Evaluation of Self-Healing Efficiency of Microcapsule-Based Self-Healing Cementitious Composites Based on Acoustic Emission Wenfeng Hao 1,* , Hao Hao 2 , Humaira Kanwal 2 and Shiping Jiang 2,* 1 College of Mechanical Engineering, Yangzhou University, Yangzhou, 225127, China 2 Faculty of Civil Engineering and Mechanics, Jiangsu University, Zhenjiang, 212013, China * Corresponding Authors: Wenfeng Hao. Email: hwf@yzu.edu.cn; Shiping Jiang. Email: spjiangvip@126.com Received: 16 May 2022 Accepted: 20 June 2022 ABSTRACT Microcapsule self-healing technology is one of the effective methods to solve the durability problem of cement- based composites. The evaluation method of the self-healing efficiency of microcapsule self-healing cement-based composites is one of the difficulties that limits the self-healing technology. This paper attempts to characterize the self-healing efficiency of microcapsule self-healing cement-based composites by acoustic emission (AE) para- meters, which provides a reference for the evaluation of microcapsule self-healing technology. Firstly, a kind of self-healing microcapsules were prepared, and the microcapsules were added into the cement-based composites to prepare the compression samples. Then, the specimen with certain pre damage was obtained by compression test. Secondly, the damaged samples were divided into two groups. One group was directly used for compression tests to obtain the damage failure process. The other group was put into water for healing for 30 days, and then compression tests were carried out to study the influence of self-healing on the compression failure process. Dur- ing the experiments, the AE signals were collected and the AE characteristics were extracted for the evaluation of self-healing efficiency. The results show that the compression pre damage test can trigger the microcapsule, and the compression strength of the self-healing sample is improved. The failure mechanism of microcapsule self- healing cement-based composites can be revealed by the AE parameters during compression, and the self-healing efficiency can be quantitatively characterized by AE hits. The research results of this paper provide experimental reference and technical support for the mechanical property test and healing efficiency evaluation of microcapsule self-healing cement-based composites. KEYWORDS Self-healing efficiency; cementitious composites; microcapsules; acoustic emission; compressive property 1 Introduction Cement-based composites are one of the most widely used materials in civil engineering. However, due to the long service time and changeable service environment, the durability of cement-based composites has attracted much attention. With the development of self-healing microcapsule technology, microcapsule self- healing cement-based composites have developed rapidly, making it a hot and difficult point in the field of new materials in civil engineering [1–6]. In particular, the lack of effective self-healing effect evaluation methods has greatly limited the design of self-healing cement-based materials. This work is licensed under a Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. DOI: 10.32604/jrm.2022.023795 ARTICLE ech T Press Science