Abstract:

In order to improve the strength, integrity and toughness of primary support concrete, and ensure the
construction safety, laboratory hardening shrinkage cracking performance experiment is carried out on high elastic
modulus PVA synthetic fiber concrete with multiple groups of mix ratios. The experimental results have been successfully
applied to construction practice of Muzhailing Highway Tunnel. By adopting the PVA synthetic fiber shotcrete in
Muzhailing Highway Tunnel, good crack resistance and toughening performance of concrete have been achieved, the
integrity and ultimate deformation capacity of the concrete have been improved, and the purpose of reducing and
controlling the primary support crack has been achieved. The shotcrere has a high crack resistance performance in tunnel
primary support with large ground stress under the condition of controllable deformation of lining structure, which is
worth popularizing.

Key words: highway tunnel, cracking, toughening, fiber shotcrete, hardening shrinkage, crack control