| Concrete as a non-homogeneous materials are usually working with cracks, which provides a more convenient path for the transmission of harmful media. Most of the studies did not take cracks into account, so it’s necessary to study on fire resistance performance of concrete structure with cracks. Concrete specimens with pre- made cracks were taken as the object of study and were heated according to the the standard temperature-time curve(ISO834). Through the test, the temperature distribution of the concrete specimens with pre-made cracks under high temperature was studied and the theoretical foundation was provided to research the fire resistance of the reinforced concrete members with cracks.In order to study the influence of crack width on concrete heat transfer under fire, both experimental study and finite element analysis are used in this paper, the law of temperature field about section after fire was selected as the main research object. The concrete contents are as follows:(1) The research status of fire test of concrete structures were summarized and analyzed. As a result, the research ideas were proposed.(2) Thermal performance of concrete was reviewed comprehensively and material parameters were determined.(3) Four concrete specimens(three with pre- made cracks and one intact control specimen) were designed and fire test was carried out on the four concrete specimens with crack widths of 0, 0.5, 1 and 3mm respectively which were pre-made. Through the test, the temperature distribution on the cracked section was studied and the test provided data support for the numerical simulation.(4) According to the actual fire test heating curve, the finite element analysis software ANSYS was used to analyze the cross-section temperature distribution of the specimens. The map of temperature field distribution and the curve of temperaturetime were obtained in this paper. The feasibility and accuracy of ANSYS numerical simulation were also discussed here. |
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