隧道喷射混凝土抗冻性室内试验研究
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摘要
喷射混凝土在各种土建工程领域有着广泛的应用,隧道工程中喷射混凝土是隧道结构体系的主要承载单元。目前,在混凝土抗冻性方面,国内外已经做了大量的研究工作,取得了丰硕的成果,但喷射混凝土抗冻性的研究却极为鲜见。为此,本文采用理论分析和室内试验的方法,对C20和C25喷射混凝土的抗冻性进行了研究,主要取得以下成果：
1、C20喷射混凝土在60个冻融循环以后,试件表面的剥落急剧增多,动弹性模量的下降较为明显,大部分试件已经接近损毁,C25喷射混凝土在100个冻融循环以后,试件表面的剥落才开始急剧增多,动弹性模量的下降也是较为明显,大部分试件接近损毁。由此可见,C25喷射混凝土比C20喷射混凝土能承受更多的冻融次数,但是二者的抗冻性都较差。
2、C20喷射混凝土试件的初始动弹性模量平均值为34.52GPa,动弹性模量与冻融次数的线性回归关系为E=-0.215N+34.94(E为动弹性模量,N为冻融次数),而C25喷射混凝土分别为39.69GPa和E=-0.135N+39.55,由此可知,随冻融次数的增加,C25喷射混凝土动弹性模量的下降速度比C20喷射混凝土小,初始动弹性模量大,足见C25喷射混凝土的抗冻性能优于C20喷射混凝土。
3、C20喷射混凝土试件质量损失率与冻融次数的线性回归关系为ω=0.1975N-0.346(ω为质量损失率,N为冻融次数),而C25喷射混凝土为ω=0.1925N-0.523,由此可知,随冻融次数的增加,C20喷射混凝土质量损失率的增加速度同C25喷射混凝土相差无几,而且在冻融试验初期,大部分试件都存在随着冻融循环的进行其质量反而增大的现象,从而说明质量这个指标不能较精确的反映C20和C25喷射混凝土抗冻性的差异。
研究成果表明：寒冷地区隧道工程中,C20喷射混凝土抗冻性较差,对隧道结构耐久性以及安全性有较大影响,而C25喷射混凝土抗冻性能相对较好,这对隧道设计有指导意义和实用价值。
Shotcrete has a wide range of applications in a variety of civil engineering field,and it is main bearing units of tunnel structure in tunnel project.Currently, frost resistance in concrete terms, has done a lot of research and has achieved fruitful results at home and abroad, but frost resistance of sprayed concrete are relatively few. Therefore, this article uses the theoretical analysis and laboratory test methods, conducted a study on frost resistance of C20 and C25 shotcrete, mainly the following results:
1. After 60 freeze-thaw cycles, the specimen surface of C20 sprayed concrete flaks proliferately, dynamic elastic modulus decreases more obvious, most of the specimen is close to the damage. After 100 freeze-thaw cycles, the specimen surface flaking of C25 sprayed concrete began to proliferate, dynamic elastic modulus of decline is more obvious, most of the specimen is close to destruction. Thus, C25 sprayed concrete can withstand more freezing times than C20 sprayed concrete, but the frost resistance are more general.
2. Initial dynamic elastic modulus of C20 sprayed concrete specimen averaged 34.52GPa, dynamic elastic modulus and freeze-thaw number of linear regression relationship as E =-0.215N+34.94 (E is dynamic elastic modulus, N is times of freeze-thaw), and C25 sprayed concrete respectively 39.69GPa and E=-0.135N+39.55. Suffice it to say, with the increasing number of freeze-thaw, dynamic elastic modulus of C25 sprayed concrete decreases more slowly than C20 sprayed concrete, and the initial dynamic elastic modulus is bigger, signifying frost resistance of C25 sprayed concrete is better than C20 sprayed concrete.
3. Quality loss of C20 sprayed concrete samples and freeze-thaw number of linear regression relationship isω=0.1975N-0.346 (ωis the quality loss, N is times of freeze-thaw), and C25 sprayed concrete asω=0.1925N-0.523. Suffice it to say, with the increasing number of freeze-thaw, C20 sprayed concrete quality loss rate of increase in speed is almost the same with C25 sprayed concrete, and in most early freeze-thaw test specimen are present the phenomenon of increasing as the freeze-thaw cycle of their quality, thereby increasing the quality of this indicator cannot be precisely reflect C20 and C25 sprayed concrete frost resistance of the differences.
Research findings show: cold regions tunnel project, C20 sprayed concrete frost resistance of poor durability to the tunnel structure, as well as security has stronger impact, and frost-resistance of C25 sprayed concrete is good, it has significance and utility value to the tunnel design.
