不同纤维掺量轻骨料混凝土冻融循环后力学性能及损伤量的研究

THE RESEARCH ON MECHANICS AND BLEMISH DEGREE OF DIFERENT FIBER CONTENT LIGHTWEIGHT AGGREGATE CONCRETE AFTER FREEZE-THAW CYCLE

采用慢冻法,对LC35纤维轻骨料混凝土进行25次、50次、75次、100次、125次、150次、200次、225次、250次、275次、300次冻融循环,利用压力机及动弹仪,测得了不同冻融循环后混凝土的抗压强度及弹性模量。根据试验结果,得到不同纤维轻骨料混凝土的抗压强度与冻融循环次数的关系、冻融后的损伤度及损伤增量,同时得出不同纤维对轻骨料混凝土性能的改善作用也不尽相同,对抗冻性能的改善顺序依次为:混合纤维>聚丙烯纤维>钢纤维,研究成果可为西北寒冷地区轻骨料混凝土的研究与应用提供实验依据和理论依据。

By adopting slow freeze-thaw method and carrying out freeze-thaw cycle times of 25, 50, 75, 100, 125, 150, 200, 225,250, 275 and 300 on the LC35 fiber lightweight aggregate concrete, The compressive strength and elastic modulus of the lightweight aggregate concrete after freeze-thaw cycle have been obtained by employing a press machine and an instrument for measuring dynamic modula. According to the testing-result, the relationship between the compressive strength and the number of freeze-thaw cycle as well as the relation between the blemish degree and the blemish increment after freeze-thaw cycle are attained. The volume fraction and species of fibers have great influence on the properties of lightweight aggregate concrete. According to frost resistance properties, the improving order is： hybrid fibers 〉 polypropylene fiber 〉 steel fiber. The result can provide an experiment and theoretical basis to the research of lightweight aggregate concrete in cold north-west region.