Novel viscosity- and thixotropy-enhancing agents for innovative construction materials

用于创新建筑材料的新型粘度和触变性增强剂

• 批准号: RGPIN-2022-04732
• 负责人: Yahia, Ammar
• 金额: $ 3.35万
• 依托单位: Université de Sherbrooke
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 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=753844
• 关键词: Novel; viscosity; thixotropy; enhancing; agents

Flowable concrete with adapted rheology, such as self-consolidating concrete, is an emerging technology that enables the casting of concrete without any of the mechanical consolidation required with conventional concrete. In flowable concrete, viscosity-enhancing admixtures are commonly incorporated to enhance flowability and prevent liquid-solid phase separation, i.e., bleeding and segregation, during transport, placing, and in-place consolidation operations. This Discovery Grant proposal focuses on the development and use of new generation of low-environmental impact, viscosity-enhancing admixtures (VMAs) based on red algae to design innovative flowable concretes characterized by higher workability than those of the conventional concrete covered in current Canadian and international standards. This research program will (i) Investigate the performance of carrageenan polymers derived from algal cell in comparison with the current VMAs used in concrete industry; (ii) Develop a comprehensive scientific basis on the performance of Kappaphycus alvarezii and kappa-carrageenan powders as VMAs in selected concrete applications; (iii) Investigate the mode of action of carrageenan biopolymers in model suspensions (i.e., inert suspensions) and in cementitious systems; (iv) Improve the performance of the carrageenan by ion-ajustement in cementitious systems, including their thickening behavior, structuration kinetics, and rate of stiffening, and identify the ionic mechanisms affecting their behavior in cementitious systems; (v) Validate the performance of the developed carrageenan modified by ionic adjustment in different concrete applications, including tall buildings, to reduce the lateral pressure on formwork and enable 3D printing, and emphasize its cost-effectiveness aspects to support its acceptance by the concrete industry. The beneficiation of red algae in concrete constitutes a very important technological advance in the construction industry. This will deliver value-added benefits to the construction industry by developing high-performance building materials with low environmental footprints and production costs associated with using VMA in cement-based matrices. The proposed research program will also provide a comprehensive scientific basis to support the optimal use of carrageenan biopolymers to design high-performance concrete with adapted rheology and thixotropy for different construction applications.

具有适当流变性的流动混凝土，例如自固结混凝土，是一种新兴技术，其使得能够在没有常规混凝土所需的任何机械固结的情况下浇注混凝土。在流动性混凝土中，通常掺入粘度增强掺合物以增强流动性并防止液-固相分离，即，在运输、浇筑和就地固结操作过程中的渗漏和离析。这项发现补助金提案的重点是开发和使用新一代的低环境影响，基于红藻的粘度增强型外加剂（VMA），以设计创新的可流动混凝土，其特点是比现行加拿大和国际标准中所涵盖的传统混凝土具有更高的可加工性。该研究计划将（i）调查源自藻类细胞的角叉菜胶聚合物与混凝土工业中使用的当前VMA相比的性能;（ii）开发关于在选定的混凝土应用中作为VMA的长叶卡帕藻和κ-角叉菜胶粉末的性能的全面科学基础;（iii）调查角叉菜胶生物聚合物在模型悬浮液中的作用模式（即，（iv）通过在水泥体系中的离子调节来改善卡拉胶的性能，包括它们的增稠行为、结构化动力学和硬化速率，并确定影响它们在水泥体系中的行为的离子机制;（v）验证所开发的通过离子调节改性的角叉菜胶在不同混凝土应用中的性能，包括高层建筑，减少对模板的侧向压力，实现3D打印，并强调其成本效益方面，以支持混凝土行业的接受。 在混凝土中去除红藻是建筑行业的一项重要技术进步。这将通过开发高性能建筑材料为建筑行业带来增值效益，这些材料具有低环境足迹和与在水泥基基质中使用VMA相关的生产成本。拟议的研究计划还将提供全面的科学依据，以支持最佳使用卡拉胶生物聚合物来设计具有适应不同建筑应用的流变性和触变性的高性能混凝土。