Infrared spectroscopy study of structural nature of geopolymeric products

The bonding status and chemical environment of SiO4 and AlO4 tetrahedras of three types of geopolymeric products were systematically investigated by infrared spectroscopy. The relationship between amorphous geopolymeric products and zeolite crystals with the same overall chemical compositions was also discussed. The infrared evidence shows that SiO4 tetrahedra is partially bonded by AlO4 during the hydration process of geopolymeric cement. The two types of tetrahedras jointly construct the three dimensional framework structures of the geopolymeric products. The mutual transformation between geopolymeric products and corresponding zeolite crystals will take place once the reaction condition is suitable, which reveals that the nature ofgeopolymeric products are probably the amorphous equivalent of the corresponding zeolite crystals.     

水泥固化温州污染土的力学性质和微观结构特性

在不同水泥掺量和龄期条件下对NaCl、油脂、Pb（NO₃）₂污染的温州软土进行水泥固化处理后,土体的强度得到改善。为进一步得出水泥固化处理对于不同污染土的处理效果,对水泥固化稳定不同的污染土进行了无侧限抗压强度试验和微观结构研究。分析了不同污染物类型、污染物掺入量、水泥掺入量以及养护龄期对水泥固化污染土强度特性的影响以及不同污染物浓度下水泥固化土微观结构的差异。试验结果表明：NaCl在一定范围内促进了水泥固化土早期强度的提高;油脂使水泥固化土的强度明显降低,压缩性增大;Pb（NO₃）₂掺入到土体中后,水泥固化土的强度总体上略有降低,掺入量与强度之间大致呈线性关系。随着水泥掺入量及龄期的增加,水泥固化污染土的强度会有显著提高。扫描电镜（SEM）结果分析得出：由于污染物的作用,污染物浓度的增加使固化土中孔隙增多,结构变得疏松。     

Application of X-ray computed tomography in characterization microstructure changes of cement pastes in carbonation process

The microstructure characteristics and meso-defect volume changes of hardened cement paste before and after carbonation were investigated by three-dimensional(3D)X-ray computed tomography(XCT),where three types water-to-cement ratio of 0.53,0.35 and 0.23 were considered.The high-resolution 3D images of microstructure and filtered defects were reconstructed by an XCT VG Studio MAX 2.0 software.The meso-defect volume fractions and size distribution were analyzed based on 3D images through add-on modules of 3D defect analysis.The 3D meso-defects volume fractions before carbonation were 0.79%,0.38% and 0.05% corresponding to w/c ratio=0.53,0.35 and 0.23,respectively.The 3D meso-defects volume fractions after carbonation were 2.44%,0.91% and 0.14% corresponding to w/c ratio=0.53,0.35 and 0.23,respectively.The experimental results suggest that 3D meso-defects volume fractions after carbonation for above three w/c ratio increased significantly.At the same time,meso-cracks distribution of the carbonation shrinkage and gray values changes of the different w/c ratio and carbonation reactions were also investigated.     

AW玻璃基骨水泥的制备及其结构性能表征

以AW生物玻璃与柠檬酸/磷酸氢钾复合固化液混合制得玻璃基生物骨水泥(GBC),利用XRD、FTIR和SEM对GBC的产物晶相、化学组成和显微结构进行了分析,并对其力学性能进行了测试。结果表明,GBC在固化反应后就已经有羟基磷灰石(HA)晶相生成;随着GBC在SBF中浸泡时间的延长,又生成了少量碳酸钙晶体,且HA晶相数量增多,抗压强度在7 d时达到最大值,骨水泥呈现多孔结构。     

水泥加固土微观结构的分形

为了明确有机质对水泥加固土强度形成所产生的影响,采用水泥对不同有机质含量的软土进行加固,通过无侧限抗压试验测定达到养护期的水泥加固土的力学指标,对有机质含量与水泥土强度的关系进行分析,利用扫描电子显微镜采集不同试样的微观结构照片,并采用WD-5图像处理系统对土样的微观结构图像进行定量分析,提取各试样中土颗粒形态的分维数值,用颗粒分布的计盒维数来表征各试样的分形特征.结果表明:有机质含量越高,颗粒分布的分维数值越大,试样的团粒化程度越低,水泥加固土的强度越差.土中有机质对水泥加固软土的效果具有一定的影响,颗粒分布分形的计盒维数与水泥加固土的强度呈负相关性.     

