C&D recycling has many benefits, 包括减少垃圾填埋和支持循环经济, but it also has many challenges. Below are just two examples of challenges faced with C&D回收以及一些策略来帮助克服它们.
Challenge 1: Market perception – virgin aggregate vs. recycled aggregate
在建筑行业中存在一种看法，即原始骨料比再生骨料提供更好的性能.
原生骨料是指从地表以上或地下开采出来的矿物. Sand, gravel and stone are obvious examples. Most virgin aggregate used in the construction industry is supplied by a local mine; however, in some cases, aggregate is transported in from distant locations. Virgin aggregate is a finite resource.
再生骨料是由建筑和拆除的再加工制成的&D) debris, either in-situ or at a recycling facility (generally, contractors will pay a tipping fee to dump C&D debris at a recycling facility). 混凝土、砖、沥青和无害土壤都是C&可以粉碎、筛分、擦洗和洗涤以产生有价值的再生骨料的碎片. Recycled aggregate is a sustainable resource.
虽然在某些承重应用中，原生骨料性能优于再生骨料的论点可能是正确的, such as reinforced concrete, it is certainly not true for many other applications, particularly non-load bearing ones. Market perception, driven by individual cognitive bias, 是否让社会相信再生骨料的质量不如原生骨料.
In many instances, 购买再生骨料可显著节省成本, particularly in haulage. Many recycling facilities are situated in urban locations, 为希望处理C .废物的承办商提供方便&D debris close to their job site, lowering haulage costs.
再生骨料比原生骨料具有更高的吨体积产率. 粗再生混凝土材料(RCM)骨料的比重范围为2.0 to 2.5，略低于原生聚集体，通常为2.65 - 2.7.
To put this in context relevant to a buying customer, 1.5” minus recycled, 碾碎后的混凝土比原始混凝土轻15%, providing 15% more volume per ton.
改变市场对再生骨料的看法不会在一夜之间发生，但C&D回收生产者可以通过采用以下一种或多种策略来开始克服这些挑战.
Strategies to change market perception
开始改变市场对再生骨料的看法, 供应商应提倡为客户的项目精心选择骨料. 请注意，在许多应用中，再生骨料是原生骨料的适当替代品. A few of these include:
- Fill sand
- Pipe bedding
- Trench backfill
- Landscaping
- Interlocking concrete blocks
- Road subbase
- Canal lining
- Landfill capping
- Screened soil
如果你考虑成为再生骨料供应商:
- 把你的回收设施建在靠近大型客户群的城市. 这将最大限度地减少与客户之间的运输成本.
- 研究当地垃圾填埋场的倾卸费，并相应地设定回收设施的倾卸费, encouraging a steady stream of C&D废料(饲料)为你的加工厂和转移材料从垃圾填埋场.
- Research local virgin aggregate prices in you market, and set your recycled aggregate prices accordingly, 特别适用于非承重应用的骨料.
- 按照招标书(征求建议书)对混凝土和道路建设用再生骨料的要求. 使用再生骨料的好处已得到确认.
提供再生骨料材料最佳应用的工具和知识将有助于改变市场对再生骨料不平等的看法.
挑战2:了解你的材料和加工能力
The biggest challenge with recycling C&D碎屑是进料的可变性和不一致性. 不一致的进料会导致菠菜网最稳定正规平台_最全菠菜网大全质量降低.
With the right strategy, however, 结合适合工作的设备和合适的设备供应商, 过程的可变性和不一致性可以用灵活性来满足.
Strategy to overcome feed inconsistencies
First and foremost, understand that C&垃圾回收厂不是为处理有害物质而设计的. C&D debris with hazardous contaminants should be rejected. C&D垃圾回收厂是为处理惰性废物而设计的，定义为:
- 未经任何重大的物理、化学或生物转变的废物
- Waste that does not dissolve, 燃烧或以其他方式发生物理或化学反应，可能造成环境污染或危害人体健康
- 不因其总浸出性而危及任何地表水或地下水质量的废物, pollutant content and the ecotoxicity of its leachate
As C&接收到碎屑后，操作人员需要了解其组成和适合处理的水平. When doing so, consider the types of C&D debris you are permitted to process. 这可以通过投资于现场原料测试来实现，包括:
- Asbestos quantification testing
- Heavy metal and hydrocarbons testing
- 废物接受标准(WAC)测试，用于分析污染物的浸出能力
了解你的回收系统在处理各种类型的垃圾时的反应&并建立在所需的处理能力和灵活性，使系统根据材料进行调整.
As C&D类杂物可以用异形钢筋封堵，有利于:
- Minimize change in direction of material flow
- Carefully design transfer points
- Include multiple stages of metal removal
- Be thoughtful in choice of belt cleaners for conveyors
- Design in sufficient room around equipment for housekeeping
成品的定期抽样有利于最大限度地提高产量和质量控制. This can be achieved with automated sampling systems.
When designing a C&D recycling plant, invest in an equipment supplier who:
- Creates a solution with your goals in mind
- 使用保守的方法来定义性能评级
- 提供监控，调整，故障排除和维护操作安全的能力
- 在您的操作生命周期内提供持续的支持
With significant infrastructure spending, 围绕碳排放的授权增加，可持续性努力呈上升趋势, there is growing demand for recycled aggregate. Although there are perceptions and challenges to overcome, recycled aggregate offers great rewards for suppliers, customers and the environment.
