新型生土材料研究

发布时间：2019-06-21 18:54

【摘要】：生土材料泛指未经过焙烧,仅仅经过简单加工的原状土质材料。除了能充分的发挥就地取材的优势,生土材料还有优良的热稳定性、良好的保温性能等特点,为人类创造出了适宜的室内居住和使用环境,此外,生土材料还具有调湿、透气、防火、能耗低、造价经济等特点,并且在服役结束后能够重新回归自然的优势。但是,传统的生土材料强度不高、体积变形大、水稳定性不好,导致生土建筑在抗震、耐水性和体积稳定性等方面存在诸多问题,而且人们对生土材料的性质缺乏足够的科学认知,这极大地妨碍了生土建筑质量的提高。我国幅员辽阔,生土蕴藏丰富,研制强度高、稳定性好、耐水性好的新型生土材料对营造舒适性好、能耗低的绿色建筑意义重大。本研究以粘性原土为主要原材料,钢厂废渣和少量助剂为改性掺合料,采用压制成型的方法制备强度高、耐水性、抗冻性好的新型生土材料。主要研究改性掺合料的组成、掺量及制备条件等对生土材料不同龄期的强度、软化系数,60天时的抗冻性和抗干湿循环性等性质影响,并对新型生土材料的导热系数做了简单的研究。通过X射线衍射分析原料与生土材料矿物组成的变化,探讨新型生土材料的形成机理。研究结果表明:1)利用改性掺合料加入到粘性原土中,仅经过简单的压实就能制备出强度较高,水稳性较好的新型生土材料。2)生土材料的强度发展较为缓慢,前期强度较低,但能一直持续发展很长时间,在60天龄期时强度最高能达到8.78MPa,并且该龄期下材料的抗冻性和抗干湿循环性能都较好;在14天左右才开始具有水稳定性,60天时水饱和强度能达到其强度的60%~80%。3)随着改性掺合料掺量的加大,生土材料的最优含水量会相应的增大,同时生土材料的强度、水饱和强度、软化系数均会增大,抗冻性和耐水性也会越来越好。当改性剂掺量为20%~25%,加水量为最优含水量,压实度为95%时,制备出的新型生土材料强度7.5MPa,软化系数80%,强度损失BDR40%,强度和水稳性等较素土均有很好的改善,又由于其制备工艺简单,造价低廉,所以具有很广阔的研究和利用前景。
[Abstract]:Raw soil materials generally refer to uncalcined, simply processed raw soil materials. In addition to giving full play to the advantages of local materials, raw soil materials also have excellent thermal stability, good thermal insulation performance and other characteristics, creating a suitable indoor living and use environment for human beings. In addition, raw soil materials also have the characteristics of moisture regulation, air permeability, fire prevention, low energy consumption, cost economy and so on, and can return to nature after service. However, the strength of traditional raw soil materials is not high, the volume deformation is large, and the water stability is not good, which leads to many problems in seismic resistance, water resistance and volume stability of raw soil buildings, and people lack enough scientific understanding of the properties of raw soil materials, which greatly hinders the improvement of raw soil building quality. China is vast in territory, rich in raw soil, high in strength, good in stability and good in water resistance, which is of great significance to the construction of green buildings with good comfort and low energy consumption. In this study, a new raw soil material with high strength, water resistance and good frost resistance was prepared by pressing molding with viscous raw soil as the main raw material, steel plant waste slag and a small amount of auxiliaries as modified admixtures. The effects of composition, content and preparation conditions of modified admixtures on the strength, soften coefficient, freezing resistance and dry and wet cycle resistance of raw soil materials at different ages were studied, and the thermal conductivity of new raw soil materials was simply studied. The formation mechanism of new raw soil materials was discussed by analyzing the mineral composition of raw materials and raw soil materials by X-ray diffraction. The results show that: 1) A new type of raw soil material with high strength and good water stability can be prepared by adding modified admixture to viscous raw soil. 2) the strength development of raw soil material is slow and the early strength is low, but it can continue to develop for a long time, and the highest strength can reach 8.78 MPA at 60 days of age. At this age, the frost resistance and dry and wet cycle resistance of the materials are better. It takes about 14 days to have water stability, and the water saturation strength can reach 60% 鈮，

本文编号：2504280