废弃混凝土再生利用的产业化研究

作为大规模城市化的产物,废弃混凝土引发了一系列的资源和环境问题.废弃混凝土的再生利用技术已经日趋成熟,而市场化推广却遇到成本、制度等方面的一系列难题.引入循环经济的理念,对废弃混凝土与再生混凝土进行成本比较、对产业化的困难和条件进行了剖析,并从技术、产业、经济等各方面提出了政策建议,也可为其它资源再生产业的发展提供一定的借鉴.     

乌鲁木齐地区再生骨料混凝土的应用初探

再生骨料混凝土的研究和应用能解决日益发展的建筑业带来的环境问题,通过对乌鲁木齐地区建筑业进行调研,具体分析了乌鲁木齐地区废弃混凝土的现状,提出其再生骨料混凝土技术在乌鲁木齐地区推广应用中存在的问题,进行了再生骨料混凝土应用的技术经济可行性分析,并对乌鲁木齐地区再生骨料混凝土的应用提出相应对策。     

再生骨料基本性质及对混凝土性能影响的研究

系统研究了废弃混凝土经破碎、分级、清洗后得到的再生骨料的基本性质，揭示了再生骨料较天然花岗岩骨料密度小、空隙率大、吸水率和吸水速率大及压碎指标大等特点。同时还讨论了再生骨料对新拌混凝土和易性和抗压强度的影响规律，再生骨料将使新拌混凝土的流动性降低，但粘聚性和保水性较好，使硬化混凝土的抗压强度略有降低。     

专利资讯

利用陶瓷抛光砖废料制备硅酸盐水泥的方法,废弃混凝土活化再生水泥技术,废弃混凝土回收方法及其装置和回收的胶凝材料的用途,铸造废砂生产混凝土砖的配方及其生产方法。     

国外对垃圾废物的开发利用

一、用废旧玻璃瓶制玻璃砂加拿大一家公司利用一种新发明的玻璃粉碎机，将回收的旧玻璃瓶，包括瓶盖、标签等，研制成细粉状，制成用途广泛的玻璃砂。这种玻璃砂比喷砂机所使用的砂料，更优越，硬度更大。它与混凝土和颜料混合起来，玻璃颗粒会闪闪发光。它能制成屋瓦和新型净水设备的内胆。用其制成的过滤器，效果比用沙或活性炭的要佳。二、将废弃混凝土再生使用日本水泥协会开发出废弃混凝土再生使用的新技术，其再生混凝土的寿命与普通混凝土大体相同。使用这种用废弃混凝土制成的再生混凝土时，不需要用碎石作骨架。仅采用组成水泥的成…     

废弃混凝土在干混砂浆中的应用研究

废弃混凝土的循环再生利用已日益成为人类关注的重要话题,符合环境保护与可持续发展战略的迫切要求。利用废弃混凝土破碎产生的再生细骨料部分取代天然细骨料来配制干混砂浆。通过试验证明:在固定配合比条件下,再生骨料替代率为50%时,干混砂浆抗压强度、保水率和抗冻融性、强度损失率等均符合M5.0中保水的指标要求。     

“黑白垃圾”再生利用又出新品

由长春应用化学研究所承担的中科院、上海浦东新区高新技术资金项目———“市政工程用粉煤灰和废旧塑料复合新材料高性能井盖、井座”最近在长春顺利通过验收 ,该项目的研究成功 ,实现了废弃资源再生 ,使“黑白垃圾”变成了宝。验收委员会专家组一致认为 :这种新型井盖、井座力学性能指标已超过同类铸铁产品 ;该项研究为我国固体废弃资源再生利用开辟了新路 ,同时还可带动相关产业的发展。据介绍 ,这种以粉煤灰与废旧塑料复合新材料制造的高性能井座、井盖的主要特点有 :性能优良 ,抗压、抗弯、抗冲击能力高于其它同类产品 ,制品力学性能好…     

废混凝土在GRC中的再生利用探究

研究了再生砖骨料的取代率对再生骨料GRC的影响及变化规律,并进一步采用正交设计方法,研究了粉煤灰、硅灰及再生混凝土骨料对GRC的影响。结果表明:再生骨料GRC的强度随废混凝土取代率的提高先增长后下降,当废混凝土取代天然砂30%,可达到或超过天然砂GRC的力学性能;当粉煤灰取代水泥10%,同时硅灰取代水泥10%,废混凝土取代天然砂30%时,其抗折、抗压强度值最大。     

再生混凝土粗集料的基本性能试验研究

对再生混凝土粗集料(d≥5mm)的基本性能进行较为系统的试验和研究,主要内容包括相对粗糙度、表观密度、吸水率、含泥量、洛杉矶磨耗、压碎值和坚固性等,并将其与普通混凝土粗集料的相关性能进行对比分析,以寻找它们之间的差异,为废弃混凝土在道路工程中的应用提供参考。     

以废弃耐火材料制备再生料研究的新进展

综述了废弃耐火材料再生利用的情况,主要介绍了国内对废弃镁铬砖、废弃镁碳砖、废弃铝镁碳砖、废弃镁钙砖、废弃滑板砖、废弃鱼雷罐砖等的再生利用研究成果与再生耐火材料的性能.结果表明,再生耐火材料的性能可以达到新产品水平.对废弃耐火材料的再生利用,可以有效地降低生产成本,同时也能减少对环境的污染,既带来了经济效益,也带来了社会效益.在此基础上,展望了废弃耐火材料今后的发展趋势.     

