硝酸钙对铝酸盐水泥强度及水化性能的影响
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摘要
在不同养护温度条件下,采用X射线衍射、微量热分析、扫描电子显微镜等研究了硝酸钙对铝酸盐水泥强度及水化性能的影响。结果表明:硝酸钙(CN)能延缓铝酸盐水泥的水化进程,在20℃其延缓程度随CN掺量提高,呈现先增大后降低。其中10%CN延缓程度最显著。在50℃其延缓程度随CN掺量提高而增大。在硝酸钙存在下,铝酸盐水泥会优先形成Gibbs自由能更低的硝酸盐钙钒石相(NO_3-AFm和NO_3-AFt),从而抑制铝酸盐水泥的相转变。CN的掺量和养护温度显著影响硝酸盐型钙钒石的形成和演变。硝酸钙大幅提高了50℃养护条件下铝酸盐水泥的抗压强度。硝酸钙的最佳掺量为10%,此时50℃养护条件下铝酸盐水泥的28 d抗压强度达到66.8 MPa,而未掺CN的铝酸盐水泥抗压强度仅为28.7 MPa。
Effect of calcium nitrate(CN) on the strength and hydration of calcium aluminate cement(CAC) at different curing temperatures was investigated. The CAC additions of CN were analyzed by X-ray diffraction, scanning electron microscopy,isothermal calorimetry and compressive strength measurement. The results show that CN can retard CAC hydration. For cured at 20 ℃, the retardation degree increases up to the ‘optimum CN' value and decreases at a higher dosage of CN with increasing the dosage of CN. The ‘optimum CN' value is 10%; For cured at 50 ℃, the retardation degree increases with increasing the dosage of CN.In the presence of CN, NO_3-AFm and NO_3-AFt are more preferred than CAH_(10) and C2_AH_8, and they are more thermostable than those typically hydrates, thus avoiding the phase conversion to a large extent. The CN addition and curing temperature affect the formation and evolution of NO_3-AFm and NO_3-AFt. For cured at 50 ℃, the compressive strength of CAC systems with CN is improved. CAC with 10% CN systems has the maximum strength(i.e., 66.8 MPa) at 28 d, while the CN-free system has the minimum strength(i.e., 28.7 MPa), the optimum dosage for CN is 10 %.
Effect of calcium nitrate(CN) on the strength and hydration of calcium aluminate cement(CAC) at different curing temperatures was investigated. The CAC additions of CN were analyzed by X-ray diffraction, scanning electron microscopy,isothermal calorimetry and compressive strength measurement. The results show that CN can retard CAC hydration. For cured at 20 ℃, the retardation degree increases up to the ‘optimum CN' value and decreases at a higher dosage of CN with increasing the dosage of CN. The ‘optimum CN' value is 10%; For cured at 50 ℃, the retardation degree increases with increasing the dosage of CN.In the presence of CN, NO_3-AFm and NO_3-AFt are more preferred than CAH_(10) and C2_AH_8, and they are more thermostable than those typically hydrates, thus avoiding the phase conversion to a large extent. The CN addition and curing temperature affect the formation and evolution of NO_3-AFm and NO_3-AFt. For cured at 50 ℃, the compressive strength of CAC systems with CN is improved. CAC with 10% CN systems has the maximum strength(i.e., 66.8 MPa) at 28 d, while the CN-free system has the minimum strength(i.e., 28.7 MPa), the optimum dosage for CN is 10 %.
引文
[1]HEWLETT P C.Lea’s Chemistry of Cement and Concrete[M].New York:Elsevier Butterworth Heinemann,1988:725-726.
[2]SCRIVENERK L,CABIRON R L.High-performance concretes from calcium aluminate cements[J].Cem Concr Res,1999,28(8):1215-1223.
[3]VALENTIN A,JADVYGA K.The effect of temperature on the formation of the hydrated calcium calcium aluminate cement structure[J].Proc Eng,2013,57:99-106.
