兰州大学机构库 >土木工程与力学学院
硫酸盐强腐蚀环境下灌注桩适应性的试验研究
Alternative TitleAdaptability Experimental Research of the Filling Pile in Strong Sulphate Corrosive Environment
汪朝成
Thesis Advisor张敬书
2011-05-30
Degree Grantor兰州大学
Place of Conferral兰州
Degree Name硕士
Keyword灌注桩 新拌混凝土 强腐蚀环境 腐蚀机理 防腐措施 抗硫酸盐腐蚀性
Abstract和预制桩相比,灌注桩也存在着混凝土现场浇注、难以正常振捣养护且混凝土在没有凝结硬化时就与周围的水、土介质接触等问题,这些问题也在很大程度上限制了灌注桩的使用。现行国家标准《工业建筑防腐蚀设计规范》明确规定,强腐蚀环境中不应采用混凝土灌注桩,只能采用预制桩。全国有许多地区的地下水、地基土中含有大量的硫酸根离子,属于强腐蚀环境,但这类地区仍然大量使用混凝土灌注桩。灌注桩能否在强腐蚀环境中使用,已成为土木工程界关注的焦点,该问题亟须解决但一直没有解决。 影响灌注桩在强腐蚀环境中使用的关键因素是混凝土在未硬化的情况下与腐蚀介质接触造成抗腐蚀能力可能降低的问题,即新拌混凝土的抗侵蚀性问题。迄今为止,国内还没有发现新拌混凝土抗硫酸盐侵蚀的试验研究资料。在国外,也只有极少数的对新拌混凝土进行抗硫酸盐侵蚀的试验研究资料。 为了比较灌注桩与预制桩在硫酸盐强腐蚀环境下的抗腐蚀性,本文采用10种不同的混凝土配合比对新拌混凝土和标准养护后的混凝土在50g/L的Na2SO4溶液中进行全浸泡试验研究,以抗压强度耐蚀系数和质量变化率作为评价指标,试验研究总计进行了870个试件,历时270天,得出了以下主要结论: (1)在270天侵蚀龄期内,新拌混凝土和标准养护后的混凝土抗硫酸盐侵蚀性都遵循先增大后减小的规律,但新拌混凝土在不同防腐措施条件下仍然具有较高的抗硫酸盐侵蚀性。 (2)新拌混凝土和标准养护后的混凝土抗硫酸盐侵蚀性与采用的防腐措施有关:防腐措施越低,新拌混凝土的腐蚀速度较慢,标准养护后的混凝土腐蚀速度较块;防腐措施越高,新拌混凝土的腐蚀速度较快,标准养护后的混凝土腐蚀速度较慢。 (3)掺入适量的粉煤灰能够显著提高新拌混凝土抗硫酸盐侵蚀性。采用的防腐措施越低、侵蚀环境越恶劣,粉煤灰的掺量一般较大,起到的效果更显著。 (4)在极端恶劣的硫酸盐侵蚀环境下,抗硫酸盐水泥能提高养护后的混凝土抗硫酸盐腐蚀性,但效果不太显著。 (5)延长试验侵蚀龄期,有助于更深刻了解新拌混凝土抗硫酸盐侵蚀的基本规律。
Other AbstractCompared to precast pile,the filling pile exists the problems of making contact with around the water and soil medium when the concrete of pile is poured on-site, difficult to normal vibration and conservation, and unhardening,which are largely limited the use of filling pile.Therefore, the current national standard "code for anticorrosion design of industrial constructions" specifies that bore concrete pile shoulds not be used in highly corrosive environment,but precast pile can be used.At present,the ground water in many areas of china,contains large amounts of sulphate ions, but a large numbers of filling piles are used in the above regions. The problem of filling piles can or not be used in the above environment, has become the focus of civil engineering realm.It is urgent that the problem be solved,but has not been solved all along. The key influence factor of the use of filling pile in strong corrosive environment is the problem of reducing corrosion resistance cased by concretes under unhardened conditions make contact with the corrosive medium.That is to say, the problem of corrosion resistance about fresh concrete.So far,no research date about sulphate resistance of fresh concrete has been found at home.There is only a very few research date about sulphate resistance of fresh concrete in the abroad. In order to compare the sulphate resistance of filling pile and precast pile in strong sulphate corrosive environment.In this paper,the tests of full immersion on fresh concrete and standard curing concrete with different concrete mix ratios of ten in Na2SO4 solution(50g/L) are performed,and using corrosive coefficient of compression strength and rate of mass change as evaluation indicators. The study carried out a total of 870 specimens, which lasted 270 days,and draws the following main conclusions: (1) Within 270 days of erosion age,the sulphate resistance of fresh concrete and standard curing concrete follows the rules of first increase and then decrease,but the fresh concrete still has a high resistance to sulfate attack under conditions of different anti-corrosion measures. (2) The resistance to sulfate attack of fresh concrete and standard curing concrete bears a relation to the use of anti-corrosion measures:the lower the anti-corrosion measures are,the slower the corrosion rate of fresh concrete and the faster the corrosion rate of standard curing concrete will be;The higher the anti-corrosion measures are,the faster the corrosion rate of ...
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Language中文
Document Type学位论文
Identifierhttps://ir.lzu.edu.cn/handle/262010/226120
Collection土木工程与力学学院
Recommended Citation
GB/T 7714
汪朝成. 硫酸盐强腐蚀环境下灌注桩适应性的试验研究[D]. 兰州. 兰州大学,2011.
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