Proposal for Durability Verification Technique of Concrete from the Viewpoing of Deteriorated Depth Under Freezing and Thawing Action

从冻融劣化深度角度提出混凝土耐久性验证技术

基本信息

批准号：
14550467
负责人：
SHOYA Masami
金额：
$ 2.05万
依托单位：
Hachinohe Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

项目摘要

The frost resistance verification of concrete in JSCE has been conducted with the relative dynamic modulus of elasticity of specimen. However, the technique of frost resistance verification with the relative dynamic modulus of elasticity is made using the small specimen in limited testing conditions, and it will be not a rational technique on the design of actual concrete structure. Therefore, it may be said that the technique is similar to the conventional method to restrict the water cement ratio of concrete.On the other side, JSCE standard specification for maintenance of concrete structures enacted in 2001, specified that frost damage in concrete structure should be rationally predicted based on the deteriorated depth due to freezing and thawing action.This study aims at the basic proposal for durability verification technique on damage of concrete from deteriorated depth focusing the surface layer of concrete structures under freezing and thawing action. The research results are summarized as follows.1.Evaluation of Frost Damage on Concrete by Using Improved Pull-off MethodFrost damages of various concretes due to freezing and thawing action, were evaluated by improved pull-off method. The assessing method for frost damage of concrete with the deteriorated depth using measured pull-off strength in the cover concrete was investigated in various test conditions. In this study, the tests were conducted changing the water cement ratio, the air content, the freezing and thawing procedure, exposed area, age of concrete and so on.2.Proposal of Durability Verification Technique of Concrete by Improved Pull-off MethodThe fundamental idea for the durability verification technique is base on deteriorated depth due to freezing and thawing action judging from the tensile strength at the distance from the concrete surface by using improved pull-off method. A new verification equation using deteriorated depth of concrete was tentatively proposed.

JSCE中混凝土的霜耐性验证是用样品的弹性的相对动态模量进行的。但是，使用小样本在有限的测试条件下使用小样本制成了使用相对动态模量进行霜冻抗性验证的技术，这将不是实际混凝土结构设计的合理技术。 Therefore, it may be said that the technique is similar to the conventional method to restrict the water cement ratio of concrete.On the other side, JSCE standard specification for maintenance of concrete structures enacted in 2001, specified that frost damage in concrete structure should be rationally predicted based on the deteriorated depth due to freezing and thawing action.This study aims at the basic proposal for durability verification technique on damage of从冰冻和解冻作用下聚焦混凝土结构表面的深度的混凝土。研究结果总结如下。1。通过使用改进的冻结和解冻作用引起的各种混凝土的拉力冻伤损害对混凝土的评估进行评估，通过改进的拉力方法评估。在各种测试条件下，研究了使用测量的推拉强度在盖子中使用测得的拉力强度的混凝土霜损伤的评估方法。在这项研究中，进行了测试，改变了水泥的比率，空气含量，冻结和解冻程序，暴露面积，混凝土年龄等。2。耐久性验证技术通过改进的拉力方法的耐久性验证技术的能力验证方法，方法是通过耐用性验证的基础，从而依靠距离的距离和距离的距离，从而避免了距离的距离，从而避免了距离的距离，从而避免了距离的距离，而距离距离距离距离距离距离距离距离距离距离距离，并且可以判断出thawawawawawawape verne的距离，而距离距离距离距离距离距离紧密的距离和the thawawawawawaps verne则是避免行动。改进的拉力方法。暂时提出了使用混凝土深度变质深度的新验证方程。