摘要
编制了三面受火且设有防火保护层的碳纤维布加固混凝土梁的截面温度场计算程序,通过算例验证了程序的正确性。利用该程序,分析了防火材料类型及厚度、保护方式、截面尺寸对加固梁截面温度分布的影响。基于数值分析结果,提出了加固梁截面温度场的实用计算方法。研究结果表明:①除梁侧防火材料末端附近产生温度突变外,小U型防火保护方式下加固梁的截面温度分布总体上与底面防火保护方式下类似;②随着受火时间增加,梁底温度在底面防火材料的保护下虽然上升相对较缓,但也很快达到环氧类胶粘剂的失效温度;③与厚度相同的厚型钢结构防火涂料相比,水泥砂浆的防火保护效果明显偏弱。
A computer program is developed to calculate the temperature fields of 3-face heated and insulated concrete beams strengthened with carbon fiber sheet （CFS） . This program is validated using experimental results from literatures. The influences of some parameters （e. g. , type of insulation material, thickness of insulation, insulation scheme, and sectional size of beam） on temperature distributions of the strengthened beams in fire are analyzed using this program. Based on the numerical results, a simplified formula is proposed to predict the temperature fields of the CFS strengthened and insulated beams in fire. Simulation results show that： （a） the thermal fields of the CFS strengthened beams with minor U-shape insulation are similar to those with insulation at beam soffit, expect for locations close to the top end of minor U-shape insulation at beam sides; （b） the temperatures at beam soffit increase slowly with an increasing of heating time due to the protection of fire insulation, but they reach the failure temperature of epoxy quickly ; and （c） the insulating effect of cement motor is much weaker than that of fireproof dope for steel structures.
出处
《工程抗震与加固改造》
北大核心
2009年第6期93-98,78,共7页
Earthquake Resistant Engineering and Retrofitting
关键词
碳纤维布
混凝土梁
温度场
防火保护层
carbon fiber sheet
concrete beam
temperature field
fire insulation