1、C20喷射混凝土在60个冻融循环以后,试件表面的剥落急剧增多,动弹性模量的下降较为明显,大部分试件已经接近损毁,C25喷射混凝土在100个冻融循环以后,试件表面的剥落才开始急剧增多,动弹性模量的下降也是较为明显,大部分试件接近损毁。由此可见,C25喷射混凝土比C20喷射混凝土能承受更多的冻融次数,但是二者的抗冻性都较差。
2、C20喷射混凝土试件的初始动弹性模量平均值为34.52GPa,动弹性模量与冻融次数的线性回归关系为E=-0.215N+34.94(E为动弹性模量,N为冻融次数),而C25喷射混凝土分别为39.69GPa和E=-0.135N+39.55,由此可知,随冻融次数的增加,C25喷射混凝土动弹性模量的下降速度比C20喷射混凝土小,初始动弹性模量大,足见C25喷射混凝土的抗冻性能优于C20喷射混凝土。
3、C20喷射混凝土试件质量损失率与冻融次数的线性回归关系为ω=0.1975N-0.346(ω为质量损失率,N为冻融次数),而C25喷射混凝土为ω=0.1925N-0.523,由此可知,随冻融次数的增加,C20喷射混凝土质量损失率的增加速度同C25喷射混凝土相差无几,而且在冻融试验初期,大部分试件都存在随着冻融循环的进行其质量反而增大的现象,从而说明质量这个指标不能较精确的反映C20和C25喷射混凝土抗冻性的差异。
研究成果表明：寒冷地区隧道工程中,C20喷射混凝土抗冻性较差,对隧道结构耐久性以及安全性有较大影响,而C25喷射混凝土抗冻性能相对较好,这对隧道设计有指导意义和实用价值。
Shotcrete has a wide range of applications in a variety of civil engineering field,and it is main bearing units of tunnel structure in tunnel project.Currently, frost resistance in concrete terms, has done a lot of research and has achieved fruitful results at home and abroad, but frost resistance of sprayed concrete are relatively few. Therefore, this article uses the theoretical analysis and laboratory test methods, conducted a study on frost resistance of C20 and C25 shotcrete, mainly the following results:
1. After 60 freeze-thaw cycles, the specimen surface of C20 sprayed concrete flaks proliferately, dynamic elastic modulus decreases more obvious, most of the specimen is close to the damage. After 100 freeze-thaw cycles, the specimen surface flaking of C25 sprayed concrete began to proliferate, dynamic elastic modulus of decline is more obvious, most of the specimen is close to destruction. Thus, C25 sprayed concrete can withstand more freezing times than C20 sprayed concrete, but the frost resistance are more general.
2. Initial dynamic elastic modulus of C20 sprayed concrete specimen averaged 34.52GPa, dynamic elastic modulus and freeze-thaw number of linear regression relationship as E =-0.215N+34.94 (E is dynamic elastic modulus, N is times of freeze-thaw), and C25 sprayed concrete respectively 39.69GPa and E=-0.135N+39.55. Suffice it to say, with the increasing number of freeze-thaw, dynamic elastic modulus of C25 sprayed concrete decreases more slowly than C20 sprayed concrete, and the initial dynamic elastic modulus is bigger, signifying frost resistance of C25 sprayed concrete is better than C20 sprayed concrete.
3. Quality loss of C20 sprayed concrete samples and freeze-thaw number of linear regression relationship isω=0.1975N-0.346 (ωis the quality loss, N is times of freeze-thaw), and C25 sprayed concrete asω=0.1925N-0.523. Suffice it to say, with the increasing number of freeze-thaw, C20 sprayed concrete quality loss rate of increase in speed is almost the same with C25 sprayed concrete, and in most early freeze-thaw test specimen are present the phenomenon of increasing as the freeze-thaw cycle of their quality, thereby increasing the quality of this indicator cannot be precisely reflect C20 and C25 sprayed concrete frost resistance of the differences.
Research findings show: cold regions tunnel project, C20 sprayed concrete frost resistance of poor durability to the tunnel structure, as well as security has stronger impact, and frost-resistance of C25 sprayed concrete is good, it has significance and utility value to the tunnel design.
