This paper analyzed the used materials of C20 sprayed concrete for tunnel primary support, discussed the influence of alkali-aggregate reaction to the long-term using of sprayed concrete, and put forward improvement ideas, so as to extend the sprayed concrete service life.%对隧道初期支护的C20喷射混凝土使用的材料进行了分析，探讨了碱-集料反应对喷射混凝土的长期使用可能产生的影响，并提出了改进的思路，以延长喷射混凝土的使用寿命。
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