地下室侧墙纤维混凝土抗裂性能研究

Study on Crack Resistance of Fiber Reinforced Concrete of Basement Spandrel Wall

目前,控制地下室侧墙裂缝主要借鉴大体积混凝土经验,不能有效地预防墙体裂缝。本文应用有限元ANSYS软件,分析掺有聚丙烯纤维的混凝土地下室侧墙浇筑后14 d内的温度、混凝土收缩应力,得出温度和应力分布、变化的一般规律,侧墙应力最大部位为侧墙中部、侧墙与底板相交处。采用经验公式计算素混凝土与相同配合比的聚丙烯纤维混凝土各龄期的抗拉强度,并与同龄期侧墙最大拉应力比较,证明混凝土中掺入合成纤维,提高了混凝土的抗裂性能,确保地下室侧墙混凝土在施工期不出现裂缝。

At present, the crack controlling of basement spandrel wall mainly depends on the experience of mass concrete crack controlling and its effect is unsatisfied. This paper applied the software ANSYS to analyze the temperature and shrinkage stress of the spandrel wall which polypropylene textile fiber was mixed. Some distribution laws of temperature and stress of spandrel wall were gained. Then this paper used the experience formula to calculate the tensile strengths of plain concrete and the same mixture ratio polypropylene fiber reinforced concrete during various concrete ages, and compared with the maximum stress occurred in the wall. The results of the comparison prove that the fiber enhances the crack resistance of the basement spandrel wall concrete as it enhances the concrete tensile strength.