【摘要】 本文研究磨细石灰石粉(Ground Limestone Powder,GLP)等量替代水泥对混凝土微观结构及抗碳化性能的影响机理。通过pH值试验测试了不同GLP用量的混凝土浆体内部孔隙溶液碱储备量,采用压汞试验(MIP)分析了GLP混凝土内浆体水化产物孔结构分布特征,并对GLP混凝土进行碳化试验。结果表明:GLP等量替代水泥,会影响混凝土浆体内部孔隙溶液的pH值,GLP用量越多,孔隙溶液pH值越低,单位体积混凝土碱储备量的减小削弱了混凝土的抗碳化能力。GLP等量替代水泥改变了混凝土浆体内部孔级配分布特征,50~200nm级有害孔孔隙率及其分孔隙百分率显著增大,浆体的总孔隙率明显增大,进一步弱化了混凝土的抗碳化能力。可通过增大GLP比表面积或降低混凝土水胶比提高混凝土抗碳化能力。更多还原

【Abstract】 The influence of ground limestone powder(GLP)which replaces cement by mass on microstructure and its action mechanism of carbonation resistance of concrete are analyzed.The alkaline matter reserved in pore solution of paste in concrete with different replacements of cement by GLP by mass is observed through the pH value test.The influence of GLP on pore structure characteristics of hydration products of concrete is investigated by method of mercury intrusion porosimeter(MIP)and the carbonation resistance of GLP concrete is tested.Results indicate that the replacements of cement by GLP will affect the pH value of pore solution inside the concrete.The pH value decreases with the increase of the replacements of cement by GLP.The reduction of the alkaline matter reserved in per unit volume concrete weakens the carbonation resistance of concrete.The replacements of cement by GLP change the distribution feature of classification porosity of paste in concrete.The porosity and the classification porosity percent of harmful pore with pore diameter in range of 50~200nm increase significantly with the total porosity of paste in concrete with GLP obviously increasing,weakening further the carbonation resistance of concrete.The carbonation resistance of concrete could be improved appropriately by increasing the specific surface area of GLP and decreasing the water-bind ratio of concrete.更多还原