During the construction of a highway in the north of Portugal, it was verified that in a few places the compaction control of the road fill materials presented unexpected results with the surface moisture density gauge (SMDG). The water content was lower than measured by oven drying, and the density and compaction grade were much higher than when using the sand cone. In an effort to understand the reasons for this unexpected offset, the road fill material was tested in situ with two different brands of SMDG, extra sand cone tests were performed and samples were collected at the test sites and tested in the laboratory to determine the water content by oven drying. The local geology, mineralogy, geochemistry and radiation level of the fill materials were studied. It was concluded that the incorrect results were caused by the presence of chemical elements in the road fill materials, mainly manganese, chlorine, cadmium and boron, which are able to capture the neutrons released by the SMDG, delivering a false low water content. An index to evaluate the susceptibility of the soil to present a false low water content (FLoW) is proposed.Despite the reliability of the SMDG in most fill control, it must always be used with great care, after crosschecking its results with other direct control tests.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.