薄层纤维素醚改性水泥浆体水化历程和微观结构研究

发布时间：2018-03-21 04:28

本文选题：纤维素醚　切入点：流变特性　出处：《武汉理工大学》2013年博士论文　论文类型：学位论文

【摘要】：我国目前正处于城镇化高速发展的关键时期,外墙外保温系统作为建筑节能的主要技术途径,其中,粘结砂浆和抗裂砂浆等薄层砂浆对于保证外墙外保温系统的节能效果和耐久性的实现起着重要的作用,在此背景下,研究薄层砂浆的水化关键问题具有特别重要的意义。本研究工作来源于“十二五”国家科技支撑计划项目(2011BAJ04802)和国家自然科学基金(50902107)。通过研究纤维素醚(cellulose ether,CE)改性水泥浆体的流变性能和热-电特性,探明多因素环境下水泥浆体的水化动力学过程。根据薄层CE改性水泥浆体的使用环境的不同,研究了快速失水条件下水泥浆体的水化规律。基于薄层水泥浆体流变特性、水化动力学过程和快速失水条件下的水化规律建立了薄层CE改性水泥浆体水化过程和界面过渡区微观结构模型,阐述了薄层CE改性水泥浆体的水化特征。本文主要的工作及所取得的重要成果如下： 1.根据CE在水溶液(拌和阶段环境)和水泥浆体(水化阶段环境)2种液相环境中的流变特性,系统研究了CE成膜过程及溶液环境(温度、pH值、离子的种类和价态)对水溶液和水泥浆体流变特性的影响,揭示了CE在不同液相环境中成膜过程及温度、pH值、离子对其在水溶液和水泥浆体中的作用机理。以表观粘度、剪切应力、屈服应力和塑性粘度为评价指标,研究了CE种类和掺量对水溶液和水泥浆体流变特性的影响。探讨了不同温度和pH值时CE在水溶液和水泥浆体中的流变特性,确立了CE的低临界溶解温度和等电点。分别研究了阳离子、阴离子及其价态对CE溶液表观粘度的影响,基于“感胶离子序”的规律阐述了离子种类和价态对CE溶液表观粘度的作用机理,揭示了CE在复杂液相环境中的成膜特征,为研究塑性阶段CE改性水泥浆体的流变特性提供了理论依据。 2.提出了CE-聚水与缓释组分(CWRC)改性水泥浆体水化动力学过程的设计与制备方法,基于对水化热和电阻率微分曲线分析,掌握了水泥水化初期的宏观热学效应及电化学特征变化规律,研究了水化热和电阻率与水泥水化进程的关系,建立了CE-CWRC-水泥三元体系水化热-电模型。分别研究了CE和CWRC对水泥水化热和电阻率的影响,指出CWRC对水泥水化各阶段的延迟作用小于CE。研究了电阻率和水化放热量与Ca(OH)2和化学结合水含量的关系,发现具有线性相关性,为研究水泥水化早期结构形成及水化进程提供了一种新的结构参数。通过对水化热和电阻率微分曲线分析,建立了CE-CWRC-水泥三元体系水化热-电模型,将水泥水化过程分为：溶解-析出平衡期、结构形成期、结构发展期和结构稳定期4个阶段,且模型中水化热和电阻率微分在表征水泥早期水化动力学过程具有较好的一致性,可以准确描述水泥水化历程及结构形成的瞬时状态。 3.首次提出了CE改性薄层水泥浆体在快速失水条件下的试验设计与评价方法,通过改变水泥浆体厚度、养护温度和基体材料的种类,系统研究了CE改性薄层水泥浆体的早期失水特征、界面性能和微观分析,探明了薄层水泥浆体的水化规律和微观结构发展机制。以失水速度和失水率为评价指标,研究了薄层水泥浆体在快速失水条件下的早期失水特征,并阐述了其失水机制。分析了水泥浆体厚度、养护温度和基体材料的种类对薄层水泥浆体界面性能的影响,指出了不同龄期时的界面破坏形式。通过XRD、FTIR和TG-DSC分析,研究了薄层水泥浆体在快速失水条件下的水化规律。通过对快速失水条件下水泥浆体表层、中间层和界面层3个区域的微观分析,探明了水化产物沿水泥浆体厚度方向上的分布规律,揭示了薄层水泥浆体的界面破坏原理,为研究外墙外保温系统中保温层脱落和保护层的空鼓、开裂等问题奠定了理论基础。 4.根据薄层水泥-CE浆体中水分和离子的迁移、CE成膜、水泥浆体的硬化过程,分析了水化产物沿薄层水泥浆体厚度方向上的分布规律,建立了实际服役环境下的薄层水泥-CE浆体水化过程和界面过渡区微观结构模型。根据CE成膜与溶解过程、薄层水泥浆体的失水机制与离子迁移过程、水化历程与微观结构发展机制、水化产物的分布规律,建立了实际服役环境下薄层水泥-CE浆体的水化过程模型。根据基体材料的孔结构与吸水特性,分析了薄层水泥浆体的失水特征、界面微结构的变化、水化产物的种类和数量分布,建立了薄层水泥浆体与基体材料间的界面过渡区微观结构模型,对于研究薄层水泥-CE浆体水化规律具有重要的理论与实际意义。
[Abstract]:Our country is in the key period of urbanization development, exterior insulation system as the main way of building energy saving technology, the bonding mortar and mortar mortar for TLC to realize energy-saving effect and durability of external thermal insulation system plays an important role in this context is very important the key problem of thin water mortar. This work comes from the "12th Five-Year" National Science and technology support program (2011BAJ04802) and the National Natural Science Foundation (50902107). Through the study of cellulose ether (cellulose ether, CE) and thermo rheological properties of modified cement paste electrical properties proved under many factors of cement the hydration kinetics. According to the thin layer of CE modified cement slurry used in different environment, study the hydration law of cement paste under the condition of rapid dehydration based on thin water. The rheological characteristics of slurry, hydration kinetics process and hydration rule under rapid dehydration conditions were established. The hydration process and interfacial transition zone microstructure model of thin layer CE modified cement paste were established, and the hydration characteristics of thin layer CE modified cement paste were expounded.
The main work of this article and the important achievements are as follows:
According to the 1. CE in aqueous solution (mixing phase) and cement paste (water phase environment) rheological properties of 2 kinds of liquid phase in the environment, the system of CE film forming process and solution environment (temperature, pH value, ion type and valence) on the rheological properties of aqueous solution and cement paste the CE revealed in different liquid phase in the film-forming process and temperature, pH value, the ions in aqueous solution and cement paste in mechanism.
The apparent viscosity, shear stress, yield stress and plastic viscosity as the evaluation index, the effects of CE type and content on the rheological properties of aqueous solution and cement paste. The effects of different temperature and pH value of CE rheological properties in aqueous solution and in cement paste, established a low Pro field solution temperature CE and isoelectric point. The Cation Anion valence were studied, and its influence on the apparent viscosity of CE solution, based on the "lyotopic series" rule describes the composition and valence state of CE ion on the apparent viscosity of the solution mechanism, reveals that the CE film characteristics in complex liquid phase in the environment, and provides a theoretical basis for the study on rheological properties of plastic phase CE modified cement slurry.
