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首页> 外文学位 >Laboratory testing of full-depth precast, prestressed concrete deck panels used in the Boone County IBRC accelerated bridge replacement project.
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Laboratory testing of full-depth precast, prestressed concrete deck panels used in the Boone County IBRC accelerated bridge replacement project.

机译：布恩县IBRC加速桥梁更换项目中使用的全深度预制预应力混凝土面板的实验室测试。

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摘要

As the United States highway infrastructure is in need of rehabilitation due to increasing traffic needs and structural inadequacies, use of precast concrete elements is increasing. Use of precast concrete systems provide various advantages, including minimizing traffic disruption, increasing the quality of the final product, and lowering life-cycle costs. Both the Federal Highway Administration and the Iowa Department of Transportation have recognized the benefits of using precast concrete elements in bridge construction to help reduce the duration of construction projects.;This thesis focuses on the laboratory testing of full-depth precast, prestressed concrete deck panels used in the construction of a continuous four-girder, three span bridge over Squaw Creek on 120th Street in Boone County, Iowa. Various laboratory tests were conducted on a single panel and on two panels connected by a closure pour. These tests ranged from determining physical properties of the panel (compressive strength and prestressing force), to determining the panel's response in various circumstances (moving with a crane, during field leveling, and under loading).;Tests were conducted to determine physical characteristics of a deck panel such as compressive strength and stress in the mild reinforcing due to prestressing. The average compressive strength of the concrete core samples was 7,600 psi, which exceeded the specified compressive strength of 5,000 psi. Prestressing strands in one post-tensioning channel were cut to determine the amount of stress in each strand due to prestressing. Of the six bars instrumented, five were found to have a stress lower than that expected from the initial prestressing force.;Strains in the mild reinforcing bars were monitored in the laboratory while a panel was lifted with a crane. Two different strap configurations were used to lift the panel; the first configuration used four lifting straps, and the second used two lifting straps. Results from these tests showed the strap configuration did not have a significant effect on the strain induced in the mild reinforcing bars. The total strain (measured plus induced due to prestressing) of a bar used during these tests had a maximum value of 70%. Panels were also leveled in the laboratory to monitor the strains in the mild reinforcement. Bars were found to utilize 86% of the yield strain during this process.;Service load tests were performed on both a single panel and two panels connected by a closure pour. Through these tests it was determined that the deck panels had adequate strength under service loads.;Both a single panel and two connected panels were tested to failure. Ultimate load tests included testing a single panel and two connected panels to a flexural failure, and testing the connected panels to a punching shear failure. The connected panels also experienced a combination punching shear and flexure failure during one test. Failures during each test occurred at loads much greater than the service loads the panels are expected to experience in the field.
机译：由于交通需求的增加和结构上的不足，美国公路基础设施需要修复，因此预制混凝土构件的使用正在增加。预制混凝土系统的使用具有多种优势，包括最大程度地减少交通中断，提高最终产品的质量以及降低生命周期成本。联邦公路管理局和爱荷华州交通运输部都认识到在桥梁施工中使用预制混凝土元素的好处，以减少建设项目的工期。本论文着重于对全深度预制，预应力混凝土面板的实验室测试用于在爱荷华州布恩县第120街的Squaw Creek上建造连续四梁，三跨度的桥梁。在一块面板上和在通过封闭浇口连接的两个面板上进行了各种实验室测试。这些测试的范围从确定面板的物理特性（抗压强度和预应力）到确定面板在各种情况下的响应（使用起重机移动，在现场找平期间以及在负载下）。甲板面板，如在预应力作用下的轻度增强中的抗压强度和应力。混凝土芯样品的平均抗压强度为7,600 psi，超过了规定的5,000 psi的抗压强度。切开一个后张紧通道中的预应力钢绞线，以确定每根钢绞线由于预应力而产生的应力量。仪器中的六根钢筋中，发现有五根应力低于初始预应力预期。在实验室中，用起重机吊起一块面板时，对轻度钢筋的应变进行了监测。两种不同的皮带配置被用来提起面板。第一种配置使用了四个提升带，第二种配置使用了两个提升带。这些测试的结果表明，带子的配置对轻度钢筋中引起的应变没有显着影响。在这些测试中使用的钢筋的总应变（测得的应力加上由于预应力而引起的最大值）的最大值为70％。在实验室中还对面板进行了调平，以监测轻度增强中的应变。发现在此过程中，钢筋利用了86％的屈服应变。在单个面板和通过封闭浇注连接的两个面板上均进行了工作负荷测试。通过这些测试，可以确定甲板面板在使用载荷下具有足够的强度。单个面板和两个连接面板都经过了测试以进行故障测试。最终的载荷测试包括测试单个面板和两个连接的面板的弯曲破坏，以及测试连接的面板的冲剪破坏。在一个测试中，连接的面板也经历了冲剪和弯曲破坏的组合。每次测试期间发生的故障所造成的负载要远远大于面板在现场所承受的服务负载。

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  • 作者

    Bowers, Ryan Paul.;

  • 作者单位

    Iowa State University.;

  • 授予单位 Iowa State University.;
  • 学科 Engineering Civil.
  • 学位 M.S.
  • 年度 2009
  • 页码 125 p.
  • 总页数 125
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 建筑科学;
  • 关键词

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