不同环境温度对纤维混凝土路面收缩开裂的演化规律研究

Research on the evolution law of shrinkage and cracking of fiber reinforced concrete pavement under different environmental temperatures

为研究不同温度条件下纤维混凝土路面结构的收缩开裂过程,文章通过室内混凝土路面板干缩试验,探讨了不同环境温度(10℃,30℃,60℃)下纤维混凝土路面收缩变形规律,分析了环境温度和纤维掺加方式对路面混凝土表面裂缝开裂宽度及裂缝面积密度变化规律,研究结果表明:掺入纤维可以有效地改善混凝土的收缩性能,降低裂缝宽度和开裂面积密度。随着温度的升高,混凝土的收缩裂缝宽度和开裂面积密度呈增加趋势。尼龙纤维的吸水性强,会增加混凝土的湿度收缩,聚乙烯醇纤维(PVA纤维)的高拉伸强度和高模量,能够有效增强混凝土的抗拉强度和刚度。聚丙烯纤维(PP纤维)能够有效降低水泥混凝土路面的收缩开裂行为,PP纤维混凝土路面板表层的裂缝宽度和裂缝面积密度较普通混凝土路面板显著降低。

In order to research the shrinkage and cracking process of fiber reinforced concrete pavement structures under different temperature conditions,this paper explored the shrinkage deformation law of fiber reinforced concrete pavement under different environmental temperatures(10℃,30℃,60℃)through the dry shrinkage tests of indoor concrete pavement panel,analyzed the changes of environmental temperature and fiber addition methods to surface crack width and crack area density of pavement concrete.The research results showed that:The addition of fibers can effectively improve the shrinkage performance of concrete,reduce crack width and crack area density.As the temperature increases,the width and density of shrinkage cracks of concrete show an increasing trend.Nylon fibers have strong water absorption and can increase the moisture shrinkage of concrete,the high tensile strength and modulus of polyvinyl alcohol fibers(PVA fibers)can effectively enhance the tensile strength and stiffness of concrete.Polypropylene fiber(PP fiber)can effectively reduce the shrinkage cracking behavior of cement concrete pavement,the crack width and crack area density of surface layer of PP fiber concrete pavement are significantly reduced compared to ordinary concrete pavement.