商品混凝土早期裂缝的机理与控制研究
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摘要
目前,混凝土已经逐渐成为人类社会不可缺少的基础材料。国内外建筑工程中所需的混凝土材料有很大一部分来自商品混凝土搅拌站供应。由于商品混凝土具有流动性高、胶凝材料用量多、砂率大等特点,导致商品混凝土收缩偏大,容易出现早期裂缝。我国商品混凝土技术发展很不平衡,西北地区商品混凝土早期裂缝问题较为严重,本文针对兰州市商品混凝土的发展现状,结合气候特点,在配合比设计、原材料甄选、搅拌及施工工艺优化等方面,实现较好控制早期裂缝的目标。
本文围绕商品混凝土早期收缩和裂缝这一主题,从形成机理、试验研究、理论探索三个方面对这一当前亟待解决的课题进行了研究。主要讨论了以下内容:
(1)对商品混凝土存在的早期收缩和早期裂缝,进行了分析和概述,结合国内外的参考资料,研究了早期裂缝产生的原因和基本形式。
(2)进行了单掺聚丙烯纤维、单掺膨胀剂、复掺聚丙烯纤维和膨胀剂的商品混凝土早期收缩试验研究。
(3)通过平板试验,研究了水胶比、矿物掺合料、早期养护对商品混凝土早期裂缝的影响。
(4)针对水胶比、砂率、矿物掺合料及聚丙烯纤维等因素对商品混凝土早期裂缝的影响,采用正交试验法对商品混凝土早期裂缝进行了试验研究。
结果表明,本文研究控制商品早期裂缝的措施是有效的,为今后同样问题的出现提供了方便,可以推广使用。
Nowadays,concrete gradually has become one of the necessary basic materials to the human beings.The concrete used by the construction project is usually supplied by the ready-mixed concrete factory.Owing to the larger liquidity,the cementitious material and the sand-aggregate ratio are large,ready-mixed concrete has large shrinkage and emerges early age cracking easily.Ready-mixed concrete technology has been developing differently in different areas of China.In northwest,the early age cracking of ready-mixed concrete is very serious.The character of climate in Lanzhou are analyzed and some approach are discussed to the goal of how to control the early age cracking due to design of mixture proportions,material selection,mix round and construction technics optimization according to the developmental actuality of ready-mixed concrete technology in Lanzhou.
This paper studies the early age shrinkage and cracking of ready-mixed concrete and it is discussed from three aspects including formation mechanics,experimental investigation and theoretical research.The following problems are mainly discussed in this dissertation.
(1)First,make an analysis and a summary of the early age shrinkage and cracking in ready-mixed concrete.With the reference to literature both at home and abroad,study the basic forms of early age cracking and reasons why cracking emerge.
(2)The paper proceed early age shrinkage experiments on the ready-mixed concrete(including only polypropylene fiber in the ready-mixed concrete,only expansive admixture in the ready-mixed concrete,both polypropylene fiber and expansive admixture in the ready-mixed concrete).
(3)Through the slab test,we research the influence of early age cracking of ready-mixed concrete from the water binder radio varieties,mineral admixture and early age curing.
(4)Adopting the method of orthogonal experimental design in the early age cracking of ready-mixed concrete,study was carried out on effect of early age cracking of ready-mixed concrete on water binder radio varieties,sand-aggregate ratio,mineral admixture and polypropylene fiber.
The experiment results indicate that the control methods on early age cracking of ready-mixed concrete are effective,it provides convenience for the similar problem and their application may be extended.
