陶瓷废弃物代砂制备混凝土的强度特征

陶瓷废弃物经破碎筛分加工制成人工砂,以此作为混凝土的细骨料进行部分或全部取代天然砂,并对制备的混凝土不同龄期的抗压强度、抗折强度等特征进行了试验研究,研究中对不同取代率、灰水比、陶瓷砂处理方式、龄期等因素对陶瓷砂混凝土强度特征进行了系统考察.研究表明,陶瓷废弃物经破碎筛分加工后,可以满足混凝土用砂规范的要求,尤其是加工过程中与部分碎石混合破碎,其人工砂的性能是优异的.可全部取代优质河砂,而纯陶瓷废弃物加工的砂配制的混凝土,其立方体抗压强度和抗折强度值均能达到设计要求,甚至可以超过同等配合比的天然河砂配制的混凝土的强度;陶瓷砂混凝土的强度与天然骨料混凝土的变化规律相似,即随灰水比的增加而提高,随龄期的增长强度不断增加.强度特征的评价为陶瓷砂混凝土的配合比设计提供了有效的依据.     

陶瓷废料用作混凝土再生骨料对混凝土性能影响研究

陶瓷废料作为再生骨料用于混凝土中,既可以减少废弃物的堆放,又可以为混凝土提供骨料的来源,因而越来越得到了关注。本文就是选取某陶瓷厂的陶瓷废料制作再生骨料,然后分别以20%、25%的取代率取代天然骨料制备混凝土,研究了混凝土的力学性能,混凝土中孔的情况及吸水特性。研究发现:混凝土的抗压强度和劈裂抗拉强度随着陶瓷再生骨料取代率的提高而提高;陶瓷再生骨料的掺加改变了混凝土中孔隙的特征;混凝土的吸水率随着陶瓷再生骨料取代率的增大而增大,但是仍具有良好的耐久性。     

陶瓷废弃物粉末火山灰活性的研究

对不同种类陶瓷废弃物(卫浴陶瓷、外墙陶瓷和地砖陶瓷废弃物)分别进行8h和16h的机械研磨,得到不同种类和不同细度的陶瓷废弃物粉末.测试分析了陶瓷废弃物粉末的比表面积、氧化物组成、晶相等.将陶瓷废弃物粉末按20%质量分数替代部分水泥,然后采用Frattini试验法和SAI(强度活性指数)试验法研究陶瓷废弃物粉末的火山灰活性.结果表明:各种陶瓷废弃物粉末均具有一定的火山灰活性;卫浴陶瓷及地砖陶瓷废弃物粉末火山灰活性随着各自比表面积的增大而显著提高;陶瓷废弃物粉末中的SiO2碱活性较低,而Al2O3与Ca(OH)2发生反应是其呈火山灰活性的主要原因.     

建筑废弃物再生原料生产混凝土砌块的技术研究

利用建筑废弃物中的废混凝土和废砖等主要无机硬质组分,通过资源化再生加工成为可用于生产混凝土砌块等产品的废混凝土再生原料、废砖再生原料或它们的混合物。本文介绍利用建筑废弃物的再生骨料和再生原料生产混凝土砌块的产品性能及其生产技术。研究表明,当利用废混凝土再生原料、废砖再生原料或它们的混合料生产混凝土砌块时,产品性能可满足现行标准要求。     

建筑垃圾变废为宝 绿色循环助企发展——浙江桐庐永东建材有限公司废弃资源利用率达90%

本刊讯浙江桐庐永东建材有限公司自混凝土砖和建筑废弃物破碎加工生产线建成以来,积极采用建筑垃圾为主要原材料,再加管桩企业的废弃资源,在混凝土砖生产和建筑废弃物破碎加工过程中,切实加强对重点污染源和重点排放点的跟踪管理,做到厂区内废弃物的可循环重复利用,坚持清洁生产、不新增废弃物、不污染环境的原则,使废弃资源利用率达到90%以上,提高了新墙材行业协同处置建筑垃圾等废弃物资源的能力,推进了产业绿色发展。     

建筑废弃物再生原料生产发泡混凝土砌块的技术研究

利用建筑废弃物中的废混凝土和废砖等主要无机硬质组分,通过资源化再生加工成废混凝土再生原料、废砖再生原料,以此为原料生产符合行业标准的发泡混凝土砌块。从发展循环经济和可持续发展的角度而言,具有显著的社会效益和环境效益。介绍了利用建筑废弃物再生原料生产发泡混凝土砌块的产品性能及其生产技术。研究表明,建筑废弃物再生原料利用率可达40%以上,且生产的B07级、B08级再生原料发泡混凝土砌块强度等级可分别达到JC/T 1062—2007《泡沫混凝土砌块》规定的A3.5级、A5.0级,其他性能均能满足该标准的规定。     

