纤维素纤维混凝土性能及在二次衬砌中的应用

对纤维素纤维混凝土工作性能、强度、抗裂性能和耐久性能进行测试,结果表明:纤维素纤维混凝土比普通混凝土有较好工作性能、早期抗裂性能和耐久性能;可提高混凝土劈裂抗拉强度和抗弯强度。因此,可应用于Ⅱ、Ⅲ级围岩条件下隧道二次衬砌结构。纤维素纤维对混凝土增强作用机理可解释为:通过纤维在混凝土中乱向分布,改善混凝土内部微观结构;减少气泡含量和气泡间距;并减小混凝土裂缝萌生和扩展概率;从而改善混凝土性能。将纤维素纤维混凝土应用于某高速铁路隧道二次衬砌结构,可满足工作性能、强度、耐久性能要求,且成型后70、280d混凝土表面没有裂缝产生。

Performance of Cellulose Fiber Concrete and Application in Secondary Lining

The working ability,strength,crack resistance performance and durability of cellulose fiber concrete were mesured.Experiment results show as follows: Cellulose fibers significantly improve the early crack resistance performance and durability,and increase the splitting tensile strength and flexural strength of concrete and so cellulose fiber concrete can be applied to secondary lining of tunnel with grades Ⅱand Ⅲ surrounding rock;the reinforced mechanism of cellulose fibers is that cellulose fibers distribute irregularly and reduce bubble contents and space to improve concrete performance;application of cellulose fiber concrete in the secondary lining structure of a high-speed railway tunnel prove cellulose fiber concrete can satisfy the design demand for the strength,durability and working ability of concrete and no cracks can be detected in the concrete surface 70 and 280 days after moulding.