NaCl和Na_2SO_4对水泥水化机理的影响
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摘要
为了深入研究氯盐、硫酸盐对水泥基材料的水化机理的影响,将NaCl和Na_2SO_4掺入水泥中,运用TAM air微量热仪、X射线衍射仪(XRD)和电感耦合等离子体发射光谱仪(ICP)探究水泥的水化动力学以及水化产物的转变.结果表明:从水化放热速率和累计放热量上分析,NaCl和Na_2SO_4都可以加速水泥水化,相同质量的NaCl加速水化效果高于Na_2SO_4.在水化过程中SO■离子浓度快速下降,然而Cl~-离子浓度在水化10 h之后才出现下降的趋势.当SO■和Cl~-同时存在时,SO■先于Cl~-与铝酸三钙(C_3A)反应,NaCl能够促进石膏溶解并且加速钙矾石生成;从XRD图谱可以发现,在掺入NaCl的水泥浆体内,水化早期不会产生Friedel盐,只有随着钙矾石转变成单硫型钙矾石(SO_4-AFm),Cl~-开始反应生成Friedel盐.根据动力学微分曲线评价了NaCl和Na_2SO_4对水化机理的影响,在水化过程中NaCl促进了结晶成核与晶体生长(NG),对相边界反应(I)过程有一定的削弱作用,而对扩散过程(D阶段)影响很小.
To investigate the influence of chloride salt and sulfate on the hydration mechanism of cement-based materials, NaCl and Na_2SO_4 were mixed into cement, and the TAM air microcalorimeter, X-ray diffractometer(XRD), and inductively coupled plasma spectroscopy(ICP) were used to investigate the hydration kinetics of cement and the transformation of hydration products. The results show that both NaCl and Na_2SO_4can accelerate cement hydration from the hydration heat release rate and the cumulative heat, and the accelerating effect of NaCl is better than that of Na_2SO_4. The concentration of SO■ decreases rapidly during the hydration process, but the Cl~- concentration does not decrease until 10 h hydration. When Na_2SO_4 and NaCl coexist,SO■ reacts with C_3A prior to Cl~-, and NaCl promotes gypsum dissolution and accelerates ettringite formation. From the XRD pattern, it can be found that in the cement slurry mixed with NaCl, Friedel salt is not produced in the early stage of hydration, and only with the conversion of ettringite into monosulfide ettringite(SO4-AFm), Cl~- starts to react to form Friedel salt. In addition, the influence of NaCl and Na_2SO_4 on the hydration mechanism of cement was discussed according to the hydration kinetic curve. During the hydration process, NaCl promotes the NG process, and has a certain weakening effect on the I process, but has little effect on the D process.
To investigate the influence of chloride salt and sulfate on the hydration mechanism of cement-based materials, NaCl and Na_2SO_4 were mixed into cement, and the TAM air microcalorimeter, X-ray diffractometer(XRD), and inductively coupled plasma spectroscopy(ICP) were used to investigate the hydration kinetics of cement and the transformation of hydration products. The results show that both NaCl and Na_2SO_4can accelerate cement hydration from the hydration heat release rate and the cumulative heat, and the accelerating effect of NaCl is better than that of Na_2SO_4. The concentration of SO■ decreases rapidly during the hydration process, but the Cl~- concentration does not decrease until 10 h hydration. When Na_2SO_4 and NaCl coexist,SO■ reacts with C_3A prior to Cl~-, and NaCl promotes gypsum dissolution and accelerates ettringite formation. From the XRD pattern, it can be found that in the cement slurry mixed with NaCl, Friedel salt is not produced in the early stage of hydration, and only with the conversion of ettringite into monosulfide ettringite(SO4-AFm), Cl~- starts to react to form Friedel salt. In addition, the influence of NaCl and Na_2SO_4 on the hydration mechanism of cement was discussed according to the hydration kinetic curve. During the hydration process, NaCl promotes the NG process, and has a certain weakening effect on the I process, but has little effect on the D process.
引文
[1] Li Y L,Zhao X L,Singh Raman R K.Mechanical properties of seawater and sea sand concrete-filled FRP tubes in artificial seawater[J].Construction and Building Materials,2018,191:977-993.DOI:10.1016/j.conbuildmat.2018.10.059.
