复合环境作用对海砂混凝土耐久性的影响
|
摘要
随着我国建设规模的扩大,河砂资源短缺的现象日益突出,许多沿海地区已经采用海砂作为混凝土细骨料。但是,由于对海砂混凝土破坏机理认识不足,海砂混凝土结构耐久性大多较差。海砂混凝土结构多处于沿海地区,自建成后一直处于碳化和氯离子侵蚀的复合环境作用下,因此有必要研究海砂混凝土的抗碳化性能及其在碳化与氯离子复合作用下的耐久性。
本文首先对山东海阳海砂及其淡化砂、长岛海砂、青岛滩砂和河砂进行了系统的基本性能试验,分析了各种砂的物理性质和有害物质含量。然后,用海阳海砂、淡化海阳海砂和河砂制备强度等级C30、C40、C50和C60的混凝土,进行加速碳化、自然碳化、碳化与氯离子侵蚀复合试验。试验后测定混凝土碳化深度、CaCO_3含量、Ca(OH)_2含量和氯离子含量,利用相关理论定性和定量分析海砂混凝土和淡化海砂混凝土在复合环境作用下的劣化机理,并与河砂混凝土进行对比,从而研究复合环境作用对海砂、淡化海砂混凝土耐久性的影响。
试验结果表明:碳化后,海砂混凝土和淡化海砂混凝土碳化深度、CaCO_3含量和Ca(OH)_2含量分布情况与河砂混凝土基本一致。随着碳化时间的增加,碳化深度增加,CaCO_3含量增大,Ca(OH)_2含量减小;随着强度等级的提高,碳化深度减小,CaCO_3含量减小,Ca(OH)_2含量增大。且碳化时间越长、强度等级越高,三种混凝土的抗碳化性能越接近。碳化与氯离子侵蚀复合作用后,海砂混凝土中的氯离子含量最高,淡化海砂混凝土和河砂混凝土无明显差异。强度等级越高,混凝土遭受外界氯离子侵蚀的程度越低,氯离子含量随浸泡时间、浸泡溶液浓度和浸泡前碳化时间的增大而增大,且在以上三种影响因素中,浸泡溶液浓度的影响程度最大,浸泡时间次之,浸泡前碳化时间的影响较小。
With the expansion of the scale of construction and the shortage of river sand resource, sea sand has already been used as fine aggregate of concrete in many coastal areas. However, because the degradation mechanism of sea sand concrete has not been fully understood, the durability of sea sand concrete structures is poor. Located in coastal area, most sea sand concrete structures are exposed to combined environmental loads of carbonation and chloride penetration since they have been built. It is necessary to study the combined carbonation and chloride penetration with respect to durability of sea sand concrete.
Firstly, an analysis of the physical properties and the contents of harmful substances of Haiyang sea sand, Haiyang washed sea sand, Changdao sea sand, Qingdao beach sand and river sand was taken. Secondly, concrete with strength class of C30, C40, C50, C60 were prepared from Haiyang sea sand, Haiyang washed sea sand and river sand. The experimental test series were described by accelerated carbonation, natural carbonation and combined carbonation and chloride penetration. Finally carbonation depth, CaCO_3 content, Ca(OH)_2 content and chloride content of concrete after different environmental loads were determined.
Results show that the principle of sea sand concrete and washed sea sand concrete is basically the same as river sand concrete after carbonation. With the increase of carbonation time, carbonation depth and CaCO_3 content increase, Ca(OH)_2 content decreases; with the strength class improved, carbonation depth and CaCO_3 content decrease, Ca(OH)_2 content increases. When the carbonation time is longer and the strength class is higher, the difference of durability among the three types of concrete is smaller. After combined carbonation and chloride penetration test, the chloride content of sea sand concrete is the highest, and that of washed sea sand concrete and river sand concrete has no significant difference. The higher the strength class is, the less chloride the concrete absorbed. Chloride content increases with the penetration time, solution concentration and carbonation time. Of the above three factors, the effect of solution concentration is the strongest, followed by penetration time, the carbonation time is the weakest.