利用陶瓷生产尾泥制备高铝质蒸压加气混凝土

在蒸压加气混凝土中掺含18%(质量分数)Al2O3的陶瓷生产尾泥替代一部分含94%(质量分数)SiO2的石英砂,研究不同替代率下蒸压加气混凝土力学性能的变化,并采用X射线衍射、扫描电镜对蒸压加气混凝土的矿物组成和微观结构进行了研究.结果表明:使用陶瓷生产尾泥替代40%(质量分数)石英砂制备的高铝质蒸压加气混凝土各项性能均优于未使用陶瓷生产尾泥的混凝土试块.陶瓷生产尾泥能促进蒸压加气混凝土水化产物的结晶,优化其各项力学性能.     

建筑废弃物产业化和工程应用

建筑废弃物资源利用产业化是解决现代城市大量建筑废弃物的有效途径。通过提高建筑废弃物处理技术,建立建筑废弃物再生利用的生产线,研制中高端再生混凝土建筑材料,并应用于实际工程。建筑废弃物再生利用一方面可解决日益增多的建筑废弃物堆积造成环境污染;另一方面可以解决混凝土制品的原材料匮乏问题。目前,浙江省已建立多条建筑废弃物资源化利用生产线,生产的再生混凝土产品已应用于实际工程,产品质量得到各方的认可,可供相关单位借鉴。     

高温发泡陶瓷及其应用

介绍制作高温发泡陶瓷的基本原理、工艺技术特点及其应用,研制的发泡陶瓷制品具有多种优异性能,并组织了批量化生产。高温发泡陶瓷的工艺技术原理虽较复杂,但生产工艺流程易于控制,使用的原材料均是低廉的陶瓷原料或工业废弃物。     

《国外建材科技》论文目录

(续)658 用氧化铬作矿化剂可生产活性贝利特水泥659 工业废弃物作为混凝土用材料的应用660高Tc陶瓷超导体的发展661 空心陶瓷纤维的制备662 柴油发动机的微晶玻璃零件663 新型FRP一纤维增强的CP树脂664石灰浆生产线665一种独特的能源666 垃圾和废水污泥的低费用可控堆肥处理667     

废弃混凝土再生利用探讨

随着我国建筑业迅猛发展,我国每年产生的废弃混凝土的量巨大并呈逐年上升的趋势。该文探讨了废弃混凝土再生利用的途径,设计了适应我国目前发展现状的再生骨料的生产工艺流程,并从环境效益和社会效益方面对废弃混凝土再生利用以及其再生利用产生的经济效益方面进行了分析,文章的分析表明废弃混凝土的再生利用一方面可以减轻废弃混凝土对环境的污染,节省其作为垃圾排放的清运和处理费用,另一方面可以充分利用废弃混凝土这种可再生资源,保护自然资源和人类的生存环境,有利于实施可持续发展战略。本文的研究表明废弃混凝土的再生利用具有很好的环保效益、社会效益和经济效益。     

Mechanical properties modeling of recycled aggregate concrete

The variability observed in the composition of construction and demolition (C&D) waste is a problem that inhibits the use of recycled aggregates in concrete production. To contribute in this field, a research was carried out varying water/cement ratio and substitution percent of natural aggregates by recycled aggregates. The experimental program used samples of main Brazilian C&D waste sources, which are concrete, mortar and red ceramic bricks as well as tiles. Results of concrete compressive strength and elastic modulus were statistically analyzed and modeled. The study shows that for both concrete properties, recycled coarse aggregate was more influential than recycled fine aggregate. However, the use of fine recycled red ceramic increased concrete strength. Coarse recycled red ceramic aggregate and fine recycled concrete aggregate exercised the largest and the smallest influence, respectively, in concrete properties.     

再生混凝土基本物理力学性能试验再研究与分析

通过实验,对再生骨料的物理性能做了研究,分析了其与天然骨料产生差别的原因,并对再生混凝土的基本力学性能进行了再研究,与天然混凝土作对比后,指出配制混凝土时天然骨料可被再生骨料部分取代配得满足强度要求的混凝土材料,达到节约骨料资源,废物再利用的目的。     

再生粗骨料对混凝土坍落度和抗压强度的影响

简述了哈尔滨市城市建筑垃圾的产生量和利用度,研究粗骨料的主要指标;采用再生粗骨料20%、30%、50%、70%、100%等质量代替天然碎石骨料配制了C30混凝土,研究了再生粗骨料对混凝土工作性和抗压强度的影响。研究结果表明:在水胶比相同时,混凝土坍落度下降,28d强度降低;若要保持混凝土坍落度基本相同,需采用增加用水量或增大减水剂的方式进行调整。     