Preparation and Microstructure of Al-pillared Interlayered Montmorillonite

Al-pillared interlayerad montmorillonite (Al-PILM) was prepared using the artifcial Na-mont-morillonite from the Qingfengshan betonite nime as a starting material mixed with Al-pillared solutions.The micorstructure of the materials was studied by an X-ray powder diffractometer and a Fourier transfomr infrared (FTIR) spectrometer,The results indicated that the basda spacing [d (001) value ] of the mateials was increased significantly to 1.9194 nm relative to Na-montmorillonite (1.2182 nm) ,After calcined for 2 h at 300 ℃ ,the significantly to 1.9194 nm relative to Na-montmorillonite (1.2182nm) ,After calcined for 2 h at 300℃,the basal spacing was stailized at 1.8394 nm and the layered structure of the materials not destroyed .Themal analysis was conduted by a thermal gravimetry and differential thermal analysis (TG-DTA) instrument,it showed that Al-PILM lost physically adsorbed water below 230.6℃ and water formed by dehydorxylation of the pillars at around 497.1℃,with a peak of the phase transformation at 903.0℃.     

AW玻璃基骨水泥的制备及其结构性能表征

以AW生物玻璃与柠檬酸／磷酸氢钾复合固化液混合制得玻璃基生物骨水泥（GBC）,利用XRD、FTIR和SEM对GBC的产物晶相、化学组成和显微结构进行了分析,并对其力学性能进行了测试。结果表明,GBC在固化反应后就已经有羟基磷灰石（HA）晶相生成;随着GBC在SBF中浸泡时间的延长,又生成了少量碳酸钙晶体,且HA晶相数量增多,抗压强度在7d时达到最大值,骨水泥呈现多孔结构。     

石墨烯对水泥净浆力学性能及微观结构的影响

为改善石墨烯纳米材料疏水性,采用硝酸氧化和超声波法制备石墨烯分散悬浮液,考察石墨烯质量分数对水泥净浆力学性能及其微观结构的影响,探讨石墨烯的增强增韧作用机制,结果表明,水泥基复合材料的抗压、抗折强度随着石墨烯质量分数的增加呈先增大后减小的趋势,且最佳质量分数为水泥质量的0.02%.通过SEM和FT-IR对硬化水泥石的结构进行表征,发现石墨烯能够促进水泥水化产物的生长,改变水化晶体的形状、尺寸,使其有形成完整、簇状的趋势,但并未与水泥发生化学反应,改变其生成物类型.     

硅酸盐水泥熟料的光学显微结构特征的研究

利用反光显微镜观察了不同煅烧制度下硅酸盐水泥熟料的显微结构特征，讨论煅烧温度和时间对水泥熟料显微结构的影响，运用此方法可初步了解生产过程中出现的种种问题，为指导水泥熟料的生产和质量监控提供可靠依据。     

Strength development and microstructure of hardened cement paste blended with red mud

Red mud was activated to be a mineral admixture for Portland cement by means of heating at different elevated temperatures from 400 °C to 700 °C. Results show that heating was effective, among which thermal activation of red mud at 600 °C was most effective. Chemical analysis suggested that cement added with 600 °C thermally activated red mud yielded more calcium ion during the early stage of hydration and less at later stage in liquid phase of cement water suspension system, more combined water and less calcium hydroxide in its hardened cement paste. MIP measurement and SEM observation proved that the hardened cement paste had a similar total porosity and a less portion of large size pores hence a denser microstructure compared with that added with original red mud. Funded by the National 973 Program of China (No. 2001CB610703)     

低掺量水泥固化土的力学特性及微观结构

针对某滩涂淤泥,开展不同淤泥初始水的质量分数、不同水泥掺量的固化土无侧限抗压强度试验、一维压缩试验以及扫描电镜试验,研究低掺量水泥固化土的力学特性与微观结构特征,探讨其与常规掺量固化土的差异. 结果表明：分界水泥掺量、最低水泥掺量与淤泥初始水的质量分数的线性关系明显;与常规掺量固化土相比,低掺量固化土的强度增长明显较慢,压缩性降低较少;固结屈服应力随水泥掺量增加而增大,在较低掺量区,固结屈服应力与水泥掺量具有非线性关系;低掺量固化土屈服前、后的孔隙形态特征以及孔隙排列特征差异较大,当固结压力小于固结屈服应力时,孔隙未呈现出明显的定向性且排列较为混乱,当固结压力大于固结屈服应力时,随着荷载的增加,孔隙形状变得圆滑,复杂程度降低,孔隙排列逐渐趋向于有序.     