本文首先对山东海阳海砂及其淡化砂、长岛海砂、青岛滩砂和河砂进行了系统的基本性能试验,分析了各种砂的物理性质和有害物质含量。然后,用海阳海砂、淡化海阳海砂和河砂制备强度等级C30、C40、C50和C60的混凝土,进行加速碳化、自然碳化、碳化与氯离子侵蚀复合试验。试验后测定混凝土碳化深度、CaCO_3含量、Ca(OH)_2含量和氯离子含量,利用相关理论定性和定量分析海砂混凝土和淡化海砂混凝土在复合环境作用下的劣化机理,并与河砂混凝土进行对比,从而研究复合环境作用对海砂、淡化海砂混凝土耐久性的影响。
试验结果表明:碳化后,海砂混凝土和淡化海砂混凝土碳化深度、CaCO_3含量和Ca(OH)_2含量分布情况与河砂混凝土基本一致。随着碳化时间的增加,碳化深度增加,CaCO_3含量增大,Ca(OH)_2含量减小;随着强度等级的提高,碳化深度减小,CaCO_3含量减小,Ca(OH)_2含量增大。且碳化时间越长、强度等级越高,三种混凝土的抗碳化性能越接近。碳化与氯离子侵蚀复合作用后,海砂混凝土中的氯离子含量最高,淡化海砂混凝土和河砂混凝土无明显差异。强度等级越高,混凝土遭受外界氯离子侵蚀的程度越低,氯离子含量随浸泡时间、浸泡溶液浓度和浸泡前碳化时间的增大而增大,且在以上三种影响因素中,浸泡溶液浓度的影响程度最大,浸泡时间次之,浸泡前碳化时间的影响较小。
With the expansion of the scale of construction and the shortage of river sand resource, sea sand has already been used as fine aggregate of concrete in many coastal areas. However, because the degradation mechanism of sea sand concrete has not been fully understood, the durability of sea sand concrete structures is poor. Located in coastal area, most sea sand concrete structures are exposed to combined environmental loads of carbonation and chloride penetration since they have been built. It is necessary to study the combined carbonation and chloride penetration with respect to durability of sea sand concrete.
Firstly, an analysis of the physical properties and the contents of harmful substances of Haiyang sea sand, Haiyang washed sea sand, Changdao sea sand, Qingdao beach sand and river sand was taken. Secondly, concrete with strength class of C30, C40, C50, C60 were prepared from Haiyang sea sand, Haiyang washed sea sand and river sand. The experimental test series were described by accelerated carbonation, natural carbonation and combined carbonation and chloride penetration. Finally carbonation depth, CaCO_3 content, Ca(OH)_2 content and chloride content of concrete after different environmental loads were determined.
Results show that the principle of sea sand concrete and washed sea sand concrete is basically the same as river sand concrete after carbonation. With the increase of carbonation time, carbonation depth and CaCO_3 content increase, Ca(OH)_2 content decreases; with the strength class improved, carbonation depth and CaCO_3 content decrease, Ca(OH)_2 content increases. When the carbonation time is longer and the strength class is higher, the difference of durability among the three types of concrete is smaller. After combined carbonation and chloride penetration test, the chloride content of sea sand concrete is the highest, and that of washed sea sand concrete and river sand concrete has no significant difference. The higher the strength class is, the less chloride the concrete absorbed. Chloride content increases with the penetration time, solution concentration and carbonation time. Of the above three factors, the effect of solution concentration is the strongest, followed by penetration time, the carbonation time is the weakest.
