针对我国内陆寒冷盐碱地区的环境特性,制备了面向该环境混凝土路面工程应用的聚丙烯纤维复合胶粉改性混凝土,采用正交试验研究了该混凝土材料的收缩性能,建立了收缩模型,并运用游程检验法检验了其显著性。结果表明,聚丙烯纤维复合胶粉改性混凝土的收缩率εt与测试龄期t符合指数函数关系,且在显著性水平α=0.01下其相关性显著;聚丙烯纤维和胶粉掺量对混凝土的收缩影响明显,并与混凝土的最大收缩率之间存在显著的数学模型关系。胶粉会增大混凝土后期的干燥收缩,纤维掺量的增加能够有效抑制混凝土的收缩,硅粉掺量为2.5%和纤维长度为6mm时混凝土的收缩最小。
Aiming at the characteristics of cold saline-alkali areas of inland in our country, polypropylene fiber compositing latex powder modified concrete(PFCLPC) is prepared for application of cement concrete pavement engineering in this environment. Shrinkage performance of the concrete is investigated through orthogonal experiment, shrinking model of PFMLPC is set up by regression analysis and the run test is used to test significance of the model. The results show that the shrinkage ratio εtof PFCLPC and the testing age t can fit the relationship of exponential function, and the correlation is significant when the significant level α is 0.01. The influence of dosage of polypropylene fiber or latex powder on shrinkage of concrete is obviously, and a significant relationship of mathematical model exists between the maximum shrinkage ratio and them. Latex powder enhances shrinkage of concrete, on the contrary, with the increasing of fiber content, the shrinkage of concrete can reduce effectively. When content of silica fume is 2.5% or fibre length is 6 mm, shrinkage of PFCLPC is minimum.