英语翻译2.2.Test schemeTwo types of strengthened beams,i.e.a single layer strengthening and a double layer strengthening,and three lengths of CFRP,i.e.0.6,1.2 and 1.6 m are considered.Fibres are used at the bottom of beams and are shown in Fig.3(

英语翻译2.2.Test schemeTwo types of strengthened beams,i.e.a single layer strengthening and a double layer strengthening,and three lengths of CFRP,i.e.0.6,1.2 and 1.6 m are considered.Fibres are used at the bottom of beams and are shown in Fig.3(
英语翻译
2.2.Test scheme
Two types of strengthened beams,i.e.a single layer strengthening and a double layer strengthening,and three lengths of CFRP,i.e.0.6,1.2 and 1.6 m are considered.Fibres are used at the bottom of beams and are shown in Fig.3(a),represented by B11,B12 and B13,respectively for single layers.In the second type of beam,1.6 m length of CFRP is used as a first layer for all the beams,and then three lengths of CFRP,i.e.0.6,1.2 and 1.6 m,are used as the second layer of strengthening,shown in Fig.3(d)–(f) and represented by B21,B22 and B23,respectively.Due to symmetry only half portions of the beams are displayed.
The beams are subjected to a four-point static load up to failure with an increment of 3 kN,as illustrated in Fig.2(a).
3.Test results
3.1.Stiffness of strengthened beams
Fig.4 shows the load versus mid-span deflection curves of strengthened RC beams.It can be seen from Fig.4 that deflections of all the strengthened beams are reduced under the same load compared with the reference beam,which indicates that CFRP can significantly improve stiffness of strengthened RC beams.Variations of the stiffness of beams are not evident prior to tensile cracks appearing on the strengthened beam.The stiffness of the beam then increases with the increase of thickness and length of CFRP after cracking has happened.Fig.4(a) shows longer CFRP can efficiently restrain the crack development than shorter ones,
Fig.4(b) shows bi-layer strengthening CFRP can efficiently restrain the crack development than uni-layer strengthening ones.Test results demonstrate that the length and thickness of CFRP influence crack patterns and ultimate failure modes of beams.CFRP is adhered only in the pure bending part of beam B11.When beam B11 is loaded,cracks appear in the end parts of fibres and propagate along at angle of 45\3 with the beam axis.Strengthening effect is not obvious because shear failure happens in this beam,which fails even earlier than the reference beam (RB) as indicated in Fig.4(a).It is the quality problem of the construction process that influences the strength of beam B13 and results in failure of this beam earlier than beam B12 as shown in Fig.4(a).(In the following
Figures RB represents reference beam.)
3.2.Ductility
Moment versus curvature curves give the macromechanical properties of members and are reflection of the member ductility.It can be seen from Fig.5 that curvatures increase slowly with the increase of moment and
retain the linear relationship prior to cracking of the tensile concrete,but increase rapidly after the concrete cracked.The speed of curvature increase of the reference beam is far faster than that of the strengthened beams.It can be seen from Fig.5(b) that there is not much difference
among curvature curves when two layers of CFRP are used to strengthen beams.The length of the second strengthening CFRP layer has little influence on curvature.

英语翻译2.2.Test schemeTwo types of strengthened beams,i.e.a single layer strengthening and a double layer strengthening,and three lengths of CFRP,i.e.0.6,1.2 and 1.6 m are considered.Fibres are used at the bottom of beams and are shown in Fig.3(
第2.2条.试验方案
两种类型,即加强了梁单层加强和一个双层加强,三个长度,即碳纤维.1 / 10时,1.2到1.6米也会被考虑到.纤维的底部使用梁和列图.3(a),表现为B11,B12,分别用单一的层次.在另一种梁、1.6米长度的碳纤维布作为第一层为所有的光束,然后三个长度,即碳纤维.1 / 10时,1.2到1.6米,用作第二层强化,显示在图3(d)-(f)和B21为代表的B22和B23,分别使用.由于只有一半的部分对称梁被显示.
这些箱梁受到四点静载荷到失败,增加了3 kN,图2(a).3.试验结果
31.加强了梁刚度
图4显示了负荷与mid-span加强了钢筋混凝土梁的挠度曲线.这样看来,图四、加强梁的挠度的降低在同样的载荷条件下参考光相比,这表明可显著提高碳纤维布加固钢筋混凝土梁加强了刚度.梁刚度的变化不明显的拉伸前出现在加固构件裂缝.然后光束的刚度增加而增加碳纤维布的厚度和长度后发生了什幺事.开裂图4(a)显示了碳纤维加固技术能够有效地抑制裂缝发展较短,图4(b)表明碳纤维布可以有效地抑制加强破坏裂纹发展uni-layer加强的.测试结果表明,长度和碳纤维布的厚度和最终影响裂缝形态结构的失效模式.只有在附着加固梁B11纯弯的一部分.这是质量问题的建构过程中的影响.3.2.延性
macromechanical曲率与性能曲线反映延展性.这样看来图5,增加缓慢增加板材
保留的线性关系破裂前拉伸混凝土,但快速增长在混凝土断裂.曲率的速度的增加速度更快的参考光比加强横梁.这样看来图5(b),并没有太大区别
在曲率曲线两层加固时用来加强横梁.第二加强的长度的影响较小,对碳纤维布层弯曲而造成的.只有这样子了 好有难度哦

2.2。试验计划
两种类型的加固梁，即加强和单层双层加强，三个碳纤维长度，即0.6，1.2和1.6米的考虑。纤维被