浅议蒸压灰砂砖砌体裂缝的控制措施

作为替代实心粘土砖的主要新型墙体材料之一的蒸压灰砂砖,在施工中由于施工方法及措施不到位,易出现开裂的问题,针对这些问题提出了具体的控制措施,经工程实践证明该措施效果显著。     

富赤泥陶瓷清水砖的研制

以氧化铝工业的一种富含钙质的废弃物——赤泥为主要原料，通过添加一些添加剂，采用压制成型技术制备了富赤泥陶瓷清水砖，达到了提高赤泥利用率的目的。采用XRD、SEM等测试手段测定了样品的理化性能及微观结构。结果表明：陶瓷清水砖的吸水率为23.33%—42.33%，气孔率为43.45%—70.86%，体积密度为1.66—2.07 g/cm^3，抗折强度为11.41—23.95 MPa。分析表明经合理烧成后的此类高钙质陶瓷清水砖中最终的物相是：石英、钙黄长石、假硅灰以及少量的刚玉。另外，讨论了添加剂及制备工艺对样品结构与性能的影响。     

BeO-Al2O3陶瓷制备及性能研究

BeO-Al2O3陶瓷是具有低膨胀率的氧化物陶瓷,烧成温度范围为1800～1870℃,密度为3.3～3.7g/cm2,这种陶瓷高温下强度大、密度小、抗腐蚀、脆性稍大.     

Tribological properties of self-lubricating laminated ceramic materials

In order to improve the tribological properties of ceramic composites, Al2O3/TiC-Al2O3/ TiC/CaF2 self-lubricating laminated ceramic composites were prepared by vacuum hot pressing sintering. Experiments were conducted to get mechanical properties and the friction and wear properties were also measured with friction and wear tester. The worn surfaces were observed by scanning electron microscope （SEM） and energy dispersion spectrum （EDS）. The wear resistance properties and the self-lubricating effect of ceramic composites were analyzed. Results show that the Al2O3/TiC-Al2O3/TiC/CaF2 self-lubricating laminated ceramic composites layers are well-defined with a higher bonding strength and the mechanical performances are uniform enough to overcome the anisotropy of weak laminated ceramic composites. In addition, the fracture toughness of Al2O3/TiC layers is also improved. Its friction coefficient and wear rates decrease with the increase of rotation speed and load. Al2O3/TiC-Al2O3/TiC/CaF2 self-lubricating laminated ceramic composites have good wear resistance because of the tribofilm formed by the CaF2 solid lubricants. The wear mechanisms of Al2O3/TiC/ CaF2 layers are abrasive wear and Al2O3/TiC layers are adhesive wear.     

The Antioxidation Properties of the In-situ Ceramic from Pyrolyzing Polysilicone Preceramic

A systematic research on the pyrolysis process of polymethysilicone ( SAR- 2) and the thermostability of the pyrolysis residue was made by the thermogravimetric analysis, DTA and infrared spectroscopy. The experimental results indicate that the pyrolysis residue of SAR- 2 converted into the amorphous SiCxO4-x phase above 900 ℃ , the residue at 1200 ℃ is the most thermostable and antioxidant . It is suitable to be used as polysilicone preceramic .     

砖混历史建筑改造中的自支撑施工方法

针对砖混历史建筑改造中经常需要拆除木楼面代之以钢筋混凝土楼面,而拆除木楼板、木梁等构件后既有墙体可能会产生因失去侧向支撑而失稳或在风荷载作用下破坏的问题,通过合理安排拆除木楼面的次序,实现用拟拆除的木楼面及屋盖作为墙体在施工期间的水平支撑,保证墙体在施工过程中的安全,在施工到楼板位置时将其拆除,保证墙体的安全,减小施工成本,提高经济效益.     

