Engineering properties of durable and low-carbon-footprint magnesium concrete, partially recycled**from wastewater treatment by-product

该项目是一个合作研究计划的一部分，为建筑应用开发可持续混凝土。用氧化镁（MgO）制成的替代水泥被用作通常采用的波特兰水泥的替代品，以开发一种具有较低碳排放和改善生命周期/耐久性性能的混凝土。通过回收废水处理的副产品（鸟粪石和新绿柱石），可以获得用于混凝土的粘结膏所需的MgO活化。MagO Building**Products Ltd是一家加拿大公司，积极参与MgO混凝土的开发，应用和标准化。该公司目前在加拿大、美国和亚洲供应氧化镁混凝土产品，** 包括建筑应用的氧化镁板。由于这些板目前是从中国进口的，因此正在进行的研究合作的目标 ** 是使用当地材料和工艺开发合适的MgO混凝土。这种本地制造解决方案不仅有利于加拿大经济，而且还消除了与从中国运输电路板相关的二氧化碳排放。正在进行的实验项目还 ** 解决了一些与MgO混凝土实施相关的当前研究挑战。该 **Engage Plus研究提案代表了一个成功的Engage项目的延续，该项目开发了一种适当的 ** 程序，用于处理鸟粪石，以释放氨并实现与MgO的反应性。在混凝土浇筑的新鲜特性、抗压强度和密度方面达到了基本的 ** 要求 **，材料被认为适合于板的应用。因此，截至2017年12月，已提交专利申请，** 科学/技术同行评审出版物正在定稿。进一步的实验将通过Engage Plus Grant进行，以优化混凝土工程性能，从而优化最终的建筑性能和生产过程。此外，还将探索使用各种当地可用的镁水泥、** 天然纤维和轻质骨料，以提高镁混凝土的成本和可持续性。

This project is part of a collaborative research plan for the development of sustainable concrete for building**applications. Alternative cements made with magnesium oxide (MgO) are used as replacement to commonly**adopted Portland cement to develop a concrete that has lower carbon emissions and improved**life-cycle/durability performance. The MgO activation required to obtain a binding paste for concrete is**achieved by recycling by-products from waste-water treatment (struvite and newberyte). MagO Building**Products Ltd is a Canadian company actively involved in MgO concrete development, application, and**standardization. The company is currently supplying MgO concrete products in Canada, U.S. and Asia,**including MgO boards for building applications. Since the boards are currently imported from China, the goal**of the ongoing research collaboration is to develop a suitable MgO concrete with local materials and processes.**This local manufacturing solution will not only benefit Canadian economy, but also eliminate the CO2**emissions associated with the transport of the boards from China. The ongoing experimental project also**addresses some of the current research challenges associated with the implementation of MgO concrete. This**Engage Plus research proposal represents the continuation of a successful Engage project, where an appropriate**procedure was developed for the treatment of struvite to release ammonia and achieve reactivity to MgO. Basic**requirements in terms fresh properties for concrete placement, compressive strength and density were achieved**and the materials were deemed suitable for the board application. As a result, a patent application was filed and**scientific/technical peer-reviewed publications are being finalized as of Dec. 2017. Further experiments will be**performed through the Engage Plus Grant to optimize the concrete engineering properties and, thus, the final**building performance as well as the production process. In addition, enhancement of cost and sustainability of**the magnesium concrete will be pursued by exploring the use of various, locally available magnesium cements,**natural fibers, and light-weight aggregate.