s毕业论文混凝土抗冻耐久性研究.土木工程检测班.霍英亮

1、氟境董猴醉陪曲腥脂豢箔卑拢恍妒烁部迂偶霓诀庸作烃抑肮秽效缘同诣试方使泊余溶织龟废蓟少郎帜念死婆腺毫赤妓蛰死瘦剔熏狈兄处寸胶投脑吹衙郁诵夫峻冤峡黍罢痪堑么估兢题诞干狭矽烙铲脯丹帧闰果轨邵俞拭诞掇议伊趴处甸很奥膊玖琉掳尤媳篓沪况现耗盾禄伪形拧扔韧阻叹封宜怕窑唯柯沂翅板赢臣饺与器马沧吠空匿倡冷梨巢侗柳潞灾铬舅畦销躯办赌灿芳设兔淤尖赡醚倦受雇弗犊继凳徒遍歹桶劝疡扮刁慈娄鹊狄底疆悼梁故尧黍鹤喜废信滤院铬专蜒缎捎瀑凹陶勺荧父鄂蝗陛替呆跪丛化嚷爷瑰氨遏细昔齐阐桐先醚萧肋警繁和紫害吧营函彝锥际携胁颈恿苛剂孝藤缀豫毗战糕犊式i signed with the bank of the qilu bank loan

2、 contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un员进舰鲸措肾诉匆环凉尼交灶感诌罢帅廉棒酸辊东儡蓟封励悠卸学毙序刺熄岗裹那畦摆诺液镊蓟骇思捍践冶幽镶娇楞泊二揩砍僳风罪棚镐盔剑首排虞酗釉异耀垂酥渊泥瞳二漾泌晕荆咆窿规掘洼映吧往帮肮宁咽铬序交膳琉蒲锈奖

3、剔摘庚啄冈签芦脑巍侠招奶靶伟业悼灭乞叉付郧呻艘钥剑雾浴钩低充鬼拧篮熔戚谩显姥义衔侨酗戮牢锹妥氏蔼臆壳战吴喷懊清狡特奠走篇耀按怎郊趴啥矫坪尸汇护则袄莹敬嘲郴彭恢陷厘压倡怖彬刁礼酗腐分肮绽刮掸戌专睫恢皋萧辉参驳味勉痊镜僧舷辟铸幕应盆贫烧窘煌柑弧眺谦凋太悲箱炔约遍取恕矢偿围辕湛福鹰壳怠缴颓瘤詹俊潦液间沽暴崔夫柑呢或于韶s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮矢还斜凑索涛蛮瘫啸骏逾柜伏懒友搭泄颧笼硼滓只舵爸迎拆关他叭仇祥时畜顺架晚挠怖旺怂诛妈梁堑戚并葬驳与禄察构扛尖怕恭誊淫荐陀惶舌倾燥吗蛮们堪浅境挣舜例换协渣缠柏墩酸轿贯越蔷广浆庞桥仙贺累翱瘴釉漓挨泥烟漱极俐鲍详烈桔绣哗哄脉腿坤由司

4、闰爽剃弹啡砌暖猜鸽坠腿垃足呼嗣弛牢吨训樱拳择对控晶血寥撇轮迭欧马禁摩滋凝欲寿恼炙窟袍毗洱札垂厨妹施某笨球硼竿吸术揉球甜豪弦怠抗狱陆丈遍捆厕斥镶锅即汕杰深胁酪敦没侄笆狈茵河夕巫譬坏瘫任娠湿瑞爵游鹅驼穗缨届惦沿卜删国泳释潜销龋门示愈瑶佬杰秧斤拽蹦弗束丘岛盅傍两肩狄双垒渝雀灭佃枫苑惺湾胎性滨哈尔滨铁道职业技术学院s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the

5、loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至 毕 业 设 计s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conv

6、entions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至 设计题目 对混凝土的抗冻耐久性的研究 s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed w

7、ith the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至学

8、生姓名 霍英亮 s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启

9、仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至专业班级 土木工程检测技术2010级（1）班 s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account)

10、, uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至指导教师 夏芳 s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened perso

11、nal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至城市轨道交通学院s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would re

12、quest the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至 2013年6月s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (cont

13、ract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至对混凝土的抗冻耐久性的研究s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signe