[2] Dong Z Q,Wu G,Zhao X L,et al.Behaviors of hybrid beams composed of seawater sea-sand concrete (SWSSC) and a prefabricated UHPC shell reinforced with FRP bars[J].Construction and Building Materials,2019,213:32-42.DOI:10.1016/j.conbuildmat.2019.04.059.
[3] Li H,Farzadnia N,Shi C J.The role of seawater in interaction of slag and silica fume with cement in low water-to-binder ratio pastes at the early age of hydration[J].Construction and Building Materials,2018,185:508-518.DOI:10.1016/j.conbuildmat.2018.07.091.
[4] Xiao J Z,Qiang C B,Nanni A,et al.Use of sea-sand and seawater in concrete construction:Current status and future opportunities[J].Construction and Building Materials,2017,155:1101-1111.DOI:10.1016/j.conbuildmat.2017.08.130.
[5] 姜梅芬,吕宪俊.混凝土早强剂的研究与应用进展[J].硅酸盐通报,2014,33(10):2527-2533.DOI:10.16552/j.cnki.issn1001-1625.2014.10.022.Jiang M F,Lü X J.Research and application progresses of concrete early strength agent[J].Bulletin of the Chinese Ceramic Society,2014,33(10):2527-2533.DOI:10.16552/j.cnki.issn1001-1625.2014.10.022.(in Chinese)
[6] Thomas J J,Allen A J,Jennings H M.Hydration kinetics and microstructure development of normal and CaCl2-accelerated tricalcium silicate pastes[J].The Journal of Physical Chemistry C,2009,113(46):19836-19844.DOI:10.1021/jp907078u.
[7] Juenger M C G,Monteiro P J M,Gartner E M,et al.A soft X-ray microscope investigation into the effects of calcium chloride on tricalcium silicate hydration[J].Cement and Concrete Research,2005,35(1):19-25.DOI:10.1016/j.cemconres.2004.05.016.
[8] Adu-Amankwah S,Black L,Skocek J,et al.Effect of sulfate additions on hydration and performance of ternary slag-limestone composite cements[J].Construction and Building Materials,2018,164:451-462.DOI:10.1016/j.conbuildmat.2017.12.165.
[9] Velandia D F,Lynsdale C J,Provis J L,et al.Effect of mix design inputs,curing and compressive strength on the durability of Na2SO4-activated high volume fly ash concretes[J].Cement and Concrete Composites,2018,91:11-20.DOI:10.1016/j.cemconcomp.2018.03.028.
[10] Shanahan N,Sedaghat A,Zayed A.Effect of cement mineralogy on the effectiveness of chloride-based accelerator[J].Cement and Concrete Composites,2016,73:226-234.DOI:10.1016/j.cemconcomp.2016.07.015.
[11] 曹园章,郭丽萍,臧文洁,等.氯盐和硫酸盐交互作用下水泥基材料的破坏机理综述[J].材料导报,2018,32(23):4142-4149.DOI:10.11896/j.issn.1005-023X.2018.23.016.Cao Y Z,Guo L P,Zang W J,et al.Failure mechanism of cement-based materials subjected to the interaction between chloride and sulfate:A review[J].Materials Review,2018,32(23):4142-4149.DOI:10.11896/j.issn.1005-023X.2018.23.016.(in Chinese)
[12] Maes M,Mittermayr F,de Belie N.The influence of sodium and magnesium sulphate on the penetration of chlorides in mortar[J].Materials and Structures,2017,50(2):153.DOI:10.1617/s11527-017-1024-8.
[13] Geng J,Easterbrook D,Li L Y,et al.The stability of bound chlorides in cement paste with sulfate attack[J].Cement and Concrete Research,2015,68:211-222.DOI:10.1016/j.cemconres.2014.11.010.
[14] 郭丽萍,张健,曹园章,等.超高性能水泥基材料复合盐侵蚀研究:合成Friedel盐和钙矾石在硫酸盐和氯盐溶液中的稳定性[J].材料导报,2017,31(23):132-137.DOI:10.11896/j.issn.1005-023X.2017.023.019.Guo L P,Zhang J,Cao Y Z,et al.A study for compound salts attack on ultra-high performance cement-based materials:The stabilities of chemically synthesized Friedel salt and ettringite in solutions of sulfates and chloride salts[J].Materials Review,2017,31(23):132-137.DOI:10.11896/j.issn.1005-023X.2017.023.019.(in Chinese)
[15] Bullard J W,Jennings H M,Livingston R A,et al.Mechanisms of cement hydration[J].Cement and Concrete Research,2011,41(12):1208-1223.DOI:10.1016/j.cemconres.2010.09.011.
