Comportement mécanique et durabilité du béton vert à base de ciment vert renforcé de plastique recyclé fonctionnalisé

性能指标和耐用性均优于水泥基，增强塑料回收性能

• 批准号: 571557-2021
• 负责人: Zimmermann, ElizabethEZ
• 金额: $ 3.28万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Alliance Grants
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=750701
• 关键词: Comportement; canique; et; durabilit; du

Background: Each year, value created by the Canadian construction industry totals over $250 billion USD. Here, reinforced concrete is an important technology because it can be formed into complex shapes and resists corrosive environments better than steel or wood. However, concrete's lifecycle has negative environmental effects, with cement production alone accounting for 5% of global CO2 emissions. Our long-term goal is to develop concrete with similar mechanical properties as current technology but with a lower carbon footprint and greater sustainability: green concrete. Our approach uses green cements reinforced with recycled plastic. Reinforcement with single-use plastics (polypropylene (PP), polyethylene terephthalate (PET)) can help manage plastic waste, while improving corrosion resistance and strength. To date, the success of plastic-cement composites has been very limited because plastic hydrophobicity prevents interaction with hydrophilic cements. Biological materials, such as seashells and bone, stem their excellent mechanical properties not only from their combination of biominerals and organic polymers, but also from the strong integration between these components. Inspired by these observations, we demonstrated that modifying the surface chemistry of plastic fibers by adding phosphate binding sites improves their integration with inorganic cements and subsequently increases the fracture toughness. These surface chemistry modifications are achieved using diazonium treatments, which we have shown to be extremely versatile with the ability to covalently bind phosphate and carboxylate moieties to a wide range of plastics.Our hypothesis is that cements with a lower carbon footprint reinforced with surface-treated recycled plastics will result in concrete with competitive mechanical behavior and improved sustainability compared to current standards. Our aims are to optimize diazonium treatments to functionalize plastic waste, examine and optimize mechanical behavior by varying cement composition and the geometry of plastic reinforcement, analyze material sustainability through artificial accelerated aging and perform a lifecycle assessment to investigate sustainability and environmental impact.Methods & Expertise: Green concrete will be fabricated from Portland and magnesium cements and reinforced with recycled plastic (PP, PET). Plastic surfaces will be treated with diazonium chemistry to introduce phosphate and carboxylate groups. Surface interactions will be investigated with electron microscopy and x-ray photo-electron spectroscopy. Mechanical properties will be measured in terms of compressive strength, bending strength and fracture toughness. Material sustainability will be assessed with artificial accelerated aging through fatigue testing, thermal cycling, and exposure to corrosive environments. A lifecycle assessment will analyze the full impact of the product from raw materials through disposal to determine the costs per year and the environmental impact in comparison to current technology.The team has complementary expertise in materials design, mechanical characterization in multi-scale materials, material surface modification and interface phenomena in materials, development of inorganic cements, and lifecycle analysis. Expected outcomes: If successful, the development of green concretes will reduce carbon emissions from the construction industry, promote the use of recycled materials, and increase sustainability of building materials.

背景：每年，加拿大建筑业创造的价值超过2500亿美元。在这里，钢筋混凝土是一项重要的技术，因为它可以形成复杂的形状，并比钢或木材更好地抵抗腐蚀性环境。但是，混凝土的生命周期具有负面的环境影响，仅水泥产量就占全球二氧化碳排放量的5％。我们的长期目标是开发具有与当前技术相似的机械性能的混凝土，但具有较低的碳足迹和更大的可持续性：绿色混凝土。我们的方法使用绿色水泥加固的塑料。用一次性塑料（聚丙烯（PP），聚对苯二甲酸酯（PET））钢筋可以帮助管理塑料废物，同时改善耐腐蚀性和强度。迄今为止，塑料水泥复合材料的成功一直非常有限，因为塑性疏水性阻止了与亲水水泥的相互作用。生物材料（例如贝壳和骨骼）不仅源于生物矿物质和有机聚合物的结合，而且还源于这些成分之间的强大整合。受这些观察的启发，我们证明了通过添加磷酸盐结合位点来修饰塑料纤维的表面化学性质可改善其与无机水泥的整合，并随后增加断裂韧性。这些表面化学的修饰是使用重氮处理来实现的，我们证明，它们具有极其用途，具有共价结合磷酸盐和羧酸盐部分与多种塑料的能力。我们的假设是，具有较低的碳足迹的水解具有较低的碳足迹增强，并具有恢复性塑料的含义，并具有较低的稳定性，并在有能力的机构中进行了竞争性的行为。我们的目的是优化时令处理以使塑料废物的功能化，检查和优化机械行为，通过变化的水泥组成和塑料增强的几何形状，通过人工加速衰老来分析材料可持续性，并进行人工化的生命周期评估，以研究可持续性和环境影响。 宠物）。塑料表面将用重氮化学处理，以引入磷酸盐和羧酸盐基团。表面相互作用将使用电子显微镜和X射线光电子光谱进行研究。机械性能将以抗压强度，弯曲强度和断裂韧性来衡量。通过疲劳测试，热循环和暴露于腐蚀性环境，将通过人工加速衰老来评估材料的可持续性。与当前技术相比，生命周期评估将分析产品从原材料到处置的全部影响，以确定每年的成本和环境影响。该团队在材料设计，多规模材料中的机械表征，材料表面修饰和界面现象方面具有互补的专业知识，材料的发展，无机水泥的开发和生命周期分析。 预期的结果：如果成功的话，绿色混凝土的发展将减少建筑业的碳排放，促进再生材料的使用并提高建筑材料的可持续性。