寻求传统建筑材料的再生之路--对青砖魅力的挖掘和发展

在快速发展的今天,现代建筑呈现多元化发展趋向。在光怪陆离的现代建筑纷繁出现的表象下,人们却始终对传统建筑文化保存着一份特有的感情。传统建筑材料对维系人们的历史情结、延续建筑文脉起到不可替代的作用。而它们的再生又将进一步推动建筑和建筑文化的发展。青砖以其传统、自然、亲切的特征于此扮演着重要角色,它的魅力值得今天的建筑师去挖掘和丰富。     

枯草芽孢杆菌B26生产多隔镰孢霉抑制物工艺优化

采用正交试验设计对枯草芽孢杆菌B26 抑制多隔镰孢霉培养基配方及用量进行优化,单因素试验对B26产生活性物质的发酵条件进行选择。以多隔镰孢霉的抑制率为指标,B26 产生拮抗效果最好的发酵培养基配方用量是：蛋白胨25g/L、淀粉45g/L 、氯化钠1.5g/L、硫酸铵1.0g/L、磷酸氢二钾1.5g/L。产生活性物质的最优发酵条件为：种子菌龄24h、接种量5%、初始pH7、装液量20%、吐温-80 用量0.5%、发酵温度30℃、转速150r/min、发酵时间60h,获得B26 菌株发酵液对多镰孢霉的抑制直径为26mm,优于其他条件培养获得的拮抗效果。     

The use of recycled paper processing residues in making porous brick with reduced thermal conductivity

Production of porous and light-weight bricks with reduced thermal conductivity and acceptable compressive strength is accomplished. Paper processing residues were used as an additive to an earthenware brick to produce the pores. SEM-EDS, XRD, XRF and TG-DTA analysis of the paper waste and brick raw material were performed. Mixtures containing brick raw materials and the paper waste were prepared at different proportions (up to 30 wt%). The granulated powder mixtures were compressed in a hydraulic press, and the green bodies were dried before firing at 1100 °C. Dilatometric behaviours, drying and firing shrinkages were investigated as well as the loss on ignition, bulk density, apparent porosity, water absorption and thermal conductivity values of the fired samples. Their mechanical and microstructural properties were also investigated. The results obtained showed that the use of paper processing residues decreased the fired density of the bricks down to 1.28 g/cm³. Compressive strengths of the brick samples produced in this study were higher than that required by the standards. Thermal conductivity of the porous brick produced in this study (<0.4 W/m K) showed more than 50% reduction compared to local brick of the same composition (0.8 W/m K). Conversion of this product to a perforated brick may reduce its thermal conductivity to very low values. Successful preliminary tests were conducted on an industrial scale.     

高掺量工业废渣陶瓷仿古砖坯料成形性能优化

研究了两个粉煤灰掺入量为70%的瓷质仿古砖坯的配方,配方中瘠性料分别达到了78%和83%,其中YL配方:粉煤灰70%,粘土22%,钾长石8%,烧成温度为1230℃,吸水率0.23%;ZXJ配方:粉煤灰70%,粘土17%,钾长石13%,T烧=1200℃,吸水率0.12%。但存在坯料球磨后的泥浆悬浮性不好,坯料成形性能较差的现象,选用了羧甲基纤维素钠(CMC)、氯化聚乙烯(CPE)、硅酸钠三种添加剂,分析了各种添加剂对高掺量粉煤灰坯泥性状,成形性能,干坯强度的影响,以寻求提高坯料成形性能的最佳途径。     

Mechanical properties of expanded polystyrene lightweight aggregate concrete and brick

In this study, mix proportion parameters of expanded polystyrene (EPS) lightweight aggregate concrete are analyzed by using Taguchi’s approach. The density, compressive strength and stress-strain behavior were tested. The optimal mixture of EPS lightweight aggregate concrete was selected among experiments under consideration to manufacture the lightweight hollow bricks. The results show that EPS dosage has the most significant effect on compressive strength of EPS lightweight aggregate concrete, then water and cement ratio, while the content of cement and sand ratio play a comparatively less important part. The relationship between density and compressive strength of EPS lightweight aggregate concrete is proposed as f_c = 2.43 × γ^2.997 × 10⁻⁹. The legitimacy of the use of EPS lightweight bricks made by EPS lightweight aggregate concrete is confirmed.     

砖混结构中控制墙顶裂缝的探讨

通过对墙体粒缝的形式、形成原因及墙体剪应力的分析，提出了墙体裂缝的控制办法和防治措施。     

Modified palm kernel shell clamp method for firing bricks

The continuing activities of finding and testing suitable alternative fuel sources for firing bricks in Ghana is reported by Kofi Obeng. Previously, the use of agricultural waste (palm kernel shells) as a fuel was reported (Building Research and Information, 25(3), 131-136). This study reports on advances made through the substitution of charcoal made from timber offcuts and waste instead of the use of firewood to ignite the palm kernel shells.     

钢包底吹氩工艺改进

分析了影响钢包底吹氩成功率的各种因素。提出了改进措施。通过实践使钢包底吹氩成功率由90％提高到99％。满足了品种钢的生产需要。     

Characterization of the First Falling Rate Period During Drying of a Porous Material

This study deals with the evolution of the surface state and its influence on the drying of porous media. Surface temperature and saturation values are obtained using optical metrology. Analysis of the experimental results allows discussion of the apparition of constant drying rate period and to characterize the transition to the falling rate period. A mathematical model is developed to account for these observations and experimental results for some physical properties of a model material. It allows determination of the internal profile of moisture and the penetration of the drying front during the falling rate period.     

Clay-bricks from recycled rock tailings

The aim of this work is to optimize the industrial applications of granite and kaolinite rock tailings in ceramics industry. Three rock tailings are selected to be characterized and equally mixed for testing. The samples are characterized using XRD, XRF, polarizing light microscope, cathodoluminescence, X-ray micro-computed tomography (3d-µCT) and SEM microscopy attached with EDAX. The rock tailings mixed batch is non-bloatable and is located in the mullite field on the FeOFe₂O₃-Al₂O₃-SiO₂ phase diagram. In addition to primary mullite, type II secondary mullite of aspect ratio (3-10:1) is characteristic within aluminosilicate glassy matrix. The 3d-µCT shows pores of lower surface area at 1200 °C due mainly to the existence of isolated rounded closed pores. The physical characteristics of the fired batch, at 1200 °C show that it can be used in the manufacture of building clay-bricks.