In order to improve the service performance of the enclosure wall under freeze-thaw environment,the freeze-thaw resistance of the mortar layer of the enclosure structure under freeze-thaw conditions was investigated with the mortar type as the variable.Cement mortar,polypropylene fiber mortar and polymer mortar enclosure specimens were designed for the freeze-thaw cycling test studies,and 100 freeze-thaw cycling test studies were conducted.The strain changes were monitored by intelligent string strain sensors and the results were verified by using a numerical model,which used sequential coupled thermal stress analysis to simulate the temperature field and the resultant strain under the action of freeze-thaw cycling.The results show that after 100 freeze-thaw cycle tests,the maximum strain value of cement mortar in the enclosure structure is more than 3.0×10-4,and cracks are generated.Compared to cement mortar,polypropylene fiber mortar and polymer mortar enclosure structure under the action of freeze-thaw cycle,the peak strain is greatly reduced,the maximum strain value is in the range of 3.0×10-5～4.0×10-5,none of the mortar layer is cracked,and the numerical simulation result is basically the same as the experimental result.The study reveals the disease formation mechanism of different mortar types of enclosure structures during freeze-thaw cycles,and proposes the enhancement of freeze-thaw resistance by mixing polymers and fibers in mortar,so as to maintains good service performance of the enclosure structure under freeze-thaw conditions.It has important engineering application value and theoretical significance for improving the durability of enclosure structures.
关键词
特种建筑材料/砂浆/冻融循环/病害/围护结构/服役性能
Key words
special building materials/mortar/freeze-thaw cycles/disease/enclosure structure/service performance
维普
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