中文摘要：

采用快速碳化法,对普通喷射混凝土及钢纤维喷射混凝土抗碳化性能进行研究,并与同配合比模筑混凝土进行对比,分析施工工艺及钢纤维对混凝土抗碳化性能影响;同时对碳化后模筑混凝土及喷射混凝土力学性能和微观结构进行分析,探讨微观结构对碳化后混凝土力学性能影响.引入施工工艺影响系数和钢纤维影响系数,建立喷射混凝土碳化深度预测模型.结果表明：施工方式对混凝土抗碳化性能影响大,钢纤维的掺入可显著提高喷射混凝土抗碳化性能且喷射混凝土碳化深度变化规律与模筑混凝土相似且更好的符合Fick第一定律.喷射混凝土中原始微气孔及裂缝为CO2的侵入提供通道,且缺陷中钙矾石、氢氧化钙等晶体为Ca CO3晶体的成核和生长提供有利条件;随着碳化反应的发展,喷射混凝土中可碳化物质不断被消耗,碳化产物持续生成并阻塞毛细孔,改变内部微观孔结构组成,使其密实度增加.

英文摘要：

The anti-carbonation of shotcrete with and without steel fiber was studied by using rapid carbonation method. Compared with formworking concrete for the same mixture with shotcrete, the effect of concrete anti-carbonation by construction technology and steel fiber was researched. Meanwhile, the mechanical properties and microstructure of the formworking concrete and shotcrete were analyzed and the influence of carbonation concrete mechanical properties by microstructure was studied. Introducing the influence coefficient of construction technology and steel fiber, the carbonation depth prediction model of shotcrete was established. The result shows that construction technology had great influence on the anti-carbonation for concrete and steel fiber could improve the anti-carbonation significantly. Moreover, the carbonation depth change law ofshotcrete was similar to formworking concrete and in accordance with Fick first law. The channels for carbon dioxide taking into shotcrete was provided by the original micro pores and creaks and the favorable conditions for calcite crystal nucleation and growing was also supplied by ettringite and portlandite which consists in defeats. With the carbonation reaction development, the carbonation substance was continuously consumed and the carbonation products were sustainably generated and the micro-pores was also blocked. This could change the microstructure composition of shotcrete and make the density increase.