Through experiment this paper compares the crack load of concrete slab with liter polypropylene fiber and glass fiber , and compare with the numerical value of theory . in the calculation assume str ess figure of the extension area is triangle or rectangle 通过试验研究对比了在混凝土板中掺入聚丙烯纤维或玻璃纤维后开裂荷载的变化情况，并与理论计算值进行比较，在理论计算中假定受拉区应力图形为三角形或矩形两种情况。
At the end of introduction , the paper presents the study content . nine rectangular beams were tested and the beams strengthened using prestressed carbon fiber sheet were compare with beams strengthened using non - prestressed carbon fiber sheet , in order to evaluate the effect of externally bonded prestressed carbon fiber reinforced plastic reinforcement on the cracking load , ultimate load and flexural stiffness of reinforced concrete beams 本文进行了9根受弯试件的试验研究，对比了预应力碳纤维布加固的受弯构件与非预应力碳纤维布加固的受弯构件的开裂荷载、极限荷载、抗弯刚度等工作性能，分析了预应力对这些性能的影响。
A material nonlinear finite element analysis for the cast - in - place reinforced concrete hollow slab that occurs from initial loading , cracking , yielding to failing is carried on . the cracking load , ultimate load , the displacement rules and the principal stress distribution rules of the hollow slab under the vertical loads are obtained . a material nonlinear finite element analysis for the single span hollow flat - plate floor is also carried on 其次对空心板进行了从加荷、开裂、屈服直至破坏的全过程材料非线性有限元计算，得到了空心板在竖向荷载作用下的开裂荷载、极限荷载及位移和应力分布规律；还对单跨无梁楼盖进行了材料非线性有限元计算，通过分析主应力场明确了柱上暗扁梁的作用；有限元计算的结果验证了以上的理论分析并得到了一些重要的结论，对改进现浇空心板无梁楼盖的构造措施有重要的参考价值。
The fourteen simply supported beams mixed with the polypropylene fiber are tested to study the effect of workability of concrete , presentation quality of structures , cracking load and stiffness of beam , and crack resistance of structures due to the polypropylene fiber 本文通过14根掺聚丙烯纤维钢筋混凝土梁的试验，主要研究掺聚丙烯纤维对混凝土和易性和结构物外观质量影响效果；对钢筋混凝土梁开裂荷载的影响；对钢筋混凝土梁刚度的增强效果；以及对钢筋混凝土结构增韧阻裂的改善效果。
A way to avoiding crack or reducing crack width of concrete or reducing distortion of member is using prestressed concrete . the writer tried to make full use of the merit of the prestressed concrete and designed prestressed concrete mandril to control crack of structure . the prestressed concrete mandril , which was firstly applied high pressure on a small concrete bar , and then was made in concrete , so it would act as reinforced bar and resist load . in this thesis the writer designed 24 mmnbers and had experimental study of them , reached the conclusion that the effect of resisting crack of the prestressed concrete mandril was good when the load was not large , it can enhance the capacity of resisting crack and reduce the crack distance and crack width , but when the loads was large , the effect of resisting crack was not good , when we used the prestressed concrete mandril and reinforced bar together in member , the effect of resisting crack was very good . the writer analysed the adherence mechanism and wreck mechanism of the prestressed concrete mandril in anxial tension members , and according to the character of the prestressed concrete mandril , the writer constructed the bond model of it . then the writer introduced the analysis theory of crack including the bond - slip theory , the non - slip theory , the synthesis theory and mathematics stat method . the different theory had different theory base , they considered that the primary affection of crack width was different . in this test , the crack distance and crack width of members which placed reinforced bar were match to the compute value of the code gb 50010 - 2002 very well . to the members which 本文共进行了24根试件的试验研究,得出了预应力混凝土芯棒能较大地提高构件抗裂承载力,在荷载小于预应力混凝土芯棒的开裂荷载时有较好的抗裂效果,能较大地减小裂缝间距和裂缝宽度,但是当荷载较大预应力混凝土芯棒开裂时预应力混凝土芯棒的抗裂效果不是很好,若将普通钢筋和预应力混凝土芯棒一起使用时则有很好的抗裂效果。本文分析了预应力混凝土芯棒在轴拉试件中的粘结机理和破坏机理,根据预应力混凝土芯棒本身的特点,提出了预应力混凝土芯棒与后浇混凝土之间的粘结模型。然后本文详细介绍了经典的裂缝分析理论粘结滑移理论、无滑移理论、综合理论和数理统计方法,各理论有着各自不同的理论基础,认为影响裂缝宽度的主要影响因素也各不相同。