2. proposed CE- water and release components (CWRC) design and preparation method of modified dynamic process of hydration of cement pastes, analysis and differential curve of water resistivity based on the grasp of the macro thermal effect and electrochemical characteristics of changes at the early hydration of cement, studied the relationship between the resistivity and the hydration heat of cement the hydration process of cement, established the CE-CWRC- three element system of heat electric model.
The effects of CE and CWRC on cement hydration heat and resistivity were studied, pointed out that the delay is less than CE. on the resistivity and the hydration heat of cement hydration and Ca CWRC stages (OH) 2 and chemical binding relationship between water content, with linear correlation, and provides a kind of new structure parameters study on cement hydration early structure formation and hydration process. Through the analysis of thermal and electrical resistivity differential curve for water, set up three yuan CE-CWRC- cement hydration heat electric model, the cement hydration process is divided into: dissolution precipitation equilibrium phase structure, structure formation period, development period and the stable period of 4 stage structure the model of hydration heat and resistivity, and the differential has good consistency in characterization of cement early hydration kinetics, can accurately describe the instantaneous state of the formation and structure of the cement hydration process.
3. first proposed the experimental design and evaluation of CE modified thin cement slurry in rapid dehydration conditions, by changing the cement paste thickness, different curing temperature and substrate material, studied early dehydration characteristics of CE modified thin cement slurry, interfacial properties and micro analysis, proved the development mechanism water law of thin cement slurry and microstructure.
The water loss rate and water loss rate as the evaluation index, to study the early dehydration feature thin cement slurry in the rapid dehydration conditions, and expounds the mechanism of water loss. Cement paste thickness analysis, different curing temperature and substrate materials on the interfacial properties of thin cement slurry's influence, pointed out that the failure form of different age the period of the interface. Through the XRD analysis of FTIR and TG-DSC, studied the hydration law of thin cement slurry in the rapid dehydration conditions. The cement slurry under the condition of rapid loss of body surface, the micro analysis of the 3 area in the middle layer and interface layer, proved the distribution of hydration products of the cement paste thickness the direction, reveals the thin layer of cement paste interface failure principle, on the exterior insulation insulation layer and protective layer hollowing off system, cracking and other problems to lay a theoretical foundation.
4. according to the migration of moisture and ion thin cement paste -CE, CE film, the hardening process of cement paste, analyze the distribution of hydration products along the thin cement paste thickness direction, the establishment of the actual working environment of the -CE thin cement slurry hydration process and microstructure of interfacial transition zone model.
According to the CE film and the dissolution process, the mechanism of water loss and ion migration process of thin cement slurry, hydration process and microstructure development mechanism, distribution of hydration products, the establishment of the actual service hydration process model of thin cement slurry -CE environment. According to the pore structure and water absorption properties of the substrate materials, analysis the water loss characteristics of thin cement slurry, change the microstructure of interface, type and quantity distribution of hydration products, the establishment of the ITZ microstructure model of thin cement slurry and matrix materials, has important theoretical and practical significance for the study of -CE thin cement slurry water law.

【学位授予单位】：武汉理工大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TU578.1

【参考文献】