废混凝土骨料、废砖粉透水混凝土配比试验

为了提高对建筑垃圾的利用率,实验利用废混凝土和废砖粉制备透水混凝土,研究水灰比、废砖粉和减水剂掺量对透水混凝土性能的影响,结果显示:胶骨比和废砖粉掺量一定时,水灰比越大,抗压强度越高,孔隙率越低;提高废砖粉掺量会使抗压强度降低,连通孔隙率提高;在水灰比一定时,提高减水剂加入量,会使抗压强度增加,连通孔隙率降低。     

全废砖再生轻骨料混凝土试验研究

将废粘土砖加工成粗细骨料,用于配制全废砖再生轻骨料混凝土.检测结果表明：所用废砖粗细骨料属轻骨料范畴,但其吸水率较大,且细骨料级配不良.试验表明：本试验配合比体系中,净水灰比为0.42,体积砂率为50％时最佳;以全废砖配制的再生砖轻骨料混凝土的强度发展规律与普通轻骨料混凝土类似,均有随水泥用量提高而强度提高的趋势,但随着所配制的混凝土强度等级的提高,再生轻骨料混凝土的强度提高趋势下降.以全废砖为骨料适合配制强度等级LC30及以下的再生轻骨料混凝土.     

废混凝土粉在建筑砂浆中的应用研究

研究了废混凝土粉以不同取代率取代建筑砂浆中的天然砂对砂浆的和易性及强度的影响,结果表明,废混凝土粉可以取代建筑砂浆中的部分天然砂配制再生骨料砂浆.     

用废砖制作利废型轻质墙体材料试验研究

采用正交试验的方法,研究了废砖、废聚苯粒及天然砂的不同配比对利废型轻质墙材性能的影响,配制出了抗压强度5.0 MPa以上,表观密度1 100 kg/m3以下,导热系数0.2 W(/m.K)以下,50次冻循环强度损失率20%以下,质量损失率5%以下的利废型轻质墙材,并讨论了骨料的不同配比与性能的关系。     

低质粉煤灰活化技术研究

系统地研究了机械粉磨、化学添加剂对低质粉煤灰粒度和活性的影响,在此基础上协同采用粉磨、化学激发剂、湿热养护、低温焙烧工艺,制备出了一种高效能水泥掺合料,可以在80%范围内等量替代水泥熟料,生产22.5砌筑水泥到52.5等级水泥.该工艺是一种大比例利用低质粉煤灰的有效途径.     

骨料特征对GRC耐久性影响

为了研究骨料特征对GRC耐久性的影响,以废混凝土再生骨料、废砖再生骨料分别取代GRC中的天然砂,分别采用自然老化和50℃加速老化的方法,研究不同性能特征的骨料对GRC长期性能的影响。结果表明:废混凝土再生骨料、废砖再生骨料表面粗糙、多孔的特征,可减少体系中Ca(OH)_2的含量、减小Ca(OH)_2的结晶尺寸;废砖再生骨料还具有火山灰效应,可消耗体系中Ca(OH)_2,因而其对GRC的耐久性改善作用较废混凝土骨料更显著;两种骨料具有的特征不但可提高GRC基体的抗折强度,还可减轻玻璃纤维被腐蚀的程度,有利于GRC耐久性的改善。     

用废泡沫塑料制保温隔热砖

山东省莱州市府前科技中心开发成功一项利用废泡沫塑料制保温隔热砖技术,成功地解决了平顶建筑物的保温隔热问题 . 该技术用废泡沫塑料为原料,选用来源广、价格低、阻燃性能好的新型结合剂,将隔热砖制成5～7 cm厚,其保温隔热效果可达到水泥聚苯保温板10～12 cm厚的水平. 该产品现已在新疆、宁夏等地投入生产,生产1 m3隔热保温砖可获利150～180元,为企业创造了显著的经济效益.     