Analysis of the Damping Behavior and Microstructure of Cement Matrix with Silane-treated Silica Fume

The surface treatment of silca fume with silane coupling agent prior w incorporation in a cement mortar resulted in composites exhibiting increuses in loss tangent by 5%-200% and storage modulus by 10%-20% , relative to the value obtained by using as-received silica fume. The scanning electron microscopy （SEM） images iindicate that there is a morphological difference in the cement paste with treated and as-received silica fume, The, X-ray diffraction （XRD）, infrared （IR） spectrum analyses and mercury intrusion porosimetry （ MIP ） have provided evidence to understand the reaction mechanism between treated silica .fume and the hydrate product of cement. This has led to the establishment of an initial microscopic model describing the damping behavior of cement matrix.     

变温下 Ba2＋对水泥浆体C－S－H微结构的影响

为从分子尺度优化C－S－H微结构提供理论依据,采用模拟大体积混凝土内部变温历程的养护制度,运用29 Si魔角旋转核磁共振（29 Si MAS NMR）结合去卷积技术,研究了变温条件下Ba（OH）2掺量为1.0％时对水泥浆体C－S－H微结构的影响规律。结果表明：在变温条件下掺加Ba（OH）2提高了水泥浆体中硅酸盐矿物水化程度,尤其在水化早期（3 d）时硅酸盐矿物水化程度增幅较大,进而使C－S－H结构中硅氧四面体二聚体数量增加,导致其C－S－H平均分子链长（MCL）显著低于纯水泥浆体,避免了纯水泥浆体在降温阶段出现C－S－H的MCL降低的现象。同时,掺加Ba（OH）2进一步降低了水泥浆体在变温过程下C－S－H中Al3＋取代Si4＋的程度。     

Microstructure and Properties of Activated Slag Cement

Activation of the slag cement was performed using a composite activator. Experimental results show that the performance of the cement is remarkably improved. The fineness and specific surface area of the cement are increased by 23.7% and 1.4% , and 3d flexural strength and compressive strength are enhanced by 20.9% and 22.9%, respectitely. Microstructure and phase composition of the hydrates were analysed by X-ray diffraction( XRD ) and scanning electron microscopy( SEM ). The results indicate that Ca(OH)2 in the hydrates decrease obvioasly. The morphology of the other hydrates appears to be flocculent, with a dense structure. The improvements of the properties is related to the microstructural changes.     

抗菌水泥的研制

以铬矿渣为主要原料合成的抗菌剂,在碱性矿渣激发剂的作用下以内掺法加入到硅酸盐水泥中,合成具有抗力功能的水泥。对其性能的测试结果表明：抗菌水泥具有较好的使用功能和杀菌效果,抗菌水泥抑菌圈直径为空白水泥的2.3倍。     

抗菌水泥的研制

以铬矿渣为主要原料合成的抗菌剂 ,在碱性矿渣激发剂的作用下以内掺法加入到硅酸盐水泥中 ,合成具有抗菌功能的水泥。对其性能的测试结果表明 :抗菌水泥具有较好的使用功能和杀菌效果 ,抗菌水泥抑菌圈直径为空白水泥的 2 .3倍     

The Microstructure and Performance of a Cement Matrix Composite Material

Through the DSC , XRD , SEM and other experimental methods , the microstructure characteristics of reactive powder concrete( RPC ) are discussed, The results show that RPC has a super high perfomance because of its lower ratio of water-binder, high pock density , optimum hydration products mixture and being strengthened by steel fiber. The high performance results from the special hydration microstructure of RPC, and its superperformance can be well explained by the centrum partile hypothesis.     

聚合物水泥防水涂料的制备及其性能的研究

以单体丙烯酸丁酯和甲基丙烯酸甲酯以及功能性单体丙烯酸、丙烯酸羟乙酯为原料,以非离子乳化剂和阴离子乳化剂的复合乳化剂为乳化体系,通过控制聚合物乳液玻璃化温度合成丙烯酸乳液,与水泥复配制备出性能优良的聚合物水泥防水涂料.并研究了液粉比对聚合物水泥防水涂料的拉伸性能和低温柔性等的影响.     

甲基取代笼形八聚倍半硅氧烷的制备及表征

八甲基笼形倍半硅氧烷在催化剂和介电领域有着广泛的应用。用甲基三乙氧基硅烷为原料在酸性催化条件下通过水解缩合的方法合成了八个甲基取代的笼形倍半硅氧烷,并通过X射线衍射2、9Si核磁共振和红外光谱对其结构进行了表征。详细讨论了反应温度、pH值、反应所需水量及反应时间对产率的影响。结果表明,在温度为60℃、pH值为3、反应配比H2O/MTES为6.61和反应时间为40 h的条件为最优化条件。