Investigation of coarse aggregate surface treatments to enhance concrete strength

阿玛贝尔白云岩是一种耐风化的岩石类型，它覆盖了汉密尔顿和马尼托林岛之间400多公里的尼亚加拉悬崖。对在安大略省开设新的Amabel白云石采石场的抵制一直很强烈。由于现有的供应接近枯竭，而开设新的采石场似乎不太可能，建筑行业将需要寻找替代的骨料来源。鸥河组内现有的采石场代表了潜在的替代来源，但初步工作表明，用鸥河石灰岩生产的混凝土不能达到用Amabel白云岩生产的混凝土的相同性能。因此，本研究的目的是修改骨料的表面特性，以帮助改善与硬化水泥浆的粘结。这种方法的优点是，混凝土生产商可以在保持相同的基本混合设计的同时，潜在地切换到表面处理的骨料。将探索和评估几种表面粘合增强方法，以生产规模对海鸥河石灰石骨料选矿的可行性，包括机械磨损以改善表面纹理，以及基于纳米二氧化硅和硅酸钠的骨料涂层。

The Amabel dolostone is the weathering-resistant rock type that caps the Niagara Escarpment for over 400 km between Hamilton and Manitoulin Island. Resistance to the opening of new Amabel dolostone quarries in Ontario has been strong. As the existing supplies approach exhaustion, and the opening of new quarries seems unlikely, the construction industry will need to find alternative aggregate sources. Existing quarries within the Gull River Formation represent a potential replacement source, but preliminary work indicates that concrete produced with Gull River limestone does not achieve the same properties as concrete produced with Amabel dolostone. Consequently, the aim of this study is to modify the surface properties of the aggregate to help improve the bond with the hardened cement paste. The advantage of this approach is that the concrete producer can potentially switch to a surface-treated aggregate while maintaining their same basic mix designs. Several surface bond enhancement methodologies will be explored and assessed for feasibility in terms of production-scale for aggregate beneficiation of Gull River limestone, including mechanical abrasion to improve surface texture, as well as aggregate coatings based on nano-silica and sodium silicate.