泵站中钢筋混凝土梁加固的变形计算

基于试验研究资料的分析,对于大型泵站中具有合适锚固的CFRP片材加固受弯构件变形计算方法进行研究,认为加固梁的弯矩-曲率曲线符合三线型规律（混凝土开裂前,混凝土开裂后,受拉钢筋屈服后）.通过解析分析,得到试验梁在通常两点加载条件下的任一加载阶段的弯矩及变形计算公式,与相应条件试验梁的试验测试结果吻合,可为泵站工程设计规程的制定提供参考。     

钢筋混凝土约束梁斜向贴CFRP抗剪加固研究

通过对 1 2根承受集中荷载作用下破坏后补好的矩形截面钢筋混凝土约束梁斜向贴 CFRP抗剪加固试验结果的分析 ,提出了 CFRP有效应变的概念 ,得出了随角度变化 CFRP抗剪承载力计算公式     

CFRP筋在活性粉末混凝土中的锚固性能

针对碳纤维增强塑料CFRP(Carbon Fiber Reinforced Polymer/Plastics)作为预应力筋或拉索时的锚固问题,提出了以活性粉末混凝土RPC(Reactive Powder Concrete)作为粘结介质的粘结式锚具.静载试验详细研究了CFRP筋的表面形状、锚固长度、根数和间距以及套筒内壁倾角等参数的变化对RPC的锚固性能的影响.试验结果表明,CFRP筋的表面形状对锚固性能的影响最为显著;对于抗拉强度不大于3 000 MPa的表面压纹CFRP筋,其临界锚固长度约为20倍CFRP筋直径;双根压纹CFRP筋锚固时的合理筋间距不宜小于1倍CFRP筋直径;本文提出的平均粘结强度和临界锚固长度计算公式具有较好的适用性.     

碳纤维增强混凝土受弯构件正截面承载力设计

提出碳纤维筋的抗弯设计强度的确定方法 ,阐述了碳纤维筋增强混凝土受弯构件的设计方法和设计所需的注意事项     

粘贴CFRP与粘贴钢板复合加固混凝土梁正截面承载力分析

本文首先提出采用粘贴CFRP与粘贴钢板复合加固以提高混凝土受弯构件的正截面承载力,利用弹塑性力学的基本原理,对复合加固混凝土梁的正截面承载力进行理论分析和推导.建立了实用的理论计算公式,理论计算结果与试验数据符合较好.     

Mechanical Properties of Concrete Cylinders Confined with CFRP Sheets Subjected to Axial Compression

Based on Drucker-Prager criterion with non-associated flow rule, numerical analysis of mechanical properties of concrete cylinders were carried out by using non-linear finite element method. The effect caused by various parameters such as wrap thickness, fiber orientation and concrete strength on axial mechanical properties of concrete cylinders is discussed. The results show that the results calculated by non-associated flow rule conform to that in the test. It is demonstrated that there is significant enhancement both in compressive strength and ductility of cylinders with the increase of wrap thickness. Moreover, the gain in axial compressive strength is observed to be higher for lower strength concrete and be highest in the cylinders wrapped with the hoop orientation.     

预应力碳纤维布加固混凝土构件

本文主要论述预应力碳纤维布加固混凝土构件技术,介绍了预应力碳纤维布加固技术产生的背景和发展情况,着重叙述了该技术相对于传统粘贴碳纤维布加固方法在技术方面的优势和现行的预应力碳纤维方法加固混凝土构件施工工艺。     

碳纤维增强聚合物 重组竹复合材的弯曲力学性能

重组竹已广泛应用于室内高档装饰、园林景观、室外防腐地板等领域,但重组竹的弹性模量比较小,为钢材的1/7~1/5,应用于建筑领域时难以充分发挥其自身高强度的特性。针对重组竹刚度较小的问题,提出一种重组竹板和碳纤维增强聚合物(CFRP)厚板嵌合粘接的新型重组竹复合材料,采用三点弯曲试验和有限元仿真方法,对CFRP 重组竹复合试件的失效模式、荷载 位移关系、应变曲线、胶层界面剥离影响等进行了研究。结果表明:重组竹试件失效模式是跨中位置处拉伸区域竹纤维断裂,且出现若干水平分层破坏,CFRP 重组竹复合试件的失效模式是CFRP与重组竹层间胶层出现大面积剥离;CFRP 重组竹复合试件的变形过程分为线弹性阶段和界面破坏阶段;CFRP可以明显提高重组竹梁的弹性模量和静曲强度,复合试件弹性模量是重组竹试件的2.33~2.94倍,静曲强度是重组竹试件的1.49~1.58倍;胶层界面剥离是CFRP 重组竹复合试件失效的重要因素,胶层界面剥离对复合试件的应变分布和挠度都有较大影响,完全剥离后试件的挠度是未剥离时的3.09倍。     

Bond properties of CFRP-high performance concrete subjected to freeze-thaw cycles

通过双面剪切试验,研究了冻融环境下CFRP-高性能混凝土界面粘结性能的发展规律。对比分析了未经冻融和经历25、50、100、150、200及300次冻融循环作用试件的破坏特征、剪应变分布、荷载滑移曲线、粘结承载力以及粘结破坏机理。结果表明,所有试件的界面破坏均发生在混凝土表层内,但随着冻融循环次数的增加,破坏界面有向胶层发展的趋势;经受冻融循环次数较少时(25、50次),界面的粘结强度、刚度及开裂荷载的变化不明显,甚至略微提高;但随着冻融循环次数的进一步增加,界面粘结性能有明显的变化,界面粘结强度、端部滑移量减小,刚度退化,初始开裂荷载水平降低,非线性特征增强。粘结极限承载力与混凝土立方体抗压强度均随冻融循环次数的增长存在先提高后下降的趋势,混凝土强度变化是界面粘结性能变化的最重要因素。     

Reliability Analysis of Reinforced Concrete Beams Strengthened with CFRP Sheets

The uniaxial load tests were conducted to investigate the material behavior of CFRP sheets. The results show that the probability distribution of CFRP tensile strength can be described by the three-parameter Weibull distribution. The design formulae for determining flexural capacity of reinforced concrete strengthened with CFRP sheet are proposed. The Monte Carlo procedure was applied to simulate the flexural capacity of reinforced concrete strengthened with CFRP sheet. By using the JC method, the reliability index was calculated based on the statistics of flexural capacity and load effect. After the analysis of the effect of the partial factor of CFRP sheet on the reliability index, the results reveal that the reliability index of all design points are the most close to target reliability index overall when the partial factor of CFRP sheet is 1.25,and in this condition the reliability index of three flexural failure modes achieve the target reliability index respectively. Therefore, the partial factor is suggested to be 1.25, which meets the requirement of reliability design.