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Drying Shrinkage of Cement-Based materials Under Conditions of Constant Temperature and Varying Humidity

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Journal of China University of Mining and Technology 2007年第3期17卷 428-431页

作者： ma bao-guo WEN Xiao-dong WANG Ming-yuan YAN Jia-jia Gao Xiao-jian Key Laboratory for Silicate materials Science and Engineering of Ministry of Education Wuhan University of Technology Wuhan Hubei 430070 China

Currently,deformations along the central axis of specimens were usually measured under fixed environmental conditions. Seldom were the effects of environmental factors on the drying-shrinkage deformation of cement-based ma-terial considered. For this paper,the drying-shrinkage deformation at different w/b ratios and different additions to mor-tars was investigated under different environments at a temperature of 20 ℃ and humidity ranging from 100% to 50%. The specimens were cured in water for 28 days before measurement. The results illustrate that mortar shows much less shrinkage under various drying conditions when a lower w/b ratio is adopted. With a decrease in relative humidity the speed of drying-shrinkage becomes gradually lower. The addition of silica fume reduces the drying-shrinkage of mortar under higher relative humidity,because the pore structure of mortar with silica fume becomes more refined. The addi-tion of fly ash increases the total porosity and the volume of coarse pores in the mortar. The drying-shrinkage of mortar under different conditions increases with the addition of more of fly ash.

关键词： humidity variation volume deformation pore structure

Effect of loess for preventing contamination of acid mine drainage from coal waste

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Journal of Coal Science & Engineering(China) 2012年第3期18卷 302-306页

作者： ma bao-guo WANG Hui-yong GAO Ran LI Shu-li College of Water Resource and Hydroelectricity Hebei University of EngineeringHandan 056021China Yongnian County Forestry Bureau ofHebei Yongnian 057150China

Acid mine drainage （AMD） that releases highly acidic, sulfate and metals-rich drainage is a serious environmental problem in coal mining areas in China. In order to study the effect of using loess for preventing AMD and controlling heavy metals contamination from coal waste, the column leaching tests were conducted. The results come from experiment data analyses show that the loess can effectively immobilize cadmium, copper, iron, lead and zinc in AMD from coal waste, increase pH value, and decrease Eh, EC, and 8024- concentrations of AMD from coal waste. The oxidation of sulfide in coal waste is prevented by addition of the loess, which favors the generation and adsorption of the alkalinity, the decrease of the population of Thiobacillusferrooxidans, the heavy metals immobilization by precipitation of sulfide and carbonate through biological sul- fate reduction inside the column, and the halt of the oxidation process of sulfide through iron coating on the surface of sulfide in coal waste. The loess can effectively prevent AMD and heavy metals contamination from coal waste in in-situ treatment systems.

关键词： acid coal waste acid mine drainage loess heavy metals contamination prevention

Durability of High Performance Color Hardener

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Journal of Wuhan University of Technology(materials Science) 2004年第4期19卷 79-81页

作者：马保国 Wuhan University of Technology

The properties of high performance color hardener (HPCH) and the mechanism were *** is a composite system, which is composed of cementitious and auxiliary cementing materials, composite additives, abrasion resistance component (aggregate) and pigment. The porosity and pore structure of the material are obviously improved due to the activation, filling and adsorption of auxiliary cementing materials, thus resulting in a great increase of binding capacity for ions in HPCH and the obstacles of ion *** density of material structure, bonding capacity of cementitious material to the abrasion-resisting component and the corrosion resistance are greatly and effectively improved by adding the auxiliary cementing materials and compound additives. According to the tests of dry shrinkage, sulphate resistance, chloride permeability and Ca(OH) 2 content distribution, the property superiority of HPCH is *** mechanism of materials modification of HPCH is explained from the microscopic point of view by testing the pore structure and pore distribution via the mercury intrusion pressure method.

关键词： high performance color hardener material modification pore distribution

Surface Modification and Model of Glassy Cementitious materials

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Wuhan University Journal of Natural Sciences 2000年第4期5卷 491-496页

作者： ma bao-guo, Li Yong-xin, He Xing-yang, Chen You-zhi College of materials Secience and Engineering,Wuhan University of Technology Wuhan, 430070,China College of materials Secience and Engineering Wuhan University of Technology Wuhan China

Basic theory of surface modification about glassy cementitous materials is presented. At the same time modified glassy cementitous materials were manufactured by means of point activation and disperse and grind aid according to technology of mechanical-chemistry. This theory about surface modification has been proved by some experimental results such as SEM, size distribution, fluidity of the paste, physical-mechanical properties of the hardened paste and heat of the hydration. The particle size of modified fly ash is tending to become smaller and the shape of microfine particles seems a ball; strength of modified glassy cementitous materials and ordinary portland cement compound paste has a obvious increment and fluidity of the paste also has a noticeable improvement; surface modification also can accelerate the formation of paste structure to a certain degree. Besides a model about the interactive mechanism of modified glassy cementitous materials and ordinary portland cement is put forward.

