In situ concrete strength assessment: Influence of the aggregate hardness on the windsor probe test results

Abstract

Experimental research was carried out to investigate the influence of aggregate hardness on Windsor probe test results. A series of concrete specimens prepared from aggregates having a variety of Mohs' hardness values and also specimens using an aggregate with a consistent class of Mohs' hardness were prepared. The models once prepared were subjected to penetration tests. After conducting the penetration tests, cores were extracted from the specimens. A comparison between penetration tests and the core strength was carried out. These show that the Windsor method is more reliable when only one class of Mohs' hardness is contained in the specimens. In this case the results can be considered acceptable. The uncertainties grow as the number of classes of Mohs' hardness increase. When testing during the presence of aggregates with different classes of hardness, it is necessary to construct suitable curves of calibration. © 2009 Palgrave Macmillan.