【作者】 陈茜；

【导师】 娄宗科；

【作者基本信息】 西北农林科技大学 ， 水工结构工程， 2009， 硕士

【摘要】 随着材料科学与工程技术的不断发展,现代工程界对混凝土的强度、耐久性及工作性等方面都提出了更高的要求,作为在混凝土改性过程中产生的新型水泥基复合材料,纤维混凝土材料以其在混凝土增强、阻裂、增韧等方面的独特优势引起了广大研究者和工程技术人员的高度关注。但目前的研究更多的体现在纤维单一因素对混凝土力学性能和断裂性能的影响,从混凝土的配合比以及各组分间相互作用的角度出发,对纤维混凝土力学性能及断裂性能的研究甚少。本文以塑钢纤维混凝土作为研究对象,进行了以下方面的工作:（1）通过对不同的纤维混凝土配合比下混凝土抗压强度的试验研究,探讨了塑钢纤维混凝土各组分对混凝土强度的影响。试验结果表明:塑钢纤维掺量为0～1%、砂率为40%、水灰比为0.5时,塑钢纤维混凝土的抗压强度随纤维体积率从36.67MPa增大到39.83MPa;砂率为30～50%、塑钢纤维掺量为0.5%、水灰比为0.5时,塑钢纤维混凝土的抗压强度首先从30.75MPa增大到36.95MPa再减小到30.75MPa;水灰比为0.4～0.6、砂率为40%、塑钢纤维掺量为0.5%时,塑钢纤维混凝土的抗压强度由47.25MPa减小到34.74MPa。并通过对试验数据的回归分析得出了塑钢纤维混凝土配合比与抗压强度的统一计算表达式,且综合比较得出当砂率为40%,纤维体积率为1%及水灰比为0.4时,纤维混凝土的抗压强度达到最大值47.66MPa。（2）通过对不同的纤维混凝土配合比下混凝土劈拉强度的试验研究,探讨了塑钢纤维混凝土各组分对混凝土劈拉强度的影响。试验结果表明:塑钢纤维掺量为0～1%、砂率为40%、水灰比为0.5时,塑钢纤维混凝土的劈拉强度从2.55MPa增大到2.73MPa;砂率对塑钢纤维混凝土的劈拉强度影响不大:水灰比为0.4～0.6、砂率为40%、塑钢纤维掺量为0.5%时,塑钢纤维混凝土的劈拉强度由3.1MPa减小到2.5MPa。并通过对试验数据的回归分析得出了塑钢纤维混凝土配合比与劈拉强度的统一计算表达式,且综合比较得出当砂率为40%,纤维体积率为1%及水灰比为0.4时,纤维混凝土的劈拉强度达到最大值3.627MPa。（3）通过试件尺寸为100mm×100mm×400mm的塑钢纤维混凝土三点弯曲梁断裂试验,研究塑钢纤维混凝土配合比对断裂韧度的影响规律。结果表明:塑钢纤维掺量为0～1%、砂率为40%、水灰比为0.5时,塑钢纤维混凝土的断裂韧度0.782MPa·m^1/2增大到1.065MPa·m^1/2;水灰比为0.4～0.6、砂率为40%、塑钢纤维掺量为0.5%时,塑钢纤维混凝土的断裂韧度从1.052MPa·m^1/2减小到0.783MPa·m^1/2;砂率对塑钢纤维混凝土断裂韧度影响不大。本文并通过对试验数据的回归分析,得出配合比与纤维混凝土断裂韧度的统一表达式,再进一步综合比较得出当塑钢钢纤维体积率为1%,砂率为40%,水灰比为0.4时塑钢纤维混凝土的断裂韧度达到最大值1.27MPa·m^1/2。（4）探讨了塑钢纤维混凝土配合比对断裂能的影响规律:塑钢纤维掺量为0～1%、砂率为40%、水灰比为0.5时,塑钢纤维混凝土的断裂能从519.9N·m^-1增大到905.9N·m^-1;水灰比为0.4～0.6、砂率为40%、塑钢纤维掺量为0.5%时,塑钢纤维混凝土的断裂能从980.9N·m^-1减小到729.2N·m^-1;砂率对塑钢纤维混凝土断裂能影响不大。本文并通过对试验数据的回归分析,得出配合比与纤维混凝土断裂能的统一表达式,再进一步综合比较得出当塑钢钢纤维体积率为1%,砂率为40%,水灰比为0.4时塑钢纤维混凝土的断裂能达到最大值1091.8N·m^-1。（5）塑钢纤维混凝土的配合比对临界裂缝嘴张开量CMODc的影响规律:塑钢纤维掺量为0～1%、砂率为40%、水灰比为0.5时,塑钢纤维混凝土的CMODc从0.391mm增大到0.546mm:水灰比为0.4～0.6、砂率为40%、塑钢纤维掺量为0.5%时,塑钢纤维混凝土的CMODc从0.528mm减小到0.387mm;砂率对塑钢纤维混凝土CMODc影响不大。本文并通过对试验数据的回归分析,得出配合比与纤维混凝土CMODc的统一表达式,再进一步综合比较得出当塑钢钢纤维体积率为1%,砂率为40%,水灰比为0.4时塑钢纤维混凝土的CMODc达到最大值0.645mm。更多还原