本文围绕商品混凝土早期收缩和裂缝这一主题,从形成机理、试验研究、理论探索三个方面对这一当前亟待解决的课题进行了研究。主要讨论了以下内容:
(1)对商品混凝土存在的早期收缩和早期裂缝,进行了分析和概述,结合国内外的参考资料,研究了早期裂缝产生的原因和基本形式。
(2)进行了单掺聚丙烯纤维、单掺膨胀剂、复掺聚丙烯纤维和膨胀剂的商品混凝土早期收缩试验研究。
(3)通过平板试验,研究了水胶比、矿物掺合料、早期养护对商品混凝土早期裂缝的影响。
(4)针对水胶比、砂率、矿物掺合料及聚丙烯纤维等因素对商品混凝土早期裂缝的影响,采用正交试验法对商品混凝土早期裂缝进行了试验研究。
结果表明,本文研究控制商品早期裂缝的措施是有效的,为今后同样问题的出现提供了方便,可以推广使用。
Nowadays,concrete gradually has become one of the necessary basic materials to the human beings.The concrete used by the construction project is usually supplied by the ready-mixed concrete factory.Owing to the larger liquidity,the cementitious material and the sand-aggregate ratio are large,ready-mixed concrete has large shrinkage and emerges early age cracking easily.Ready-mixed concrete technology has been developing differently in different areas of China.In northwest,the early age cracking of ready-mixed concrete is very serious.The character of climate in Lanzhou are analyzed and some approach are discussed to the goal of how to control the early age cracking due to design of mixture proportions,material selection,mix round and construction technics optimization according to the developmental actuality of ready-mixed concrete technology in Lanzhou.
This paper studies the early age shrinkage and cracking of ready-mixed concrete and it is discussed from three aspects including formation mechanics,experimental investigation and theoretical research.The following problems are mainly discussed in this dissertation.
(1)First,make an analysis and a summary of the early age shrinkage and cracking in ready-mixed concrete.With the reference to literature both at home and abroad,study the basic forms of early age cracking and reasons why cracking emerge.
(2)The paper proceed early age shrinkage experiments on the ready-mixed concrete(including only polypropylene fiber in the ready-mixed concrete,only expansive admixture in the ready-mixed concrete,both polypropylene fiber and expansive admixture in the ready-mixed concrete).
(3)Through the slab test,we research the influence of early age cracking of ready-mixed concrete from the water binder radio varieties,mineral admixture and early age curing.
(4)Adopting the method of orthogonal experimental design in the early age cracking of ready-mixed concrete,study was carried out on effect of early age cracking of ready-mixed concrete on water binder radio varieties,sand-aggregate ratio,mineral admixture and polypropylene fiber.
The experiment results indicate that the control methods on early age cracking of ready-mixed concrete are effective,it provides convenience for the similar problem and their application may be extended.
引文
[1]王铁梦.工程结构裂缝控制[M].中国建筑工业出版社,1997.
[2]曹同芳.商品混凝土早期裂缝的成因及防治措施[J].混凝土,2000,(5):24-25.
[3]游建.浅谈泵送混凝土施工中温度裂缝的成因及控制[J].山西建筑,2006,32(11):117-118.
[4]王建兵,谢东.混凝土工程裂缝的产生原因辑预防[J].煤炭技术,2003,22(12).
[5]简华丽,袁继雄,谢慧才.泵送混凝土早期裂缝分析[J].四川建筑科学研究,2003,29(4):68-70.
[6]彭振滨,陈迎明,刘安邦.混凝土收缩机理及其诊治原理[J].混凝土,2003:30-32.
[7]薛军鹏.外加剂在商品混凝土中的适应性问题[J].西部探矿工程,2006,(7):234-236.
[8]王信刚.外加剂对水泥基材料早期变形性能影响的研究[D].武汉大学硕士学位论文.2004.
[9]郭毅霖,李悦,霍达.骨料与纤维用量对混凝土早期自收缩影响效应的研究[J].(6):50-52.
[10]周梅,刘睿,郭彦霜.掺合料品种与用量对混凝土性能的影响[J].辽宁工程技术大学学报 2006,25(4):210-213.
[11]A.Radocea.Autogenous Volume Change of Concrete at Very Early Age[J].Magazine of Concrete Researsh,1998,50(2):107-109.
[12]S.Lepage,M.Balbaki,E.Dallaire.Early Shrinkage Development in the High Performance Concrete[A].Cement,Concrete and Aggregates,1999,21(2):31-35.
[13]E.Tazawa,S.Miyazawa.Influence of Cement and Admixture on Autogenous Shrinkage of Cement Paste[J].Cement and Concrete Research,1995,25(2):81-87.
