外文翻译---受纯剪应力的力学纤维增强混凝土构件（含word版） .pdf

受纯剪应力受纯剪应力的的力学纤维增强混凝土构件力学纤维增强混凝土构件 nobuhiro hisabe (1), isamu yoshitake (2), hiroshi tanaka (3) and sumio hamada (2) （1 1）三）三菱化学功能性产品，公司，日本菱化学功能性产品，公司，日本 （2 2）土木与环境工程，山口大学，日本）土木与环境工程，山口大学，日本 （3 3）橘材料有限公司，日本）橘材料有限公司，日本 （4 4）土木与环境工程，山口大学，日本）土木与环境工程，山口大学，日本 摘要 摘要 更高的强度混凝土和轻混凝土已被用于细长混凝土结构施工。 这种混凝土也 要求优越的结构性能和较高的耐用性。对于耐久性混凝土结构设计合理，混凝土 结构性能，必须进行评估得当。本研究的目的是为了获得各种剪切行为的具体内 容，并量化为各种混凝土构件的剪切破坏增援。frc 的元素的力学行为是由简 单的实验纯剪切机评价。本研究的具体材料包括高强度混凝土和高性能轻混凝 土。 每个无纤维混凝土试件的脆性破坏，从一个裂缝引起的。相反，第一次与 纤维混凝土试件裂纹的产生是在中心部分和一些裂缝各环节最大负荷发生后。 剪 应力和 frc 的元素的力学行为变形之间的关系进行了调查，其中这种关系不能 在脆性材料的情况下获得。在纯剪应力，frc 的元素比普通混凝土更好地体现 了韧性性能。至于最终的强度，剪切强度纯 frc 的元素比普通混凝土强度高几 乎百分之二十。 1 1。简介。简介 我们进行了各种关于梁，剪力墙和平面板强度字段混凝土的抗剪强度的研 究。这些成员的剪切破坏，不仅造成纯剪应力，在元素组成的混凝土和钢筋还造 成联合剪应力和正常剪应力。另一方面，一些检测方法已经制定了剪切强度。在 传统的测试方法中，提供了沿一个或两个平面强制剪。然而，破坏面与45倾向 于受到剪切方向，这意味着该特征值不能从这些测试方法得到裂缝传递。剪切强 度可以由莫尔圆由两个或三个轴压力测试提供的数字得到。只有由 m.柯林斯开 发的试验机提供了一个相当大的测试墙板抗剪强度。 简化试验机在两个方向上承 受负荷的研究是 kanakubo 从柯林斯机的改进。 这些机器适用于两个方向几个插 孔，可以轻松地载入反映混凝土构件的受力状态，尤其是相当大的钢筋混凝土膜 成员。通常很大大概试样可能不是正确的材料试验。因此，作者开发了简单的纯 剪切机，改变了单向轴力进入纯剪切力在以往的研究中;我们已经报道了由纯剪 切机的具体内容强度特性。 图1：简化纯剪切机 图2：轴向荷载传递 图3：纯剪切试样 钢纤维钢筋混凝土（frc）比普通混凝土具有优异的韧性性能。在最近几年 已经报道了其应用到各个具体的结构。因此，在这项研究中，由简单的纯剪切机 进行了钢纤维钢筋混凝土（frc）评估。 2。纯剪切试验。纯剪切试验 2.1简体纯剪切试验机简体纯剪切试验机 简化的纯剪切试验机在本研究采用图1所示，负载转移到剪切力的方向，如 图2所示。此机可设置在阿姆斯莱式万能试验机，并可以通过纯混凝土膜元件改 变主题的单轴力的方向剪切力。 2.2标本标本 目前研究的测试样品是一个206x206x100mm 的方形混凝土膜图3.11所示， 每一个钢板螺栓附在装货板。 混凝土切割膜是在角落关机， 以避免复杂应力状态。 受到剪应力的面积可以进行评估的170x170mm 内部分。该地区有一个小角落里 过多的地区，这一地区的剪切强度是不够大。 表1：混凝土材料 水泥 细骨料 粗骨料 混合材 材料 高早强水泥 海砂 珠光体 安德西特 高效减水剂 密度g/cm3 3.13 2.60 0.85 2.70 1.05 表2：配合比混凝土配合比 2.3试验参数试验参数 为测试样本配比见表1和2。这些具体包含正常和轻骨料混凝土。轻骨料是由 珠光体，密度约为0.85。剪切强度测试也进行类似的混合比例的砂浆。高硅酸盐 水泥早期采用的混凝土和砂浆，测试年龄为7天。 在钢纤维钢筋混凝土（frc）的配比中，钢纤维1.0的混合混凝土。本研 究采用两端带钩钢纤维（0.6x30mm） 。 一般而言，非常低的拉伸强度和剪切强度的混凝土被称为比抗压强度。为了 探讨不同强度的混凝土剪力墙的行为，水灰比分别设置为30，45和60。此外， 抗压强度和劈拉强度试件进行调查缸（直径为100mm 和200mm 的高度） 。 a）钢纤维混凝土 b）普通混凝土 图4：失效模式 表3：失效模式及强度 图5：纯剪切强度 图6：位移传感器附件 3。实验结果与讨论。实验结果与讨论 3.1纯剪应力状态下纯剪应力状态下 图4显示为普通混凝土试件和纯剪应力下的钢纤维钢筋混凝土（frc）标本 试验样品的失效模式。从表3给出的测试的标本和强度试验的结果勾画了出故障 模式。 这些照片和草图表明，普通混凝土故障发生在垂直左右的标本中。这些现象 暗示了纯剪切破坏的发生是由于主拉应力。 另一方面，虽然在最大负荷下裂纹发生，frc 的标本，没有几个裂缝。失 败型钢纤维没有失败，这些纤维被掏出。此外，部分轻集料已经分裂以失败，而 正常总额几乎没有失败。 3.2纯剪切强度纯剪切强度 与纯剪切强度和水胶比的关系如图5所示。 纯剪切强度下降为水胶比的增加。 在与水的比例为30水泥混凝土轻骨料混凝土之间几乎和正常骨料混凝土纯剪 切强度类似。采用水胶比60的轻质混凝土纯剪切强度约为正常骨料混凝土 60。砂浆的强度略高于混凝土强度，对纯剪切强度与破坏现象骨料混凝土的 影响略低于混凝土。纯净的钢纤维钢筋混凝土的抗剪强度分别为10-20，比 普通混凝土高。这些结果代表了钢纤维混凝土的强化作用。 图7：位移负荷 表4：位移负荷区 w/c（%） area (kn*mm) 30 161.0 45 129.3 60 99.4 3.3纯剪切行为纯剪切行为 在普通混凝土具有脆性破坏的情况下，很难定量评估失效行为。然而，为了 取得钢纤维钢筋混凝土（frc）行为是比较容易的，因为它的延展性。因此，本 研究旨在评估前后裂纹纯剪应力下的钢纤维钢筋混凝土（frc）发生的行为。位 移传感器（62毫米）的附着在试样表面，如图5所示。 图7显示了轻骨料混凝土构件 frc 的负载和位移之间的关系。这些数字代 表前开裂变形都很小，并与裂缝的发展进步。 表4显示了从负载和位移0毫米范围确定的区域。 在 w / c= 45和30的值 比 w / c= 60多1.3和1.6倍。 4。结论。结论 纯剪切机的开发，以确定混凝土构件抗剪强度。纯剪切试验进行，以取得各 种混凝土断裂行为，其中包括钢纤维钢筋混凝土（frc） 。本研究结论归纳如下： 1）每个失效模式是失败的分裂分子，即使在钢纤维钢筋混凝土（frc） 。 2）普通混凝土和纯剪应力 frc 的脆性破坏，造成了破坏韧性分别。 3）钢纤维钢筋混凝土（frc）的纯剪切强度比普通混凝土高。 4）负载和位移面积往往是对混凝土强度的增加而递增。 鸣谢鸣谢 作者在此感谢他们详细的意见和支持本庄小姐稻盛和夫先生。 