Abstract To reduce the secondary lining concrete cracks of the tunnel during the operating period, preventive mea? sures shall be taken during construction, and the crack self-healing technology is an effective method to achieve this goal. Through comparison with the technologies such as shape-memory alloy (SMA) method, hollow-core optical fiber and hollow-core fiber method, microbial mineralization method and capsule-based coating self-healing technique, it is concluded that the microcapsule-based coating self-healing technology has the following advantages:easy concrete mixing, even distribution of capsules, rapid response to cracks and long-term sustainability. This technology has been applied to the construction of Liyang Jiaoweiqin Tourist Complex Tunnel, in which self-healing capsule materials have been tested and detected and the anti-cracking effect and self-healing capacity of concrete mixed with microcapsules have been traced and observed. The research shows that the self-healing capacity of the secondary lining concrete mixed with microcapsules is extremely strong. With stress sensitivity, high bond strength and permeability, the self-healing agent can obviously reduce the width of cracks on 7 d after cracks occur, and cracks can be basically healed on 21 d and completely healed on 28 d.
Abstract：
To reduce the secondary lining concrete cracks of the tunnel during the operating period, preventive mea? sures shall be taken during construction, and the crack self-healing technology is an effective method to achieve this goal. Through comparison with the technologies such as shape-memory alloy (SMA) method, hollow-core optical fiber and hollow-core fiber method, microbial mineralization method and capsule-based coating self-healing technique, it is concluded that the microcapsule-based coating self-healing technology has the following advantages:easy concrete mixing, even distribution of capsules, rapid response to cracks and long-term sustainability. This technology has been applied to the construction of Liyang Jiaoweiqin Tourist Complex Tunnel, in which self-healing capsule materials have been tested and detected and the anti-cracking effect and self-healing capacity of concrete mixed with microcapsules have been traced and observed. The research shows that the self-healing capacity of the secondary lining concrete mixed with microcapsules is extremely strong. With stress sensitivity, high bond strength and permeability, the self-healing agent can obviously reduce the width of cracks on 7 d after cracks occur, and cracks can be basically healed on 21 d and completely healed on 28 d.
CAO Yan1 WANG Ruiwen1,
2 ZHAO Weiwei2 SHI Qibin3 PAN Xuhui3 OU Dingfu1,
2
.Application Research on the Bionic Self-healing Technology for Secondary Lining Concrete of Tunnels[J] MODERN TUNNELLING TECHNOLOGY, 2022,V59(6): 250-257
2022, Vol. 59 