【Abstract】 With the continuous development of Materials Science and Engineering Technology,modem engineering on the strength of concrete,durability,etc,have put forward higher requirements.As a new type of cement-based composites in the modified course of the concrete produced,fiber reinforced concrete materials were caused great concern of the vast number of researchers and engineers for the unique advantage on enhance its in concrete,crack resistance,toughness,etc.However,the current study pay more attention in a single factor to influence of fiber mechanical properties of concrete and fracture properties,from the mixing ratio,as well as the concrete interaction between the various components of the mechanical propertiesand fracture properties of fiber reinforced concrete are very little.In this paper,plastic fiber reinforced concrete is studied on the following areas:（1）Through the experiments of compressive strength of plastic fiber reinforced concrete in the different mixing ratio research the of each component of plastic fiber reinforced concrete to the impact of the strength of concrete.The experimental results show that:The compressive strength of plastic fiber reinforced concrete is increased from 36.67MPa to 39.83MPa when the plastic fiber volume rate of 0-1%, sand ratio of 40%,water-cement ratio of 0.5 of the plastic fiber reinforced concrete;The compressive strength of plastic fiber reinforced concrete is increased from the 30.75MPa to 36.95MPa firstly and then reduced to 30.75MPa when sand ratio of 30-50%,plastic volume rate of 0.5%,water-cement ratio of 0.5 of plastic fiber reinforced concrete;The compressive strength is reduced from the 47.25MPa to 34.74MPa when water-cement ratio of 0.4-0.6,sand ratio of 40%,plastic fiber volume ratio of 0.5%of plastic fiber reinforced concrete.Through regression analysis of experimental data of compressive strength of the plastic fiber reinforced concrete obtained the expression of the unity of the calculation,and then indicated that when the sand ratio of 40%,fiber volume rate of 1%and water-cement ratio of 0.4,the compressive strength of fiber reinforced concrete reach the maximum 47.66MPa.（2）Through the experiments of splitting tensile strength of plastic fiber reinforced concrete in the different mixing ratio research the of each component of plastic fiber reinforced concrete to the impact of the strength of concrete.The experimental results show that:The splitting tensile strength of plastic fiber reinforced concrete is increased from 2.55MPa to 2.73MPa when the plastic fiber volume rate of 0-1%, sand ratio of 40%,water-cement ratio of 0.5 of the plastic fiber reinforced concrete;The splitting tensile strength is reduced from the 3.1MPa to 2.5MPa when water-cement ratio of 0.4-0.6,sand ratio of 40%, plastic fiber volume ratio of 0.5%of plastic fiber reinforced concrete:Sand ratio on splitting tensile strength of plastic fiber reinforced concrete have little impact.Through regression analysis of experimental data of splitting tensile strength of the plastic fiber reinforced concrete obtained the expression of the unity of the calculation,and then indicated that when the sand ratio of 40%,fiber volume rate of 1%and water-cement ratio of 0.4,the splitting tensile strength of fiber reinforced concrete reach the maximum3.627MPa.（3）Through three-point bending beam fracture experiment of the sample size of 100mm×100mm×400mm of plastic fiber reinforced concrete study the law of influence of plastic fiber reinforced concrete mixing ratio to the fracture toughness,The results show that:The fracture toughness of plastic fiber reinforced concrete is increased from 0.782MPa·m^1/2to 1.065MPa·m^1/2when the plastic fiber volume rate of 0～1%,sand ratio of 40%,water-cement ratio of 0.5 of plastic fiber reinforced concrete;The fracture toughness is reduced from the 1.052MPa·m^1/2 to 0.783MPa·m^1/2 whenwater-cement ratio of 0.4～0.6,sand ratio of 40%,plastic fiber volume ratio of 0.5%of plastic fiber reinforced concrete;Sand ratio on fracture toughness of plastic fiber reinforced concrete have little impact.The paper through regression analysis of experimental data of fracture toughness of the plastic fiber reinforced concrete obtained the expression of the unity of the calculation,and then indicated that when the sand ratio of 40%,fiber volume rate of 1%and water-cement ratio of 0.4,the fracture toughness of fiber reinforced concrete reach the maximum 1.27MPa·m^1/2.（4） Studing the law of influence of plastic fiber reinforced concrete mixing ratio to the fracture energy:The fracture energy of plastic fiber reinforced concrete is increased from 519.9N·m^-1to 905.9N·m^-1 when the plastic fiber volume rate of 0～1%,sand ratio of 40%,water-cement ratio of 0.5 of plastic fiber reinforced concrete;The fracture energy is reduced from the 980.9N·m^-1 to 729.2N·m^-1 when water-cement ratio of 0.4～0.6,sand ratio of 40%,plastic fiber volume ratio of 0.5%of plastic fiber reinforced concrete; Sand ratio on fracture energy of plastic fiber reinforced concrete have little impact.The paper through the regression analysis of experimental data of fracture energy of the plastic fiber reinforced concrete obtained the expression of the unity of the calculation,and then indicated that when the sand ratio of 40%,fiber volume rate of 1%and water-cement ratio of 0.4,the fracture toughness of fiber reinforced concrete reach the maximum 1091.8N·m^-1.（5） The law of influence of plastic fiber reinforced concrete mixing ratio to the critical crack mouth opening displacement:The critical crack mouth opening displacement of plastic fiber reinforced concrete is increased from 0.391mm to 0.546mm when the plastic fiber volume rate of 0～1%,sand ratio of 40%, water-cement ratio of 0.5 of plastic fiber reinforced concrete;The critical crack mouth opening displacement is reduced from the 0.528mm to 0.387mm when water-cement ratio of 0.4～0.6,sand ratio of 40%,plastic fiber volume ratio of 0.5%of plastic fiber reinforced concrete;Sand ratio on critical crack mouth opening displacement of plastic fiber reinforced concrete have little impact.The paper through the regression analysis of experimental data of critical crack mouth opening displacement of the plastic fiber reinforced concrete obtained the expression of the unity of the calculation,and then indicated that when the sand ratio of 40%,fiber volume rate of 1%and water-cement ratio of 0.4,the critical crack mouth opening displacement of fiber reinforced concrete reach the maximum 0.645mm.更多还原