引文
[1]程良奎.喷射混凝土[M].北京：中国建筑工业出版社,1990
[2]于书翰,杜谟远.隧道施工[M].北京：人民交通出版社,2001.05
[3]陈建勋.隧道冻害防治技术的研究[D].西安：长安大学,2004
[4]王毅才.隧道工程[M].北京：人民交通出版社,2000
[5]关宝树.隧道工程施工要点集[M].北京：人民交通出版社,2003
[6]关宝树.隧道工程设计要点集[M].北京：人民交通出版社,2003
[7]刘信斌.混凝土抗冻性研究[D].成都：西南交通大学,2007
[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]龚洛书,柳春圃.混凝土的耐久性及其防护修补[M].北京：中国建筑工业出版社,1990
[10]A.M.内维尔.混凝土的性能[M].北京：中国建筑工业出版社,1983
[11]杨英姿,赵亚丁,巴恒静.关于混凝土抗冻性试验方法的讨论[J].低温建筑技术,2006
[12]冯乃谦.新实用混凝土大全[M].北京：科学出版社,2005
[13]刘秉京.混凝土结构耐久性设计[M].北京：人民交通出版社,2007
[14]王永祥,丁加林,王宏兴.混凝土抗冻理论及应用[J].西安：西北水利发电,2005.03
[15]鲁飞,李亚军.混凝土冻融破坏原因及防治措施[J].乌鲁木齐：西部探矿工程,2004.12
[16]鲍平,姚美仙.浅析混凝土冻融破坏的机理和影响因素[J].包头：包钢科技,2002.10
[17]胡伟.水泥混凝土抗冻性的主要影响因素与改善措施[J].沈阳：辽宁交通科技,2004
[18]陈志强,周际东.影响混凝土抗冻性的主要因素及其对策[J].乌鲁木齐：西部探矿工程,2006
[19]沙际德,引气混凝土的抗冻机理[J].混凝土,1990
[20]张云理,高效防冻剂[J].混凝土与水泥制品,1992
[21]傅智,碾压泥凝土抗冻性初步试验研究[J].混凝土,1991
[22]王玉瑛,我国混凝土冬期施工技术发展概况[J].混凝土,1990
[23]贾耀东,谢永江,朱长华.国外混凝土抗冻性控制要求和试验方法综述[J].混凝土,2005
[24]EN 206-1:2000 Concrete-Part 1:Specification,performance,production,and conformity.
[25]黄士元.混凝土的抗冻性及其试验方法[J].混凝土及加筋混凝土,1983
[26]RILEM TC 117-FDC Materials and Sructures,1995,28. Ⅰ.Setzer,R.Auberg. Freezeing-thaw and decing salt resistance of concrete testing by CDF method,CDF resistance limit and evaluation of precision.16-31. Ⅱ.Draft recommendation for test method for the freeze-thaw resistance of concrete test with water(CF) or with sodium chloride solution(CDF).175-182.Ⅲ.Draft recommendation for test method for the freeze-thaw resistance of concrete Slab test and cube test.366-371.
[27]SS 13 72 44 Concrete testing-Hardened concrete-Scaling at freezing,1992
[28]RILEM TC 176-IDC 2002 Recommendations of RILEM TC 176:Test methods of frost resistance of concrete.
[29](SL211-98)水工建筑物抗冰冻设计规范[S].北京：中国水利水电出版社,1998
[30]陈肇元.混凝土结构耐久性设计与施工指南[M].北京：中国建筑工业出版社,2004
[31]张颖,张粉芹,王起才.国内外混凝土的抗冻性试验的分析与探讨[J].成都：四川建筑,2007
[32]王宝卿,杨晶杰.混凝土抗冻性能试验方法的探讨[C].中国水利学会第二届青年科技论坛论文集,郑州：黄河水利出版社,2005
[33](GBJ82-85)普通混凝土长期性能和耐久性能试验方法[S].北京：中国建筑工业出版社,1985
[34](JTG E30-2005)公路工程水泥及水泥混凝土试验规程[S].北京：人民交通出版社,2005
[35](GBJ0086-2001)锚杆喷射混凝土支护技术规范[S].北京：中国计划出版社,2001
[36]熊大玉,王小虹.混凝土外加剂[M].北京：化学工业出版社,2001
[37]黄士元.混凝土的抗冻性及其试验方法[J].混凝土及加筋混凝土,1983
[38]张应立等.现代混凝土配合比设计手册[M].北京：人民交通出版社,2002
[39]DT-10W动弹仪说明书.天津：天津市京润建筑仪器厂
[40]李金玉,曹建国,徐文雨.混凝土冻融破坏机理的研究[J].北京：水利学报,1999
[41]龚洛书.混凝土实用手册[M].北京：中国建筑工业出版社,1995.5
[42]曹建国,李金玉.高强混凝土抗冻性的研究[J].上海：建筑材料学报,1999
[43]黄士元.混凝土的耐久性与混凝土结构物的安全性[J].苏州：混凝土与水泥制品,1996
