Papers by Keyword: Width Effect

Abstract: An experimental study on downward flame spread over extruded polystyrene (XPS) foam at a high elevation is presented. The flame shape, flame height, mass loss rate and flame spread rate were measured. The influences of width and high altitude were investigated. The flame fronts are approximately horizontal. Both the intensity of flame pulsation and the average flame height increase with the rise of sample width. The flame spread rate first drops and then rises with an increase in width. The average flame height, mass loss rate and flame spread rate at the higher elevation is smaller than that at a low elevation, which demonstrates that the XPS fire risk at the higher elevation area is lower. The experimental results agree well with the theoretical analysis. This work is vital to the fire safety design of building energy conservation system.

Abstract: Research on building insulation materials and their safety is an important topic in the field of building energy conservation. The objective of this paper is to analyze the coupling effects of the width and external radiation on the downward RPU foam flame spread characteristics. The most important flame characteristics including flame height, mass loss rate, flame spread rate were studied experimentally. The results suggest that with increasing external radiation levels, flame spread rate was larger. Under the condition of the external radiation heat flux exceeds a critical level, the RPU foam would be deformed and detached from the board when the flame spread to a certain distance. It also leads to a much higher flame height due to sufficient combustion. Additionally, the flame propagation firstly accelerated when it reaches to a certain distance and then becomes a stable subject to the preheating of the external radiation heat resource.

Abstract: Carbon fiber reinforced polymer (CFRP) sheets have been extensively used for strengthening deteriorated concrete structures. The effectiveness of such strengthening depends upon the load transfer from concrete to the FRP composite. Shear debonding is usually caused by a crack that forms and then propagates at the interface between the adherents. The influence of the geometric parameters of the adherents on the fracture propagation is still a subject of research. This paper presents an experimental investigation performed on direct shear specimens to study the influence of the relative width of FRP and concrete on the load carrying capacity of the bond and the stress transfer between the adherents.