Polymer (GFRP) is presented. Three wall specimens in the scale of 1/2 were tested by the horizontal cyclic loading combined with constant gravity loads. The seismic strengthening effects by two different FRP retrofitting schemes are compared in aspect of the failure modes, shear capacity, hysteresis response, deterioration of rigidity and ability of energy dissipation. The experimental results indicate that the increasing degree of shear capacity and the improvement of seismic behavior of the SGFRP-strengthened wall are significantly superior to that of the wall strengthened with epoxy-based CFRP; and the overcoat of sprayed GFRP can bond tightly and work well together with the masonry to play a critical role in earthquake resistance.

Experimental Investigation on Axial Compressive Behavior of Masonry Column Strengthened by SGFRP

3 masonry columns were strengthened by Sprayed Glass Fiber Reinforced Polymer (SGFRP), and a research of the seismic behavior of them tested by axial loading experiment was presented. The failure modes of the specimens were described, and the data about the load capacity and deformations of masonry columns strengthened by SGFRP were gathered during the experiment. The results showed that the ultimate loads of the reinforced columns increased greatly, and the deformation capacity and the ductility of the columns improved significantly too. Comparing the strengthening effects of the columns when the thickness of strengthen layer and the length of the glass fiber are different, the most effective and reasonable reinforce suggestions are proposed.

Analysis of Heat Transfer by Thermal Bridge of Corner Wall in a New Glass Regenerated Pumice External Wall System

This paper was based on heat insulating members made by a new type of waste glass regenerative pumice, with the characteristics of light weight, permeable water retention, ventilation, heat insulation, fire retardant, etc. In the external wall heat insulating system of building envelops, the thermal bridge of external wall corner was simulated with ANSYS. The temperature field and flux field distribution will be shown respectively of non-insulation, self-insulation, internal insulation and external insulation. Through comparing the heat preservation of different insulation forms, the external insulation was better than internal insulation and self-insulation. Besides, considering the imperfection of calculating the wall average heat transfer coefficient in current energy saving standards, a simplified method was presented to calculate the linear heat transmission coefficient with ANSYS. The two coefficients were compared to serve the latest research.

Application on the Sprayed FRPC in Engineering

The spayed fiber reinforcement polymer concrete (FRPC) is a kind of new composite material and construction methods, combining good characteristics of the spayed concrete with FRPC. The spayed FRPC widely applied into civil engineering, water project, buildings, road and bridge, and repairing and strengthening various contractures, which obtained engineering success and economic benefit. Firstly, the physical and mechanical performance of sprayed FRPC is introduced. Secondly, applications on sprayed FRPC are summarized in engineering at home and abroad. At last, some advices for application and development of spayed FRPC technology in China are given.

General Introduction of the Performance of Sprayed FRPC

The spayed fiber reinforcement polymer concrete (FRPC) is a kind of new composite material and construction methods, combining good characteristics of the spayed concrete with FRPC. The research and application in China and overseas of the RFPC technology are briefly introduced. The study in China mainly focuses on the physical and mechanical performance and application style, both the theory and application of which are relatively mature. The spayed FRPC widely applied into civil engineering, water project, buildings, road and bridge, and repairing and strengthening various contractures, which obtained engineering success and economic benefit.