聚丙烯纤维对边坡支护用喷射混凝土性能的影响

Influence on the Performance of Shotcrete for Slope Support by Adding Polypropylene Fiber

为了克服喷射混凝土易开裂、脆性大等不足,通过掺入聚丙烯纤维以提升喷射混凝土的工作性能、抗压强度与抗渗性能,并结合粉煤灰、减水剂等掺量变化,探究聚丙烯纤维喷射混凝土的优化配合比方案。结果表明,经配合比优化处理后,聚丙烯纤维喷射混凝土的各项性能均能够满足边坡支护工程规范要求,其中粉煤灰掺量调整为胶凝材料质量配比的20%,掺加质量分数为0.8%的减水剂和1.0 kg/m^(3)聚丙烯纤维时,喷射混凝土的回弹率为7.6%,满足工程规范要求。

In order to overcome the shortcomings of easy cracking and high brittleness of shotcrete,it is pro⁃posed to improve its workability,compressive strength and impermeability by adding polypropylene fibers.Combined with dosage change such as fly ash and water reducing agents,the optimal mix proportion scheme of polypropylene fiber reinforced shotcrete is explored.The results show that the various properties of poly⁃propylene fiber reinforced shotcrete after being optimized by the mix proportion method can meet the re⁃quirements of slope support engineering specifications.Among them,the fly ash content is adjusted to 20%of the mass ratio of cementitious materials,when adding water reducing agent with mass fraction of 0.8%and 1.0 kg/m^(3) polypropylene fiber,the rebound rate of shotcrete is 7.6%,which meets the requirements of engineering specification.