钢纤维膨胀混凝土增强机理及其应用

钢纤维膨胀混凝土是一种集承重与防渗为一体的新型建筑材料，可望在水工结构和面板堆石坝中应用。目前，我国在这方面的研究才刚刚起步，至今仍未查阅到国外有关这方面的研究资料。本文围绕这种新材料基本力学变形性能及其应用，主要作了如下研究工作。 对钢纤维膨胀混凝土的膨胀收缩性能、基本力学性能、单轴拉伸和单轴受压条件下的变形性能，进行了系统的试验研究及理论分析；建立了钢纤维膨胀混凝土的膨胀收缩过程数学表达式、强度计算公式、与变形钢筋的粘结强度计算公式及其单轴拉伸、单轴受压条件下的应力～应变全曲线数学模拟方程。 在试验研究基础上，对钢纤维膨胀混凝土的增强机理进行了深入的研究，认为钢纤维膨胀混凝土中钢纤维的增强作用体现在两方面：一是限胀增强作用；二是阻裂增强作用。钢纤维膨胀混凝土强度计算公式，除考虑钢纤维阻裂增强作用外，还应考虑钢纤维限胀增强作用。根据功能守恒原理，推导出了与钢纤维混凝土强度计算公式相衔接的、同时考虑钢纤维的限胀增强及阻裂增强作用的、钢纤维膨胀混凝土抗拉及抗弯强度计算公式。为方便使用，根据本文试验条件及结果，给出了与试验结果符合良好的钢纤维膨胀混凝土抗拉及抗弯强度的简化计算公式。 鉴于混凝土输水管要求具有良好的抗裂及抗渗性能，本文选工程中有代表性的水管作为钢纤维膨胀混凝土试件模型，对钢纤维膨胀混凝土管、配筋配筋钢纤维混凝土、配筋钢纤维膨胀混凝土管及钢纤维增强自应力混凝土管，在内压作用下的力学变形性能进行了系统的试验研究和理论分析；提出了钢纤维增强自应力混凝土管自应力值的计算方法；给出了试验管体在内压作用下的承载力计算公式；对钢纤维增强自应力混凝土管和钢纤维膨胀混凝土管进行了经济比较分析，结果表明，钢纤维膨胀混凝土管及钢纤维增强自应力混凝土管，性能优良，其推广和应用将带来可观的经济效益和社会效益。
工业羊毛毡
Steel fiber reinforced expansive concrete is a new building material which has good mechanical performance and permeability resistance. It is expected to be used in hydraulic structure and rock-filled dams. At present, the study in this field is still in its primary development period in our country, and there is little further research references abroad until now. The paper is concentrated on the fundamental mechanical performance and applications of steel fiber reinforced expansive concrete. The main contents of my project are as follows. Systematic experimental study and theoretical analysis have been performed on the expansion and shrinkage property, fundamental mechanical performance, characteristic bf tension and compression of the material. Based on the results, the mathematical expression of expansion and shrinkage process, strength calculation formula of steel fiber reinforced expansive concrete, bond strength calculation expression of the concrete and deformed reinforcement, and strain- stress curve have been presented. Based on the test results, study on the reinforcing mechanism of steel fiber in expansive concrete has been carried out. It is believed two kinds of reinforcement should be expressed in the strength formula of steel fiber reinforced expansive concrete. One is the reinforcement of the limited expansion, another is of the anti-crack. According to the principle of ?conservation of power and energy?, a strength expression which is linked with the strength expression of steel fiber reinforced concrete is worked out. For convenient usage in engineering, the simplified expression of strength has been given, on the test condition and results ,which shows good agreement with the test results. Typical pipes in practice have been selected in the paper as specimen models of steel fiber. expansive reinforced concrete, because concrete water transfer pipes demand to have good crack and permeability resistance. Systematic experimental and analytical studies have been carried out on mechanical and deformation characteristic under internal pressure for steel fiber reinforced expansive concrete pipes, reinforced pipes of using steel fiber reinforced concrete and of using steel fiber reinforced expansive concrete and steel fiber reinforced auto-stress concrete pipes. Computational method for the auto-stress value of II steel fiber reinforced auto-stress concrete pipes and calculating formula to predict the crack resistance capacity under internal pressure of testing pipes have been given. The economic of steel fiber reinforced auto-stress concrete pipe and steel fiber expansive concrete pipe has been compared with that of others. And the results show that both kinds of pipes have good performance, and their application will bring considerable economical and social benefits