[14]巴恒静,高小建.高性能混凝土早期自收缩测试方法研究[J].工业建筑,2003(8):1-4.
[15]安明喆,朱金栓,覃维祖.高性能混凝土自收缩的抑制措施[J].混凝土,2001,(5):37-41.
[16]田倩,孙伟,缪昌文等.高性能混凝土自收缩测量方法探讨[J].建筑材料学报,2005,8(1):82-89.
[17]R.Springenschmid.Avoidance of Thermal Cracking in Concrete at Early Ages[A]Report of work of RILEM Technical Committee-199 TCE,1998,Munich.
[18]R.Springenschmid,R.Breitenbucher and M.Mangold.Development of Thermal Cracking Frame and the Temperature-Stress Testing Machine[A].In Themal Cracking In Concrete at Early Age,Proceedings of the Intemational RILEM Symposium[C],1994:137-144.
[19]P.H.Emmons.Selecting Durable RepairMaterials:Performance Criteria[J].Concrete International,2000:38-45.
[20]Parviz,Soroushian and Siavosh.Control of Plastic Shrinkage Cracking with Speciality Cellulose Fibers[J].ACI Materials Journal,1998:429-435.
[21]P.Kraai.A Proposed Test to Determine the Cracking Potential Due to Drying Shrinkage of Concrete[J].Concrete Construction,1985:775-778.
[22]W.J.Weiss,S.P.Shah.Shrinkage Cracking of Restrained Concrete Slabs[J].J.of Engineering Mechanics.ASCE,1998,124(7):765-774.
[23]R.W.Carlson,T.J.Reading.Model Study of Shrinkage Cracking in Concrete Building Walls[J].ACI Structural Journal,1998:395-403.
[24]Heather.T.See,Emmanuel.K.Attiogbe and Matthew.A.Miltenberger.Shrinkage Cracking Characteristics of Concrete Using Ring Specimens[J].ACI Materials Journal,2003,100(3):239-245.
[25]巴恒静,高小建.约束条件下高性能混凝土的早期开裂[J].混凝土,2002(5):3-6.
[26]罗素蓉,郑建岚,胡晓凌.泵送高流态混凝土抗裂试验研究[C].第五届“高强与高性能混凝土及其应用”学术讨论会论文集[A],2004:38-44.
[27]李丽,孙伟,刘志勇.用平板法研究高性能混凝土早期塑性收缩开裂[J].混凝土,2003(12):33-37.
[28]陈翠红,王元,李景欢金恒刚.大流态混凝土早期裂缝原因分析及控制措施[J].混凝土,2003(5):33-35.
[29]Parviz Soroushian,Siavosh Ravanbakhsh.Control of Plastic Shrinkage Cracking with Specialty Cellulose Fibers[J].ACI Materials Journal,1998,95(4):429-435.
[30]Karri P.Proposed Test to Determine the Cracking Potential due to Drying Shrinkage of Concrete[J].Concrete Construction.Construction.1985,30(9):775
[31]S.P.Shah,M.E.karaguler.Effects of Shrinkage-Reducing Admixtures on Restrained Shrinkage Cracking of Concrete[J].ACI Materials Journal,1992,89(3):289-295.
[32]Karl Wiegrink,Shashidhara Marikunte.Shrinkage Cracking of High-Strength Concrete[J].ACI Materials Journal.September-October 1996,93(5):409-415.
[33]候景鹏,袁勇,柳献.混凝土早期收缩试验方法评价[J].混凝土与水泥制品,2003(5):1-4.
[34]K.Kovler.Testing System for Determining the Mechanical Behavior of Early Age Concrete under Restrained and Free Uniaxial Shrinkage[J].Materials and Structure,1994,27(3).
[35]Paigon.Equipment for the Analysis of Behavior of Concrete Under Restrained Shrinkage at Early Ages[J].Magazine of Concrete Rescearch,2000.
[36]陈肇元等.混凝土结构耐久性设计与施工指南[S].CCES01-2004,2005.
[37]施惠生,方伟.混凝土早期开裂的原因分析(二)[J].建筑技术与应用,2004(1):19-20.