Reusing ceramic wastes in concrete

The ceramic industry is known to generate large amounts of calcined-clay wastes each year. So far a huge part is used in landfills. Reusing these wastes in concrete could be a win–win situation. For one hand by solving the ceramic industry waste problem and at the same time leading to a more sustainable concrete industry by reducing the use of non renewable resources like cement and aggregates and avoiding environmental problems related to land filled wastes. This paper examines the feasibility of using ceramic wastes in concrete. Results show that concrete with 20% cement replacement although it has a minor strength loss possess increase durability performance. Results also show that concrete mixtures with ceramic aggregates perform better than the control concrete mixtures concerning compressive strength, capillary water absorption, oxygen permeability and chloride diffusion thus leading to more durable concrete structures.     

废弃混凝土再生骨料应用的经济性分析

利用废弃混凝土再生骨料配制再生混凝土在发达国家已引起高度重视。总结国内外废弃混凝土的现状和废弃混凝土再生骨料的应用情况,从政府的政策支持、天然骨料的紧缺程度等方面对再生骨料的应用进行了定性经济分析,并从定量的角度对再生骨料的生产成本进行了具体的估算和分析,可以得出再生骨料应用具有很好的经济效益、社会效益、环保效益以及很好的市场应用前景。     

Effects of contaminants on the properties of concrete paving blocks prepared with recycled concrete aggregates

The use of recycled aggregates for preparing concrete products has been successfully implemented and gaining wider acceptance. However, the allowable level of contaminating materials (e.g., crushed clay bricks, crushed ceramic tiles, waste glass cullet, wood chips, etc.) in the recycled concrete aggregate, in the some of the current specifications, is low (<1%) due to stringent quality control standards that are usually taken from specifications for raw granular virgin materials. This paper presents a recent study on the properties of concrete paving blocks prepared with recycled concrete aggregates that are contaminated by materials (tiles, clay bricks, glass, wood) commonly found in the construction and demolition waste. The density, compressive strength, tensile splitting strength, water absorption value, abrasion resistance, skid resistance and some durability parameters were measured for laboratory prepared samples. The results show that it is feasible to allow a higher level of contamination in the recycled concrete aggregates for making the concrete products. Recommendations are made on how the specifications could be revised to facilitate a wider application of recycled aggregates that is contaminated by foreign materials.     

Use of concrete road recycled aggregates for Roller Compacted Concrete

Construction waste management is a quite important economical and environmental deal for our societies. More than 2 million tons demolition and construction wastes are annually produced only in Wallonia, Southern Region of Belgium; recycling has clearly to be promoted. Roller Compacted Concrete (RCC) is a special dry concrete made of aggregates, water and low quantity of cement, laid down and compacted like a soil, for the construction of massive structures like dams or large horizontal surfaces like road foundations. The topic of this research is the replacement of natural aggregates by concrete road recycled aggregates in the mix design of concrete. Characteristics of aggregates are of prime importance for the quality of the concrete: Los Angeles, water absorption and specific gravity. It has been observed that RCC with natural and concrete road recycled aggregates are similar for solid compactness, while no major influence of cement content – when around 200 kg – may be detected. However, compressive strength is higher for RCC with natural aggregates. This study clearly shows the opportunity of using concrete road recycled aggregates for RCC in basements.     

混凝土材料完全循环利用的探讨

根据国内外混凝土材料循环利用的研究发展现状,提出了混凝土材料完全循环利用的可能性,具体分析了混凝土材料完全循环利用的途径和方法,并通过实验证实了混凝土材料可以多次循环利用,从而实现混凝土材料的生态化生产和使用.     

Effect of crushed ceramic and basaltic pumice as fine aggregates on concrete mortars properties

This study examines the suitability of ceramic industrial wastes and huge amounts of basaltic pumice as a possible substitute for conventional crushed fine aggregates. Experiments were carried out to determine abrasion resistance, chloride penetration depths and the compressive strengths of concrete with crushed ceramic waste and basaltic pumice fine aggregates and to compare them with those of conventional concretes. Test results indicated that ceramic wastes and basaltic pumice concretes had good workability. Furthermore, it was found that abrasion resistance of crushed ceramic (CC) and crushed basaltic pumice (CBP) concretes was lower than that of conventional concretes. Test results also showed that maximum abrasion rate was obtained from specimen control (Mo), while minimum abrasion rate is obtained from M3 (60% crushed ceramic concrete) specimens. Abrasion resistance was increased as the rate of fine CC was decreased. Abrasion resistance of concrete was strongly influenced by its compressive strengths and CC and crushed CBP content. The crushed ceramic addition percentage decreased as the chloride penetration depth increased. Results of this investigation showed that CC and CBP could be conveniently used for low abrasion and higher compressive strength concretes.