[16] Scrivener K L,Nonat A.Hydration of cementitious materials,present and future[J].Cement and Concrete Research,2011,41(7):651-665.DOI:10.1016/j.cemconres.2011.03.026.
[17] Jansen D,Goetz-Neunhoeffer F,Lothenbach B,et al.The early hydration of ordinary Portland cement (OPC):An approach comparing measured heat flow with calculated heat flow from QXRD[J].Cement and Concrete Research,2012,42(1):134-138.DOI:10.1016/j.cemconres.2011.09.001.
[18] Jansen D,Neubauer J,Goetz-Neunhoeffer F,et al.Change in reaction kinetics of a Portland cement caused by a superplasticizer:Calculation of heat flow curves from XRD data[J].Cement and Concrete Research,2012,42(2):327-332.DOI:10.1016/j.cemconres.2011.10.005.
[19] Cheung J,Jeknavorian A,Roberts L,et al.Impact of admixtures on the hydration kinetics of Portland cement[J].Cement and Concrete Research,2011,41(12):1289-1309.DOI:10.1016/j.cemconres.2011.03.005.
[20] Quennoz A,Scrivener K L.Hydration of C3A-gypsum systems[J].Cement and Concrete Research,2012,42(7):1032-1041.DOI:10.1016/j.cemconres.2012.04.005.
[21] Scrivener K L,Juilland P,Monteiro P J M.Advances in understanding hydration of Portland cement[J].Cement and Concrete Research,2015,78:38-56.DOI:10.1016/j.cemconres.2015.05.025.
[22] Minard H,Garrault S,Regnaud L,et al.Mechanisms and parameters controlling the tricalcium aluminate reactivity in the presence of gypsum[J].Cement and Concrete Research,2007,37(10):1418-1426.DOI:10.1016/j.cemconres.2007.06.001.
[23] Mota B,Matschei T,Scrivener K.The influence of sodium salts and gypsum on alite hydration[J].Cement and Concrete Research,2015,75:53-65.DOI:10.1016/j.cemconres.2015.04.015.
[24] Haghtalab A,Badizad M H.Solubility of gypsum in aqueous NaCl + K2SO4 solution using calcium ion selective electrode—investigation of ionic interactions[J].Fluid Phase Equilibria,2016,409:341-353.DOI:10.1016/j.fluid.2015.10.011.
[25] Zhang Y X,Yang Z H,Guo D,et al.Effect of chloride salts and bicarbonate on solubility of CaSO4 in aqueous solutions at 37 ℃[J].Procedia Environmental Sciences,2013,18:84-91.DOI:10.1016/j.proenv.2013.04.012.
[26] 文静,余红发,吴成友,等.氯氧镁水泥水化历程的影响因素及水化动力学[J].硅酸盐学报,2013,41(5):588-596.DOI:10.7521/j.issn.0454-5648.2013.05.03.Wen J,Yu H F,Wu C Y,et al.Hydration kinetic and influencing parameters in hydration process of magnesium oxychloride cement[J].Journal of the Chinese Ceramic Society,2013,41(5):588-596.DOI:10.7521/j.issn.0454-5648.2013.05.03.(in Chinese)
[27] 彭小芹,兰聪,王淑萍,等.水化硅酸钙粉体对水泥水化反应过程及机理的影响[J].建筑材料学报,2015,18(2):195-201.DOI:10.3969/j.issn.1007-9629.2015.02.003.Peng X Q,Lan C,Wang S P,et al.Effects of the C-S-H powder on the hydration process and mechanism of cement[J].Journal of Building Materials,2015,18(2):195-201.DOI:10.3969/j.issn.1007-9629.2015.02.003.(in Chinese)
[28] 阎培渝,郑峰.水泥基材料的水化动力学模型[J].硅酸盐学报,2006,34(5):555-559.DOI:10.3321/j.issn:0454-5648.2006.05.009.Yan P Y,Zheng F.Kinetics model for the hydration mechanism of cementitious materials[J].Journal of the Chinese Ceramic Society,2006,34(5):555-559.DOI:10.3321/j.issn:0454-5648.2006.05.009.(in Chinese)
[2] Dong Z Q,Wu G,Zhao X L,et al.Behaviors of hybrid beams composed of seawater sea-sand concrete (SWSSC) and a prefabricated UHPC shell reinforced with FRP bars[J].Construction and Building Materials,2019,213:32-42.DOI:10.1016/j.conbuildmat.2019.04.059.