引文
1 李真.江砂并非取之不尽--访长江水利委员会副主任沈泰[N].中国水利报,2003-03-18
2 S.J.de Groot.Marine sand and gravel extraction in the North Atlantic and its potential environmental impact,with emphasis on the North Sea[J].Ocean Management,1986,10(1):21-36
3 王圣洁,杨子庚,吴桑云,陈江.中国滨海建筑砂开采的环境地质问题和可持续发展对策.海洋地质动态,2000(1):5-8
4 陈坚,胡毅.我国海砂资源的开发与对策[J].海洋地质动态,2005(7):4-8
5 曹雪晴,谭启新,张勇,姜玉池,原晓军.中国近海建筑砂矿床特征.岩石矿物学杂志,2007(3),164-170
6 郑容跃,袁丽莉,贺志敏.宁波地区的海砂问题及其对策.混凝土,2004(10):22-24
7 陈肇元,徐有临,钱稼茹.土建结构工程的安全性与耐久性[J].施工技术,1995(7):35-37
8 金伟良,赵羽习.混凝土结构耐久性[M].北京:科学出版社,2002
9 How to Make Today's Concrete Durable for Tomorrow.The institution of Civil Engineers,London,1985
10 唐明述.提高重大混凝士T程的耐久性[J].中国华工,1996(3):34-37
11 洪定海.论防止混凝土结构中钢筋腐蚀破坏的规范问题.全国钢筋混凝土结构标准技术委员会混凝土耐久性成立大会报告,天津,1991
12 Rasheeduzzafar,Dakhil,Fahd.The deterioration of concrete structures in the environment of the MiddleEast[J].ACI Journal,Proceedings,1984,81(1):13-20
13 洪乃丰.钢筋混凝土基础设施腐蚀与耐久性.混凝土结构耐久性及耐久性设计会议论文集.北京:清华大学:2002(11):119-124
14 卢木.混凝土耐久性研究现状和研究方向[J].工业建筑.1997,27(5):1-6
15 中国工程院土木水利建筑学部.土建结构工程的安全性与耐久性--现状、问题与对策.2003,8
16 方德友.我国铁路桥梁病害浅析与对策.大连:中国铁道学会桥梁病害诊断及剩余寿命评估学术研讨会,1995
17 张泳,付君.浅析沿海地区的海砂滥用问题及其防治.福建建筑,2005,(2):70-72
18 洪定海.混凝土中钢筋的腐蚀与保护[M].北京:中国铁道出版社,1998
19 杨医博,梁松,莫海鸿,陈尤雯.抗氯盐高性能混凝土技术手册[M].北京:中国水利水电出版社,知识产权出版社.2006
20 混凝土结构耐久性设计与施工指南.中国土木工程协会.第4.0.8条
21 普通混凝土用砂、石质量及检验方法标准(JGJ52-2006)[S]
22 陈士强,罗春燕等.HEC海砂混凝土性能及其在康熙岭海堤建设中的应用[J].广西水利水电, 2004(3):2-7
23 洪乃丰.海砂对钢筋混凝土的腐蚀与对策[J].混凝土,2002,(8):12-14
24 Y/T923 1-98,钢筋阻锈剂使用技术规程[S].
25 Babushkin,V.I.,Matveyev,G.M.,and Mcbedlov Petrosyan,O.P.Thermodynamics of Silicaten.Springer Verlag.1985
26 V.G.Padadakis,C.G.Vayenas,et al.Fundamental modelling and experimental investigation of concrete carbonation[J],ACI Materials Journal,1991,(88):363-373
27 刘祖华,梁发云.混凝土碳化研究现状述评.四川建筑科学研究.2000(3):52-54
28 范子彦.碳化混凝土的抗压强度[硕士学位论文].上海:同济大学土木学院.1997
29 蒋利学,张誉.混凝土碳化深度的计算与试验研究[J].混凝土,1996,(4):12-17
30 方璟.大坝混凝土耐久性研究[J].混凝土与水泥制品,1993,(6):31-36
31 Papadakis V G,et Al,physical and characteristics affecting the durability of concrete.ACI Materials Journal,1991(88):186-196
32 Papadakis V G,et aL,fundamental modeling and experimental investigation of concrete carbonation problem,chemical engineering science,1991(46):1333-1338
