木寨岭公路隧道高弹模PVA合成纤维喷射混凝土抗裂技术研究与探讨

为提高初期支护混凝土的强度、密实性、韧性,保障施工安全,通过开展室内多组配合比的高弹模PVA 合成纤维混凝土硬化 收缩开裂性能试验测试进行试配,并成功应用于木寨岭公路隧道现场实际施工。在木寨岭公路隧道喷射混凝土施工中添加高弹模 PVA 合成纤维,使混凝土具有良好的抗裂、增韧性能,极限变形能力增大,混凝土的完整性提高,达到了减少初期支护混凝土产生裂 缝、控制开裂的效果。对高地应力大变形的隧道初期支护,在支护结构变形可控的条件下,抗裂性能显著,值得借鉴与推广。

Experimental Study on Crack Resistance Technology of PVA Synthetic Fiber Shotcrete with High Elastic Modulus for Muzhailing Highway Tunnel

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.