[3] Li H,Farzadnia N,Shi C J.The role of seawater in interaction of slag and silica fume with cement in low water-to-binder ratio pastes at the early age of hydration[J].Construction and Building Materials,2018,185:508-518.DOI:10.1016/j.conbuildmat.2018.07.091.
[4] Xiao J Z,Qiang C B,Nanni A,et al.Use of sea-sand and seawater in concrete construction:Current status and future opportunities[J].Construction and Building Materials,2017,155:1101-1111.DOI:10.1016/j.conbuildmat.2017.08.130.
[5] 姜梅芬,吕宪俊.混凝土早强剂的研究与应用进展[J].硅酸盐通报,2014,33(10):2527-2533.DOI:10.16552/j.cnki.issn1001-1625.2014.10.022.Jiang M F,Lü X J.Research and application progresses of concrete early strength agent[J].Bulletin of the Chinese Ceramic Society,2014,33(10):2527-2533.DOI:10.16552/j.cnki.issn1001-1625.2014.10.022.(in Chinese)
[6] Thomas J J,Allen A J,Jennings H M.Hydration kinetics and microstructure development of normal and CaCl2-accelerated tricalcium silicate pastes[J].The Journal of Physical Chemistry C,2009,113(46):19836-19844.DOI:10.1021/jp907078u.
[7] Juenger M C G,Monteiro P J M,Gartner E M,et al.A soft X-ray microscope investigation into the effects of calcium chloride on tricalcium silicate hydration[J].Cement and Concrete Research,2005,35(1):19-25.DOI:10.1016/j.cemconres.2004.05.016.
[8] Adu-Amankwah S,Black L,Skocek J,et al.Effect of sulfate additions on hydration and performance of ternary slag-limestone composite cements[J].Construction and Building Materials,2018,164:451-462.DOI:10.1016/j.conbuildmat.2017.12.165.
[9] Velandia D F,Lynsdale C J,Provis J L,et al.Effect of mix design inputs,curing and compressive strength on the durability of Na2SO4-activated high volume fly ash concretes[J].Cement and Concrete Composites,2018,91:11-20.DOI:10.1016/j.cemconcomp.2018.03.028.
[10] Shanahan N,Sedaghat A,Zayed A.Effect of cement mineralogy on the effectiveness of chloride-based accelerator[J].Cement and Concrete Composites,2016,73:226-234.DOI:10.1016/j.cemconcomp.2016.07.015.
[11] 曹园章,郭丽萍,臧文洁,等.氯盐和硫酸盐交互作用下水泥基材料的破坏机理综述[J].材料导报,2018,32(23):4142-4149.DOI:10.11896/j.issn.1005-023X.2018.23.016.Cao Y Z,Guo L P,Zang W J,et al.Failure mechanism of cement-based materials subjected to the interaction between chloride and sulfate:A review[J].Materials Review,2018,32(23):4142-4149.DOI:10.11896/j.issn.1005-023X.2018.23.016.(in Chinese)
[12] Maes M,Mittermayr F,de Belie N.The influence of sodium and magnesium sulphate on the penetration of chlorides in mortar[J].Materials and Structures,2017,50(2):153.DOI:10.1617/s11527-017-1024-8.
[13] Geng J,Easterbrook D,Li L Y,et al.The stability of bound chlorides in cement paste with sulfate attack[J].Cement and Concrete Research,2015,68:211-222.DOI:10.1016/j.cemconres.2014.11.010.
[14] 郭丽萍,张健,曹园章,等.超高性能水泥基材料复合盐侵蚀研究:合成Friedel盐和钙矾石在硫酸盐和氯盐溶液中的稳定性[J].材料导报,2017,31(23):132-137.DOI:10.11896/j.issn.1005-023X.2017.023.019.Guo L P,Zhang J,Cao Y Z,et al.A study for compound salts attack on ultra-high performance cement-based materials:The stabilities of chemically synthesized Friedel salt and ettringite in solutions of sulfates and chloride salts[J].Materials Review,2017,31(23):132-137.DOI:10.11896/j.issn.1005-023X.2017.023.019.(in Chinese)
[15] Bullard J W,Jennings H M,Livingston R A,et al.Mechanisms of cement hydration[J].Cement and Concrete Research,2011,41(12):1208-1223.DOI:10.1016/j.cemconres.2010.09.011.
