Transport- und Löseprozesse im Gesteinskorn beim Ablauf einer AKR sowie Grundlagenuntersuchungen an AKR-Gelen

AKR 过程中岩石颗粒的传输和溶解过程以及 AKR 凝胶的基础研究

基本信息

批准号：
202323396
负责人：
Professor Dr.-Ing. Horst-Michael Ludwig
金额：
--
依托单位：
F. A. Finger-Institut für Baustoffkunde
依托单位国家：
德国
项目类别：
Research Units
财政年份：
2011
资助国家：
德国
起止时间：
2010-12-31 至 2018-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/202323396?language=en
关键词：
Transport und seprozesse im Gesteinskorn

项目摘要

Within the research group 1498, sub-project 5 shall pursue the following 6 objectives: 1. It is to clarify, to what extent a mechanical pre-damage and cyclic loading can drive a critical amount of NaCl solu-tion into concrete. 2. The influence of processing-related micro cracks in aggregate grains shall be verified for another rock type. 3. By means of a nanoCT-system, the volume of ASR-gel formed in concrete prisms during the FIB cyclic climate storage test method shall be determined. The main ob-jective here is to elucidate, if there is a critical amount of gel that, if exceeded, will cause concrete deterioration as a function of the correspondingly measured expansions and the composition of the gels. This information is of particular interest for the modelling in sub-project 3. 4. Swelling pressures of synthetic ASR-gels will be measured as a function of their composition, water content and amount. With respect to its composition, besides the Ca-content it is the Na-content that is of particular interest here, because it is affected by an external supply of NaCl. Furthermore it shall be clarified, if the swelling ability of a gel is preserved below a certain content of water and what amount of gel is necessary to produce a deleterious pressure. In addition, the role of SiO2 dissolution for the swelling process will be investigated by measuring swelling pressures of rock powders subjected to artificial pore solutions. For a thermodynamic modelling, also solubility products and enthalpies of reaction will be determined for synthetic ASR-gels. The obtained data are of great importance for modelling the ASR damaging process within the scope of sub-project 3. 5. As a function of temperature and NaCl concentration, SiO2 dissolution rates shall be determined. For that purpose, the dissolution experiments already started in funding period 1 will be continued and extended, for what two more aggregates (crushed gravel, rhyolite) will be used among other extensions. By running an SEM/EBSD-analysis, by what size and deformation of single quartz crystals can be determined spatially resolved, quartz will be investigated before and after the dissolution attack. It is of major interest to learn what influence the dissolution attack has on the quartz microstructure and what link between microstructure and dissolution rate exists respectively. 6. By means of an image analysis software, concrete thin sections shall be used for a more quantitative instead qualitative and describing appraisal. The main focus is the detection of cracks to characterize the degree of the cracking more quantitatively (number, width, lengths and area of the cracks) and by deriving an appropriate specific value to compare the degree of damage caused by ASR for different concretes.

在研究小组1498中，子项目5应追求以下6个目标：1。澄清机械预损伤和循环负载在多大程度上可以将关键量的NACL溶液推向混凝土。 2。对于另一种岩石类型，应验证与加工相关的微裂纹的影响。 3。通过纳米精系统，应确定在FIB环状气候存储测试方法中混凝土棱镜形成的ASR-GEL的体积。如果有关键的凝胶，如果超过的凝胶将导致具体的劣化，则这里的主要原理是阐明凝胶的量，这是相应测量的膨胀和凝胶组成的函数。该信息对于子项目中的建模特别感兴趣。4。合成ASR凝胶的肿胀压力将作为其成分，水含量和量的函数进行测量。关于其组成，除了CA包含外，这里特别感兴趣的是NA含量，因为它受到NACL的外部供应的影响。此外，如果将凝胶的肿胀能力保留在一定的水含量下，以及产生有害压力的必要量，则应澄清它。此外，SIO2溶解在肿胀过程中的作用将通过测量受人工孔溶液的岩石粉末的肿胀压力来研究。对于热力学建模，还将确定用于合成ASR凝胶的溶解性产物和反应的焓。获得的数据对于在子项目范围内建模ASR损坏过程非常重要，因此应确定SIO2溶解速率作为温度和NaCl浓度的函数。为此，将继续并扩展资金1中已经开始的溶出实验，因为在其他扩展中将使用两个骨料（碎碎石，节奏）。通过运行SEM/EBSD分析，可以通过空间分辨单个石英晶体的大小和变形，在溶解攻击之前和之后将研究石英。了解溶解攻击对石英微结构的影响以及微观结构与溶解速率之间的联系是主要的兴趣。 6。通过图像分析软件，混凝土薄部分应用于更定量的定性和描述评估。主要的重点是检测裂纹以更定量（数量，宽度，长度和裂纹面积），并通过得出适当的特定值以比较ASR造成的损害程度，以更定量地表征裂纹的程度。