[38]F.H.Wittman.On the Action of Capillary Pressure[J].Cement and Concrete Research,1976,16:49-56.
[39]杨建森.高性能混凝土的变形性能及其控制[J].混凝土,2001(10):13-17.
[40]冷发光.刘江山,邢峰.克裂速纤维增强混凝土收缩性能试验研究[J].混凝土,2001(4):34-37.
[41]张佚伦.聚丙烯纤维混凝土早期收缩与抗裂性能试验研究[D].浙江大学硕士学位论文,2006.
[42]S.Lepage,M.Balbaki,E.Dallaire.Early Shrinkage Development in the high performance concrete[J].Cement Concrete and Aggregates,1999(2):31-35.
[43]钱晓倩,詹树林.减水剂对混凝土收缩和裂缝的负影响[J].铁道科学与工程学报,2004(2):19-25.
[44]Kejin wang,Surendra P.Shah and Pariya Phuaksuk.Plastic Shrinkage Cracking in Concrete Materials-Influence of Fly Ash and Fibers[J].ACI Materials Journal,2001,98(6):455-464.
[45]姚武,郑欣.混凝土配合比对收缩影响的正交试验研究[J].建筑材料学报,2006,9(1):92-98.
[46]Surendra P.Shah,Chengsheng Quyang.A Method to Predict Shrinkage Cracking of Concrete[J].ACI Materials Journal,1998,95(4):399-346.
[47]张承志.商品混凝土[M].北京:化学工业出版社,2006.
[48]王川.大流动性混凝土塑性收缩裂缝研究[D].重庆大学硕士学位论文,2002.
[49]李晓斌.混凝土收缩成因及裂缝控制研究[D].重庆大学工程硕士学位论文,2003.
[50]蔡正,王足献.正交设计在混凝土中的应用[M].北京:中国建筑工业出版社,1985.
[51]姚激.混凝土结构温度裂缝分析与计算机仿真模拟[D].昆明理工大学硕士学位论文,2002.
[52]李伟.商品混凝土—建筑业进步的趋势[J].中外建筑,2002(3).
[53]童育林.大体积混凝土裂缝控制研究[D].重庆大学工程硕士学位论文,2004.
[54]曲成.混凝土结构裂缝成因分析及加固技术[D].大连理工大学硕士学位论文,2002.
[55]焦予民.商品混凝土搅拌站称量系统的设计细节浅析[J].建筑机械技术与管理,2005(3).
[56]邹琢晶.推广使用商品混凝土势在必行—商品混凝土技术经济分析[D].四川大学工程硕士学位论文,2004.
[57]黄宋堂.钢筋混凝土结构早期裂缝的成因与控制[J].施工技术,2006(10):42-44.
[58]黄建军,赵俊德,张全喜.浅谈商品混凝土裂缝的控制[J].山西建筑,2002,28(8):116-117.
[59]姚明甫,詹炳根.养护对高性能混凝土塑性收缩的影响[J].合肥工业大学学报,2005,28(2):180-184.
[60]丁晓春,唐华,郭永平.炎热环境中混凝土配合比对塑性收缩裂缝的影响[J].中国建材科技,2000,(5):43-47.
[2]曹同芳.商品混凝土早期裂缝的成因及防治措施[J].混凝土,2000,(5):24-25.
[3]游建.浅谈泵送混凝土施工中温度裂缝的成因及控制[J].山西建筑,2006,32(11):117-118.
[4]王建兵,谢东.混凝土工程裂缝的产生原因辑预防[J].煤炭技术,2003,22(12).
[5]简华丽,袁继雄,谢慧才.泵送混凝土早期裂缝分析[J].四川建筑科学研究,2003,29(4):68-70.
[6]彭振滨,陈迎明,刘安邦.混凝土收缩机理及其诊治原理[J].混凝土,2003:30-32.
[7]薛军鹏.外加剂在商品混凝土中的适应性问题[J].西部探矿工程,2006,(7):234-236.
[8]王信刚.外加剂对水泥基材料早期变形性能影响的研究[D].武汉大学硕士学位论文.2004.