33 颜承越.混凝土碳化与强度关系的建立与应用.混凝士与水泥制品.1993(6):19-21
34 K.Kamimura,ph.D.,P.j.Sereda,Msc.andE.G.Swenson,Msc.Changes in weight and dimension in the drying and carbonation of Portland cement mortars.Concrete research,1965,Vol.17,No.50:5-14
35 Folker H.Wittmann.Repair and maintenance of reinforced concrete structures.AEDIFICATIO Publishers 2001,transfer 2:73-84
36 V G.papadakis,C.G.Vayenas,M.N.Fardjs.Fundamental modeling and experimental investigation of concrete carbonation.ACI Materials Journal,1991(4)
37 谢永江.氢氧化钙对混凝土耐久性的贡献与危害.第五界全国混凝土耐久性学术交流会.2000年10月:304-307
38 V.T.Nagala,C.L.Page.Effects of carbonation on pore structure and diffusion properties of hydrated cement pastes[J],Cement and Concrete Research,1997,pp.995-1007
39 P.J.Dewaele,E.J.Reardon,and R.Dayal.Permeability and porosity changes associated with cement grout carbonation[J],Cement and Concrete Research,1991,pp.441-454
40 B.Johannesson,P.Utgenannt.Microstructural changes caused by carbonation of cement mortar[J],Cement and Concrete Research,2001,pp.925-931
41 方璟,梅国兴,陆采荣.碳化对混凝土性能影响的研究[J].水利水电技术,1996,(2):58-64
42 赵铁军,李淑进.碳化对混凝土渗透性及孔隙率的影响[J].工业建筑,2003,33(1):46-48
43 P.A.Claisse,I.G.Shaaban.Permeability and pore volume of carbonated concrete[J],ACI Materials Journal,1999,96(3):378-381
44 L.J.Parrott,et al.A study of carbonation-induced corrosion[J].Magazine of Concrete Research,1994,166(46):23-28
45 蒋利学,贡春成.混凝士部分碳化区长度的分析与计算[J].工业建筑,1999,29(1):4-7
46 Y.F.Houst,F.H.Wittmann.Depth profile of carbonates formed during natural carbonation[J],Cement and Concrete Research,2002,32(2002):1923-1930
47 Vladim(?)r(?)ivica.Corrosion of reinforced induced by environment containing chloride and carbon dioxide[J],Bull.Mater.Sic.2003,26,(6):605-608
48 D.J.Anstice,C.L.Page,and M.M.Page.The pore solution phase of carbonated cement pastes [J],Cement and Concrete Research,2004,35(2005):377-383
49 J.P.Broomfield.Corrosion of steel in concrete[M],London,E&FN Spon,1992,pp.28-30
50 K.Tuutti.Corrosion of steel in concrete,CBI,Research Report 4,Stockholm,Sweden,1982,pp.82-84
