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

该项目是一项合作研究计划的一部分，旨在开发用于建筑**的可持续混凝土。用氧化镁（MgO）制成的替代水泥被用来替代常用的波特兰水泥，以开发一种碳排放更低、寿命周期和耐久性性能更好的混凝土。通过回收废水处理的副产品（鸟粪石和新铍）来获得混凝土粘结膏所需的氧化镁活化。MagO建筑**产品有限公司是一家加拿大公司，积极参与MgO混凝土的开发、应用和**标准化。公司目前在加拿大、美国和亚洲供应MgO混凝土产品，**包括建筑用MgO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用当地的材料和工艺开发一种合适的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目前与MgO混凝土实施相关的一些研究挑战。这个Engage Plus研究计划代表了一个成功的Engage项目的延续，该项目开发了一个适当的程序来处理鸟粪石，以释放氨并实现对MgO的反应性。在混凝土浇筑、抗压强度和密度方面的新性能方面达到了基本要求，并且材料被认为适合板的应用。因此，截至2017年12月，提交了一份专利申请，并最终确定了**份科学/技术同行评审出版物。进一步的实验将通过Engage Plus赠款进行，以优化混凝土工程性能，从而优化最终的建筑性能以及生产过程。此外，通过探索使用各种当地可用的镁水泥、天然纤维和轻质骨料，镁混凝土的成本和可持续性将得到提高。

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.