节点文献
路用柔性水泥基复合材料制备与性能研究
Fabrication and Properties of Flexible Cement Based Compound for Road Surface
【作者】 何维帅;
【导师】 姜洪义;
【作者基本信息】 武汉理工大学 , 材料科学与工程, 2008, 硕士
【摘要】 基于隧道路面的特殊使用环境,路面材料既要保持强度高、耐久性好、防火、防水害、施工安全等优点,又要满足行车舒适性。研究和制备一种具有低弹性模量、高韧性特点的柔性水泥混凝土路面材料,具有广泛的应用前景。本文通过研究路用柔性水泥砂浆的性能,为水泥混凝土路面材料的研究提供依据。本文采用单因素和正交试验方法,在降低柔性水泥砂浆弹性模量,提高柔韧性,保证必要的强度的前提下,优化了以纤维、聚合物及橡胶粉为主要组分的柔性水泥砂浆的配合比。同时,借助扫描电子显微镜(SEM)表征手段,对集料-水泥石界面、孔结构进行了研究。通过对柔性水泥砂浆物理力学性能、路用性能和微观结构的系统研究,揭示了柔性水泥砂浆的组成、结构与性能之间的相互影响和变化规律。取得如下研究结果:1.通过配合比的优化,确定了两种聚合物柔性水泥砂浆最佳配比参数:即纤维体积掺量为0.1%,橡胶粉取代砂的体积率为10%,两种聚合物聚灰比(乳液固含量与水泥质量之比)分别为20%和3.5%。所配制的水泥砂浆抗压都大于20MPa,折压比大于0.32,抗压弹性模量小于12.2GPa,具有优良的韧性、体积稳定性及耐久性能。2.水泥砂浆中掺入橡胶粉后,砂浆中的孔隙增多,从而显著的削弱了砂-水泥石,橡胶粉-水泥石界面的结合程度,大幅度降低砂浆的强度,并明显的增加了砂浆的干缩率,但是加入橡胶粉后砂浆的柔韧性有明显的改善。3.纤维的加入对水泥砂浆的强度影响不大,但对砂浆早期收缩抗裂有非常积极的作用,明显得降低了砂浆的干缩率,提高了砂浆的抗渗性,同时使砂浆的柔韧性也有略微改善。4.由聚合物和橡胶粉对水泥砂浆的改性结果发现,砂浆内部聚合物乳液形成连续网络,在保证低弹性模量的前提下,进一步增强了橡胶粉砂浆的抗压强度,为该材料在路面上的应用奠定了基础。
【Abstract】 Special application environment of pavement in tunnels demand that the pavement not only have common cement concrete pavement advantages in construction, waterproof,fireproofing security, durability, but also have riding comfort. Exploring a low elastic modulus and high toughness flexible cement concrete pavement materials, have abroad applied field.A single factor and an orthogonal experimental method is adopted to optimize the mix proportion of rubberized lightweight aggregate concrete, in order to decrease the elastic modulus on the premise of necessary strength. Simultaneity, researched the interface between aggregates and hardened cement paste and pore structure by the micro-hardness test, polarizing microscope image analysis and SEM images. Based on the systematic study on the mechanical performance, pavement performance and microstructure, the relation among the constituents, structure and performance and the joint effects are investigated. According to the above research results, the following conclusions can be obtained:1. The optimize mix proportion parameter are: PPF ratio is 1.0%, the mix amount of rubber particles is 10%, polymer-cement ratio is 20% or 3.5%. It with compressive strength above 20Mpa, ratio of bending strength to compressive strength is above 0.32, elastic modulus less than 12.2GPa was produced. It has low shrinkage,high toughness and good durability as well.2. When the introduction of cement mortar in a certain amount of rubber particles add in the porous mortar, it can significantly weaken the interface of sand-cement and rubber- combination of cement. The ratio of mortar Shrinkage significant increased and the intensity reduced, but the mortar flexibility after the accession to the rubber have significantly improved.3. The effect of the cement mortar strength is slight with the addition of PPF . Early contract for mortar crack is a very active role, mortar shrinkage rate is obviously lower, the permeability of the mortar increased, while the mortar flexibility is improved slightly.4. With the rubber and polymer modifing, cement mortar was found that the internal mortar emulsion polymer formed the formation of networks, while ensuring low modulus of elasticity on the premise of the rubber particles,it further enhance the strength of the mortar. It is the foundation for the material uesed in the application.
【Key words】 Rubber; Polymer; Ratio of bending strength to compressive strength; Elastic modulus; Microstructure;