碱激发矿渣固化土压平衡盾构渣土的试验研究

Experimental Study on Alkali Activated Slag Solidification of Earth Pressure Balance Shield Muck

利用碱激发高炉矿渣对土压平衡盾构渣土进行固化,考察了矿渣掺量、液固比、碱激发剂、成型压力、养护温度等因素对固化土力学性能的影响,分析了固化反应的主要产物及固化土的微观结构,研究了固化土的抗酸抗盐侵蚀能力。结果表明:碱激发高炉矿渣对土压平衡盾构渣土具有较好的固化能力,在配比范围内,随着高炉矿渣掺量的增加,固化渣土抗压强度和表观密度增大;固化渣土强度的主要来源是碱激发高炉矿渣生成的C-S-H和C-A-S-H;氢氧化钠和水玻璃的复合激发相对于单一激发固化效果更好,液固比、成型压力和养护温度对于固化渣土的抗压强度有一定影响;硫酸钠对所制备的固化渣土的侵蚀作用较小,而硫酸和盐酸的侵蚀作用相对较大。

Alkali-activated blast furnace slag is used to solidify soil pressure balance shield muck. The effects of slag content, liquid-solid ratio, alkali activator, molding pressure and curing temperature on mechanical properties of solidified earth pressure balance(EPB) shield muck were investigated. The main products of solidification reaction and microstructure of solidified muck were analyzed, and the acid and salt resistance of solidified soil was studied. The results show that alkali-activated blast furnace slag has good solidification ability for EPB shield muck. With the increase of blast furnace slag content, the compressive strength and apparent density of solidified soil increase;the main source of strength of solidified muck is C-S-H and C-A-S-H generated by alkali-activated blast furnace slag;the combined excitation of sodium hydroxide and sodium silicate has better solidification effect than single excitation molding pressure and curing temperature have certain influence on the compressive strength of solidified soil. The erosion of sodium sulfate on the prepared solidified soil is small, while that of sulfuric acid and hydrochloric acid is relatively large.