基于热传导的粉煤灰钢纤维超高强混凝土温度裂缝控制

Temperature Crack Control of Ultra-high Strength Concrete with Fly Ash Steel Fiber Based on Heat Conduction

传统裂缝控制技术对混凝土温度场的计算能力较差,导致疲劳裂纹扩展速率较快,且裂缝修复能力较差。为此,提出基于热传导的粉煤灰钢纤维超高强混凝土裂缝控制方法。通过对粉煤灰、水泥、砂石等用量分析,合理调整粉煤灰钢纤维超高强混凝土的配制比例,完善混凝土材料配比。借助热传导理论,以粉煤灰钢纤维超高强混凝土微元体为研究对象,通过傅里叶定律获取粉煤灰钢纤维超高强混凝土内部总净热量;通过控制粉煤灰钢纤维超高强混凝土温度场的绝热温度、内部实际温度以及表面温度,控制施工中混凝土的温变,使用化学修补法与灌浆修补法,对产生裂缝的混凝土进行修补,完成了粉煤灰钢纤维超高强混凝土裂缝控制技术的研究。实验结果表明:采用所提技术配制的混凝土疲劳裂纹扩展速率较慢,且其抗压强度较强,具有一定实际意义。

The traditional crack control technology has poor ability to calculate the temperature field of concrete,which leads to the rapid growth rate of fatigue crack and the poor repair ability of crack.For this reason,the crack control method of fly ash steel fiber ultra-high strength concrete based on heat conduction is proposed.By analyzing the amount of fly ash,cement,sand and so on,the proportion of preparation of ultra-high strength concrete made of steel fiber of fly ash is adjusted reasonably,and the proportion of concrete material is improved.With the help of heat conduction theory,the total net heat inside the ultra-high strength concrete of fly ash steel fiber is obtained by Fourier law with micro element body as the research object.By controlling the temperature field of steel fiber reinforced high strength concrete of fly ash adiabatic temperature,internal temperature and surface temperature,control of the construction of concrete temperature change,the use of chemical repair method and repairing method for repairing of concrete cracks,completed the steel fiber reinforced high strength concrete crack control technology of fly ash.The experimental results show that the fatigue crack growth rate of concrete prepared by the proposed technique is slow and its compressive strength is strong,which has certain practical significance.