Improving Developmental Characteristics of Reinforcing Bars

9402563达尔文这项研究代表了美国四十多年来对钢筋几何形状的首次重大重估的继续。该研究利用了目前的研究成果来开发新的变形模式，以优化棒材的发育特征。试验用于评估新钢筋（有或没有环氧涂层）对粘结性能的改善，以及对钢筋、覆盖层和钢筋间距的影响。并对新筋在循环荷载作用下的粘结特性进行了评价。断裂力学概念以及载荷和阻力因素设计技术用于开发合理的而不是经验的设计程序。这项研究是与钢筋生产商、制造商、涂料应用商和环氧粉末制造商一起进行的。重点放在改进的钢筋变形模式，是成本效益和实用。

9402563 Darwin The research represents the continuation of the first major revaluation of reinforcing bar geometry in the United States in over forty years. The study capitalizes on current research efforts to develop new deformation patterns that optimize bar development characteristics. Tests are used to evaluate the improvement in bond provided by the new bars, both with and without epoxy coating, as a function of confining reinforcement, cover, and bar spacing. The bond characteristics of the new bars also evaluated under cyclic loading. Fracture mechanics concepts and load and resistance factor design techniques are used to develop rational, rather than empirical, design procedures. The research is carried out in conjunction with reinforcing bar producers, fabricators, coating applicators, and epoxy powder manufacturers. Emphasis is placed on improved bar deformation patterns that are cost effective and practical.