C25纳米硅粉干喷混凝土工艺及力学性能试验研究

Experimental Research on Process and Mechanical Properties of C25 Nanometer Silica FumeDry Shotcrete

白鹤滩水电站尾水洞、调压室、厂房等部位开挖施工中,受高地应力及硬脆性玄武岩地质条件影响,顶拱围岩片帮、开裂现象频发。为尽快封闭岩面,有效控制围岩早期松弛变形,确保洞室安全,建设相关方提出了在喷射混凝土中掺纳米硅粉材料的技术构想,经多次开展相关试验,达到了预期应用效果。总结形成的C25纳米硅粉干喷混凝土工艺满足一次喷射最大厚度,抗压强度、黏结强度、抗拉强度等力学性能也有较大提高,该成果的推广应用对洞室锚喷支护施工具有重要意义。

During excavation and construction of tailrace tunnel,surge chamber and power house of Baihetan Hydropower Station,roof arch surrounding rocks are frequently cracked due to high ground stress and geological conditions of hard and brittle basalt.In order to close the rock surface as soon as possible,effectively control the early relaxation and deformation of surrounding rocks and ensure the safety of the tunnel chamber,the technical conception of mixing nanometer silica fume in shotcrete has been put forward by relevant construction parties.Relevant tests have been carried out for many times and the expected application effect has been achieved.The C25 nanometer silica fume dry shotcrete process is concluded to meet the maximum thickness of primary shotcrete,and its mechanical properties such as compressive strength,bonding strength and tensile strength are also greatly improved.The popularization and application of this achievement is of great significance to the tunnel anchor-shotcrete support construction.