基于闪长岩机制砂的隧道喷射混凝土配合比设计OA

Tunnel construction produces a large amount of waste slag,which cannot be effectively utilized due to various factors.By using tunnel slag to prepare manufactured sand to replace natural sand,resources can be saved;costs can be reduced,and the environment can be protected.Based on the Xi'an-Shiyan high-speed railway project,the physical and mechanical properties of diorite along the tunnel were tested;the physical properties and concrete performance of manufactured sand and natural sand were comparatively studied,and the effects of water-binder ratio and sand ratio on the performance of shotcrete were analyzed by designing multiple sets of mix proportion tests.The results indicate that diorite has few impurities,good stability,and a low radioactivity index,which is suitable for preparing manufactured sand;compared with natural sand,manufactured sand particles are characterized by rough surfaces,a high fineness modulus,and a high water demand,and meanwhile,the manufactured sand concrete has slightly poorer fluidity but higher strength;when the water-binder ratio is 0.410.43,and the sand ratio is 51%52%,the overall performance of the manufactured sand shotcrete is optimal,and the designed mix proportion shows a good application effect in field trial spraying.It is practicable to apply diorite manufactured sand in shotcrete,which can meet the engineering requirements of tunnel shotcrete,and its application in concrete materials can be further promoted in the future.