权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Development of Method for Measuring Residual Expansion of Cores Taken from Concrete Structures Affected by ASR

开发测量受 ASR 影响的混凝土结构中的芯材残余膨胀的方法

基本信息

批准号：
18560451
负责人：
KURODA Tamotsu
金额：
$ 1.98万
依托单位：
Tottori University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18560451/
关键词：
Concrete Alkali-Silica Reaction Residual Expansion Accelerated test Durability Maintenance

项目摘要

This study developed an accelerated test method to judge the residual expansivity of concrete affected by ASR at the early stage. The current method, which measures the residual expansion of the concrete core, does not correspond to environments where seawater deicing salts, etc. penetrate concrete and promote ASR. Therefore, we addressed this problem by examining an accelerated test method with which the concrete cores were immersed in an NaOH or NaCl solution.The following results were obtained:1. Effect of Storage TemperatureASR expansion became small when the storage temperature rose excessively in the low solution concentration, but it increased with rising storage temperature in the high solution concentration.2. Effects of Kind of Solution and its ConcentrationASR expansion became small when the solution concentration rose excessively at low storage temperature, but it increased with rising solution concentration at high storage temperature. The core immersed in the NaOH solution generated larger expansion at the early stage than the core in the NaCl solution.3. Effect of Initial Alkali Content of ConcreteASR expansion of the core with a higher initial alkali content before immersion in the NaOH solution was larger.4. Effect of Degree of Concrete Deterioration due to ASRFor the concrete immersed in the NaOH solution, when the deterioration of the concrete had progressed more before the start of the test, the ASR expansion of the core after the start of the test became smaller.5. Proposal of Accelerated Curing ConditionBased on the results obtained within the range of this study, an acclerated curing condition was proposed to judge the residual expansivity of concrete at the early stage.

本研究开发了一种加速试验方法来判断早期ASR对混凝土残余膨胀率的影响。目前测量混凝土芯残余膨胀的方法不适合海水除冰盐等渗透混凝土并促进 ASR 的环境。因此，我们通过研究一种将混凝土芯材浸入NaOH或NaCl溶液中的加速试验方法来解决这个问题。得到了以下结果： 1．储存温度的影响在低浓度溶液中，当储存温度过高时，ASR膨胀变小；而在高浓度溶液中，随着储存温度的升高，ASR膨胀增大。 2．溶液种类及其浓度的影响在低储存温度下，当溶液浓度过度升高时，ASR膨胀变小，但在高储存温度下，随着溶液浓度的升高，ASR膨胀增大。浸泡在NaOH溶液中的岩心比浸泡在NaCl溶液中的岩心早期产生了更大的膨胀。 3．混凝土初始碱含量的影响初始碱含量较高的核心在NaOH溶液中浸泡前的ASR膨胀较大。 4． ASR对混凝土劣化程度的影响对于浸泡在NaOH溶液中的混凝土，当试验开始前混凝土的劣化进展较多时，试验开始后核心的ASR膨胀变小。 5．加速养护条件的建议根据本研究范围内获得的结果，提出了加速养护条件来判断混凝土早期的残余膨胀率。