石英纤维及其 Mini复合材料强度及分布规律

针对国产石英纤维强度，本工作采用液相浸渍法（硅溶胶、石英浆料和氮化硅浆料）制得Mini复合材料，利用两参数Weibull分布，对其强度及分布进行了研究，采用Kolmogrov非参数检验对其分布进行了检验．同时研究了热处理对纤维束强度分布的影响．结果表明，可用两参数Weibull分布表征纤维束及其Mini复合材料强度分布．热处理使纤维强度急剧下降，且强度分散性变大；相同处理温度下，由硅溶胶制得的Mini复合材料强度较高，分散性较小；而石英或氮化硅浆料制备的Mini复合材料强度较低．     

双膨胀低热矿渣水泥的膨胀过程研究

本文借助水泥强度和净浆膨胀测定方法与ＸＲＤ对高镁水泥熟料－矿渣－石膏系统的双膨胀低热矿硅酸盐水泥进行了研究。得到（１）低热矿渣水泥净浆膨胀随ＳＯ３含量和时间的变化规律；（２）低热矿渣水泥强度随ＳＯ３含量的变化规律；（３）在水泥中适量ＳＯ３和熟料中ＭｇＯ含量小于５％时，钙钒石膨胀和水镁石膨胀具有连续性、整体性和稳定性；（４）矿渣的掺入有助于钙钒石的形成及其数量的增加和水泥膨胀率的增加与稳定。     

聚丙烯共混改性研究

将少量（１％）自制的甲基丙烯酸十八醇酯（ＳＭＡ）与丙烯酰胺（ＡＭ）共聚物Ｐ（ＳＭＡ－ＡＭ）添加剂聚丙烯（ＰＰ）中进行共混，能大幅度提高聚丙烯的亲水性和粘合强度。Ｐ（ＳＭＡ－ＡＭ）的加入，改善了ＰＰ的流变性能，对ＰＰ的结晶度和拉伸强度影响不大。俄歇电子能谱（ＡＥＳ）分析表明，Ｐ（ＳＭＡ－ＡＭ）在ＰＰ共混物表面富集。     

拉伸强度具有“协同效应”的二元多相共混物研究

研究几种二元多相共混物的拉伸强度与组分的结构、界面区相容性、共混组成的关系。界面区对伸强度有两种作用，当界面区粘接强度小于临界值时，界面区的存在降低了共混物的拉伸强度；当界面区粘接强度大于临界值时，界面区的存在提高了共混物的拉伸强度。使共混物在拉伸强度方面具有“协同效应”的必要条件是：每个组分必须有交联网络结构；共混物的界面区粘接强度必须大于临界值。     

SOFC阴极材料（La0.85Sr0.15）（Mn1—7Cry）O3＋δ的非化学整比,晶体结构,电导

研究了掺杂Ｃｒ２Ｏ对（Ｌａ０．８５Ｓｒ０．１５）ＭｎＯ３（以Ｃｒ只好以代Ｍｎ）Ｍｎ＾４＿离子的含量、氧非化学整比、晶体结构、电导率和热膨胀系数的影响。结果表明，随Ｃｒ取代Ｍｎ的摩尔比ｙ增加「Ｍｎ＾４＋」／「Ｍｎ＋Ｃｒ」比率和氧的非化学整比δ减小，而「Ｍｎ＾３＋」比率不变；ＬＳＭＣ的昌体结构仍属菱表六面体，且结构和成分（δ）从室温到１０００℃保持稳定；ＬＳＭＣ的导电激活能增大，但在１０００℃时电导率     

Fe73.5Cu1Mo3Si13.5B9微晶软磁合金的结构及其对磁性的影响

对Ｆｅ７３．５Ｃｕ１Ｍｏ３Ｓｉ１３．５Ｂ９微晶软磁合金的结构及其对合金磁性的影响了研究，结果表明，在最佳磁性能下，晶相点阵常数ａ＝０．２８４３ｎｍ，相当于Ｆｅ（Ｓｉ）固溶体中含Ｓｉ％（ｍｏｌ／ｍｏｌ）：１８－２０，体积百分数Ｖ＝７４．８％，晶粒尺寸Ｄ＝１４．６ｎｍ；残余非晶层厚度δ＝１．２３ｎｍ；当Ｔ退火≥５６０℃时明显有Ｆｅ－Ｂ化合物析出。Ｆｅ７３．５Ｃｕ１Ｍｏ３Ｓｉ１３．５Ｂ９合金的磁性不仅与     

