Raw data and supplementary material of the second inter-laboratory testing program (RRT2, self-healing concrete with MgO-based expansive minerals) of the EU COST action SARCOS

This data is the result of a collaboration of scientists working on the development of self-healing concrete within the framework of the European Cooperation in Science and Technology (COST) Action “Self-healing as preventive repair of concrete structures” SARCOS CA15202. In the framework of SARCOS 6 inter-laboratory testing programs are being executed to investigate possible standard test methods for self-healing concrete, each of the testing programs focusing on a different self-healing technique:<br> (1) Concrete with mineral additions,<br> (2) Concrete with the addition of magnesium oxide,<br> (3) Concrete enhanced with crystalline admixtures,<br> (4) High performance fibre reinforced concrete enhanced with crystalline admixtures,<br> (5) Concrete with preplaced macrocapsules containing polymeric healing agent, and<br> (6) Concrete with encapsulated bacteria. The data which can be found here have been obtained in the inter-laboratory testing program 2. In total, 9 labs from seven different European countries participated in this inter-laboratory test: University of Cambridge (UK), Cardiff University (UK), Politecnico di Torino (Italy), Institute for Construction Sciences Eduardo Torroja (IETCC-CSIC) (Spain), University of Córdoba (Spain), Kaunas University of Technology (Lithuania), Riga Technical University (Latvia), Cracow University of Technology (Poland), National Centre for Scientific Research “Demokritos” -NCSRD (Greece). All specimens were cast at Riga Technical University and were then distributed to different labs, where they were tested. The methodology used is based on water permeability tests, water capillary absorption tests, and crack width measurements, comparing their performance to evaluate self-healing. The inter-laboratory test was split up in two parts. Fibre-reinforced concrete prisms with and without mineral additions were cracked in a three-point bending test with a passive crack-width control and studied in a capillary water absorption test. Concurrently, fibre-reinforced concrete discs with and without mineral additions were cracked using a splitting test-setup able to produce tensile cracks, and subsequently exposed to water permeability test to evaluate the water flow going through the cracks. After initial pre-cracking, all the samples were stored submerged in water to promote the self-healing reactions during three predefined periods of 1, 3 and 6 months. The same samples were tested before healing, and at the above-mentioned three monitoring periods to monitor the healing process. Crack widths were observed through optical microscopy and the crack mouth healing calculated thereafter. A final complementary test was also done to assess the durability of the cracked and self-healed specimens through chloride ingress tests.本数据集为欧洲科学与技术合作组织（European Cooperation in Science and Technology，COST）行动计划“作为混凝土结构预防性修复的自修复技术（self-healing concrete）”SARCOS CA15202框架下，致力于自修复混凝土研发的科研团队合作成果。 在SARCOS框架内，共开展6项实验室间测试计划，以探究自修复混凝土的标准化测试方法，每项计划聚焦一种不同的自修复技术： (1) 掺合矿物外加剂的混凝土 (2) 掺加氧化镁的混凝土 (3) 掺加晶体外加剂的改性混凝土 (4) 掺加晶体外加剂的高性能纤维增强混凝土 (5) 内置含高分子修复剂的大尺寸预放置胶囊的混凝土 (6) 封装有细菌的混凝土 本数据集的数据来自第2项实验室间测试计划。本次测试共有来自7个欧洲国家的9家实验室参与：剑桥大学（英国）、卡迪夫大学（英国）、都灵理工大学（意大利）、爱德华多·托罗亚建筑科学研究所（IETCC-CSIC，西班牙）、科尔多瓦大学（西班牙）、考纳斯理工大学（立陶宛）、里加工业大学（拉脱维亚）、克拉科夫理工大学（波兰）、国家科学研究“德谟克利特”中心-NCSRD（希腊）。 所有试件均在里加工业大学浇筑，随后分发至各合作实验室开展测试。本次测试采用的方法基于透水试验（water permeability tests）、毛细吸水试验（water capillary absorption tests）以及裂缝宽度测量（crack width measurements），通过对比试件性能以评估自修复效果。 本次实验室间测试分为两个部分：其一，对掺加与未掺加矿物外加剂的纤维增强混凝土棱柱体试件，采用被动裂缝宽度控制的三点弯曲试验（three-point bending test with a passive crack-width control）使其产生裂缝，并开展毛细吸水试验；其二，对掺加与未掺加矿物外加剂的纤维增强混凝土圆盘试件，采用可产生拉伸裂缝的劈裂试验装置（splitting test-setup able to produce tensile cracks）使其开裂，随后开展透水试验以评估裂缝处的水流情况。 试件在初始预开裂后，被置于水下养护，分别在1、3和6个月三个预设周期内促进自修复反应。所有试件均在自修复前以及上述三个监测周期节点进行测试，以追踪自修复进程。裂缝宽度通过光学显微镜（optical microscopy）观测，并据此计算裂缝口修复程度。 此外还开展了一项补充试验，通过氯离子侵入试验（chloride ingress tests）评估开裂并经自修复后的试件的耐久性。