采用80℃蒸汽养护快速实验方法,研究了2种不同类型含碱集料——霞石正长岩和白岗岩对碱–硅酸反应的影响,并通过在150℃不同的碱溶液中压蒸集料的方法,对含碱集料的析碱机理进行了分析。结果表明:霞石正长岩和白岗岩对碱–硅酸反应膨胀的影响与使用水泥的碱含量有关。在使用低碱水泥时,霞石正长岩和白岗岩使碱–硅酸反应膨胀显著增大,而在使用高碱水泥时,霞石正长岩和白岗岩对碱–硅酸反应膨胀促进作用均减弱;在饱和Ca(OH)2溶液中的霞石矿物能稳定存在,随着碱含量的增加,霞石矿物发生分解,而长石矿物均能稳定存在,与碱溶液的反应仅在长石矿物表面区域进行。长石矿物与混凝土孔溶液中Ca2+之间的离子交换反应是混凝土中长石矿物析碱的主要原因。

[1]邓敏,唐明述,兰祥辉,等.国外关于混凝土碱含量限定的规范与我国应采取的措施[J].混凝土与水泥制品,1994(4):8–14.DENG Min,TANG Mingshu,LAN Xianghui,et al.China Concr Cem Prod(in Chinese),1994(4):8–14. [2]van AARDT J H P,VISSER S.Calcium hydroxide attack on feldspars and clays:Possible relevance to cement-aggregate reactions[J].Cem Concr Res,1977,7(6):643–648. [3]STARK D.Alkali-aggregate reactivity in the Rocky Mountain region[A]//Proceedings of the4th International Conference on Alkali-Aggre-gate Reaction in Concrete[C],Purdue,USA,1978:235–244. [4]GRATTAN-BELLEW P E,BEAUDOUIN J J.Effect of phlogopite mica on alkali-aggregate expansion in concrete[J].Cem Concr Res,1980,10(6):789–797. [5]KAWAMURA M,KOIKE M,NAKANO K.Release of alkalis from reactive andesitic aggregates and fly ashes into pore solution in mortars[A]//Proceedings of the8th International Conference on Alkali-Aggre-gate Reaction in Concrete[C],Kyoto,Japan,1989:271–278. [6]GILLOTT J E,ROGERS C A.Alkali-aggregate reaction and internal release of alkalis[J].Mag Concr Res,1994,46(167):99–112. [7]GILLOTT J E,ROGERS C A.The behavior of silicocarbonatite ag-gregates from the Montreal area[J].Cem Concr Res,2003,33(4):471–480. [8]DURAND B.A note about alkali contribution from aggregates in concrete affected by ASR[A]//Proceeding of11th International Con-ference on AAR[C],Québec City,Canada,2000:169–177. [9]ST JOHN D A,GOGUEL R L.Pore solution/aggregate of alkalies in hardened concrete[A]//Proceedings of the9th International Confer-ence on Alkali-aggregate Reaction in Concrete[C],London,UK,1992:894–901. [10]GOGUEL R.Alkali release by volcanic aggregates in concrete[J].Cem Concr Res,1995,25(4):841–852. [11]GOGUEL R,MILESTONE N B,Alkali release from basalts and alkalinity of pore solution in mortar[A]//Proceedings of the11th In-ternational Conference on Alkali-Aggregate Reaction in Concrete[C],Québec City,Canada,2000:179–188. [12]CONSTANTINER D,DIAMOND S.Alkali release from feldspars into pore solutions[J].Cem Concr Res,2003,33(4):549–554. [13]BéRUBéM A,DORION J F,RIVEST M.Distribution of alkalies in concrete structures affected by ASR and contribution by aggregates[A]//Proceedings of the11th International Conference on Alkali-AggregateReaction in Concrete[C],Québec City,Canada,2000:139–148. [14]BéRUBéM A,DORION J F,RIVEST M.Laboratory assessment of alkali contribution by aggregates to concrete and application to con-crete structures affected by ASR[J].Cem Concr Res,2002,32(8):1215–1227. [15]王玉江,王晓峰,邓敏,等.霞石正长岩对碱–硅酸反应的影响[J].硅酸盐通报,2007,26(3):456–461.WANG Yujiang,WANG Xiaofeng,DENG Min,et al.Bull Chin Ceram Soc(in Chinese),2007,26(3):456–461. [16]王玉江.集料碱析出及其对AAR的影响[D].南京:南京工业大学,2006.WANG Yujiang.Alkali releasing from aggregate and the effect on AAR(in Chinese,dissertation).Nanjing:Nanjing University of Tech-nology,2006. [17]BéRUBéM A,FOURNIER B.Alkali releasable by Aggregates in concrete-significance and test methods[A]//Proceedings of the12th International Conference on Alkali-Aggregate Reaction in Concrete[C],Beijing,China,2004:1130–1135. [18]WANG Yujiang,MO Liwu,DENG Min,et al.Thermodynamic analy-sis on decomposition of feldspar mineral under alkali condition[A]//Proceedings of the12th International Conference on Alkali-Aggregate Reaction in Concrete[C],Beijing,China,2004:211–220. [19]王玉江,余桂郁,邓敏,等.含碱矿物碱性环境下分解的热力学分析[J].硅酸盐学报,2006,34(3):345–352.WANG Yujiang,YU Guiyu,DENG Min,et al.J Chin Ceram Soc(in Chinese),2006,34(3):345–352.