莫来石质蜂窝陶瓷材料的制备与性能研究

利用挤出成型法制备了莫来石质蜂窝陶瓷材料，研究了材料的高温力学性能。并对其进行了理论分析。     

废铝灰制备陶瓷清水砖的研究

铝灰是一种采源于电解铝厂、铝型材厂、铸造铝合金厂等铝冶炼企业的工业废渣。以废铝灰为主要原料，添加一定量的粘土、石英和降低烧成温度的添加剂，采用压制成型法制备了高性能的陶瓷清水砖。经研究发现用于降低烧成温度的复合添加剂的加入不仅大大降低了烧成温度，而且可有效控制样品的收缩变形。制备的清水砖的主要由（CaAl2Si2O8,α-Al2O3等晶相组成，气孔率为30％～50％，抗折强度〉20MPa，抗压强度〉60MPa。这种陶瓷清水砖是传统的墙体材料粘土烧结砖的良好的替代品。     

轻质陶瓷隔热材料的制备及其性能表征

以短切莫来石纤维为原料,硅溶胶为黏结剂,采用浸渍过滤的方法制备陶瓷隔热材料。该材料气孔率高达89．95％,体积密度仅为0．262g／cm^3,常温耐压强度为338．16kPa,200℃下导热系数λ为0．067W／（m·K）,具有轻质多孔陶瓷隔热材料的典型特点。     

机制生土砖与砂浆法向粘结性能的影响因素

为研究机制生土砖与砂浆法向粘结性能的影响因素,分别对凿毛和未凿毛的机制生土砖与改性砂浆在7、14、28 d龄期下共72个试件进行拉伸粘结强度试验,探讨不同界面状态的机制生土砖在不同龄期下与改性砂浆法向粘结强度的变化规律和破坏形态特点,分析界面状态、龄期等因素对机制生土砖与砂浆法向粘结性能和破坏形态的影响。研究表明：机制生土砖与砂浆间的法向粘结强度值与界面状态和龄期有关,法向粘结强度随龄期的增大而提高,界面状态为凿毛时法向粘结强度有所降低,砂浆种类对机制生土砖与砂浆法向粘结强度影响显著。     

TiC陶瓷滤片的制备及其性能研究

在对TiC陶瓷的性能及其制备工艺进行分析研究的基础上,利用SHS/PHIP技术制备了致密的TiC-TiB2复相陶瓷材料,并对材料进行切割加工成型和清洗,得到和所需滤片形状相同的TiC-TiB2复相陶瓷片,然后再根据TiC和TiB2化学性能的差异,用王水的强腐蚀性溶解其中的TiB2陶瓷相从而得到孔隙大小均匀的、性能优异的TiC陶瓷滤片.用该方法制备的TiC陶瓷滤片,孔隙的直径范围在2~3μm,分布均匀,可以在任何性质的液体中使用,也可用于熔融金属液的过滤.     

Preparation and properties of dental zirconia ceramics

Y2O3-stabilized tetragonal zireonia polyerystalline (Y-TZP) ceramics with high-performance were prepared for dental application by use of the micro-emulsion and two-step sintering method.The crystal phase,morphology,and microstructure of the reaction products were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM),and transmission electron microscopy (TEM).XRD results show that the ceramics mainly consist of tetragonal zirconia.Physical and mechanical properties test results show that the bending strength,fracture toughness,and the density of full sintered Y-TZP ceramics are llS0 MPa,5.53 crown machined with this material by CAD/CAM system exhibits a verisimilitude configuration and the material's expansion coefficient well matches that of the glaze.These results further indicate that the product can be used as a promising new ceramic material     

赤泥质陶瓷清水砖的制备及坯釉结合机理

研究了以赤泥、页岩等工业固体废物为原料,添加一系列改善坯体制备及样品烧结性能的添加剂,采用压制成型方法制备高性能的艺术型清水砖。对工业固体废物制备陶瓷清水砖的坯体组成进行优化调整,得到较优性能的坯体,探讨了清水砖的装饰方法,研究了釉料与坯体的结合机理。结果表明,这种艺术型清水砖表面色彩鲜明,坯釉结合性能好,适于用作别墅及高档住宅、建筑的墙体材料。     

砌体结构的纵横墙整体空间作用试验研究

针对砌体规范中墙体抗震验算中的不足之处 ,通过模型砖墙试验 ,研究了带翼缘墙在水平荷载作用下的恢复力特性曲线、砖墙破坏特征以及纵墙的影响等 ,并提出了在墙体抗震验算中应当考虑纵横墙共同作用的建议     

分汊河道水沙输移特征试验

根据分流河道的水沙特性,对现有的水沙输移计算模式进行了分类,总结了分汊河道分流分沙计算模式在国内外研究发展的现状,并进行了简要的分析评论,继而通过水槽试验对分汊河道整体水流结构和底沙输移演化特征进行了初步的探讨.试验结果表明:在汊道洲头和洲尾的局部范围内流速减小较明显,洲尾处出现水流分离区且左右两侧为高流速区;主、支汊流量的分配决定底沙输移强度,最大冲刷深度在主汊分流口下游.     

