Expansive Soil Stabilization by Bagasse Ash Partial Replacem

发布时间：2024-05-12 02:27

　　本文研究了甘蔗渣灰部分替代普通硅酸盐水泥(OPC)对膨胀土岩土性能的影响。研究了水泥处理膨胀土的压实特性、微观结构、张拉强度、抗压强度、CBR值、剪切波速和小应变剪切模量。按不同比例设计制备土样,在7天、14天和28天的不同养护时间进行了标准击实试验、无侧限抗压强度试验、CBR试验、巴西劈裂试验和弯曲元试验。并进行了X射线衍射和扫描电镜测试。X射线衍射分析表明,甘蔗渣灰的主要矿物为石英和白晶石。扫描电镜分析表明,蔗渣灰中存在不同粒径的颗粒,有许多纤维状颗粒。结果表明,用蔗渣灰代替OPC可以改善处理后土壤的压实特性,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还可以提高处理膨胀土的早期强度。结果表明,不同置换比例的试样的拉伸强度均有所提高,这可能是由于蔗渣灰纤维结构长,抗拉伸破坏能力强。当置换率不大于20%时,部分置换试件的CBR值甚至高于单独用水泥处理的试件。经处理后土体的弯曲单元试验表明,刚度存在明显的各向异性,但随着固化时间的延长和置换率的增加,刚度逐渐降低。试验结果表明,蔗渣灰是一种有效的矿物掺合料,CBA20(20%)是水泥的最佳替代率。。

【文章页数】：71 页

【学位级别】：硕士

【文章目录】：
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



本文编号：3970721