SOFC阴极材料(La_0.85Sr_0.15)(Mn_(1-y)Cr_y)O_(3 δ)的非化学整比、晶体结构、电导率和热膨胀性能

研究了掺杂Ｃｒ２Ｏ３对（Ｌａ０．８５Ｓｒ０．１５）ＭｎＯ３（以Ｃｒ部分取代Ｍｎ）Ｍｎ４＋离子的含量、氧非化学整比、晶体结构、电导率和热膨胀系数的影响。结果表明，随Ｃｒ取代Ｍｎ的摩尔比ｙ增加［Ｍｎ４＋］／［Ｍｎ＋Ｃｒ］比率和氧的非化学整比δ减小，而［Ｍｎ４＋］／［Ｍｎ３＋］比率不变；ＬＳＭＣ的晶体结构仍属菱形六面体，且结构和成分（δ）从室温到１０００℃保持稳定；ＬＳＭＣ的导电激活能增大，但在１０００℃时电导率趋于相同，热膨胀性能基本未受影响     

DBM-g-PE与PVC的相互作用研究EI

采用固相接枝法制备了ＤＢＭ－ｇ－ＰＥ，用红外光谱分析证明了接枝物确实存在。ＰＶＣ／ＣＰＥ＝１００／５合金性能测定结果表明，添加５份接枝物的合金（Ａ），缺口冲击强度、拉伸强度分别为１８．２ｋＪ／ｍ２和５３．０ＭＰａ；而添加５份ＰＥ的合金（Ｂ），其相应性能为５．１ｋＪ／ｍ２和３３．８ＭＰａ。不加接枝物的合金（Ｃ），虽有高韧性，但拉伸强度却由５３．０ＭＰａ降至５０．２ＭＰａ。ＤＳＣ、ＳＥＭ的结果均表明，ＰＥ接枝ＤＢＭ后与ＰＶＣ的相互作用增强，与ＣＰＥ协同作用能增韧、增强ＰＶＣ，并探讨了其机理。     

添加Al_2O_3对SiC板粒／Y－TZP复合材料力学性能的影响

本文以ＳｉＣ板粒、ＺｒＯＣｌ２－８Ｈ２Ｏ、ＡｌＣｌ３和Ｙ（ＭＯ）３为原料，利用共沉淀和热压烧结工艺，制备ＳｉＣ板粒／Ｙ－ＴＺＰ和（含Ａｌ２Ｏ３）ＳｉＣ板粒／Ｙ－ＴＺＰ复合材料．测试了材料的室温和高温力学性能．研究了添加Ａｌ２Ｏ３对ＳｉＣ板粒／Ｙ－ＴＺＯ复合材料的影响．结果表明，ＳｉＣ板粒／Ｙ－ＴＺＰ复合材料与Ｙ－ＴＺＰ陶瓷相比，其室温强度和韧性出现明显下降，高温强度也没有改善；而在ＳｉＣ板粒与Ｙ－ＴＺＰ复合的基础上，添加Ａｌ２Ｏ３可明显提高材料的强度和断裂韧性，同时，材料的高温强度也获得显著改善．     

16Mn钢在H2S溶液中的脆断敏感性

采用慢性变速率拉伸实验（ＳＳＲＴ）、扫描电镜及电化学渗氢技术研究了Ｈ２Ｓ浓度、电位对１６Ｍｎ钢在Ｈ２Ｓ溶液中脆断敏感性的影响，结果表明：１６Ｍｎ钢在Ｈ２Ｓ溶液中的断裂是一种氢脆控制的断裂，随Ｈ２Ｓ浓度（Ｎ）增大，应力腐蚀断裂的机理从韧性转变的脆性；１６Ｍｎ钢片在Ｈ２Ｓ溶液中的稳态渗氢电流值ＩＨ和Ｈ２Ｓ浓度（Ｎ）满足ＩＨ＝８．５２５×Ｎ＾０．７２４９；ＩＨ受温度的影响主要表现在氢在１６Ｎｎ钢中的扩散     

Improving the structure of the interfacial zone and its influence on the long-term behavior of mortars

The structure of the interfacial zone between cement paste and aggregate was improved by using a pretreated quartz aggregate on whose surface the hydraulic mineral β?C₂S was directly formed. The composition and morphology of the structure of the interfacial zone was examined, and its influence was studied by comparisons between mortars made with pretreated quartz aggregate and with normal quartz aggregate. The results showed that the composition and morphology of the interfacial zone were substantially improved by the hydration of the mineral β?C₂S of the pretreated quartz aggregate. The influence of the interfacial structure on the strength of mortars was related to structural development. It appears to be slight at early hydration, but significant at late hydration.     

