低掺量聚乙烯醇纤维混凝土抗冻性研究

发布时间：2018-06-30 18:06

本文选题：聚乙烯醇纤维混凝土 + 耐久性　；参考：《济南大学学报(自然科学版)》2017年04期

【摘要】：采用快速冻融法,在水、氯化钠溶液分别作用下,研究聚乙烯醇(PVA)纤维对混凝土抗冻性能影响。结果表明:在200次水冻融循环实验中,当PVA纤维掺量在0.1%~0.5%(体积分数,以下同)时,随着PVA纤维掺量的增加,混凝土的抗冻耐久性呈现先改善后劣化的趋势,PVA纤维掺量为0.3%时混凝土抗冻性能最好;在经过200次水冻融循环作用后,空白组试件完全损坏,而PVA纤维掺量为0.3%的混凝土的相对动弹性模量损失率为32%,质量损失率为1.2%,冻融后的试件仍然表现出较好的性能;氯盐溶液冻融实验与水冻融实验具有相同趋势,但是氯盐-冻融联合作用下的混凝土比水冻融破坏更加严重;低掺量PVA纤维在混凝土浆体中可以均匀分散,在水泥基体中可承受由受冻膨胀产生的拉应力,减少基体内部裂缝的出现,从而改善混凝土的抗冻耐久性。
[Abstract]:The effect of polyvinyl alcohol (PVA) fiber on the freezing resistance of concrete was studied by rapid freeze-thaw method under the action of water and sodium chloride solution. The results show that in 200 times of water freezing and thawing experiments, when the PVA fiber content is 0.1% or 0.5% (volume fraction, the same below), the content of PVA fiber increases with the increase of PVA fiber content. The antifreeze durability of concrete shows the tendency of improving first and then deteriorating. The concrete has the best frost resistance when the content of PVA fiber is 0.30.After 200 cycles of freezing and thawing, the blank specimens are completely damaged. However, the loss rate of relative dynamic elastic modulus and mass loss of concrete with 0.3% PVA fiber content are 3232 and 1.2 respectively. The frozen and thawed specimens still exhibit good properties, and the freezing and thawing experiments of chloride solution have the same trend as those of water freeze-thaw experiment. However, the concrete under the combined action of chlorine salt and freeze-thaw is more serious than that of water freeze-thaw, and the low content PVA fiber can be uniformly dispersed in the concrete slurry, and the tensile stress caused by the frozen expansion can be withstood in the cement matrix. Reduce the appearance of cracks inside the matrix, thereby improving the frost durability of concrete.
【作者单位】：河北工业大学土木工程学院;济南荣军建材有限公司;济南大学材料科学与工程学院;
【基金】：山东省科技重大专项(新兴产业)项目(2015ZDXX0702B01) 高性能土木工程材料国家重点实验室开放基金项目(2013CEM003)
【分类号】：TU528

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