活性粉末混凝土热工参数试验研究

Experimental study on thermal parameter of reactive powder concrete

采用热线法对4种不同体积纤维掺量(素活性粉末混凝土、体积掺量0.2%聚丙烯纤维、体积掺量2%钢纤维、混合掺加体积掺量0.2%聚丙烯纤维和2%钢纤维)、几何尺寸为230 mm×165 mm×65 mm的活性粉末混凝土(RPC)试件进行导热系数测定试验,获得了常温及100、200、300、400、500、600、700、800、900℃下的RPC导热系数实测值。研究温度、纤维种类和掺量对RPC导热系数的影响,拟合得到了RPC导热系数随温度升高而降低的关系式。并将RPC导热系数与高强混凝土和普通混凝土对比,结果表明,RPC的导热系数高于高强混凝土和普通混凝土。进行RPC试件的反演分析用高温试验,测量高温炉内试件中心温度。综合RPC导热系数实测值与试件中心实测升温曲线,采用ABAQUS有限元分析软件对高温下RPC试件的温度场进行模拟,进而反推出与各测点温度相对应的RPC比热容值,建立了常温至100℃及600~900℃时为常值,100~600℃随温度升高而增大的RPC比热容计算式。

Using hot wire method,experiments on the thermal conductivity coefficient of 230 mm × 165 mm × 65 mm reactive powder concrete( RPC) test specimens with four different fiber volumes( RPC without fiber,RPC with polypropylene fiber volume content of 0. 2%,RPC with steel fiber volume content of 2% and RPC with volume content0. 2% polypropylene fiber and 2% steel fiber) were made in the temperature of room temperature,100 ℃,200 ℃,300 ℃,400 ℃,500 ℃,600 ℃,700 ℃,800 ℃ and 900 ℃. Research on the thermal conductivity of RPC influenced by temperature,fiber types and fiber volumes has been carried out. The formula reflecting the increase of RPC thermal conductivity with the increase of temperature was fitted. The thermal conductivity coefficient of RPC was compared with high strength concrete and normal concrete. The results show that the thermal conductivity coefficient of RPC is higher than high strength concrete and normal concrete. The inversion test on different fiber volumes in RPC in high temperature was completed,including the measurement of the center temperature of specimens in stove.Combined with the measured values of thermal conductivity of RPC and the temperature curve of specimen center,the simulation of temperature field of RPC specimens in the high temperature was made using the software ABAQUS,and their specific heat capacity was further obtained by inversion. The establishment of the calculation formula for the specific heat capacity of RPC was completed,showing that the constant specific heat capacity is a constant from room temperature to 100 ℃ and from 600 ℃ to 900 ℃,while increases with the increase of temperature from 100 ℃ to