低应力水平下混凝土中氯离子扩散行为多尺度分析方法

混凝土的扩散渗透性能与其微观结构（包括细观尺度上粗骨料颗粒与砂浆之间的界面过渡区及砂浆本身的微观结构等）密切相关。在微观尺度上,砂浆和界面过渡区均可视为由无孔砂浆基质和孔隙水夹杂相组成的两相复合材料,二者的主要区别表现为孔隙率不同。在外荷载作用下,砂浆和界面过渡区的毛细孔隙率及孔隙连通性会发生改变,从而改变混凝土的扩散渗透性能。基于此,该文建立了低应力水平下混凝土中氯离子扩散行为多尺度理论分析方法,获得了混凝土表观扩散系数与外荷载（以体应变表征）及砂浆和界面过渡区当前孔隙率的定量关系。分析所采用的主要参数为砂浆和界面过渡区的毛细孔隙率、无孔砂浆基质和骨料相的力学参数、骨料相和界面过渡区的体积分数、外荷载等。与已有文献数据对比知,该文分析结果与之吻合良好,表明了理论分析方法的合理性与准确性。此外,基于该方法,探讨分析了混凝土微/细观结构对其宏观扩散性能的影响。     

The interfacial zone and bond strength between aggregates and cement pastes incorporating high volumes of fly ash

The weak transition zone between aggregate and cement paste controls many important properties of concrete. A number of studies dealing with interfacial zone are available in the literature for normal concrete and concrete containing silica fume. High-volume fly ash concrete for structural applications was developed at CANMET in the 1980s, but to date there has been no information available for interfacial zone in high-volume fly ash concrete.In this paper, the orientation index and mean size of Ca(OH)₂ crystals in the aggregate-paste interfacial zone were determined by the X-ray diffractometer. The bond strength between the aggregate and paste was also investigated. It was found that, at the age of 28 days, there was no obvious transition zone between the aggregate and cement paste incorporating high volumes of fly ash. The higher the paste strength, the higher is the bond strength.     

Crumb rubber aggregate coatings/pre-treatments and their effects on interfacial bonding, air entrapment and fracture toughness in self-compacting rubberised concrete (SCRC)

The interfacial-bonding, interfacial transition zone (ITZ), and porosity are regarded as the key factors affecting hardened concrete properties. The aim of this study was to experimentally improve the bonding between the rubber aggregate and cement paste by different methodologies including water washing, Na(OH) pre-treatment, and both cement paste and mortar pre-coating. All methods were assessed by determining mechanical and dynamic properties, then correlating this with ITZ porosity and interfacial gap void geometry, along with quantification of the fracture energy during micro crack propagation using fractal analysis. The results indicated that pre-coating the rubber by mortar gave the best results in terms of fracture toughness and energy absorption showing good agreement between observations made at both micro and macro scales.     

Modeling the influence of the interfacial zone on the DC electrical conductivity of mortar

The interfacial zone separating cement paste and aggregate in mortar and concrete is believed to influence many of the properties of these composites. The available experimental evidence, obtained on artificial geometries, indicates that the DC electrical conductivity of the interfacial zone, because of its higher porosity, may be considerably larger than that of the bulk cement paste matrix. This paper presents the theoretical framework for quantitatively understanding the influence of the interfacial zone on the overall electrical conductivity of mortar, based on realistic random aggregate geometries. This understanding is also used, via an electrical analogy with Darcy's law, to make predictions about the effect of the interfacial zone on fluid permeability. The results obtained for mortar should also pertain to concrete.     

