摘要
本文介绍了应用混凝土冻融变形特性预测抗冻标号的测试方法及成果,并建立了按混凝土冻融变形率预测抗冻标号的数学模式,发现两者间具有良好的相关性。同时在实际工程中还进行了验证试验,结果表明误差较小,效果良好。因此认为仅通过一次可数次冻融试验即可预测混凝土抗冻标号的设想是可以实现的。但今后仍应在实际工程中广泛积累数据,并逐步完善已建立的数学模式,以期尽快应用到工程施工中去。据分析,应用此种快速检测法可缩短冻融试验周期70％～80％以上。从而解决了混凝土抗冻性试验结果落后无可奈何花落去于工程需要的难题。同时还可节约试验费用90％以上。 文中还介绍了国内首次建立的测量混凝土冻融变形的仪表测试系统,其仪表测量精度可达到0.21μm,超过目前美国及苏联同类测量系统的测量精度。
The deformation characteristics of concrete subject to freezing and thawing is used to predict the frost-resistance grade of concrete. The test method and its results are given. A mathematic model has been established to predict the frost-resistance grade of concrete on the basis of the deformation rate of concrete subject to freezing and thawing and a good correlation between the deformation rate and the frost resistance grade has been observed. A verification test was also carried out on a practical project and the result proved satisfactory with little discrepancy. It is therefore believed that the assumption that the frost resistance grade of concrete may be predicted by one freeze-thaw test or seveval freeze-thaw tests can be realized. However, it is still necessaty to accumulate data in a wider scale from practical projects and further improve the established mathematic model so that it can be employed on practical works as soon as possible. According to an analysis, by using the rapid prediction method, the period for freeze-thaw tests can be shortened by 70-80% ,thus solving the problem that frost resistance test results of concrete lag behind the requirements for practical works and at the same time cutting laboratory expenditure on frost resistance tests by more than 90%.An instrumentation system for measuring the deformation of concrete subject to freezing and thawing cycles, which has been established in China for the first time, is described and the measuring precision of the system can reach 0. 21μm which surpasses that of similar systems in the U. S. and the former USSR.