[4]KIRCA?NDER,YAMAN??AGüR,TOKYAYMUSTAFA.Compressive strength development of calcium calcium aluminate cement-GGBFS blends[J].Cem Concr Comp,2013,35(1):163-170.
[5]COLLEPARD M,MONISI S,PICCIOLI P.The influence of pozzolanic materials on the mechanical stability of aluminous cement[J].Cem Concr Res,1995,25(5):961-968.
[6]李早元,伍鹏,程小伟,等.矿渣对铝酸盐水泥石性能影响的研究[J].硅酸盐学报,2014,33(12):3338-3342.LI Zaoyuan,WU Peng,CHENG Xiaowei,et al.J Chin Ceram Soc,2014,33(12):3338-3342.
[7]李早元,张松,张弛,等.热力采油条件下粉煤灰改善铝酸盐水泥石耐高温性能及作用机理研究[J].硅酸盐通报,2012,31(5):1101-1105.LI Zaoyuan,ZHANG Song,ZHANG Chi,et al.Bull Chin Ceram Soc(in Chinese),2012,31(5):1101-1105.
[8]马聪,步玉环,赵邵彪,等.固井用铝酸盐水泥改性试验研究[J].建筑材料学报,2015,18(1):100-106.MA Cong,BU Yuhuan,ZHAO Shaobiao,et al.J Build Mater(in Chinese),2015,18(1):100-106.
[9]杨宏章,孙加林,章荣会.用碳酸钙微粉改性的高铝水泥及其耐热性能[J].硅酸盐学报,2006,34(4):452-457.YANG Hongzhang,SUN Jialin,ZHANG Ronghui.J Chin Ceram Soc,2006,34(4):452-457.
[10]LUZ AP,PANDOLFELLI VC.CaCO3 addition effect on the hydration and mechanical strength evolution of calcium aluminate cement for endodonticapplications[J].Ceram Int,2012,38:1747-1425.
[11]邢昊.石灰石粉对高铝水泥性能影响研究[D].长沙:中南大学,2010.XING Hao.Effect of limestone powders on the property of Highalumina cement(in Chinese,dissertation).Changsha:Central south university,2010.
[12]肖佳,勾成福,邢昊,等.石灰石粉对高铝水泥性能的影响[J].建筑材料学报,2011,14(3):366-370.XIAO Jia,GOU Chengfu,XING Hao,et al.J Build Mater(in Chinese),2011,14(3):366-370.
[13]FALZONE G,BALONIS M.X-AFm stabilization as a mechanism of bypassing conversion phenomena in calcium calcium aluminate cements[J].Cem Concr Res,2015,72:54-68.
[14]SANT G,SANT M B.Inorganic admixtures for mitigating against conversion phenomena in high-alumina cements:US,0107934[P].2016-04-21.
[15]DAMIDOT D,LOTHENBACH B,HERFORT D.Thermodynamics and cement science[J].Cem Concr Res,2011,41(7):679-695.
[16]BALONIS M.The influence of inorganic chemical accelerators and corrosion inhibitors on the mineralogy of hydrated Portland cement systems(Dissertation),University of Aberdeen,Scotland,2010,2365.
[17]BALONIS M,MEDALA M,GLASSER F P.Influence of calcium nitrate and nitrite on the constitution of AFm and AFt cement hydates[J].Adv Cem Res,2011,23(3):129-143.
[18]RENAUDIN G,RAPIN J P,HUMBERT B.Thermal behavior of the nitrated AFm phase Ca4Al2(OH)12(NO3)2·4H2O and structure determination of the intermediate hydrate Ca4Al2(OH)12(NO3)2·H2O[J].Cem Concr Res,2000,30(2):307-314.
[2]SCRIVENERK L,CABIRON R L.High-performance concretes from calcium aluminate cements[J].Cem Concr Res,1999,28(8):1215-1223.