蒸压灰砂砖墙片抗震性能试验研究

通过对蒸压灰砂砖墙片抗震性能的试验研究,揭示了其破坏特征,和到了墙片的滞回曲线及其它性能指标,对灰砂砖建筑的抗震性能作出评定;为该类建筑的抗震设计提供依据和方法。     

Preparation and Properties of Phenolic Resin/Montmorillonite Intercalation Nanocomposites

1　IntroductionIntercalationcompoundingisoneoftheeffectivemethodstopreparepolymerbasecompositeswithexcellentproperties .Thepolymercanbeintercalatedintotheinor ganicmaterialswithlayeredstructures ,especiallysilicateclay ,throughintercalationcompoundingtoformthepoly merlayeredinorganicintercalationcomposites[1] .Amongmanylayeredsilicateclays ,montmorillonite (MMT)isof tenusedtopreparetheintercalationcomposites .MMTisasilicateclaymineralabundantinthenaturalworld .Itbe longsto 2∶1layeredsilica…     

Processing and mechanical properties of network ceramic/steel composites by pressureless infiltration

A new style Ni-containing alumina ceramic foam based continuous three-dimensional interconnected skeleton was prepared by impregnating a polymeric sponge with aqueous ceramic slurry.Subsequently,alumina ceramic foam/steel metal matrix composites（MMCs） were prepared successfully by sand mold casting technique.The microstructure and mechanical properties of MMCs were investigated by SEM,EDS and compressive test.The results show that the depth of infiltration is about 40 μm to the bonding interface of ceramic/steel and the fracture strength σmax and plastic strain limit εp of composite are 520 MPa and 11.2%,respectively.The fretting wear mechanism of MMCs is mainly performed at the oxidative wear mode with lower load/friction frequency and the predominant oxidation wear together with slight adhesive wear and abrasive wear multiple mode with higher load/ friction frequency.Moreover,the infiltration bonding and continuous three-dimensional interconnected ceramic skeleton play a vital role in the stability of the bonding interface and excellent mechanical properties.     

Preparation and microstructure of glass-ceramics and ceramic composite materials

The technology and microstructure of glass-ceramics and ceramic composite materials were studied. A suitable ceramic body was chosen on the basis of the sintering temperature of CaO-Al2O3-SiO2 system glass-ceramics. According to the expansion coefficient of the ceramic body, that of CaO-Al2O3-SiO2 system glass-ceramics was adjusted, fl-wollastonite was found present as the major crystalline phase in glass- ceramic. The CaO-Al2O3-SiO2 system glass-ceramic layer and ceramic body could be sintered together by adjusting the sintering period. The compositions of glass-ceramic layer and ceramic body diffuse mutually at 1 100 ℃, resulting in an interface between them. To achieve good sintered properties of glass-ceramics and the chosen ceramic body, at least a four-hour sintering time is used.     

考虑粘性泥沙运动的黄河口二维水沙输移数学模型

为研究黄河口的水沙输移规律,采用基于无结构三角网格下的有限体积法建立了平面二维水沙数学模型.模型中分别采用不同方法处理粘性和非粘性沙的输移源项,并引入经验证的粘性沙输移源项改进公式.采用已有的概化水槽冲淤试验资料对模型进行了验证,然后应用于1982年6月至1983年5月期间黄河口水沙输移的数值模拟,计算得到的潮位过程及冲淤量与实测资料符合较好,结果表明模型能够较好地模拟考虑粘性沙运动的黄河口非均匀沙不平衡输移.最后比较了不同泥沙输移源项处理方式对模拟结果的影响,计算表明在黄河口水沙输移数值模拟中需要采用非均匀沙模型并同时考虑粘性和非粘性泥沙的输移.