Benchmark your project
Because you and others in the supply-chain rely upon testing companies, like Simtec, to pass-off your work, we created the Optimum Compliance BenchmarkTM (OCB).
We have documented the practices and procedures that produce the conditions for an optimum compliance outcome, going far beyond minimum compliance requirements (see the sample below).
Using Simtec historical data, we found that approximately 95% of the compliance levels not being met were due to low-quality materials being used. The remaining 5% was simply a result of not adhering to best practice. The Simtec OCB datasheets help mitigate those risks.
or call 0116 319 6100 to ask our team about how the OCB can help you minimise risk on your projects.
Example OCB Datasheet
Unbound Layer Testing
CBR (Determination of the equivalent California Bearing Ratio using the plate bearing test)
Validation of results
By using a UKAS accredited testing organisation results will be accepted by all UK Government agencies, including Highways England and local authorities.
BS1377: Part 9: 1990 Clause 4.1 Design Manual for Pavement Foundations CD 225 IAN73/06 Rev 1:2009 (Withdrawn)
Establishing testing layers
In most cases (depending on the layer thickness) formation and capping requires a 450mm diameter plate and a Sub-base requires a 300mm diameter plate.
Adhere to specified min CBR % for the relevant Local Highways Authority or Highways England.
Preparation & compaction
Formation & Sub-Formation: Proof roll the Subgrade before test. Capping Layer materials require compaction to the requirements of Table 6/1 – Series 600 of the SHW.
Type 1 Sub-Base: Ensure appropriate thickness and adequate compaction. Avoid segregation of stone materials and ensure smooth level test surface.
Kentledge provision should be in excess of 6 tonnes and have an accessible flat area to seat the jack. A Back Hoe digger or a 360 excavator is ideal.
Length of time
Kentledge is required for the duration of the test. Testing at each location typically lasts 30 mins. Individual test duration will vary according to the ground conditions.
Weather does not adversely affect the testing regime. However, rain over a prolonged period will distort the CBR value of both the formation and sub-base layers. Avoid testing when the surface is frozen or affected by frost and snow or is saturated.