[2]于书翰,杜谟远.隧道施工[M].北京：人民交通出版社,2001.05
[3]陈建勋.隧道冻害防治技术的研究[D].西安：长安大学,2004
[4]王毅才.隧道工程[M].北京：人民交通出版社,2000
[5]关宝树.隧道工程施工要点集[M].北京：人民交通出版社,2003
[6]关宝树.隧道工程设计要点集[M].北京：人民交通出版社,2003
[7]刘信斌.混凝土抗冻性研究[D].成都：西南交通大学,2007
[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]龚洛书,柳春圃.混凝土的耐久性及其防护修补[M].北京：中国建筑工业出版社,1990
[10]A.M.内维尔.混凝土的性能[M].北京：中国建筑工业出版社,1983
[11]杨英姿,赵亚丁,巴恒静.关于混凝土抗冻性试验方法的讨论[J].低温建筑技术,2006
[12]冯乃谦.新实用混凝土大全[M].北京：科学出版社,2005
[13]刘秉京.混凝土结构耐久性设计[M].北京：人民交通出版社,2007
[14]王永祥,丁加林,王宏兴.混凝土抗冻理论及应用[J].西安：西北水利发电,2005.03
[15]鲁飞,李亚军.混凝土冻融破坏原因及防治措施[J].乌鲁木齐：西部探矿工程,2004.12
[16]鲍平,姚美仙.浅析混凝土冻融破坏的机理和影响因素[J].包头：包钢科技,2002.10
[17]胡伟.水泥混凝土抗冻性的主要影响因素与改善措施[J].沈阳：辽宁交通科技,2004
[18]陈志强,周际东.影响混凝土抗冻性的主要因素及其对策[J].乌鲁木齐：西部探矿工程,2006
[19]沙际德,引气混凝土的抗冻机理[J].混凝土,1990
[20]张云理,高效防冻剂[J].混凝土与水泥制品,1992
[21]傅智,碾压泥凝土抗冻性初步试验研究[J].混凝土,1991
[22]王玉瑛,我国混凝土冬期施工技术发展概况[J].混凝土,1990
[23]贾耀东,谢永江,朱长华.国外混凝土抗冻性控制要求和试验方法综述[J].混凝土,2005
[24]EN 206-1:2000 Concrete-Part 1:Specification,performance,production,and conformity.
[25]黄士元.混凝土的抗冻性及其试验方法[J].混凝土及加筋混凝土,1983
[26]RILEM TC 117-FDC Materials and Sructures,1995,28. Ⅰ.Setzer,R.Auberg. Freezeing-thaw and decing salt resistance of concrete testing by CDF method,CDF resistance limit and evaluation of precision.16-31. Ⅱ.Draft recommendation for test method for the freeze-thaw resistance of concrete test with water(CF) or with sodium chloride solution(CDF).175-182.Ⅲ.Draft recommendation for test method for the freeze-thaw resistance of concrete Slab test and cube test.366-371.
[27]SS 13 72 44 Concrete testing-Hardened concrete-Scaling at freezing,1992
[28]RILEM TC 176-IDC 2002 Recommendations of RILEM TC 176:Test methods of frost resistance of concrete.
[29](SL211-98)水工建筑物抗冰冻设计规范[S].北京：中国水利水电出版社,1998
[30]陈肇元.混凝土结构耐久性设计与施工指南[M].北京：中国建筑工业出版社,2004
[31]张颖,张粉芹,王起才.国内外混凝土的抗冻性试验的分析与探讨[J].成都：四川建筑,2007
[32]王宝卿,杨晶杰.混凝土抗冻性能试验方法的探讨[C].中国水利学会第二届青年科技论坛论文集,郑州：黄河水利出版社,2005
[33](GBJ82-85)普通混凝土长期性能和耐久性能试验方法[S].北京：中国建筑工业出版社,1985
[34](JTG E30-2005)公路工程水泥及水泥混凝土试验规程[S].北京：人民交通出版社,2005
[35](GBJ0086-2001)锚杆喷射混凝土支护技术规范[S].北京：中国计划出版社,2001
[36]熊大玉,王小虹.混凝土外加剂[M].北京：化学工业出版社,2001
[37]黄士元.混凝土的抗冻性及其试验方法[J].混凝土及加筋混凝土,1983
[38]张应立等.现代混凝土配合比设计手册[M].北京：人民交通出版社,2002
[39]DT-10W动弹仪说明书.天津：天津市京润建筑仪器厂
[40]李金玉,曹建国,徐文雨.混凝土冻融破坏机理的研究[J].北京：水利学报,1999
[41]龚洛书.混凝土实用手册[M].北京：中国建筑工业出版社,1995.5
[42]曹建国,李金玉.高强混凝土抗冻性的研究[J].上海：建筑材料学报,1999
[43]黄士元.混凝土的耐久性与混凝土结构物的安全性[J].苏州：混凝土与水泥制品,1996