参考文献参考文献 1 noguchi, t., nonlinearity behaviour of concrete-compressive, tensile, shearing test, concrete journal, vol.39, no.9 (2001) 110-114 (in japanese) 2 vecchio, f., j. and collins, m., p., the modified compression-field theory for reinforced concrete elements subjected to shear, aci journal, 83(2) (1986) 219-231. 3 ito, m., kanakubo, t., shear behaviour of reinforced concrete panels subjected by bending moment, proceedings of the japan concrete institute, vol.23, no.3 (2001) 1027-1032 (in japanese) 4 tanaka, h., et al, the properties of lightweight aggregate concrete for pre-cast bridge slab, system-based vision for strategic and creative design, isec-02(3) (2003) 1899- 1905. page 1 mechanical behavior of fiber reinforced concrete element subjected to pure shearing stress nobuhiro hisabe (1), isamu yoshitake (2), hiroshi tanaka (3) and sumio hamada (2) (1) mitsubishi chemical functional products, inc., japan (2) department of civil and environmental engineering, yamaguchi university, japan (3) tachibana material co., ltd., japan (4) department of civil and environmental engineering, yamaguchi university, japan abstract higher strength concrete and lighter concrete have been employed for the construction of slender concrete structure. such concrete also requires for superior structural performance and higher durability. for rational design of durable concrete structure, the structural performance of concrete must be evaluated appropriately. the purpose of the present study is to obtain the shearing behaviour of various concrete elements, and to quantify various reinforcements for shear failure of concrete member. mechanical behaviour of frc element is evaluated experimentally by the simple pure shearing machine. the concrete materials in the present study include high strength concrete and high performance lightweight concrete. every concrete specimen without fiber was brittle failure caused from a crack. conversely, first crack in concrete specimen with fiber occurred in the centre section and some cracks occurred in various sections after max loading. the relationship between shearing stress and deformation of frc elements were investigated, which such relations cannot be obtained in case of brittle materials. frc elements under pure shearing stress indicated extreme more ductile performance than plain concrete. as the ultimate strength, pure shearing strength of frc elements had almost 20 percent higher than the strength of plain concrete. 1. introduction various studies on the shear strength of concrete have been conducted in the field of strength of the beam, shear wall and flat slabs. the shear failure of these members is not only caused by pure shear but combined stresses under shear and normal stresses in the element consisted of concrete and reinforcement. on the other hand, several testing methods have been developed for the shear strength1). in the conventional testing methods, compulsory shear was provided along one or two planes. however, the failure plane is chained with cracks inclined by 45 to the plane subjected to shear, which implies that the characteristic value can not be obtained from these testing methods. the shear strength could be obtained by the figure