【作者】 张丽；

【导师】 黄伟；

【作者基本信息】 安徽工业大学 ， 市政工程， 2010， 硕士

【摘要】 高强钢筋尤其是HRB500级钢筋作为受力主筋的构件由于缺乏足够的试验依据,未被列入现行《混凝土结构设计规范》GB50010-2002,而作为HRB500级钢筋的一种——HRB500低成本高性能钢筋(以下HRB500(LH))是马鞍山钢铁股份有限公司采用钒氮合金微合金化革新工艺新近研制的热轧带肋钢筋新品种。与HRB500级钢筋相比,HRB500(LH)钢筋在强度和延性上未有下降,但生产所需钒氮合金含量则有一定程度减少,降低了钢筋生产成本,故称之为低成本高性能钢筋。为了研究HRB500(LH)级钢筋作为混凝土构件受力主筋适用性,需对HRB500(LH)钢筋混凝土构件进行力学性能试验研究。本文着重研究HRB500(LH)钢筋混凝土梁构件受弯性能。共设计两组构件,第一组为7根配HRB500(LH)钢筋不掺钢纤维的混凝土梁,第二组为6根配HRB500(LH)钢筋不同钢纤维掺量的混凝土梁。通过集中荷载作用下梁的静力试验,观察试件从加载开始到裂缝出现直至梁完全破坏丧失承载能力全过程的试验现象,量测了试件开裂荷载和极限荷载等荷载值和纵筋应变、混凝土受压应变等应变值以及挠度值等。通过试验数据分析,并对照现行《混凝土结构设计规范》和《钢纤维混凝土结构设计与施工规程》相关内容,得出结论:1)无论是掺加钢纤维和不掺钢纤维的受弯构件,其正截面承载力实测值均稍大于计算值,HRB500(LH)钢筋混凝土梁的承载力计算可沿用现行规范或规程相关计算公式。2) HRB500(LH)钢筋混凝土受弯构件的挠度可按《混凝土结构设计规范》GB50010-2002中规定公式计算,但应进行适当修正,本文建议对挠度值应乘以扩大系数1.25;钢纤维混凝土梁的挠度计算值亦可按《钢纤维混凝土结构设计与施工规程》相关公式计算,并乘以扩大系数1.25予以调整。3)《混凝土结构设计规范》所给最大裂缝宽度计算方法在一定程度上能够反映HRB500(LH)钢筋混凝土梁裂缝的发展规律,但其修正尚需继续探讨;掺加钢纤维的混凝土梁的裂缝计算值与实测值符合较好,可直接采用《钢纤维混凝土结构设计与施工规程》相关公式。更多还原

【Abstract】 There is not enough experiment about the properties of high strengh especially HRB500 reinforced concrete members,so it hasn’t been taken in by new Code for design of concrete structures (GB50010-2002).as one of HRB500 steel bars low-cost and high-performance (called HRB500(LH) below)is a new hot-rolled ribbed steel bar which was first developed by Maanshan Iron and Steel Company used v-n micro alloyed process.Compared to HRB500 steel bars it has many merits,such as high-strength and strong ductility ,and low-cost for a reduced content of v-n alloy,So called HRB500(LH) steel bar. In order to popularize this new kind of steel bar in engineering area of our country,the experiment researches should be done on the main characteristic of HRB500 reinforced flexural members.Two groups beams with HRB500(LH) steel bar were designed to test its bending properties,one group has 7 beams with HRB500(LH) and another 6 steel fiber reinforced concrete beams with HRB500(LH). All of the beams are subjected to monotonic concentrated load,The test phenomena from the begin to occurrence of initial crack and to the failure of the test specimen were recorded continuously and analysed.Load values such as crack- appearing load and failure load,the strain of embedded steel steel bar and concrete,as well as mid-deflection of the specimen were obtained.By analyzing the test data,and compare to calculated value according to the existing Code and Specification for design and construction of Steel fiber reinforced concrete structures(CECS38-1992) ,The result indicates:1)both beams no matter steel fiber reinforced concrete beams or beams with no steel fiber ,the value of carrying capacity is a little larger than the one calculated by the Code or Specification,the formula for calculating the carrying capacity of the beams still can be used.2) the deflection under limit state of serviceability can be calculated by formulas in existing Code for Code for design of concrete structures (GB50010-2002) ,while it should be enlarged by a coefficient 1.25 according to the datas,so as the steel fiber reinforced concrete beams to Specification for design and construction of Steel fiber reinforced concrete structures.3) the formula for calculating the crack-width in existing Code can reflects the law of crack propagation of HRB500(LH) reinforced concrete members to a certain extent,but calculated method couldn,t used formula given in the code and how to modify need to be discussed more. the values of crack-width measured and calculated according to Specification for design and construction of Steel fiber reinforced concrete structures matched well to the steel fiber reinforced concrete beams.更多还原