冬季施工中,混凝土容易遭受低溫的影響,往往造成不可恢復性的損傷;同時,耐久性也有很大程度上的損失。用粉煤灰、硅灰替代混凝土中的部分水泥,不僅可以促進工業(yè)廢料循環(huán)再利用,還可以改善混凝土的部分性能,這已成為工程中的常規(guī)方法。但這種方法在負溫混凝土中的應(yīng)用研究卻較為少見,尤其是恒負溫條件下。本文研究了不同恒負溫養(yǎng)護條件下?lián)胶狭戏N類和摻量對水泥基材料的強度、耐久性與孔結(jié)構(gòu)的影響。試驗結(jié)果表明,受凍溫度對水泥基材料的性能有較大影響,其強度與抗氣體滲透性能隨受凍溫度降低而降低。尤其在-20℃下性能增長緩慢甚至隨齡期增加而降低,應(yīng)避免在過低負溫下進行施工作業(yè)。硅灰摻合料對改善恒負溫養(yǎng)護條件下水泥基材料的早期強度、氣體滲透性、孔隙分布等方面均有良好的作用,其中氣體滲透性與孔隙分布隨摻量增加而優(yōu)化,但強度隨摻量提高變化不大;而粉煤灰摻合料對水泥基材料的各方面性能隨摻量增加有一定程度的劣化,應(yīng)謹慎確定合適摻量后再使用。 

【文章來源】：哈爾濱工業(yè)大學黑龍江省 211工程院校 985工程院校

【文章頁數(shù)】：53 頁

【學位級別】：碩士

【文章目錄】：
摘要
Abstract
Chapter 1
    1.1 Research background
    1.2 Research at home and abroad
        1.2.1 Research at abroad
        1.2.2 Research at home
    1.3 Analysis of literature review
Chapter 2.Study on strength of frozen cement-based materials at constant low-temperature
    2.1 Introduction
    2.2 Test materials
        2.2.1 Cement
        2.2.2 Admixtures
    2.3 Forming cement paste specimens and mechanical performance testmethod
    2.4 Experiment plan
        2.4.1 Freezing temperature
        2.4.2 Age of specimen
        2.4.3 Admixtures
        2.4.4 Speciment size and quantity
    2.5 Effects of age on the strength
        2.5.1 Silica fume admixture
        2.5.2 Fly ash admixture
    2.6 Effect of admixture on the strength
        2.6.1 Silica fume admixture
        2.6.2 Fly ash admixture
    2.7 Chapter summary
Chapter 3 Study on durability of frozen cement-based materials at low-temperature
    3.1 Introduction
    3.2 Experiment plan
        3.2.1 Cement paste specimens
        3.2.2 Gas permeability
        3.2.3 Gas permeability test method
    3.3 Effect of age on gas permeability
        3.3.1 Silica fume admixture
        3.3.2 Fly ash admixture
    3.4 Effect of admixture on the strength
        3.4.1 Silica fume admixture
        3.4.2 Fly ash admixture
    3.5 Chapter summary
Chapter 4 Study on pore structure of frozen cement-based materials at constant low-temperature
    4.1 Introduction
    4.2 Pore structure test method
    4.3 Experimental plan
        4.3.1 Freezing tempreture
        4.3.2 Age of specimen
        4.3.3 Admixture
        4.3.4 Specimen size and quality
    4.4 Pore structure analisys of cement-based materials
        4.4.1 Effect of admixture on pure structure
        4.4.2 Effect of age on pure structure
    4.5 Chapter summary
Chapter 5 Processing data by using a meta-analysis
    5.1 Introduction
    5.2 Analysis of study on strength data
    5.3 Analysis of study on durability data
    5.4 Analysis of study on pore structure data
    5.5 Chapter summary
Conclusion
References
Acknowledgements
Resume



本文編號：2907236