Dynamic CBR Test and Measurement Research Papers

Dynamic CBR Test to Assess the Soil Compaction Katarzyna Zabielska-Adamska and Maria J. Sulewska ASTM Journal of Testing & Evaluation VOL. 43 NO. 5 SEPTEMBER 2015

Rather than use California Bearing Ratio (CBR) as a method of compaction assessment and an indicator of soil bearing capacity, a much more efficient method for the compaction control is the dynamic CBR (CBRd). This methodology is conducted by using a loading system employing a light falling weight deflectometer (LFWD), consisting of a falling weight to produce a defined force pulse on the CBR piston. In this paper, the CBR research was done for both static (classic) and dynamic methods on fly ash specimens without soaking them to replicate field conditions. A force of 2.44 kPa was applied to all specimens subjected to penetrations. Test results obtained from the tests on fly ash revealed that dynamic CBR could be recommended in the cases of embedded fine-grained soil with moisture contents insignificantly greater or less than optimum water content.
Dynamic CBR as a method of embankment compaction assessment – Katarzyna Zabielska-Adamska – Head of Geotechnics, Faculty of Civil & Environmental Engineering – Politechnika Białostocka (Bialystok University of Technology – Poland)

In engineering practice, earth construction requires suitable soil compaction, usually relating to the Proctor methods. Materials of the built-in embankment and the subgrade have their own specifications, dependant on the kind of earth structure and soil plasticity characteristics. Care should be taken not to use compaction degree (% of maximum compaction) as the only parameter to assess soil compaction. This applies to both cohesive soil and to fly ash whose permeability and mechanical properties dependent on moisture content at compaction. Therefore, for these types of soils California Bearing Ratio could be used as a method of compaction assessment being an indicator of soil bearing capacity. The CBR research was done for both static (classic) and dynamic methods on fly ash samples without soaking them to replicate field conditions. The dynamic CBR tests were conducted by using Light Weight Deflectometer consisting of a falling weight to produce a defined load pulse of the CBR piston. The CBR test could be used for running compaction control during embankment erection, which specially refers to dynamic CBR test due to the speed of research execution.
Der Dynamische CBR-Versuch – eine neue Qualitätskontrolle für den Erdbau – Geotechnik; Ausgabe 4, Seite 271 – 274 (2000) – Professor Dr.-Ing. Hans-Henning Schmidt und Dipl.-Ing. Jürgen Volm (German)
Dynamisches Labor- und Feldpruefgeraet zur Bestimmung des CBR-Wertes von Mineralbeton – Die Strasse Vol 26 Issue 1, Seite 48-51 (1986) – Weingart W., Hanebutt J. und Rummelt W.