Particle size effect on the strength of rice husk ash blended gap-graded Portland cement concrete

Rice husk ash (RHA) has been used as a highly reactive pozzolanic material to improve the microstructure of the interfacial transition zone (ITZ) between the cement paste and the aggregate in high-performance concrete. Mechanical experiments of RHA blended Portland cement concretes revealed that in addition to the pozzolanic reactivity of RHA (chemical aspect), the particle grading (physical aspect) of cement and RHA mixtures also exerted significant influences on the blending efficiency. The relative strength increase (relative to the concrete made with plain cement, expressed in %) is higher for coarser cement. The gap-grading phenomenon is expected to be the underlying mechanism. This issue is also approached by computer simulation. A stereological spacing parameter (i.e., mean free spacing between mixture particles) is associated with the global strength of the blended model cement concretes. This paper presents results of a combined mechanical and computer simulation study on the effects of particle size ranges involved in RHA-blended Portland cement on compressive strength of gap-graded concrete in the high strength/high performance range. The simulation results demonstrate that the favourable results for coarser cement (i.e., the gap-graded binder) reflect improved particle packing structure accompanied by a decrease in porosity and particularly in particle spacing.     

Atomic force and lateral force microscopy (AFM and LFM) examinations of cement and cement hydration products

The objective of this work was to better understand how atomic force microscopy (AFM) and lateral force microscopy (LFM) techniques can be used as tools to understand the nanostructure and microstructure of cement and cement hydration products. AFM and LFM techniques were used on mortar samples to distinguish between CSH, CH, and unhydrated cement particles. The LFM technique appears to be more sensitive to topographic changes than conventional AFM and it can more clearly distinguish between the different phases at high magnification (low scan range). AFM could also be used to calculate the roughness of the interfacial transition zone (ITZ) between aggregate and the cement paste at different ages. The rough surface at the interface of the paste and aggregate is generally interpreted as higher porosity. It was found that a reduction in roughness (i.e., porosity) occurred for samples that were cured for a longer time which are consistent with the explanation of porosity.     

Prediction of the chloride diffusion coefficient of concrete

It has been experimentally verified that the structure of the interfacial transition zone (ITZ) in concrete differs from that of bulk cement paste. As such, concrete should be modeled as a three-phase material at a mesoscopic level. This paper presents a three-phase composite model for predicting the chloride diffusion coefficient of concrete. Taking the inclusion as aggregate and the matrix as cement paste, the composite circle model is established by adding an ITZ layer in between the inclusion and the matrix. Solving the asymmetrical problem analytically, a closed-form solution for the chloride diffusion coefficient of concrete is derived. After verifying this model with experimental results, the effects of the aggregate area fraction, the chloride diffusion coefficient of ITZ, the ITZ thickness, the maximum aggregate diameter and the aggregate gradation on the chloride diffusion coefficient of concrete are evaluated in a quantitative manner. It is found that the chloride diffusion coefficient of concrete decreases with the increase of the aggregate area fraction and the maximum aggregate diameter, but increases with the increase of the chloride diffusion coefficient and thickness of ITZ. It is also found that the aggregate gradation has a significant influence on the chloride diffusion coefficient of concrete.     

The influence of mixing on the microstructure of the cement paste/aggregate interfacial zone and on the strength of mortar

The influence of mixing on the microstructure of the cement paste/aggregate bond has been investigated. Back-scattered electron microscopy was used in conjunction with quantitative image analysis to examine the microstructure of the interface between limestone aggregate and the cement matrix in a series of mortars. The distribution of porosity and anhydrous material along the paste/aggregate interface was shown to be dependent upon the relative abundance of water at the aggregate surface during mixing. Improvements in the interfacial microstructure were shown to correlate with improvements in strength and fracture properties. The interfacial zones seen in the limestone mortars were compared with a model interfacial system. A new classification system for two types of interfacial regions in mortar is proposed.     

石英岩尾砂与水泥浆体微界面的改性

采用电石渣对石英岩尾砂进行煅烧改性,利用X射线衍射仪、背散射扫描电镜和能谱分析等方法对改性石英岩尾砂矿物组成和微观结构进行表征,并研究了改性石英岩尾砂的水化性能。通过背散射扫描电镜和压汞仪分析了掺改性石英岩尾砂水泥浆体的微界面结构与孔结构。结果表明:改性石英岩尾砂具有复合结构,内部是惰性的石英岩尾砂,表层为矿物β-C2S层。改性石英岩尾砂可水化生成C-S-H凝胶,改善了石英岩尾砂与水泥浆体的微界面,降低了水泥浆体的孔隙率。