To analysis the anti-carbonation property of metakaolin-slag geopolymer, the method of accelerated carbonation with CO2 water solution at hydrothermal condition was adopted. The compressive strength, pore structure, permeability and micro-morphology of specimens at different ages were analyzed and compared with hardened cement pastes. The results showed that the anti-carbonation property of geopolymer was better than that of cement paste. After 28 d and 90 d carbonation, the compressive strength of geopolymer declined by 4.44％ and 11.08％respectively when compared to those specimens after water curing for 28 d and 90 d (the compressive strength of cement paste was respectively reduced by 8.61％ and 33.55％). The porosity was 11.47％ and 14.85％ (on the contrary, the porosity of cement paste was 27.45 ％ and 31.63 ％) and the pore size mainly distributed between 0 nm and 50 nm. Geopolymer samples did not permeate at the driving pressure of 7.0 MPa while cement paste had permeability of 1.27× 10-3 μm2 and 1.82× 10-3 μm2. When the driving pressure was improved to 15.0 MPa, the permeability of geopolymer was respectively 2.80× 10-3 μm2 and 5.90× 10-3 μm2, only about 1/10 of that of cement paste. The microstructure showed that the 90 d carbonation product of geopolymer was compacter than the carbonated cement.%采用高温纯CO2水溶液加速碳化的方法,通过对不同龄期碳化试样的抗压强度和孔结构测试、渗透率测定及微观形貌分析,并结合净浆水泥石的碳化性能进行同步比较,对偏高岭土-矿渣基地聚合物的碳化性能进行了研究.结果表明:偏高岭土-矿渣基地聚合物的抗碳化能力明显优于净浆水泥石.地聚合物碳化28 d和90 d时,试样的抗压强度分别比同龄期水养试样降低了4.44%和11.08(水泥石分别降低了8.61%和33.55%);试样总孔隙率仅为11.47%和14.85(水泥石总孔隙率分别为27.45%和31.63%),且孔径分布均主要集中于0～50 nm区间;地聚合物试样在7.0 MPa的驱替压力下不渗滤,而水泥石的渗透率分别为1.27x10-3μm2 和1.82x10-3μm2,15 MPa压力下地聚合物的渗透率为2.80×10μm3和5.90x10-3μm2,仅为水泥石渗透率的1/10左右;地聚合物碳化90 d时,试样结构连续致密,而水泥石结构疏松,胶凝相基本消失.
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