Improving sustainable development practice in concrete production through the monitoring of fresh concrete properties using an in-drum sensor

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Concrete is the most utilized construction material and is unique in the way it is produced, transported and then cast in formwork of varying shapes and sizes. From the concrete plant to the job-site, everyone involved closely follow rules and procedures so that a few weeks later, the hardened material has indeed reached its prescribed properties -the most common being compressive strength. Consistent quality in concrete production is an essential element in the ready-mix concrete industry and insuring batch-to-batch uniformity is, in fact, an ever present challenge. Our ability to measure and monitor the properties of fresh concrete before it reaches the formwork, traditionally done by measuring temperature and workability before placement, is of the utmost importance. If irregularities are detected on the fresh concrete (i.e. deviation from the specifications), the load (truck) is rejected resulting in material and time losses, extra costs and even construction issues such as cold joints. In some cases, non-compliance is only detected from the hardened concrete properties evaluation (usually discovered 28 days after concrete placement); the consequences are much more significant at that point, and can go from increased maintenance efforts and/or reduction in the structure's service life to outrageous remedial cost if not complete replacement, thus severely impacting all aspects of sustainability. The last two decades have seen an incense use of modern mixture designs often incorporation of supplementary cementing materials of various types and various origins. The effect is that concrete producers are therefore faced with an increasing number of parameters to control to produce consistent and high quality concretes. The traditional approach of measuring, punctually at the time of delivery, the temperature and workability has unfortunately proven oftentimes its many shortcomings. It is therefore the objective of this CRD Grant to explore means and methods to improve concrete production quality by evaluating the potential of using an in-drum automated sensor system. This will improve the quality of the final product, facilitate real-time quality control activities on the job-site during delivery and allow for substantial waste reduction by reusing more recycled water and reducing the amount of concrete directed to waste.