碳化混凝土中不同深度处pH值变化规律研究
|
摘要
采用浸取法和挤压法对碳化混凝土不同深度处pH值变化规律展开研究。考虑了水胶比、水泥用量和粉煤灰用量3个因素对碳化混凝土不同深度处pH值的影响。实验结果表明,碳化混凝土存在部分碳化区、完全碳化区和未碳化区。水胶比对碳化混凝土不同深度处pH值影响不大,而粉煤灰和水泥的用量对碳化混凝土不同深度处pH值有较大的影响;水泥用量对部分碳化区的长度影响较小,粉煤灰的使用对混凝土碳化有促进作用,但减小了部分碳化区的长度。采用挤压法得到的结论与浸取法的结果一致。但是挤压法所得到的孔溶液pH值更可靠,更具有说服力。因此采用挤压法对碳化混凝土不同深度处的pH值进行研究比较合理。
This paper adopted leaching and extrusion method to study the p H variation in different depth. Water-cement ratio,fly ash content,cement content were considered as three main factors affecting the p H of carbonated concrete at different depth and were researched in the test. The result showed that incomplete carbonation zone,complete carbonation zone and none carbonation zone were existed in the carbonated concrete. The influence of water-cement ratio on the p H in different depth was small,while the influence of fly ash content and cement content on that is great. The cement content had little effect on the length of incomplete carbonation zone,and fly ash could decrease the length of incomplete carbonation zone. The conclusion obtained by extrusion method is consistent with leaching method. However,the hole liquor p H obtained by extrusion method is more reliable and more persuasive. So that using extrusion method to study the p H variation in carbonated concrete is reasonable.
This paper adopted leaching and extrusion method to study the p H variation in different depth. Water-cement ratio,fly ash content,cement content were considered as three main factors affecting the p H of carbonated concrete at different depth and were researched in the test. The result showed that incomplete carbonation zone,complete carbonation zone and none carbonation zone were existed in the carbonated concrete. The influence of water-cement ratio on the p H in different depth was small,while the influence of fly ash content and cement content on that is great. The cement content had little effect on the length of incomplete carbonation zone,and fly ash could decrease the length of incomplete carbonation zone. The conclusion obtained by extrusion method is consistent with leaching method. However,the hole liquor p H obtained by extrusion method is more reliable and more persuasive. So that using extrusion method to study the p H variation in carbonated concrete is reasonable.
引文
[1]施锦杰,孙伟.混凝土中钢筋锈蚀研究现状与热点问题分析[J].硅酸盐学报,2010,38(9):1753-1764.
[2]吴国坚,翁杰,俞素春,等.混凝土碳化速率多因素影响试验研究[J].新型建筑材料,2014(6):33-40.
[3]Mc Polin D O,Basheer P A M,Long A E,et al.New test method to obtain p H profiles due to carbonation of concretes containing supplementary cementitious materials[J].Journal of Materials in Civil Engineering,2007,19(11):936-946.
[4]石明霞,龙广成.中等强度自密实混凝土的碳化性能[J].新型建筑材料,2009(5):1-5.
[5]潘洪科,海然,杨林德.多因素作用下混凝土碳化模型的验证分析[J].新型建筑材料,2009(5):6-9.
[6]Sagues A A,Moreno E I,Andrade C,et al.Evolution of p H during in-situ leaching in small concrete cavities[J].Cement Concrete Research,2007,27(11):1747-1759.
[7]黄利频,郑建岚.测试混凝土孔溶液的p H值研究混凝土的碳化性能[J].福州大学学报:自然科学版,2012(6):794-799.
[8]Andreas Leemann,Peter Nygaard,Josef Kaufmann,et al.Relation between carbonation resistance,mix design and exposure of mortar and concrete[J].Cement and Concrete Composites,2015,62:33-43.
[9]Pu Qi,Jiang Linhua,Xu Jinxia,et al.Evolution of p H and chemical composition of pore solution in carbonated concrete[J].Construction and Building Materials,2012,28(1):519-524.
[2]吴国坚,翁杰,俞素春,等.混凝土碳化速率多因素影响试验研究[J].新型建筑材料,2014(6):33-40.
[3]Mc Polin D O,Basheer P A M,Long A E,et al.New test method to obtain p H profiles due to carbonation of concretes containing supplementary cementitious materials[J].Journal of Materials in Civil Engineering,2007,19(11):936-946.
[4]石明霞,龙广成.中等强度自密实混凝土的碳化性能[J].新型建筑材料,2009(5):1-5.
[5]潘洪科,海然,杨林德.多因素作用下混凝土碳化模型的验证分析[J].新型建筑材料,2009(5):6-9.
[6]Sagues A A,Moreno E I,Andrade C,et al.Evolution of p H during in-situ leaching in small concrete cavities[J].Cement Concrete Research,2007,27(11):1747-1759.
[7]黄利频,郑建岚.测试混凝土孔溶液的p H值研究混凝土的碳化性能[J].福州大学学报:自然科学版,2012(6):794-799.
[8]Andreas Leemann,Peter Nygaard,Josef Kaufmann,et al.Relation between carbonation resistance,mix design and exposure of mortar and concrete[J].Cement and Concrete Composites,2015,62:33-43.
[9]Pu Qi,Jiang Linhua,Xu Jinxia,et al.Evolution of p H and chemical composition of pore solution in carbonated concrete[J].Construction and Building Materials,2012,28(1):519-524.