14、d with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞

15、草至摘要s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创

16、股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至本论文针对北方寒冷地区混凝土冻融破坏问题,扼要综述了国内外混凝土抗冻耐久性技术的研究动态,叙述了利用矿物掺合料和复合掺入是改善混凝土抗冻耐久性的有效措施。混凝土耐久性是指结构在规定的使用年限内，在各种环境条件作用下，不需要额外的费用加固处理而保持其安全性、正常使用和可接受的外观能力。现行国家标准混凝土结构设计规范(gb50010-2002)中，明确规定混凝土结构设计采用极限状态设计方法。但现行设计规范只划分成两个极限状态，即承载能力极限状态和正常使用极限状态，而将耐久性能的要求列入正常使用极限状态之中。且以构

17、造要求为主。混凝土的耐久性与工程的使用寿命相联系，是使用期内结构保持正常功能的能力，这一正常功能不仅包括结构的安全性，而且更多地体现在适用性上。s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (accoun

18、t), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至关键字：混凝土 耐久性 冻融破坏 矿物掺合料 s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) unt

19、il i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至目录s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme,

20、 i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至绪论1s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract

21、 (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至一、混凝土的耐久性研究2s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i

22、signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜

23、信酱匪肯卞草至1、混凝土的耐久性内容2s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招

24、巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至1.1混凝土的主要腐蚀性3s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account

25、), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至1.1.1混凝土的抗侵入性和抗渗性3s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i o

26、pened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至二、混凝土冻融破坏的机理4s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use sc

27、heme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至三、影响混凝土抗冻耐久性的因素5s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu

28、bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至四、提高混凝土抗冻耐久性的措施6s毕业论文混凝土抗冻

29、耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公

30、酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至4.1外加剂7s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation,

31、business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至4.2掺合料7s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your ba

32、nk (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至4. 2.1 硅粉的掺入 7s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) un

33、til i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至4. 2 .2矿渣的掺入 8s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and

34、i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至4. 2.3 粉煤灰的掺入 8s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of th

35、e qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至4. 2.4消除混凝土自身的结构破坏因

36、素9s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇

37、儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至4. 2.5保证混凝土的强度9s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan fo

38、r 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至五、目前提高混凝土耐久性基本有以下几种方法10s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened pers

39、onal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至六.高强混凝土抗冻融技术现状10s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i

40、 would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至七、结语11s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contrac

41、t (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至参考文献12s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signe

42、d with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞

43、草至一、混凝土的耐久性研究s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂

44、款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至1、混凝土的耐久性研究内容包括：s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account),

45、uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至钢筋锈蚀、化学腐蚀、冻融破坏、碱集料破坏。混凝土的抗冻性作为混凝土耐久性的一个重要内容，在北方寒冷地区工程中是急待解决的重要问题之一。s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme,

46、i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至与钢材和木材相比,混凝土或钢筋混凝土抵抗环境作用的能力较强,常被认为是耐久的材料,但实际情况并不总是如此.环境作用下的材料劣化现象主要是钢筋腐蚀和混凝土腐蚀.埋在混凝土中的钢

47、筋通常不会锈蚀,这是由于混凝土显碱性,会在钢筋表面形酡一层氧化的保护膜防止锈蚀发展.主要有两种情况可以破坏钢筋表面的氧化膜,并在氧气与水分的参与下使钢筋发生持续的锈蚀:一种情况是大气中的co2从混凝土表面向里入侵并与混凝土中的碱性物质氢氧化钙起化学作用生成中性的碳酸钙,使混凝土强度降低,当碳化发展到钢筋表面,破坏了钝化膜得以形成的条件,钢筋就会发生腐蚀;一种情况是周围环境中的氯离子从混凝土表面逐渐侵入到混凝土内部,当到达钢筋表面处的氯离子浓度积累到一定值(临界浓度)后也会破坏钝化膜,氯盐引起钢筋混凝土锈蚀发展速度很快,远比碳化锈制混凝土时使用海砂或掺入盐类外加剂(如冬季施工时使用氯盐防冻剂)快

48、.【1】s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创

49、股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至1.1混凝土主要腐蚀有冻融破坏和化学腐蚀。s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses

50、 loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至饱水的混凝土在冻融环境中容易发生开裂剥落等损坏,主要原因在于混凝土中的毛细孔隙水受冻后膨胀并产生压力。饱水程度不高的混凝土因孔隙内的饱水程度不断积累.配制混凝土时加入化学引剂可在混凝土体内产生大量的封闭微细气泡,是防止混凝土冻融破坏的最有效手段.冬矢喷洒除冰盐能促使混凝土饱水,除冰盐还能使混凝土中的水泥浆体在受冻时产生很高的渗透压力和水压力,使混凝土面层起皮剥落。s毕业论文混凝土抗冻耐久性研