[9]郭毅霖,李悦,霍达.骨料与纤维用量对混凝土早期自收缩影响效应的研究[J].(6):50-52.
[10]周梅,刘睿,郭彦霜.掺合料品种与用量对混凝土性能的影响[J].辽宁工程技术大学学报 2006,25(4):210-213.
[11]A.Radocea.Autogenous Volume Change of Concrete at Very Early Age[J].Magazine of Concrete Researsh,1998,50(2):107-109.
[12]S.Lepage,M.Balbaki,E.Dallaire.Early Shrinkage Development in the High Performance Concrete[A].Cement,Concrete and Aggregates,1999,21(2):31-35.
[13]E.Tazawa,S.Miyazawa.Influence of Cement and Admixture on Autogenous Shrinkage of Cement Paste[J].Cement and Concrete Research,1995,25(2):81-87.
[14]巴恒静,高小建.高性能混凝土早期自收缩测试方法研究[J].工业建筑,2003(8):1-4.
[15]安明喆,朱金栓,覃维祖.高性能混凝土自收缩的抑制措施[J].混凝土,2001,(5):37-41.
[16]田倩,孙伟,缪昌文等.高性能混凝土自收缩测量方法探讨[J].建筑材料学报,2005,8(1):82-89.
[17]R.Springenschmid.Avoidance of Thermal Cracking in Concrete at Early Ages[A]Report of work of RILEM Technical Committee-199 TCE,1998,Munich.
[18]R.Springenschmid,R.Breitenbucher and M.Mangold.Development of Thermal Cracking Frame and the Temperature-Stress Testing Machine[A].In Themal Cracking In Concrete at Early Age,Proceedings of the Intemational RILEM Symposium[C],1994:137-144.
[19]P.H.Emmons.Selecting Durable RepairMaterials:Performance Criteria[J].Concrete International,2000:38-45.
[20]Parviz,Soroushian and Siavosh.Control of Plastic Shrinkage Cracking with Speciality Cellulose Fibers[J].ACI Materials Journal,1998:429-435.
[21]P.Kraai.A Proposed Test to Determine the Cracking Potential Due to Drying Shrinkage of Concrete[J].Concrete Construction,1985:775-778.
[22]W.J.Weiss,S.P.Shah.Shrinkage Cracking of Restrained Concrete Slabs[J].J.of Engineering Mechanics.ASCE,1998,124(7):765-774.
[23]R.W.Carlson,T.J.Reading.Model Study of Shrinkage Cracking in Concrete Building Walls[J].ACI Structural Journal,1998:395-403.
[24]Heather.T.See,Emmanuel.K.Attiogbe and Matthew.A.Miltenberger.Shrinkage Cracking Characteristics of Concrete Using Ring Specimens[J].ACI Materials Journal,2003,100(3):239-245.
[25]巴恒静,高小建.约束条件下高性能混凝土的早期开裂[J].混凝土,2002(5):3-6.
[26]罗素蓉,郑建岚,胡晓凌.泵送高流态混凝土抗裂试验研究[C].第五届“高强与高性能混凝土及其应用”学术讨论会论文集[A],2004:38-44.
[27]李丽,孙伟,刘志勇.用平板法研究高性能混凝土早期塑性收缩开裂[J].混凝土,2003(12):33-37.
[28]陈翠红,王元,李景欢金恒刚.大流态混凝土早期裂缝原因分析及控制措施[J].混凝土,2003(5):33-35.
[29]Parviz Soroushian,Siavosh Ravanbakhsh.Control of Plastic Shrinkage Cracking with Specialty Cellulose Fibers[J].ACI Materials Journal,1998,95(4):429-435.
[30]Karri P.Proposed Test to Determine the Cracking Potential due to Drying Shrinkage of Concrete[J].Concrete Construction.Construction.1985,30(9):775
[31]S.P.Shah,M.E.karaguler.Effects of Shrinkage-Reducing Admixtures on Restrained Shrinkage Cracking of Concrete[J].ACI Materials Journal,1992,89(3):289-295.
