半刚性基层材料温缩系数测定影响因素研究

准确测定半刚性基层材料温缩系数比较困难,建议测试中采用能够自动采集数据的测试系统,用石英玻璃作为温度补偿片并使用标距较长的电阻应变片,在操作过程中应该特别注意应变胶的选择、试件表面处理方式以及测试温度的变化控制。通过试验研究了不同应变胶、不同试件表面处理方式以及不同的恒温时间对测试结果的影响。试验结果表明,为提高测试准确性和精度,温度补偿片上使用的应变胶应及时更新且应与被测试件上的应变胶种类保持一致;对于表面粗糙的试件,可以采用水泥浆或二灰(石灰、粉煤灰)浆均匀涂抹在表面以改善试件表面粗糙的现象,但厚度应足够薄,以填充表面但不形成一层为宜。缩短恒温段时间有利于加快试验进度,但每个恒温段的恒温时间不能小于2 h。

Research on Influence Factor in Semi-rigid Base Course Material Temperature Shrinkage Coefficient Test Using Strain Gauge

Generally,it is difficult to get temperature shrinkage coefficient of semi-rigid base course material accurately using electric-resistance strain gauge in the lab.The recommendation is to use auto data acquisition system to get data,use silica glass as temperature compensate part and use longer electric-resistance strain gauge.Besides these,selecting appropriate adhesive,making specimen surface more smooth and controlling temperature change reasonably are also important.Through lab experiment,testing errors caused by(adhesive),sample surface treatment method and temperature constant stage were studied.The results show that in order to get accurate data,same adhesive should be used to stick electric-resistance strain gauge on compensate part and samples,and coarse surface of specimen should be daubed with cement or lime-fly ash slurry layer which should be thin enough,temperature constant stage should longer than 2 hours during the testing process.