关键词： glassy eementitous materials surface modification point activation grind aid model

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地下工程混凝土的梯度功能设计与性能研究

中国矿业大学学报 2008年第3期37卷 354-359页

作者：王信刚马保国南昌大学建筑工程学院江西南昌330031 武汉理工大学硅酸盐材料工程教育部重点实验室湖北武汉430070

为了解决地下工程混凝土的耐久性技术难题，在地下工程混凝土的结构设计中引入梯度功能设计思路．采用Cl-离子扩散法检测功能梯度混凝土的抗渗性能，采用收缩试验评价其收缩变形一致性，采用显微硬度计、SEM测试其微观性能．结果表明，... 详细信息

为了解决地下工程混凝土的耐久性技术难题，在地下工程混凝土的结构设计中引入梯度功能设计思路．采用Cl-离子扩散法检测功能梯度混凝土的抗渗性能，采用收缩试验评价其收缩变形一致性，采用显微硬度计、SEM测试其微观性能．结果表明，与单一的高性能混凝土相比，功能梯度混凝土的抗渗性能明显提高，特别是其抗离子渗透性，Cl-扩散系数DNEL下降了1～2个数量级，表观Cl^-扩散系数Da下降了50％左右；功能梯度混凝土的收缩变形匹配良好；适用于地下工程结构混凝土保护层的无细观界面过渡区水泥基材料的集料与水泥石界面过渡区由传统混凝土的60～100pm细化为30pm以下，从而有效地阻断了侵蚀性介质的渗入通道．

关键词：梯度功能设计抗渗性耐久性收缩界面过渡区

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矿物掺合料对混凝土抗酸雨侵蚀特性的影响

建筑材料学报 2013年第3期16卷 416-421页

作者：王凯马保国张泓源华东交通大学土木建筑学院江西南昌330013 武汉理工大学硅酸盐建筑材料国家重点实验室湖北武汉430070

通过室内加速腐蚀试验,用球压痕和超声波方法研究了含不同矿物掺合料(高钙粉煤灰、磨细高炉矿渣、硅粉)混凝土在模拟酸雨(pH=2)下的损伤劣化过程及特点.结果表明:在混凝土中掺入一定量、适宜的矿物掺合料,因其发生火山灰反应而使体系Ca(... 详细信息

通过室内加速腐蚀试验,用球压痕和超声波方法研究了含不同矿物掺合料(高钙粉煤灰、磨细高炉矿渣、硅粉)混凝土在模拟酸雨(pH=2)下的损伤劣化过程及特点.结果表明:在混凝土中掺入一定量、适宜的矿物掺合料,因其发生火山灰反应而使体系Ca(OH)2含量降低、微结构更加致密,在一定程度上延缓了酸雨对混凝土的侵蚀破坏进程,提高了混凝土的耐酸雨侵蚀能力,其中尤以高钙粉煤灰、磨细高炉矿渣和硅粉三元复掺效果最为明显,但总体上延缓作用有限,含矿物掺合料混凝土在酸雨侵蚀持续作用下仍会遭到严重侵蚀破坏.含矿物掺合料混凝土酸雨侵蚀破坏主要是H+溶蚀性破坏和SO2-4膨胀性破坏共同作用的结果.

关键词：混凝土酸雨侵蚀矿物掺合料表面损伤内部损伤

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非离子纤维素醚改性水泥浆的孔结构

建筑材料学报 2013年第1期16卷 121-126,137页

作者：欧志华马保国蹇守卫湖南工业大学土木工程学院湖南株洲412007 武汉理工大学硅酸盐建筑材料国家重点实验室湖北武汉430070

通过表观密度测试及宏观、微观孔结构观察,研究不同分子结构非离子纤维素醚对水泥浆孔结构的影响.结果表明,非离子纤维素醚会导致水泥浆孔隙率增加;非离子纤维素醚改性水泥浆黏度相近时,羟乙基纤维素醚(HEC)改性水泥浆的孔隙率比羟丙基... 详细信息