关于进口废PET饮料瓶砖的探讨

从环保和经济的角度出发,我国已逐步放开废PET饮料瓶(砖)的进口。随着废PET饮料瓶(砖)的大量进口,相关问题也逐渐凸显出来。本文结合进口废PET饮料瓶(砖)监督管理工作实际,从检测指标、企业管理等方面进行探讨,提出相应意见和建议。     

废玻璃钢粉填充丁腈橡胶的性能研究

研究了废玻璃钢粉填充丁腈橡胶的性能。从取向和非取向两个方面探讨了废玻璃铜粉含量对丁腈橡胶性能的影响，比较了废玻璃铜粉和碳酸钙对丁腈橡胶性能的影响。结果表明，玻璃钢粉对于丁腈橡胶具有一定的补强作用，随着玻璃钢粉加入量的增加，电阻率略有下降；由于玻璃短纤维的存在使得胶片取向与非取向方向的性能有所差异。综合性能考虑，使用20份废玻璃钢粉的复合材料具有较高的性能价格比。     

管桩余浆的合理开发利用

对管桩余浆常用的几种回收利用方法作了分析对比,提出了较为完善的余浆干法利用方法,将余浆固化后经破碎、烘干、粉磨,再用作混凝土的掺合料,更加有利于发挥余浆的潜在活性.     

Use of waste brick as a partial replacement of cement in mortar

The aim of this study is to investigate the use of waste brick as a partial replacement for cement in the production of cement mortar. Clinker was replaced by waste brick in different proportions (0%, 5%, 10%, 15% and 20%) by weight for cement. The physico-chemical properties of cement at anhydrous state and the hydrated state, thus the mechanical strengths (flexural and compressive strengths after 7, 28 and 90 days) for the mortar were studied. The microstructure of the mortar was investigated using scanning electron microscopy (SEM), the mineralogical composition (mineral phases) of the artificial pozzolan was investigated by the X-ray diffraction (XRD) and the particle size distributions was obtained from laser granulometry (LG) of cements powders used in this study. The results obtained show that the addition of artificial pozzolan improves the grinding time and setting times of the cement, thus the mechanical characteristics of mortar. A substitution of cement by 10% of waste brick increased mechanical strengths of mortar. The results of the investigation confirmed the potential use of this waste material to produce pozzolanic cement.     

Towards zero industrial waste: Utilisation of brick dust waste in sustainable construction

Laboratory investigations were carried out to establish the potential utilisation of brick dust (BD) in construction. The dust is a waste material from the cutting of fired clay bricks. Currently, the disposal of the dust is a problem to the brick fabrication company, and hence an environmental pollution concern. The dust was stabilised either used on its own or in combination with Pulverised Fuel Ash (PFA), a by-product material from coal combustion. The traditional stabilisers of lime and/or Portland Cement (PC) were used as controls. The main aim was to use a sustainable stabiliser material, where these stabilisers were partially replaced with Ground Granulated Blastfurnace Slag (GGBS), a by-product material from steel manufacture. Compacted cylinder test specimens were made at typical stabiliser contents and moist cured for up to 56 days prior to testing for compressive and California Bearing Ratio (CBR) strength tests, and to linear expansion during moist curing and subsequent soaking in water. The results obtained showed that partial substitution of the dust with PFA resulted in stronger material compared to using it on its own. The blended stabilisers achieved better performance. These results suggest technological, economic as well as environmental advantages of using the brick dust and similar industrial by-products to achieve sustainable infrastructure development with near zero industrial waste.     

废旧天然胶胶粉应用研究

以80目的废天然胶胶粉为研究对象,处理后将其分别以20%,30%的比例添加到天然混炼胶(NR)中,制备废胶粉/NR共混硫化胶;同时,通过邻苯二甲酸酐(PA)和高芳烃油对胶粉进行处理改性,制备了全胶粉弹性体。拉伸强度测试表明,对于共混胶弹性体,NR混炼胶空白样的拉伸强度为19.21 MPa,添加20%,30%比例的胶粉/NR共混硫化胶的拉伸强度可以分别达到18.03 MPa,17.23 MPa;改性后制备的全胶粉混炼胶硫化样品拉伸强度达到8.12 MPa,超过了再生胶的国标标准。同时应用扫描电子显微镜SEM分析、比较了各试样断裂面的微观结构,应用比表面仪BET和SEM表征了胶粉的表面形貌与结构,发现胶粉表面呈现"绒球"状,具有较好的表面性能。     

A study on engineering characteristics of asphalt concrete using filler with recycled waste lime