[3]VALENTIN A,JADVYGA K.The effect of temperature on the formation of the hydrated calcium calcium aluminate cement structure[J].Proc Eng,2013,57:99-106.
[4]KIRCA?NDER,YAMAN??AGüR,TOKYAYMUSTAFA.Compressive strength development of calcium calcium aluminate cement-GGBFS blends[J].Cem Concr Comp,2013,35(1):163-170.
[5]COLLEPARD M,MONISI S,PICCIOLI P.The influence of pozzolanic materials on the mechanical stability of aluminous cement[J].Cem Concr Res,1995,25(5):961-968.
[6]李早元,伍鹏,程小伟,等.矿渣对铝酸盐水泥石性能影响的研究[J].硅酸盐学报,2014,33(12):3338-3342.LI Zaoyuan,WU Peng,CHENG Xiaowei,et al.J Chin Ceram Soc,2014,33(12):3338-3342.
[7]李早元,张松,张弛,等.热力采油条件下粉煤灰改善铝酸盐水泥石耐高温性能及作用机理研究[J].硅酸盐通报,2012,31(5):1101-1105.LI Zaoyuan,ZHANG Song,ZHANG Chi,et al.Bull Chin Ceram Soc(in Chinese),2012,31(5):1101-1105.
[8]马聪,步玉环,赵邵彪,等.固井用铝酸盐水泥改性试验研究[J].建筑材料学报,2015,18(1):100-106.MA Cong,BU Yuhuan,ZHAO Shaobiao,et al.J Build Mater(in Chinese),2015,18(1):100-106.
[9]杨宏章,孙加林,章荣会.用碳酸钙微粉改性的高铝水泥及其耐热性能[J].硅酸盐学报,2006,34(4):452-457.YANG Hongzhang,SUN Jialin,ZHANG Ronghui.J Chin Ceram Soc,2006,34(4):452-457.
[10]LUZ AP,PANDOLFELLI VC.CaCO3 addition effect on the hydration and mechanical strength evolution of calcium aluminate cement for endodonticapplications[J].Ceram Int,2012,38:1747-1425.
[11]邢昊.石灰石粉对高铝水泥性能影响研究[D].长沙:中南大学,2010.XING Hao.Effect of limestone powders on the property of Highalumina cement(in Chinese,dissertation).Changsha:Central south university,2010.
[12]肖佳,勾成福,邢昊,等.石灰石粉对高铝水泥性能的影响[J].建筑材料学报,2011,14(3):366-370.XIAO Jia,GOU Chengfu,XING Hao,et al.J Build Mater(in Chinese),2011,14(3):366-370.
[13]FALZONE G,BALONIS M.X-AFm stabilization as a mechanism of bypassing conversion phenomena in calcium calcium aluminate cements[J].Cem Concr Res,2015,72:54-68.
[14]SANT G,SANT M B.Inorganic admixtures for mitigating against conversion phenomena in high-alumina cements:US,0107934[P].2016-04-21.
[15]DAMIDOT D,LOTHENBACH B,HERFORT D.Thermodynamics and cement science[J].Cem Concr Res,2011,41(7):679-695.
[16]BALONIS M.The influence of inorganic chemical accelerators and corrosion inhibitors on the mineralogy of hydrated Portland cement systems(Dissertation),University of Aberdeen,Scotland,2010,2365.
[17]BALONIS M,MEDALA M,GLASSER F P.Influence of calcium nitrate and nitrite on the constitution of AFm and AFt cement hydates[J].Adv Cem Res,2011,23(3):129-143.
[18]RENAUDIN G,RAPIN J P,HUMBERT B.Thermal behavior of the nitrated AFm phase Ca4Al2(OH)12(NO3)2·4H2O and structure determination of the intermediate hydrate Ca4Al2(OH)12(NO3)2·H2O[J].Cem Concr Res,2000,30(2):307-314.