Waste management strategies for concrete

Recycling and reuse of waste such as building rubble, concrete lumps, etc. generated at construction and demolition sites form part of a wider, complex issue, primarily relating to improving supplies of construction material and solving problems of disposal of waste construction material. Within the framework of the sustainable development of the environment, the use of waste materials with minimum environmental impact has received much attention. The conversion of a large amount of demolished waste into an alternative resource will conserve the depleting natural resources of building materials. Demolished waste is mainly used as a non-stabilized base or sub-base in highway construction. The present paper discusses the recycling process and makes an effort to assess a safe and economic use of recycled concrete as a structural grade material for the construction industry. Extensive tests of structural properties such as compressive strength, flexural strength and split tensile strength of recycled concrete were carried out, in which cement and similarly fine aggregate were partially replaced by demolished waste to obtain recycled concrete and recycled aggregate concrete whose properties were compared with results for the conventional concrete.     

重复再生混凝土性能和环境影响研究

基于生命周期评价方法,考虑混凝土重复再生利用的环境影响分配,对重复再生混凝土的性能和环境影响进行研究,并基于功效系数法优化出混凝土最佳重复再生次数.研究结果表明,再生混凝土的坍落度,强度和电通量随着重复再生循环次数的增加而下降,经3次重复再生后,混凝土28d立方体抗压强度为33.3MPa,满足设计要求,而坍落度和电通量与普通混凝土相比,分别减小和增大了38.9%和85.7%;混凝土材料的生态效率随着混凝土重复再生次数的增加而提高,混凝土材料的GWP、CED和CMR的值均随着混凝土重复再生次数的增加而降低,降低幅度从高到低依次为：CMR > GWP > CED;综合考虑混凝土的坍落度,混凝土抗压强度、电通量、GWP、CED和CMR等6个指标,4种混凝土配合比情景中,混凝土总功效系数从高到低依次为：一次再生混凝土 > 二次再生混凝土 > 三次再生混凝土 > 普通混凝土.     

关于我国废干电池再生利用技术研究的几点思考

对我国废干电池再生利用技术研究提出了几点看法，认为我国废干电池再生利用技术既要注意环境无害化、资源化，还要考虑产业化和适应性问题，使我们的技术既有高的技术含量又符合我国国情。     

建筑垃圾再生骨料生产工艺及应用研究

采用进口移动式破碎-磁选-筛分设备,将混凝土类建筑垃圾加工成再生骨料,并掺入制备混凝土、干混砂浆、道路无机混合料。检测结果表明,再生制品性能可满足使用要求,再生骨料替代天然骨料比例可达到50%以上。     

Concrete made with recycled tire rubber: Effect of alkaline activation and silica fume addition

The present work deals with the investigation of the potential use of recycled tire rubbers in cement matrices. This facilitates the development of concrete with a lesser environmental impact. Thus, it contributes to developing construction in a sustainable way. Concrete formulations were produced with the replacement of 10% sand aggregate by recycled tire rubber using conventional rubber and rubber modified with alkaline activation and silica fume addition to improve the mechanical properties. The water/cement ratio (or composition) and the testing age were used as additional variables. The concrete characterization was performed by testing the compressive strength, elastic modulus, density and microstructure (SEM). The recycled tire rubber proved to be an excellent aggregate to use in the concrete. It was observed that its compressive strength was reduced by only 14% (28 days), in comparison to the conventional concrete, reaching 48 MPa for the mixture with higher resistance. The concrete compositions were found to be lighter and a reduced interface was observed between the rubber and cement matrix after the chemical treatment. The rubberized concrete can support construction sustainability, minimize the consumption of natural resources by using an industrial residue and produce a material with special features.     

工业和建筑固体废弃物再生研究

为了减轻我国的工业/建筑固体废弃物的污染压力,通过对工业和建筑固体废物、粉煤灰、水泥以及外加剂的组合配比实验,优化制作具有轻质高性能的混凝土建筑砌块的方法,并对所研制的混凝土砌块的强度和导热性能进行了测试,最终结果显示砌块性能良好。预计此类复合建筑材料可以在未来的市政建筑中发挥应有的作用。     

Freeze/thaw durability of concrete with recycled demolition aggregate compared to virgin aggregate concrete

An increasing trend towards the use of sustainable processes has led to recycled materials being incorporated into concrete. It is generally recognised that crushed recycled construction aggregate material produces concrete of a lower compressive strength, when used as an aggregate replacement due to deleterious materials within the aggregate.It is generally accepted that in the UK, freeze/thaw attack is, after chloride-induced corrosion, the most common cause of concrete deterioration. This paper addresses the freeze/thaw durability of recycled aggregate concrete using a paired comparison test based upon weight loss and final compressive strength.Recycled aggregate concrete was found to be of at least equal durability to concrete manufactured with virgin aggregates. This was due to careful selection of the replacement aggregate and treatment prior to batching.Durability is an important material property and recycled aggregates need to be widely tested to gain confidence for use within the industry and this work shows future possibilities.