Some conclusions are revealed from these results : the bearing press capacity of concave concrete block wall is a little smaller compare to normal block wall , but the shear bearing capacity , the crack load and ultimate load are distinct lager than the later , and the amount of cracks are more than normal block masonry 分析结果表明,凹形砌块墙体受压承载力比普通砌块墙体的受压承载力略低,而受剪承载力明显高于普通砌块墙体。凹形砌块砌体与普通砌体相比,凹形砌块墙体的开裂荷载、极限荷载明显要高,砌体内的裂缝数量要多。
Speaking in detail , for every specimen , we study the for of the cracking load , yield load and failure load ; the ductility property ; the property of hystersis curvs and keleton - frame curves ; the degree of initial stiffess and stiffness degadation . secondly , the two different suo nlgn use ltslaences ， wmcn are ootll shear wsll sttllctlllt ， are tab6n as instanop the shear ’ wsi is oin 卜 hot8qopo inww 田 l ！ s ot 以 j 口 willo 地 劝 忧 地 epo o odod sqo8qopt solidndls ofr c l w means or0 卜 0nm elemem ana 吹 lsptwtodd ’ mlmwe m 加 柏 mm are d an 邑 以 胡 a ann compcomparen in severm es 叮 wsllcll as scu 一 阳 i 朗 l p 一 ndnd mdede so ess d laterm seimic e anu so on ’ inatty ， tiep 训 颁 oility of hollow shear wal of rc in d suo ra use reslaences s ant l 首先研究在低周反复水平加载试验下试验对象的强度、变形和能量的特性：开裂荷载、屈服荷载、破坏荷载；各试件的滞回曲线和骨架曲线；延性情况；初始刚度和刚度退化等参数：进而用satwe有限元程序分析对比了某一小高层剪力墙结构在采用空心剪力墙板和采用普通实心剪力墙作为墙体的结构受力异同点，在质量、主振型、刚度、水平地震效应等方面做了对比。
( 3 ) reinforced concrete frame columns modeled by using three - dimensional solid element to concrete and three - dimensional bar to reinforcing steel bar , and at the same time consideration the adhesive bond between reinforcing steel bar and concrete , the fem is used . by choosing reasonable element , determining mesh division and load steps , simulation of load - displacement , cracking , yielding and ultimate load , crack development history , and calculating fail crack diagram of reinforcement concrete frame columns under laterally monotonic load are conducted . the analyses are compared with the experimental results ( 3 )混凝土用三维实体单元、钢筋用空间杆单元对钢筋混凝土框架柱进行三维建摸，而且同时考虑了钢筋和混凝土的粘结性能，通过合理的单元选取、网格划分及荷载步的确定，模拟了单调荷载作用下钢筋混凝土框架柱的荷载啦移曲线、开裂荷载、屈服荷载及最大荷载、裂缝发展规律、计算破坏裂缝图，并与相应的试验结果进行了比较分析。
From the experiments , we can see the affect of concrete performances mixing with liter polypropylene fiber and glass fiber is minor . compare with common concrete , the crack - load of concrete slab mixing with liter polypropylene fiber and glass fiber is marked improved . mixing with liter polypropylene fiber and glass fiber , the behavior of cracks - resisting of is marked improved , and the cracks are controlled and smeller 研究表明，在混凝土中掺入低掺量的聚丙烯纤维或玻璃纤维对抗压强度及抗拉强度的影响较小；纤维混凝土板比普通混凝土板的开裂荷载有较为显著的提高；加入低掺量的聚丙烯纤维后，混凝土板的抗塑性开裂性能有显著提高，可以抑制、细化裂缝。
In the thesis , the design issues of repairing and strengthening reinforced concrete structure using ferrocement have been provided , and the equations of brittle ratio , cracking load , ultimate load and vertical deflection have been inferred too . at last , a conclusion is shown that the theoretical equations share a good agreement with the experimental results of the tested beams 本文就钢丝网复合砂浆加固受弯构件的设计进行了探讨，提出了界限加强率、开裂荷载、极限荷载以及挠度的计算公式，并将计算公式的结果与试验结果进行比较，取得了较好的吻合。
