Investigation of coarse aggregate surface treatments to enhance concrete strength

Amabel白云岩是一种耐风化的岩石类型，覆盖了汉密尔顿和马尼图林岛之间400多公里的尼亚加拉悬崖。对在安大略开设新的Amabel白云岩采石场的抵制一直很强烈。 由于现有的供应接近枯竭，新采石场的开放似乎不太可能，建筑业将需要寻找替代骨料来源。Gull River地层内的现有采石场代表了潜在的替代来源，但初步工作表明，用Gull River石灰石生产的混凝土无法达到与Amabel白云岩生产的混凝土相同的性能。 因此，本研究的目的是修改集料的表面性能，以帮助改善与硬化水泥浆体的粘结。这种方法的优点是，混凝土生产商可以在保持相同的基本配合比设计的同时，潜在地切换到表面处理骨料。将探索和评估几种表面粘结增强方法在Gull River石灰石骨料净化生产规模方面的可行性，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.