of mohrs circle provided by two or three axes stress test. only a testing machine page 2 developed by m. collins2) provides the shear strength by testing a rather large panel wall. a simplified testing machine subjected loads in two directions is employed in studies by kanakubo3), which is modified from the collins machine. these machines apply several loading jacks in two directions and can easily reflect the stress states in concrete members, especially rather large reinforced concrete membrane members. presumably the test specimens are also large, which may not be proper for material tests. therefore, the authors have developed the simple pure shearing machine which changes uni-axis force into the pure shearing force, in former research; we have reported the pure shearing strength characteristic of the concrete elements by the machine. steel fiber reinforced concrete (frc) has excellent ductile performance compared with plain concrete. its applications to the various concrete structures have been reported in recent years. therefore, in this study, mechanical behaviour of frc element has been evaluated by the simple pure shearing machine. 2. pure shearing experiment 2.1 simplified pure shearing test machine the simplified pure shearing test machine which was employed in this study is shown in figure 1, and the load was transferred to shear force direction as indicated in figure 2. this machine can be set in the amsler type universal testing machine, and can subject the pure shearing force to concrete-membrane element by changing the direction of the uni- axial force. 2.2 specimen the test specimen in the present study is a square concrete-membrane element with 206x206x100mm shown in figure 3. 11 steel bolts per one plate were attached for the 480 480 loading plate jigpin pin frame (mm) 480 480 loading plate jigpin pin frame (mm) figure 1: simplified pure shearing machine c l c l jig loading plate long aperture frame specimen oa b load c l c l jig loading plate long aperture frame specimen oa b load figure 2: transfer of axial load 170 100 loading plate 1818 206 170 volt 100 100 volt rubber (mm) 170 100 loading plate 1818 206 170 volt 100 100 volt rubber (mm) figure 3: pure shearing test specimen page 3 loading plate. concrete membrane is cut off at the corners in order to avoid the complicate stress condition. the area subjected shear stress can be evaluated by inner section of 170x170mm. the corner region has a little excessive area, this region is not sufficiently large for the evaluation of shearing strength. 2.3 experimental parameter mix proportions for the test specimens are given in tables 1 and 2. these concrete contains normal and lightweight aggregate concretes. the lightweight aggregate is made of pearlite, and the density is approximately 0.85. the shear strength test is also conducted to the mortars with similar mix proportions. the high early portland cement was employed for the concrete and mortar. the age at the test was 7th day. in the mix proportion for steel fiber reinforced concrete (frc), 1.0 vol.