本文研究了甘蔗渣灰部分替代普通硅酸鹽水泥(OPC)對膨脹土巖土性能的影響。研究了水泥處理膨脹土的壓實特性、微觀結構、張拉強度、抗壓強度、CBR值、剪切波速和小應變剪切模量。按不同比例設計制備土樣,在7天、14天和28天的不同養(yǎng)護時間進行了標準擊實試驗、無側限抗壓強度試驗、CBR試驗、巴西劈裂試驗和彎曲元試驗。并進行了X射線衍射和掃描電鏡測試。X射線衍射分析表明,甘蔗渣灰的主要礦物為石英和白晶石。掃描電鏡分析表明,蔗渣灰中存在不同粒徑的顆粒,有許多纖維狀顆粒。結果表明,用蔗渣灰代替OPC可以改善處理后土壤的壓實特性,使其最大干密度降低,最佳含水量提高。用蔗渣灰部分替代OPC還可以提高處理膨脹土的早期強度。結果表明,不同置換比例的試樣的拉伸強度均有所提高,這可能是由于蔗渣灰纖維結構長,抗拉伸破壞能力強。當置換率不大于20%時,部分置換試件的CBR值甚至高于單獨用水泥處理的試件。經處理后土體的彎曲單元試驗表明,剛度存在明顯的各向異性,但隨著固化時間的延長和置換率的增加,剛度逐漸降低。試驗結果表明,蔗渣灰是一種有效的礦物摻合料,CBA20(20%)是水泥的最佳替代率。。

【文章頁數(shù)】：71 頁

【學位級別】：碩士

【文章目錄】：
摘要
Abstract
1 Introduction
    1.1 Background and literature review
    1.2 The engineering damage of expansive soil
    1.3 Methods of expansive soil treatment
        1.3.1 Mechanical soil stabilization
        1.3.2 The chemical stabilization
            1.3.2.1 Cement stabilization
            1.3.2.2 Lime stabilization
            1.3.2.3 Bitumen stabilizaiton
            1.3.2.4 Nano silica stabilizaiton
            1.3.2.5 Chemical compounds stabilization
            1.3.2.6 Pozzolanic material stabilization
2 Research Goals and Scope
    2.1 Research objective
    2.2 Scope of the study
3 Testing Materials and Experimental Program
    3.1 The materials
        3.1.1 Expansive Soil
        3.1.2 Portland Cement
        3.1.3 Bagasse ash
    3.2 Preparation of experiments
        3.2.1 Preparation of soils
            3.2.1.1 Atterberg Limits
            3.2.1.2 Particle size distribution of soil
        3.2.2 Mix proportion
        3.2.3 Experimental program
4 Experimental Result discussion
    4.1 Compaction characteristic
        4.1.1 The principal of compaction test
        4.1.2 Testing Results
            4.1.2.1 The maximum dry density
            4.1.2.2 The optimum moisture content
    4.2 Unconfined compression test
        4.2.1 Test introduction and procedure
        4.2.2 The result of the test
    4.3 Tensile strength test
        4.3.1 Brief introduction
        4.3.2 Test approach and the result
    4.4 Relation between the tensile strength and UCS
    4.5 XRD test
        4.5.1 Test Principle
        4.5.2 Data and result analyzing
    4.6 California bearing ratio (CBR) test
        4.6.1 CBR background
        4.6.2 Importance and use
        4.6.3 Test procedure and result
    4.7 SEM test
        4.7.1 Introduction
        4.7.2 SEM principle
        4.7.3 SEM result
    4.8 Stiffness anisotropy measurement by BE
        4.8.1 The concept of stiffness anisotropy
        4.8.2 Test prepration
        4.8.3 Result
5 Discussions and Conclusion
    5.1 Discussions
    5.2 Conclusions
Acknowledgement
References



本文編號：3970721