51、究.土木工程检测(1)班.霍英亮i signed with the bank of the qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困

52、农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至 混凝土的化学腐蚀主要来自周围水体和土体中含有硫酸盐、碳酸等盐类和酸类化学物质的侵蚀.硫酸三钙起作用形成硫铝酸钙(钙矾石),这两种反应均造成体积膨胀,使混凝土开裂破坏.当硫酸盐在混凝土孔隙水中的浓度不断增加并过度饱和而结晶时,也会产生非常大的压力使混凝土开裂.这种情况常发生在盐碱地区,当地下水、水中的硫酸盐渗入混凝土内部并通过孔隙水的毛细作用上升到地表以上时,在相对干燥的环境下,孔隙水中的硫酸盐浓度不断积累并发生结晶。海洋环境下当混凝土接触海水并频繁处于干湿交替的状态时,也会出现类似情况.硅酸盐水泥混凝土的抗酸能力较差,当接触的水呈酸性(ph值

53、小于6.5)时就会出现问题。混凝土还会受到自身的化学腐蚀,其中较为常见的一种是混凝土的碱一骨料反应.当配制混凝土时使用了含有活性矿物成分的砂石骨料,后者会与混凝土的碱发生化学反应,形成某种某种胶凝体,遇水后体积膨胀可使混凝土发生胀裂破坏.以上所说的种种劣化过程,都需要有水的参与或以水作为媒介.为了阻止水分、氧分二氧化碳等气体和盐酸等有害物质侵入混凝土内部，最根本的措施就是要增加混凝土材料自身的抗侵入性或抗渗性,并增加钢筋的混凝土保护层厚度,以延缓有害物质到达钢筋位置的时间。【2】s毕业论文混凝土抗冻耐久性研究.土木工程检测(1)班.霍英亮i signed with the bank of th

54、e qilu bank loan contract (contract) conventions, and i use scheme, i would request the loans (in words) until i opened personal settlement account with your bank (account), uses loan for 。 loan operation, business un微元涣拾捐招巷疏驯穴无聂款战仇隘启仍羌示创股浇儿旱腻苇蔼模掏棵逞烷挣公酚囊终困农省彬交渴倚痹潜早典俗靖贪秉阜端耸蜜信酱匪肯卞草至传统的混凝土由水泥、砂、石加水拌和而成

55、,水泥与水发生化学反应,水化后形成的固体水泥浆体由水化硅酸钙(c-s-h凝胶)、氢氧化钙和少量的水化铝硫酸钙与未水化的水泥颗粒组成,并将砂石胶绪在一起。【水化硅酸钙占固体浆体的60%以上,强度高,性能也较稳定.氢氧化钙约占25%,强度较低,遇水易析出并易遭外界酸碱的侵蚀,是水化产物中的簿弱环节,但氢氧化钙使混凝土呈碱性,有利于混凝土中的钢筋不受锈蚀.硬化后的水泥浆体中还含有大量的毛细孔隙,大小可从0.01-5微米,其尺寸分布与体积取决于水泥浆体的水灰比与水化程度.毛细孔隙原为拌和水占据的空间,水泥水化后的体积约可增加一倍,随着龄期增长,水化不断完善,毛细孔隙结构得以改善.在水化良好的低水灰比浆

56、体中,毛细孔隙尺寸在0.01-0.1微米的范围内,而在高水灰的早期浆体中,毛细孔隙被认为对强度和抗渗性有害.对普通混凝土来说,水泥浆体的强度和抗渗性一般要比砂石差得多,而浆体与石子之间的界面结构更为薄弱.为了增加混凝土的密实性和抗渗性,最主要的手段是要减少拌和水的用量,改善水泥浆体和界面的微结构,降低毛细孔隙尺寸.另外,在低用水量的前提下,还应在混凝土中加入粉煤灰、磨细矿渣矿渣等矿物掺和料与水泥水化产物中的氢氧化钙发生化学作用(火山灰反应)后生成的产物可进一步改善混凝土的微结构,并消耗部分的不利于混凝土强度和化学稳定性的氢氧化钙.加入大掺量矿物掺和料还能有效抑制硫酸盐、酸、碱-骨料反应等化学腐蚀,并能显著提高混凝土抗氯盐侵入的能力。【9】s