[16] Scrivener K L,Nonat A.Hydration of cementitious materials,present and future[J].Cement and Concrete Research,2011,41(7):651-665.DOI:10.1016/j.cemconres.2011.03.026.
[17] Jansen D,Goetz-Neunhoeffer F,Lothenbach B,et al.The early hydration of ordinary Portland cement (OPC):An approach comparing measured heat flow with calculated heat flow from QXRD[J].Cement and Concrete Research,2012,42(1):134-138.DOI:10.1016/j.cemconres.2011.09.001.
[18] Jansen D,Neubauer J,Goetz-Neunhoeffer F,et al.Change in reaction kinetics of a Portland cement caused by a superplasticizer:Calculation of heat flow curves from XRD data[J].Cement and Concrete Research,2012,42(2):327-332.DOI:10.1016/j.cemconres.2011.10.005.
[19] Cheung J,Jeknavorian A,Roberts L,et al.Impact of admixtures on the hydration kinetics of Portland cement[J].Cement and Concrete Research,2011,41(12):1289-1309.DOI:10.1016/j.cemconres.2011.03.005.
[20] Quennoz A,Scrivener K L.Hydration of C3A-gypsum systems[J].Cement and Concrete Research,2012,42(7):1032-1041.DOI:10.1016/j.cemconres.2012.04.005.
[21] Scrivener K L,Juilland P,Monteiro P J M.Advances in understanding hydration of Portland cement[J].Cement and Concrete Research,2015,78:38-56.DOI:10.1016/j.cemconres.2015.05.025.
[22] Minard H,Garrault S,Regnaud L,et al.Mechanisms and parameters controlling the tricalcium aluminate reactivity in the presence of gypsum[J].Cement and Concrete Research,2007,37(10):1418-1426.DOI:10.1016/j.cemconres.2007.06.001.
[23] Mota B,Matschei T,Scrivener K.The influence of sodium salts and gypsum on alite hydration[J].Cement and Concrete Research,2015,75:53-65.DOI:10.1016/j.cemconres.2015.04.015.
[24] Haghtalab A,Badizad M H.Solubility of gypsum in aqueous NaCl + K2SO4 solution using calcium ion selective electrode—investigation of ionic interactions[J].Fluid Phase Equilibria,2016,409:341-353.DOI:10.1016/j.fluid.2015.10.011.
[25] Zhang Y X,Yang Z H,Guo D,et al.Effect of chloride salts and bicarbonate on solubility of CaSO4 in aqueous solutions at 37 ℃[J].Procedia Environmental Sciences,2013,18:84-91.DOI:10.1016/j.proenv.2013.04.012.
[26] 文静,余红发,吴成友,等.氯氧镁水泥水化历程的影响因素及水化动力学[J].硅酸盐学报,2013,41(5):588-596.DOI:10.7521/j.issn.0454-5648.2013.05.03.Wen J,Yu H F,Wu C Y,et al.Hydration kinetic and influencing parameters in hydration process of magnesium oxychloride cement[J].Journal of the Chinese Ceramic Society,2013,41(5):588-596.DOI:10.7521/j.issn.0454-5648.2013.05.03.(in Chinese)
[27] 彭小芹,兰聪,王淑萍,等.水化硅酸钙粉体对水泥水化反应过程及机理的影响[J].建筑材料学报,2015,18(2):195-201.DOI:10.3969/j.issn.1007-9629.2015.02.003.Peng X Q,Lan C,Wang S P,et al.Effects of the C-S-H powder on the hydration process and mechanism of cement[J].Journal of Building Materials,2015,18(2):195-201.DOI:10.3969/j.issn.1007-9629.2015.02.003.(in Chinese)
[28] 阎培渝,郑峰.水泥基材料的水化动力学模型[J].硅酸盐学报,2006,34(5):555-559.DOI:10.3321/j.issn:0454-5648.2006.05.009.Yan P Y,Zheng F.Kinetics model for the hydration mechanism of cementitious materials[J].Journal of the Chinese Ceramic Society,2006,34(5):555-559.DOI:10.3321/j.issn:0454-5648.2006.05.009.(in Chinese)