添加高吸水性树脂混凝土相关性能与绿色施工应用研究

发布时间：2018-05-31 06:55

本文选题：高吸水性树脂(SAP) + 混凝土　；参考：《天津大学》2015年博士论文

【摘要】：高吸水性树脂(SAP)在混凝土工程中的应用是一项重要的工程技术革新,相关研究工作在国内外均属刚刚起步,存在许多空白之处。本课题研究工作主要从从添加高吸水性树脂混凝土的相关重要性能入手,揭示高吸水性树脂混凝土的相关特性,拓展了其在绿色施工中的应用。本文针对混凝土添加高吸水性树脂后,力学性能存在的抗压强度提升或降低的不确定性展开详细研究。通过SAP多级粒径、多种添加量和混凝土不同水灰比的多重组合,对混凝土抗压强度特征表现和相关影响因素进行了全面的分析和探讨。研究表明,掺量和粒径的不同,对混凝土的力学性能具有一定的影响。粒径对于混凝土强度的早期发展具有较强的影响性。当粒径相对较大时,易于提高早龄期强度;但整体来看,SAP添加量在0.2%左右、粒径为30~50目时,混凝土抗压强度综合效果最好。进一步通过压汞分析(MIP)、扫描电镜(SEM)与图像分析软件(Image pro)相结合的方法,定性和定量的对高吸水性树脂混凝土的微观孔结构特征进行了相关分析与研究。分析了高吸水性树脂对混凝土内部孔隙发展的影响方式,以及其特有的气孔结构特征对混凝土相关性能的影响。研究结果显示,SAP的添加数量和SAP的粒径变化对混凝土的微观性能指标影响程度较大,气孔率、气孔平均孔径和气孔平均间距系数均有不同程度的增加。10μm~200μm和200μm~800μm级别的气孔率对SAP混凝土强度相关性较强。高水灰比和小粒径会提高10μm~200μm级别的气孔率;高水灰比和高添加量对于200μm~800μm级别气孔影响较大,应严格控制小于800μm范围内的气孔的形成。进一步确定了SAP的使用原则:低水灰比,粗粒径,低掺量。文中还通过径向基函数(RBF)神经网络定量分析了试样强度与孔结构特征之间的关系,建立了强度与孔结构特征之间的定量关系式,给出了分级孔隙率和分级气孔率的重要性排序:10μm~200μm、200μm~800μm、大于1μm、0.1~1μm、小于0.1μm、800μm~1600μm。同时,本文又对添加SAP的混凝土的水化反应进行了详细的研究,通过TG-DSC热分析研究,证明了高吸水性树脂在混凝土水化反应中的积极作用,提出了全新的SAP促进水泥水化反应的解释原理。研究发现,SAP的添加量增加有利于CH生产;SAP进入混凝土凝胶体系后,不仅影响水化产物的生成量,也影响水化产物的水化过程,在SAP胶凝溶液独特的空间网状结构、亲水基团离子交换和Ca2+离子互锁的共同作用下,有效促进了水泥的水化反应。进而,通过对SAP混凝土渗透性能与其微观结构相结合的研究方法,对SAP混凝土渗透性的机理进行了充分的研究。研究表明,SAP加入混凝土后,能够有效提高混凝土的抗渗性能。SAP改变了混凝土内部孔隙连通状况,通过减小毛细管的压力和改变孔隙的形式,提高了毛孔的阻力值;SAP在混凝内部形成了混凝土内部的“阈值效应”,增大了液体渗流阻力。最后,本文结合绿色施工的理念,概念性的提出了添加高吸水性树脂的混凝土在绿色施工中的全新应用,并进行了初步的试验验证,把建筑材料和施工环境保护进行了有机的结合,为高吸水性树脂混凝土的应用开拓了全新的应用领域。
[Abstract]:The application of high water absorbent resin (SAP) in concrete engineering is an important engineering technical innovation. The related research work is just starting at home and abroad, and there are many blanks. This research work mainly starts with the important performance of adding super absorbent resin concrete, and reveals the phase of high water absorbable resin concrete. In this paper, a detailed study is carried out on the uncertainty of the compressive strength improvement or reduction of mechanical properties after adding high water absorbent resin to concrete. Through multiple combinations of SAP multilevel particle size, various additions and different concrete ratio of concrete, the characteristics of concrete compression strength are shown. A comprehensive analysis and discussion are made on the related factors. The study shows that the difference of content and particle size has a certain effect on the mechanical properties of concrete. The particle size has a strong influence on the early development of concrete strength. When the particle size is relatively large, it is easy to increase the strength of the early age. However, as a whole, the addition of SAP is 0.2%. When the particle size is 30~50 mesh, the compressive strength of concrete is the best. Further, by combining the method of MIP, scanning electron microscope (SEM) and image analysis software (Image Pro), the microscopic pore structure characteristics of high water absorbent concrete are analyzed and studied qualitatively and quantitatively. The high water absorption resin is analyzed. The influence on the internal pore development of concrete and the influence of its characteristic pore structure on concrete related properties. The results show that the amount of SAP added and the change of particle size of SAP have great influence on the micro performance index of concrete, the porosity, the pore average pore diameter and the average pore space coefficient of the pores have different degrees. The porosity of.10 mu m~200 m and 200 mu m~800 mu m has a strong correlation with the strength of SAP concrete. High water cement ratio and small particle size will increase the porosity of 10 mu m grade; high water cement ratio and high addition have great influence on the porosity of 200 mu m~800 m grade, and should strictly control the formation of pores within the range of less than 800 mu. Further determination The principle of the use of SAP: low water cement ratio, coarse particle diameter and low content. The relationship between the strength of the specimen and the pore structure characteristics is quantitatively analyzed by the radial basis function (RBF) neural network. The quantitative relation between the strength and the pore structure characteristics is established, and the importance ranking of the graded porosity and the graded porosity is given: 10 mu m~200 mu m, 200 M~800 mu m, greater than 1 mu m, 0.1~1 mu m, less than 0.1 mu m, 800 mu m~1600 mu m. at the same time, the hydration reaction of concrete adding SAP is studied in detail. Through TG-DSC thermal analysis, the active effect of high water absorbent resin in the hydration reaction of concrete is proved, and a new principle for explaining the hydration reaction of cement is proposed. It is found that the addition of SAP is beneficial to the production of CH. After SAP enters the concrete gel system, it not only affects the production of hydration products, but also affects the hydration process of the hydration products. The hydration of SAP cementitious solution, with the unique spatial network structure, the hydrophilic group ion exchange and the Ca2+ ion interlock, effectively promotes the hydration of cement. And then, through the research method combining the permeability of SAP concrete with the microstructure of concrete, the mechanism of the permeability of SAP concrete is fully studied. The study shows that, after SAP is added to the concrete, the permeability of concrete can be improved effectively by.SAP, and the capillary pressure can be reduced by reducing the pressure of the capillary. Force and change the form of pore, increase the resistance value of pore; SAP formed the "threshold effect" inside the concrete inside the coagulant, and increased the resistance of liquid seepage. Finally, this paper, combining the concept of green construction, conceptually proposed the new application of the coagulant soil with high water absorption resin in the green construction, and carried out a preliminary study. The experimental verification shows that the organic combination of building materials and construction environment protection has opened up a new application field for the application of super absorbent polymer concrete.
【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TU528

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