51 马红岩.海砂对水泥基材料水化行为及护筋性能的影响研究[D].深圳大学硕士学位论文,2008
52 柳俊哲.混凝土碳化研究与进展(3)--腐蚀因子的迁移[J].混凝土,2006(1):51-54
53 Ihekwaba N,Hope B,Hansson C.Carbonation and Electrochemical Chloride Extraction from concrete[J].Cement and Concrete Research,1996,26(7):1095-1107
54 李淑进.混凝士的渗透性与耐久性研究.青岛理工大学硕士学位论文.2002年3月:54-59
55 L.J.Partout et al.,A Study Of Carbonation-induced Corrosion,Magazine Of Concrete Research,1994,Vol.46,No.166:23-38
56 温连军.青岛地区混凝土碳化性能研究[硕士学位论文].青岛:青岛理工大学,2006.06,pp.22-23
57 F.M.Lea.水泥和混凝土化学(第三版).唐明述,杨南如等译.建筑工业出版.1980年:133-135
58 A.Gerds.Depth of Carbonation and Chloride Profile.Transfer 2 repair and maintenance of reinforced concrete structures.Shizao zhou,F.H.Wittmann editors.2001:73-84
59 Lutz Franke,Kritsada Sisomphon.A new chemical method for analyzing free calcium hydroxide content in cementing material.Cement and Concrete Research.2004:1161-1165
2 S.J.de Groot.Marine sand and gravel extraction in the North Atlantic and its potential environmental impact,with emphasis on the North Sea[J].Ocean Management,1986,10(1):21-36
3 王圣洁,杨子庚,吴桑云,陈江.中国滨海建筑砂开采的环境地质问题和可持续发展对策.海洋地质动态,2000(1):5-8
4 陈坚,胡毅.我国海砂资源的开发与对策[J].海洋地质动态,2005(7):4-8
5 曹雪晴,谭启新,张勇,姜玉池,原晓军.中国近海建筑砂矿床特征.岩石矿物学杂志,2007(3),164-170
6 郑容跃,袁丽莉,贺志敏.宁波地区的海砂问题及其对策.混凝土,2004(10):22-24
7 陈肇元,徐有临,钱稼茹.土建结构工程的安全性与耐久性[J].施工技术,1995(7):35-37
8 金伟良,赵羽习.混凝土结构耐久性[M].北京:科学出版社,2002
9 How to Make Today's Concrete Durable for Tomorrow.The institution of Civil Engineers,London,1985
10 唐明述.提高重大混凝士T程的耐久性[J].中国华工,1996(3):34-37
11 洪定海.论防止混凝土结构中钢筋腐蚀破坏的规范问题.全国钢筋混凝土结构标准技术委员会混凝土耐久性成立大会报告,天津,1991
12 Rasheeduzzafar,Dakhil,Fahd.The deterioration of concrete structures in the environment of the MiddleEast[J].ACI Journal,Proceedings,1984,81(1):13-20
13 洪乃丰.钢筋混凝土基础设施腐蚀与耐久性.混凝土结构耐久性及耐久性设计会议论文集.北京:清华大学:2002(11):119-124
14 卢木.混凝土耐久性研究现状和研究方向[J].工业建筑.1997,27(5):1-6
15 中国工程院土木水利建筑学部.土建结构工程的安全性与耐久性--现状、问题与对策.2003,8
16 方德友.我国铁路桥梁病害浅析与对策.大连:中国铁道学会桥梁病害诊断及剩余寿命评估学术研讨会,1995
17 张泳,付君.浅析沿海地区的海砂滥用问题及其防治.福建建筑,2005,(2):70-72
18 洪定海.混凝土中钢筋的腐蚀与保护[M].北京:中国铁道出版社,1998
19 杨医博,梁松,莫海鸿,陈尤雯.抗氯盐高性能混凝土技术手册[M].北京:中国水利水电出版社,知识产权出版社.2006
20 混凝土结构耐久性设计与施工指南.中国土木工程协会.第4.0.8条
21 普通混凝土用砂、石质量及检验方法标准(JGJ52-2006)[S]
