摘要
面板堆石坝的混凝土面板层属于大面积敞开式薄壁结构,在基础及钢筋的约束下,易产生塑性裂缝和早期干缩裂缝,研究了纤维素纤维和聚丙烯纤维对面板混凝土塑性裂缝及早期干缩裂缝的作用以及对混凝土抗渗性和抗冻性的影响.研究结果表明:纤维素纤维在混凝土塑性阶段具有显著的减裂效果,减裂率达到86.2%,而聚丙烯纤维的减裂率为52.0%;纤维素纤维和聚丙烯纤维对早期干燥收缩裂缝具有抑制作用,减裂率分别为66.7%和52.2%;纤维素纤维和聚丙烯纤维提高了混凝土抗渗性和抗冻性,其中纤维素纤维混凝土的抗渗等级提高了2个等级,聚丙烯纤维混凝土提高1个等级,两种纤维混凝土的抗冻性提高了50个标号.
The concrete face slab of rockfill dam has a large surface area and a relatively small thickness, thus under the restraints of foundation and reinforcements, it inclines to form plastic cracking and early dry shrinkage cracking. In this paper, the effects of cellu- lose fiber and polypropylene fiber on plastic cracking and early dry shrinkage cracking of face slab concrete, and also on concrete im- permeability and freezing resistibility. The results show that cellulose fiber has notable effect on concrete plastic cracking and reduces cracking area by 86.2% , while polypropylene fiber only reduces cracking area by 52.0% ; cellulose fiber and polypropylene fiber both have certain effects on reducing early dry shrinkage cracking, cracking area reduced by 66.7% and 52.2% respectively; cellulose fi- ber and polypropylene fiber can improve concrete impermeability and freezing resistibility, in which, the impermeability grade of cellu- lose fiber concrete is improved by 2, that of polypropylene fiber concrete is improved by 1, and the freezing resistibility grade is both improved by 50.
出处
《华北水利水电学院学报》
2012年第6期116-120,共5页
North China Institute of Water Conservancy and Hydroelectric Power
关键词
纤维素纤维
塑性裂缝
早期干缩裂缝
抗渗性
抗冻性
cellulose fiber
plastic cracking
early dry shrinkage cracking
impermeability
freezing resistibility
