ABSTRACT Development and commercialization of self-healing concrete is hampered due to a lack of standardized test methods. Six inter-laboratory testing programs are being executed by the EU COST action SARCOS, each focusing on test methods for a specific self-healing technique. This paper reports on the comparison of tests for mortar and concrete specimens with polyurethane encapsulated in glass macrocapsules. First, the pre-cracking method was analysed: mortar specimens were cracked in a three-point bending test followed by an active crack width control technique to restrain the crack width up to a predefined value, while the concrete specimens were cracked in a three-point bending setup with a displacement-controlled loading system. Microscopic measurements showed that with the application of the active control technique almost all crack widths were within a narrow predefined range. Conversely, for the concrete specimens the variation on the crack width was higher. After pre-cracking, the self-healing effect was characterized via durability tests: the mortar specimens were tested in a water permeability test and the spread of the healing agent on the crack surfaces was determined, while the concrete specimens were subjected to two capillary water absorption tests, executed with a different type of waterproofing applied on the zone around the crack. The quality of the waterproofing was found to be important, as different results were obtained in each absorption test. For the permeability test, 4 out of 6 labs obtained a comparable flow rate for the reference specimens, yet all 6 labs obtained comparable sealing efficiencies, highlighting the potential for further standardization.

中文翻译：

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满足自愈混凝土测试方法标准化的需要：对具有大胶囊的混凝土的实验室间研究

摘要 由于缺乏标准化的测试方法，自愈混凝土的开发和商业化受到阻碍。欧盟成本行动 SARCOS 正在执行六个实验室间测试计划，每个计划都侧重于特定自愈技术的测试方法。本文报告了砂浆和混凝土试样与封装在玻璃大胶囊中的聚氨酯的试验比较。首先，分析了预开裂方法：砂浆试件在三点弯曲试验中开裂，然后采用主动裂缝宽度控制技术将裂缝宽度限制到预定值，而混凝土试件在三点弯曲试验中开裂。带有位移控制加载系统的点弯曲设置。显微测量表明，随着主动控制技术的应用，几乎所有的裂纹宽度都在一个狭窄的预定范围内。相反，对于混凝土试件，裂缝宽度的变化更大。预开裂后，通过耐久性试验表征自愈合效果：砂浆试件进行透水性试验，确定愈合剂在裂缝表面的扩散，而混凝土试件经受两次毛细管水吸收测试，在裂缝周围区域应用不同类型的防水材料。发现防水质量很重要，因为在每次吸收测试中都获得了不同的结果。对于渗透性测试，6 个实验室中有 4 个获得了与参考样本相当的流速，