% of steel fiber was mixed in the concrete. the present study employed the steel fiber (0.6x30mm) with hook ends. generally, very low tensile and shearing strength of concrete is known compared with the compressive strength. in order to investigate the shearing behaviour of concrete with various strength, water cement ratios were set as 30, 45 and 60%. in addition, compressive strength and splitting tensile strength were investigated by cylinder specimen (diameter of 100mm and height of 200mm). table 1: materials of concrete cement（c)fine aggregate（s）admixture（ad) density(g/cm3)3.132.600.852.701.05 materials high early strength portland cement sea sandpearlite coarse aggregate（g) andesitesuperplasticizer table 2: mix proportion of concrete unit weight per volume (kg/m3) w/c (%)w c s g sf 30 160533 709 937 45 160355 774 1023 normal concrete 60 160267 806 1066 30 160533 709 295 45 160355 774 322 lightweight aggregate concrete 60 160267 806 336 78.9 sfrc a) sfrc b) normal concrete figure 4: failure mode page 4 table 3: failure modes and strength 61.45.5344.43.72 54.24.9838.21.96 41.84.6939.33.47 39.03.6130.21.85 29.83.7620.21.84 27.42.9420.11.29 fps=1.48(n/mm2) normal concrete (plain) w/c 60% fc(n/mm2)ft(n/mm2) fps=2.00(n/mm2)fps=1.11(n/mm2) lightweight aggregate concrete (plain) w/c 60% ft(n/mm2)fc(n/mm2)ft(n/mm2) ft(n/mm2) fps=3.24(n/mm2) normal concrete (sfrc) w/c 45% fc(n/mm2) fc(n/mm2)ft(n/mm2) fps=3.28(n/mm2)fps=2.97(n/mm2)fps=2.62(n/mm2) normal concrete (plain) w/c 45% fps=1.70(n/mm2)fps=2.06(n/mm2) fc(n/mm2)ft(n/mm2) fps=1.61(n/mm2) lightweight aggregate concrete (sfrc) w/c 30% lightweight aggregate concrete (plain) w/c 45% fc(n/mm2)ft(n/mm2) fps=4.53(n/mm2)fps=3.86(n/mm2)fps=4.16(n/mm2) fc(n/mm2) normal concrete (sfrc) w/c 30% fps=1.65(n/mm2) fps=2.53(n/mm2) lightweight aggregate concrete (sfrc) w/c 60% fps=2.59(n/mm2) ft(n/mm2) ft(n/mm2) ft(n/mm2) ft(n/mm2) fc(n/mm2) fps=2.35(n/mm2)fps=2.49(n/mm2) fc(n/mm2) fps=2.68(n/mm2) fps=1.76(n/mm2)fps=1.94(n/mm2) lightweight aggregate concrete (sfrc) w/c 45% fc(n/mm2) fps=2.24(n/mm2) fps=2.91(n/mm2) ft(n/mm2) fps=2.33(n/mm2)fps=2.24(n/mm2)fps=2.53(n/mm2) fps=2.75(n/mm2)fps=2.94(n/mm2) lightweight aggregate concrete (plain) w/c 30% fps=2.86(n/mm2) fps=3.43(n/mm2)fps=3.90(n/mm2)fps=3.79(n/mm2) normal concrete (plain) w/c 30% fps=3.30(n/mm2) fps=2.40(n/mm2) fc(n/mm2) fc(n/mm2) normal concrete (sfrc) w/c 60% fps=3.09(n/mm2) page 5 3. experimental results and discussion 3.1 failure under pure shearing stress failure modes of the test specimens are shown in the figure 4 for the specimens of plain concrete and the specimens of frc under pure shearing stress. table 3 gives failure modes sketched from tested specimens and the results of strength test. these photographs and sketches indicate that failure of plain concrete occurs vertically around middle of the specimen. these phenomenon implies the pure shearing failure occurs due to principal tensile stress. on the other hand, although the crack occurred under the maximum load, frc specimens were failed with several cracks. the steel fiber in failure section was not failed, those fibers were pulled out. additionally, the lightweight aggregate in failure section had been splitted, whereas the normal aggregate had hardly failed. 