This study focuses on determining the engineering characteristics of asphalt concrete using mineral fillers with recycled waste lime, which is a by-product of the production of soda ash (Na(2)CO(3)). The materials tested in this study were made using a 25%, 50%, 75%, and 100% mixing ratio based on the conventional mineral filler ratio to analyze the possibility of using recycled waste lime. The asphalt concretes, made of recycled waste lime, hydrated lime, and conventional asphalt concrete, were evaluated through their fundamental engineering properties such as Marshall stability, indirect tensile strength, resilient modulus, permanent deformation characteristics, moisture susceptibility, and fatigue resistance. The results indicate that the application of recycled waste lime as mineral filler improves the permanent deformation characteristics, stiffness and fatigue endurance of asphalt concrete at the wide range of temperatures. It was also determined that the mixtures with recycled waste lime showed higher resistance against stripping than conventional asphalt concrete. It was concluded from various test results that a waste lime can be used as mineral filler and, especially, can greatly improve the resistance of asphalt concrete to permanent deformation at high temperatures.     

Mercury speciation in fluorescent lamps by thermal release analysis

In this work, mercury speciation in phosphorus powder matrices and soda lime glass waste from new and spent fluorescent lamp wastes has been studied by thermo-desorption/atomic absorption spectrometry (TDAAS), X-ray diffraction (XRD), cold vapor-atomic absorption (CV-AAS) and atomic emission spectrometry/inductively coupled plasma (ICP/AES). TDAAS results show the presence of oxidized forms of mercury, i.e., Hg(1+) and Hg(2+), especially in wastes with high mercury concentration. Such forms are mobile, and therefore represent a potential hazard waste material. Glass TD profiles of spent fluorescent lamps suggested the presence of mercury strongly linked to the matrix, which desorbs only at high temperatures.     

Removal of manganese and zinc from Kahrizak landfill leachate using daily cover soil and lime

The possibility of in situ removal of heavy metals found in leachate generated at municipal solid waste landfills was studied through amendment of daily cover soil. Kahrizak landfill, which receives the waste generated at Tehran, was selected as the source of leachate and soil samples. Manganese and zinc were selected in this study. The soil sample taken from the Kahrizak site contained about 17% clay, which was presumed to have significant capability for removing manganese and zinc. This capability was assumed to be enhanced further through the addition of lime and consequently to improve the potential for chemical precipitation of the selected metals. The in situ removal experiment was accomplished through a set of seven columns filled with the sampled soil with varying contents of lime (i.e., from 0% to 6% by dry weight). Fresh leachate of low pH was added to the columns on a daily basis. Concentrations of manganese and zinc were measured in the influent and effluent during 40 days when biological clogging resulted in a condition of almost no outflow in the columns. The results indicated a substantial increase in removal efficiency through the addition of lime to the daily cover soil. Desorption resulting from the low pH of fresh leachate occurs at later stages compared to the column with no lime addition.     

废旧橡胶胶粉低温粉碎技术研究进展及趋势

介绍了国内外废旧橡胶低温粉碎技术(液氮冷冻粉碎法、空气膨胀制冷法)的研究进展,指出其在我国应用缺乏经济可行性。将液化天然气(LNG)冷能直接用于废旧橡胶低温粉碎可有效降低生产成本,应用前景广阔,是我国未来精细和微细胶粉生产领域的重要研究内容和发展方向之一。     

Preparation of briquettes from the Golden Horn bottom sediments by hydro-thermal agglomeration process.

The Golden Horn (GH) sediments, which consist mainly of clay, organic substances and heavy metals, are formed with the contribution of industrial and domestic wastes released in the Golden Horn Estuary. On account of their mineralogical and chemical composition, these sediments may be regarded as a suitable raw material for briquette production. In this study, the utilization of GH dredged bottom sediments was investigated for preparation of briquettes. Dried GH sediments were mixed with lime and sand in different percentages, moulded at various squeezing pressures and hardened under several steam pressure values by autoclaving. The briquettes produced through these different process conditions were tested for compressive strength according to the Turkish standards (TS705). It was found that variations in compressive strength were dependent on the amount of lime (Ca(OH)2) and sand (SiO2) added. Results show that the compressive strength increased with increasing lime and decreasing sand in the mixtures prepared for briquettes. It is concluded that briquettes with a compressive strength value of 294 kgf cm(-2) can be produced. This allows the GH sediments to be taken into account as a raw material in brick production, as far as compressive strength requirements are concerned. This possibility may represent an important way either for reducing environmental pollution or for recycling waste materials in industrial applications.