[32]Karl Wiegrink,Shashidhara Marikunte.Shrinkage Cracking of High-Strength Concrete[J].ACI Materials Journal.September-October 1996,93(5):409-415.
[33]候景鹏,袁勇,柳献.混凝土早期收缩试验方法评价[J].混凝土与水泥制品,2003(5):1-4.
[34]K.Kovler.Testing System for Determining the Mechanical Behavior of Early Age Concrete under Restrained and Free Uniaxial Shrinkage[J].Materials and Structure,1994,27(3).
[35]Paigon.Equipment for the Analysis of Behavior of Concrete Under Restrained Shrinkage at Early Ages[J].Magazine of Concrete Rescearch,2000.
[36]陈肇元等.混凝土结构耐久性设计与施工指南[S].CCES01-2004,2005.
[37]施惠生,方伟.混凝土早期开裂的原因分析(二)[J].建筑技术与应用,2004(1):19-20.
[38]F.H.Wittman.On the Action of Capillary Pressure[J].Cement and Concrete Research,1976,16:49-56.
[39]杨建森.高性能混凝土的变形性能及其控制[J].混凝土,2001(10):13-17.
[40]冷发光.刘江山,邢峰.克裂速纤维增强混凝土收缩性能试验研究[J].混凝土,2001(4):34-37.
[41]张佚伦.聚丙烯纤维混凝土早期收缩与抗裂性能试验研究[D].浙江大学硕士学位论文,2006.
[42]S.Lepage,M.Balbaki,E.Dallaire.Early Shrinkage Development in the high performance concrete[J].Cement Concrete and Aggregates,1999(2):31-35.
[43]钱晓倩,詹树林.减水剂对混凝土收缩和裂缝的负影响[J].铁道科学与工程学报,2004(2):19-25.
[44]Kejin wang,Surendra P.Shah and Pariya Phuaksuk.Plastic Shrinkage Cracking in Concrete Materials-Influence of Fly Ash and Fibers[J].ACI Materials Journal,2001,98(6):455-464.
[45]姚武,郑欣.混凝土配合比对收缩影响的正交试验研究[J].建筑材料学报,2006,9(1):92-98.
[46]Surendra P.Shah,Chengsheng Quyang.A Method to Predict Shrinkage Cracking of Concrete[J].ACI Materials Journal,1998,95(4):399-346.
[47]张承志.商品混凝土[M].北京:化学工业出版社,2006.
[48]王川.大流动性混凝土塑性收缩裂缝研究[D].重庆大学硕士学位论文,2002.
[49]李晓斌.混凝土收缩成因及裂缝控制研究[D].重庆大学工程硕士学位论文,2003.
[50]蔡正,王足献.正交设计在混凝土中的应用[M].北京:中国建筑工业出版社,1985.
[51]姚激.混凝土结构温度裂缝分析与计算机仿真模拟[D].昆明理工大学硕士学位论文,2002.
[52]李伟.商品混凝土—建筑业进步的趋势[J].中外建筑,2002(3).
[53]童育林.大体积混凝土裂缝控制研究[D].重庆大学工程硕士学位论文,2004.
[54]曲成.混凝土结构裂缝成因分析及加固技术[D].大连理工大学硕士学位论文,2002.
[55]焦予民.商品混凝土搅拌站称量系统的设计细节浅析[J].建筑机械技术与管理,2005(3).
[56]邹琢晶.推广使用商品混凝土势在必行—商品混凝土技术经济分析[D].四川大学工程硕士学位论文,2004.
[57]黄宋堂.钢筋混凝土结构早期裂缝的成因与控制[J].施工技术,2006(10):42-44.
[58]黄建军,赵俊德,张全喜.浅谈商品混凝土裂缝的控制[J].山西建筑,2002,28(8):116-117.
[59]姚明甫,詹炳根.养护对高性能混凝土塑性收缩的影响[J].合肥工业大学学报,2005,28(2):180-184.
[60]丁晓春,唐华,郭永平.炎热环境中混凝土配合比对塑性收缩裂缝的影响[J].中国建材科技,2000,(5):43-47.