22 陈士强,罗春燕等.HEC海砂混凝土性能及其在康熙岭海堤建设中的应用[J].广西水利水电, 2004(3):2-7
23 洪乃丰.海砂对钢筋混凝土的腐蚀与对策[J].混凝土,2002,(8):12-14
24 Y/T923 1-98,钢筋阻锈剂使用技术规程[S].
25 Babushkin,V.I.,Matveyev,G.M.,and Mcbedlov Petrosyan,O.P.Thermodynamics of Silicaten.Springer Verlag.1985
26 V.G.Padadakis,C.G.Vayenas,et al.Fundamental modelling and experimental investigation of concrete carbonation[J],ACI Materials Journal,1991,(88):363-373
27 刘祖华,梁发云.混凝土碳化研究现状述评.四川建筑科学研究.2000(3):52-54
28 范子彦.碳化混凝土的抗压强度[硕士学位论文].上海:同济大学土木学院.1997
29 蒋利学,张誉.混凝土碳化深度的计算与试验研究[J].混凝土,1996,(4):12-17
30 方璟.大坝混凝土耐久性研究[J].混凝土与水泥制品,1993,(6):31-36
31 Papadakis V G,et Al,physical and characteristics affecting the durability of concrete.ACI Materials Journal,1991(88):186-196
32 Papadakis V G,et aL,fundamental modeling and experimental investigation of concrete carbonation problem,chemical engineering science,1991(46):1333-1338
33 颜承越.混凝土碳化与强度关系的建立与应用.混凝士与水泥制品.1993(6):19-21
34 K.Kamimura,ph.D.,P.j.Sereda,Msc.andE.G.Swenson,Msc.Changes in weight and dimension in the drying and carbonation of Portland cement mortars.Concrete research,1965,Vol.17,No.50:5-14
35 Folker H.Wittmann.Repair and maintenance of reinforced concrete structures.AEDIFICATIO Publishers 2001,transfer 2:73-84
36 V G.papadakis,C.G.Vayenas,M.N.Fardjs.Fundamental modeling and experimental investigation of concrete carbonation.ACI Materials Journal,1991(4)
37 谢永江.氢氧化钙对混凝土耐久性的贡献与危害.第五界全国混凝土耐久性学术交流会.2000年10月:304-307
38 V.T.Nagala,C.L.Page.Effects of carbonation on pore structure and diffusion properties of hydrated cement pastes[J],Cement and Concrete Research,1997,pp.995-1007
39 P.J.Dewaele,E.J.Reardon,and R.Dayal.Permeability and porosity changes associated with cement grout carbonation[J],Cement and Concrete Research,1991,pp.441-454
40 B.Johannesson,P.Utgenannt.Microstructural changes caused by carbonation of cement mortar[J],Cement and Concrete Research,2001,pp.925-931
41 方璟,梅国兴,陆采荣.碳化对混凝土性能影响的研究[J].水利水电技术,1996,(2):58-64
42 赵铁军,李淑进.碳化对混凝土渗透性及孔隙率的影响[J].工业建筑,2003,33(1):46-48
43 P.A.Claisse,I.G.Shaaban.Permeability and pore volume of carbonated concrete[J],ACI Materials Journal,1999,96(3):378-381
44 L.J.Parrott,et al.A study of carbonation-induced corrosion[J].Magazine of Concrete Research,1994,166(46):23-28
45 蒋利学,贡春成.混凝士部分碳化区长度的分析与计算[J].工业建筑,1999,29(1):4-7
46 Y.F.Houst,F.H.Wittmann.Depth profile of carbonates formed during natural carbonation[J],Cement and Concrete Research,2002,32(2002):1923-1930
47 Vladim(?)r(?)ivica.Corrosion of reinforced induced by environment containing chloride and carbon dioxide[J],Bull.Mater.Sic.2003,26,(6):605-608
48 D.J.Anstice,C.L.Page,and M.M.Page.The pore solution phase of carbonated cement pastes [J],Cement and Concrete Research,2004,35(2005):377-383
49 J.P.Broomfield.Corrosion of steel in concrete[M],London,E&FN Spon,1992,pp.28-30
50 K.Tuutti.Corrosion of steel in concrete,CBI,Research Report 4,Stockholm,Sweden,1982,pp.82-84
51 马红岩.海砂对水泥基材料水化行为及护筋性能的影响研究[D].深圳大学硕士学位论文,2008
52 柳俊哲.混凝土碳化研究与进展(3)--腐蚀因子的迁移[J].混凝土,2006(1):51-54
53 Ihekwaba N,Hope B,Hansson C.Carbonation and Electrochemical Chloride Extraction from concrete[J].Cement and Concrete Research,1996,26(7):1095-1107
54 李淑进.混凝士的渗透性与耐久性研究.青岛理工大学硕士学位论文.2002年3月:54-59
55 L.J.Partout et al.,A Study Of Carbonation-induced Corrosion,Magazine Of Concrete Research,1994,Vol.46,No.166:23-38
56 温连军.青岛地区混凝土碳化性能研究[硕士学位论文].青岛:青岛理工大学,2006.06,pp.22-23
57 F.M.Lea.水泥和混凝土化学(第三版).唐明述,杨南如等译.建筑工业出版.1980年:133-135
58 A.Gerds.Depth of Carbonation and Chloride Profile.Transfer 2 repair and maintenance of reinforced concrete structures.Shizao zhou,F.H.Wittmann editors.2001:73-84
59 Lutz Franke,Kritsada Sisomphon.A new chemical method for analyzing free calcium hydroxide content in cementing material.Cement and Concrete Research.2004:1161-1165