【作者】 马南湘；

【导师】 张玉新； 沈全振；

【作者基本信息】 广西大学 ， 结构工程， 2008， 硕士

【摘要】 混凝土的开裂是普遍存在的,它会严重影响混凝土的质量,特别是导致混凝土的耐久性下降。目前建筑业已成为国民经济的支柱产业,但现浇混凝土楼板的开裂、渗漏问题已成为影响建筑物使用耐久性的严重问题之一,并成为工程质量投诉的热点问题。为了探讨解决现浇混凝土楼板中长期非荷载抗裂性的难题,本文分析现浇混凝土楼板中长期裂缝产生的原因,探讨了混凝土结构裂缝产生的机理,通过聚丙烯纤维混凝土的平板中长期抗裂试验、抗渗试验和单轴拉伸力学性能试验分析,研究聚丙烯纤维对提高混凝土中长期抗裂、抗渗等耐久性能的效果和机理。将研究成果应用于实际工程中,以解决现浇混凝土楼板的开裂、渗漏等耐久性问题,提高经济效益和社会效益,具有现实意义。本文的研究工作有三个主要方面,第一方面为试验研究,主要包括:(1)聚丙烯纤维对混凝土中长期非荷载抗裂性能影响。(2)聚丙烯纤维对混凝土抗渗透性能的影响。(3)聚丙烯纤维对混凝土的单轴拉伸力学性能影响。第二方面为聚丙烯纤维混凝土楼板三个工程应用实例分析。第三方面为聚丙烯纤维混凝土楼板应用的经济、社会效益分析。研究结果表明:(1)聚丙烯纤维对混凝土中长期裂缝有较好的抑制作用,对混凝土中长期抗裂性能的提高有较大的贡献。聚丙烯纤维混凝土是一种性能优良的材料,可以有效地解决现浇混凝土楼板易开裂、渗漏等问题。(2)聚丙烯纤维能有效改善混凝土的抗渗性能。(3)聚丙烯纤维使得混凝土的抗拉强度、拉伸极限应变、临界断裂时的最大裂缝宽度增加。(4)聚丙烯纤维混凝土在职工住宅楼等三个实际工程中的成功应用表明:聚丙烯纤维混凝土楼板的抗裂抗渗性能普遍得到提高,取得了良好的应用效果。(5)使用聚丙烯纤维混凝土楼板具有较显著的经济效益和社会效益。更多还原

【Abstract】 Concrete cracking is ubiquitous, which seriously affects concrete quality and causes concrete durability decreasing in particular. Now the building industry has become a pillar industry of national economy. However, cracking and leaking of cast-in-place concrete floor has become one of the serious problems and a hot problem of engineering quality complaints.To discuss solution to the problem of mid-long term non-load crack resistance of cast-in-place concrete floor, the paper analyzes the cause of mid-long term cracking of cast-in-place concrete floor and discusses the formation mechanism of concrete structure cracking, and studies the effects and formation mechanism of concrete mid-long crack resistance and permeation resistance improved by polypropylene fiber based on the experimental analysis on slab mid-long crack resistance and permeation resistance and uniaxial tensile test of polypropylene fiber concrete. That the research achievement is put into practical engineering has practical significance, which can improve both economic and social benefits by means of solving the cracking and leaking problem of cast-in-place concrete floor.The research work of the paper focuses on three basic aspects. The one is experimental research, including the effects polypropylene fiber has on concrete mid-long term non-load crack resistance, concrete permeation resistance and concrete uniaxial tension. The other is engineering application concerning three case studies on polypropylene fiber concrete floor. Another is economic and social benefit analysis on application of polypropylene fiber concrete floor. The research results of the paper show as follows: one is polypropylene fiber has better inhibition action on concrete mid-long cracking and greater contribution to improving concrete mid-long crack resistance. Polypropylene fiber concrete, which can effectively solve the problem of cracking and leaking of cast-in-place concrete floor, is a type of material with good performance. Two is polypropylene fiber can effectively improve concrete permeation resistance. Three is polypropylene fiber enhances concrete tensile strength, limit tensile stain and maximum crack width of critical fracture. Four is the successful application of polypropylene fiber concrete to the three practical projects such as employees’ residential building shows that crack resistance and permeation resistance of polypropylene fiber concrete floor experiences general increase and achieves good application effects. Five is the application of polypropylene fiber concrete floor has coMParatively remarkable economic and social benefits.更多还原