钢纤维混凝土工业地坪变形及防裂研究

发布时间：2018-08-08 20:28

【摘要】：随着我国工业化进程逐步推进，工业地坪应用也逐渐增多。由于工业地坪本身构造及施工特点，其极易产生裂缝。开裂会对工业地坪的使用造成影响，维修工作的难度大，因此有必要展开其抗裂性能方面的研究。本文围绕工业地坪变形及抗裂性能问题，通过理论分析、工程调研、现场试验、有限元模拟及技术经济分析等手段，对工业地坪裂缝的原因及影响因素进行了系统分析，，提出了经济有效的抗裂施工工法。本文首先从两个方面进行了理论研究，包括钢纤维混凝土基本理论及混凝土收缩应力理论研究，分析了钢纤维混凝土的防裂、受力特点及混凝土收缩裂缝的影响因素、徐变与应力松弛等，同时给出了温度应力计算公式的推导过程，并根据工程实际情况确定了计算温度应力的基本参数；其次，调研已有工程的地坪开裂情况，针对开裂设计了钢纤维混凝土地坪相关试验，进行钢纤维混凝土与普通混凝土抗压试验、钢纤维混凝土与钢筋混凝土抗弯试验、钢纤维混凝土及普通混凝土构件自由干缩试验和钢纤维混凝土工业地坪现场变形观测试验。经过收缩理论分析、对比分析、回归分析、有限元模拟得到以下结论：（1）对RC-80/60-BN型钢纤维掺量15kg/m3的钢纤维混凝土抗压强度比同等级普通混凝土提高4%-9%；（2）钢纤维混凝土30天的收缩量较普通混凝土小约20%；（3）钢纤维混凝土地坪切缝最佳时间为浇筑后36-60小时；（4）得出了RC-80/60-BN型钢纤维掺量15kg/m3的工业地坪的韧度、韧度比及弯矩承载力极限值；（5）得到了切缝及分仓缝应力释放计算公式；（6）覆地膜素土夯实地基条件下，180mm厚RC-80/60-BN型钢纤维掺量15kg/m3的钢纤维混凝土工业地坪切缝最大间距为9m；（7）提出了基于试验结果的合理施工工法，有效避免地坪开裂。
[Abstract]:Along with our country industrialization advancement step by step, the industrial floor application also increases gradually. Because of the structure and construction characteristics of industrial floor, it is easy to produce cracks. The cracking will affect the use of industrial floor, and the maintenance work is difficult, so it is necessary to study its crack resistance. In this paper, the causes and influencing factors of industrial floor cracks are systematically analyzed by means of theoretical analysis, engineering investigation, field test, finite element simulation and technical and economic analysis. An economical and effective anti-crack construction method is put forward. In this paper, the basic theory of steel fiber concrete and the theory of concrete shrinkage stress are studied in two aspects, and the crack prevention and stress characteristics of steel fiber reinforced concrete are analyzed, as well as the influencing factors of concrete shrinkage crack. Creep and stress relaxation, etc., at the same time, the derivation process of calculating formula of temperature stress is given, and the basic parameters of calculating temperature stress are determined according to the actual situation of engineering. The steel fiber reinforced concrete (SFRC) floor test was designed for cracking, the compressive test of SFRC and ordinary concrete, the flexural test of SFRC and RC were carried out. Free shrinkage test of steel fiber reinforced concrete and ordinary concrete members and field deformation observation test of steel fiber reinforced concrete industrial floor. Through shrinkage theory analysis, contrast analysis, regression analysis, finite element simulation, the following conclusions are obtained: (1) the compressive strength of steel fiber reinforced concrete (SFRC) with RC-80/60-BN steel fiber content 15kg/m3 is increased by 4- 9% than that of ordinary concrete of the same grade; (2) the shrinkage of steel fiber reinforced concrete in 30 days is about 20% less than that of ordinary concrete; (3) the optimum time of cutting joint of steel fiber reinforced concrete floor is 36-60 hours after pouring; (4) the toughness of industrial floor with RC-80/60-BN steel fiber content of 15kg/m3 is obtained. (5) the formula of stress release of slit and silo joint is obtained, (6) the maximum spacing of steel fiber reinforced concrete (RC-80/60-BN) thick steel fiber with 180mm thick RC-80/60-BN steel fiber is 9 m under the condition of compacted foundation with mulching film soil. (7) the reasonable construction method based on test results is put forward to effectively avoid floor cracking.
【学位授予单位】：青岛理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU755

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