通过表观密度测试及宏观、微观孔结构观察,研究不同分子结构非离子纤维素醚对水泥浆孔结构的影响.结果表明,非离子纤维素醚会导致水泥浆孔隙率增加;非离子纤维素醚改性水泥浆黏度相近时,羟乙基纤维素醚(HEC)改性水泥浆的孔隙率比羟丙基甲基纤维素醚(HPMC)和甲基纤维素醚(MC)改性水泥浆小;基团含量相似的HPMC纤维素醚,黏度/相对分子质量越低,其改性水泥浆孔隙率越小.非离子纤维素醚掺入水泥浆后,降低了液相表面张力,使得水泥浆容易形成气泡;非离子纤维素醚分子定向吸附在气泡气-液界面,同时还增加了水泥浆液相黏度,使得水泥浆稳定气泡的能力增强.

关键词：非离子纤维素醚水泥浆孔结构分子结构表面张力黏度

超低离子渗透性水泥基材料的组分及其结构与性能

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中南大学学报（自然科学版） 2009年第1期40卷 145-152页

作者：王信刚马保国李相国南昌大学建筑工程学院江西南昌330031 武汉理工大学硅酸盐材料工程教育部重点实验室湖北武汉430070

采用加速扩散法测试超低离子渗透性水泥基材料(ULIPCM)的离子传输性能,采用显微硬度、压汞法(MIP)、扫描电镜-能谱仪(SEM-EDXA)研究其微观结构,提出ULIPCM的界面过渡区结构模型。结果表明:ULIPCM的Cl-扩散系数≤0.8×10-13m2/s,6h导电量... 详细信息

采用加速扩散法测试超低离子渗透性水泥基材料(ULIPCM)的离子传输性能,采用显微硬度、压汞法(MIP)、扫描电镜-能谱仪(SEM-EDXA)研究其微观结构,提出ULIPCM的界面过渡区结构模型。结果表明:ULIPCM的Cl-扩散系数≤0.8×10-13m2/s,6h导电量≤300C;与高性能混凝土(HPC)相比,ULIPCM的Cl-扩散系数下降1～2个数量级,6h导电量下降约40%,ULIPCM的Cl-渗透性能非常低;ULIPCM用作海洋工程结构混凝土保护层时,其厚度≥1.5cm。ULIPCM的集料与水泥石界面过渡区的微观结构和性能得到显著改善,有利于提高其抗渗性能,尤其是ULIPCM的集料与水泥石界面过渡区由传统混凝土的60～100μm细化为30μm以下,从而有效地阻断侵蚀性介质的渗入通道。

关键词：水泥基材料抗离子渗透性能寿命预测界面过渡区

粉煤灰-脱硫石膏水泥基材料水化活性及微结构

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土木建筑与环境工程 2011年第5期33卷 137-142页

作者：高英力陈瑜马保国长沙理工大学交通运输工程学院长沙410114 武汉理工大学硅酸盐材料工程教育部重点实验室武汉430070

采用DTA-TG、XRD、SEM以及宏观水化收缩和强度试验等手段研究了粉煤灰-脱硫石膏-水泥三元复合胶凝体系的水化过程、活性效应及微观结构等,根据试验结果总结了复合胶凝材料的水化动力学过程。结果表明,粉煤灰-脱硫石膏水泥石的钙矾石吸... 详细信息

采用DTA-TG、XRD、SEM以及宏观水化收缩和强度试验等手段研究了粉煤灰-脱硫石膏-水泥三元复合胶凝体系的水化过程、活性效应及微观结构等,根据试验结果总结了复合胶凝材料的水化动力学过程。结果表明,粉煤灰-脱硫石膏水泥石的钙矾石吸热峰强于基准样;在各组分相互活性激发和外掺激发剂作用下,粉煤灰-脱硫石膏水泥石中2次水化效应明显;SEM、XRD表明水泥石早期有明显的钙矾石生成,同时粉煤灰颗粒的表面侵蚀现象明显,进一步说明复合胶凝体系的早期活性得到有效激发,硬化后综合性能得到有效保证。且宏观收缩及强度试验也从侧面印证了微观试验结果。粉煤灰-脱硫石膏水泥基复合胶凝材料体系的研发可大量消耗燃煤电厂的工业废渣,具有显著的"绿色"效应。

关键词：粉煤灰脱硫石膏活性水化微观结构