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，该计划旨在开发用于建筑**应用的可持续混凝土。用氧化镁(MgO)制成的替代水泥被用来替代通常采用的波特兰水泥，以开发出碳排放更低、寿命周期/耐久性能更好的混凝土。获得混凝土粘结剂所需的氧化镁活化**是通过回收废水处理的副产品(鸟粪石和新橄榄石)实现的。Mago Building**Products Ltd是一家加拿大公司，积极参与氧化镁混凝土的开发、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，**包括用于建筑应用的氧化镁板材。由于这些电路板目前都是从中国进口的，目前正在进行的研究合作的目标**是利用当地的材料和工艺开发一种合适的氧化镁混凝土。**这一本地制造解决方案不仅将使加拿大经济受益，还将消除与中国的电路板运输相关的二氧化碳排放**。正在进行的实验项目还**解决了目前与实施氧化镁混凝土相关的一些研究挑战。这个**Engage Plus研究提案代表了一个成功的Engage项目的继续，在该项目中，为鸟粪石的处理开发了适当的**程序，以释放氨并实现对氧化镁的反应性。在混凝土浇筑、抗压强度和密度方面达到了基本**要求，材料被认为适合板材应用。结果，提交了一项专利申请，**截至2017年12月，经科学/技术同行评审的出版物正在定稿。进一步的实验将**通过Engage Plus Grant进行，以优化混凝土的工程性能，从而优化最终的**建筑性能以及生产过程。此外，将通过探索使用各种当地可获得的镁水泥、**天然纤维和轻质骨料来提高**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.