【作者】 冯波；

【导师】 安珍； 周海龙； 陈宝；

【作者基本信息】 内蒙古农业大学 ， 工程硕士（专业学位）， 2019， 硕士

【摘要】 资源的合理有效利用是可持续发展的核心。水泥土以天然土与一定量水泥为原料制成,这种材料广泛应用于岩土工程以及基础建设领域,拥有造价成本低、取材方便、施工简便等优点。然而普通水泥土在耐久性以及早期强度方面表现较差。论文将沙柳粉碎后,作为外加剂加入到水泥土当中,探究其对水泥土力学性能以及耐久性能的影响,为平茬后待利用的沙生灌木乃至废旧木材的利用寻找新途径。1.用粉碎机将沙柳进行粉碎,并根据产物形态与长度大小之间的差异进行分类。根据分类结果设计单因素与正交试验方案进行无侧限抗压强度试验,通过单因素试验得出养护龄期对于水泥土抗压强度影响为正相关。比较粉状、纤维状、丝状的沙柳作为外加剂时,最优形态为木丝。针对木丝这一形态,设计正交试验,采用三因素四水平的方法综合考虑水泥掺量、木丝的不同长度大小、木丝掺量三个因素进行探究。综合各试验结果得出,水泥掺量为15%、木丝长度约为11.8mm掺量为1.5%时水泥土抗压强度最高,并称其为改性水泥土。2.对试验得出的应力应变曲线进行进一步分析,比较各形态的外加剂对水泥土变形特性中峰值应变、韧性以及弹性模量的影响。设置验证试验对改性水泥土力学性能进行验证。接下来通过观察试件破损后照片,并结合相应的应力应变曲线,对各水泥土破损规律进行讨论。3.对比分析改性水泥土与普通水泥土的耐冻融、耐干湿以及耐腐蚀性能,得出改性水泥土的耐冻融与耐腐蚀性能皆有所提升。在于湿循环15次以内的水泥土强度不仅没有下降反而有所提升。采用扫描电镜观测各水泥土的微观结构特征,结合水泥土固化过程,分析各外加剂对水泥土的影响。更多还原

【Abstract】 The rational and effective utilization of resources is the core of sustainable development.Cement-soil is made from natural soil and a certain amount of cement.This kind of material is widely used in geotechnical engineering and infrastructure construction fields.It has the advantages of low cost,convenient materials and simple construction.However,ordinary cement-soil performs poorly in terms of durability and early strength.Therefore,in this paper,salix was crushed and added into cement-soil as an admixture to explore its effect on mechanical properties and durability of cement-soil,so as to find a new way for the utilization of sandy shrubs and even waste wood to be used after flat stubble.Firstly,the salix was crushed with a grinder,and the products were classified according to the difference of shape and length.According to the classification results,the unconfined compressive strength test was carried out by designing single factor and orthogonal test scheme,and the single factor test showed that the influence of curing age on the compressive strength of cement-soil was positively correlated.When comparing the admixtures of powdery,fibrous and filamentous salix,the optimum shape is wood silk.In view of the shape of wood fiber,the orthogonal test was designed by using the method of three factors and four levels to comprehensively consider the cement content,different lengths of wood fiber and wood fiber content of three factors.According to the comprehensive test results,when the cement content is 15%and the length of wood wire is about 11.8mm and the content is 1.5%,the cement-soil has the highest compressive strength and is called as modified cement-soil.Then the stress-strain curve obtained from the test is further analyzed to compare the effects of various admixtures on the peak strain,toughness and elastic modulus in the deformation characteristics of cement-soil.A verification test was set up to verify the mechanical properties of the modified cement soil.Then,by observing the photos of the damaged specimens and combining with the corresponding stress-strain curves,the damage laws of cement and soil are discussed.Finally,the freeze-thaw resistance,dry and wet resistance and corrosion resistance of modified cement-soil are compared with that of ordinary cement-soil,and the freeze-thaw resistance and corrosion resistance of modified cement-soil are improved.Cement-soil strength within 15 wet and dry cycles did not decrease but increased.The microstructure of cement-soil was observed by sem,and the effect of admixtures on cement-soil was analyzed.更多还原