Classification of aggregates for fire

The quality of the natural stone aggregates change with each shipment and it greatly influences the fire-performance of the concrete. For this reason, it would be advantageous if there would be a classification system for aggregates for fire or fire-related temperatures. The classification of the aggregate itself instead of the concrete could be faster and more economical solution in the long run, it could prevent the need to deconstruct concrete based on 28-day test results in case of an insufficient aggregate. This study aims to provide preliminary measurements and conclusions for such a system based on the Hummel-tests after heat loading with supplementary tests such as scanning electron microscope and derivatograph to better understand the changes of the inner structure. For this study quartz, crushed andesite and crushed limestone were tested. The Hummel tests were evaluated based the changes of the grain size distribution and showed promising results, but further testing is required with more samples to calibrate and to confirm the usability of the method. (C) 2020 The Author(s). Published by Elsevier Ltd.

Automated summary

The quality of natural stone aggregates varies with each shipment, impacting the fire performance of concrete. Establishing a classification system for aggregates based on fire or fire-related temperatures could provide a faster and more economical solution. Preliminary measurements and conclusions for such a system were provided in this study, using Hummel-tests and supplementary tests, but further testing with more samples is needed to confirm usability.