【作者】 马文明；

【导师】 叶献国；

【作者基本信息】 合肥工业大学 ， 结构工程， 2013， 硕士

【摘要】 钢筋混凝土结构广泛应用于工程实践领域，然而普通混凝土已难以满足工程应用需求，高强钢筋和高强混凝土的推广应用成为必然，预应力技术能够显著增加结构的刚度。故开展集高强材料和预应力技术于一体而又广泛应用的受弯构件试验研究和分析，符合社会发展需求，具有重要工程应用价值，利于节能减排降耗。本文共开展了12根高强钢筋高强混凝土预应力梁的抗弯性能试验研究，研究的因素主要包括混凝土强度等级、换算配筋率、预应力强度比等，检测的指标主要包括竖向荷载、挠度变形、钢筋和混凝土的应变、裂缝宽度及其演化规律等。通过试验研究和分析，取得以下结论：（1）高强钢筋高强混凝土预应力适筋梁受弯破坏属于延性破坏，包括开裂前阶段、带裂缝工作阶段和钢筋屈服后直至失效三个阶段；（2）混凝土强度等级以影响钢筋屈服后的抗弯性能为主，且高强度等级混凝土试验梁后期承载力下降较小；（3）非预应力筋配筋率对试验梁开裂前的抗弯性能基本无影响，对开裂后抗弯性能影响显著，即发生相同变形时，配筋率越高承载力越高，且该趋势持续到试验结束；（4）相同张拉控制应力条件下，预应力筋配筋率越高开裂弯矩越大；相同弯矩作用下，预应力配筋率越高变形越小，其极限承载力也越高。本文还基于大型通用有限元软件ANSYS开展了数值模拟研究，在模型验证的基础上，通过静力非线性分析方法，研究了混凝土强度、钢筋强度以及预应力大小对承载性能的影响规律，取得的结论主要包括：（1）混凝土强度等级主要影响高强钢筋高强混凝土预应力梁的后期承载性能；（2）钢筋级别对预应力高强高性能混凝土梁早期受力性能基本无影响，待加载后期则表现为高强钢筋抵抗变形的能力更大；（3）预应力大小显著影响高强钢筋高强混凝土预应力梁的变形性能，随着施加预应力的减小，梁的挠度变形增大，且增速变快。上述试验研究和数值计算成果，不仅能够加深对高强钢筋高强混凝土预应力梁的抗弯性能认识水平，而且相关成果可以直接服务于工程实践。围绕施工技术、构造措施、抗震性能等领域值得进一步研究。更多还原

【Abstract】 Reinforced concrete structures are widely used in the field of engineering field.However, the common concrete has been difficult to meet the demand of engineeringapplications, so the popularization and application of high-strength steel andhigh-strength concrete has been inevitable. The prestressed technology cansignificantly increase the structure’s stiffness. So it is necessary to carry out theresearch and analysis of the prestressed high-strength concrete beams withhigh-strength reinforcement, and it is an important value in engineering, conducive toenergy conservation and pollution reduction.By the bending performance test of12prestressed high strength-concrete beamswith high-strength bars, the reasons which influence the bending performance of thebeam such as the concrete strength grade, non-prestressed reinforcement ratio and theprestressed reinforcement ratio were searched, the experiment date included thevertical load, the deflection, the strain of steel and concrete, the crack width and itsevolution. The test results show that:(1) The fracture model of the prestressedhigh-strength concrete beam with high-strength bars is ductile fracture model, itincluded three stages: the stage before cracking, the working stage with cracks andthe damage stage after yielding.(2) The concrete strength grade has an influence onthe bending performance mainly after yield, The higher the concrete strength was, theless the bearing capacity of beam decreased.(3) The unprestressed reinforcement ratiohave little effection on the flexural test beams before cracking, after cracking thehigher reinforcement ratio, the bigger bearing capacity.(4) With the same tensioncontrol stress, the higher the prestressed tendon reinforcement ratio, the greater thecracking moment, and under the act of the same bending moment, the smallerdeformation and the higher ultimate bearing capacity.This article is also based on the ANSYS finite element software to carry out thesimulation study of prestressed high-strength concrete beams with high-strength bars,based on the analysis of the numerical model, the parameters which influence thebending performance of the beam such as the concrete strength grade, non-prestressed reinforcement ratio and the prestressed reinforcement ratio were searched, and got theconclusion:(1) The concrete strength grade has an influence on the bendingperformance mainly after yield.(2) The unprestressed reinforcement ratio have littleeffection on the flexural test beams At the early stage, after the load application thehigher reinforcement ratio, the bigger bearing capacity.(3) The size of the prestresshas a great influence on the deformation performance of the prestressed high-strengthconcrete beams with high-strength bars. With the reduction of the prestress, thedeflection of the beam increases, and growth become faster.The experimental study and numerical calculation results is helpful not only tomake us have a deep understand of the flexural properties of high strength reinforcedconcrete prestressed beams, but also the result can be directly served in theengineering practice. It should be further studied at in the field of constructiontechnology, construction measures, and seismic performance.更多还原