3.2 pure shearing strength the relationships between pure shearing strength and water-cement ratios are shown in figure 5. the pure shearing strength decreases as increase of water-cement ratio. the concrete with water-cement ratio of 30% has almost similar pure shearing strength between lightweight aggregate concrete and normal aggregate concrete. the pure shearing strength of lightweight aggregate concrete with water- cement ratio of 60% was approximately 60% of that of normal aggregate concrete. the strength of mortar is a little lower than strength of concrete. the aggregate in concrete influences on the pure shear strength and failure phenomenon. pure shearing strength of steel fiber reinforced concrete were 10%-20% higher than that of plain concrete. these results represents the strengthening effect of concrete by the steel fiber. capacity： 2mm displacement transducer 62mm capacity： 2mm displacement transducer 62mm figure 6: attachment of displacement transducer 1 1.5 2 2.5 3 3.5 4 4.5 1530456075 w/c(%) pure shearing strength(n/mm2) normal concrete lightweight aggregate concrete sfrc 1 1.5 2 2.5 3 3.5 4 4.5 1530456075 w/c(%) pure shearing strength(n/mm2) normal concrete lightweight aggregate concrete sfrc 1 1.5 2 2.5 3 3.5 4 4.5 1530456075 w/c(%) pure shearing strength(n/mm2) normal concrete lightweight aggregate concrete plain 1 1.5 2 2.5 3 3.5 4 4.5 1530456075 w/c(%) pure shearing strength(n/mm2) normal concrete lightweight aggregate concrete plain figure 5: pure shearing strength page 6 3.3 pure shearing behaviour in case of plain concrete having brittle failure, it is difficult to evaluate failure behaviour quantitatively. however, to obtain the failure behaviour of frc is relatively easy because of its ductility. therefore, this study is intended to evaluate behaviour before and after crack occurrence in the frc element under pure shearing stress. the displacement transducers (62 mm) were attached on the surface of the specimen as shown in figure 5. figure 7 shows the relationships between load and displacement in lightweight aggregate concrete element of frc. these figures represent that deformations before cracking were very small and were progressed with development of cracks. table 4 shows the area determined from load and displacement range of 0 and 2mm. the value of w/c=45% and 30% became 1.3 and 1.6 times greater than that of w/c = 60 %. 4. conclusions the pure shearing machine was developed in order to determine shearing strength of concrete element. a pure shearing test was conducted in order to obtain the fracture behaviour of various concrete, which include frc. the conclusions of this study are summarized as follows: 1) every failure mode was cleavage failure even in frc elements. 2) plain concrete and frc under pure shearing stress resulted in brittle failure and ductile failure, respectively. 3) the pure shearing strength of frc was higher than that of plain