The Influence of the Binder Type & Aggregate Nature on the Electrical Resistivity of Conventional Concrete

由于其有趣的新鲜，硬化和耐久性相关的特性，混凝土在许多土木工程应用中得到越来越多的应用。抗压强度，通常在28天测量，是混凝土最重要的硬化状态性能，经常被用作其“微观结构质量”的指标。另一方面，建筑行业在优化施工进度和减少延误方面的压力越来越大，这使得对材料的“早期”特性进行快速、彻底和可靠的控制**势在必行。在这方面已经提出了许多先进的技术，并且已经发现电阻率（ER）是一种非破坏性和廉价的技术，能够表征微观结构的发展，从而评估胶凝材料（如混凝土）随时间的力学和耐久性相关性能。相反，最近的文献数据证明，ER可能会受到多种参数的显著影响，如测试设置（即表面电阻率与体积电阻率与内部电阻率）、材料孔隙率和水分含量、粘合剂类型/数量、补充胶结材料（SCMs）的存在，以及混合物中使用的骨料的性质（即岩浆、变质岩、沉积岩）。这使得不同原材料配比的混凝土配合比的实际基准复杂化。在此背景下，Giatec Scientific Inc.是一家位于渥太华的世界领先公司，该公司使用无线传感器和移动应用程序的尖端技术来收集与混凝土相关的各种数据。** Giatec最有前途的市场之一是测量传统混凝土中的ER及其与材料随时间的机械性能（例如抗压强度）的相关性。Giatec目前正在**寻求像申请人这样的混凝土材料专家的专业知识，通过首次合作**研究粘合剂类型/数量和骨料性质对具有广泛原材料的传统混凝土混合料的ER响应的影响。研究结果将有助于Giatec增强其现有的**ER设备，提高测试结果的准确性，并提高所提供服务的整体质量

Concrete has been increasingly used in a number of civil engineering applications due to its interesting fresh,**hardened and durability-related properties. Compressive strength, normally measured at 28 days, is the most**important hardened state property of concrete and is often used as an indicator of its "microstructure quality".**On the other hand, pressure is mounting in the construction industry to optimize construction scheduling and**reduce delays which makes imperative to have a fast, thorough and reliable control of the "early-age" properties**of the material. Numerous advanced techniques have been proposed in this regard, and it has been found that**electrical resistivity (ER), a non-destructive and inexpensive technique, is able to characterize microstructure**development and thus evaluate mechanical and durability-related properties of cementitious materials, such as**concrete, over time. Conversely, recent literature data have evidenced that ER may be significantly influenced**by a variety of parameters such as the test setup (i.e. surface resistivity vs bulk resistivity vs internal resistivity),**material porosity and moisture content, binder type/amount and presence of supplementary cementing materials**(SCMs) along with the nature of the aggregates used in the mix (i.e. magmatic vs. metamorphic vs.**sedimentary rocks), which complicates the practical benchmark of concrete mixtures proportioned with distinct**raw materials. In this context, Giatec Scientific Inc. is a world-leading Ottawa-based company that uses**cutting-edge technologies of wireless sensors and mobile apps to collect a variety of data related to concrete.**One of the most promising markets for Giatec is the measurement of ER in conventional concrete and its**correlation with the mechanical properties of material over time (e.g. compressive strength). Giatec is currently**seeking the expertise of a concrete materials expert such as the applicant through a first-time collaboration to**study the impact of the binder type/amount and aggregate's nature on the ER response of conventional concrete**mixtures presenting a wide range of raw materials. The research results will help Giatec to enhance its current**ER device, increase the accuracy of the test outcomes and improve the overall quality of the services offered to