2006 Cells 27 and 28 Construction Report

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Date Created
2006-11
Description
The purpose of this report is to provide details on the 2006 reconstruction of Cells 27 and 28 on MnROAD’s Low Volume Road. There were three significant aspects of research behind the test cell reconstruction: field validation of a Geocomposite Capillary Barrier Drain (GCBD) for limiting moisture changes in pavements, Intelligent Compaction (IC) research performed on the unbound base and subgrade layers, and accelerated testing of PG 52-34 binder to support a Local Road Research Board (LRRB) project. This report documents the previous pavement condition, pavement structural and mix designs, instrumentation plan, field construction activities, material sampling, and laboratory test results. Significant effort in communication and coordination between research and construction personnel led to a successful construction project.

Validation of DCP and LWD Moisture Specifications for Granular Materials

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Date Created
2006
Report Number
2006-20
Description
Advances in technology have produced a new generation of in situ soil testing devices. Implementation of quality assurance procedures that make use of these devices would improve test precision, increase inspector efficiency and safety, and allow for the direct verification of values used in mechanistic design procedures. During this study, the dynamic cone penetrometer (DCP) and light weight deflectometer (LWD) were used on laboratory prepared specimens. It was found that the Mn/DOT DCP specification accurately assessed compaction quality, although there were some suggestions for improvement. This study reached the following conclusions and recommendations. The DCP penetration should continue until the cone passes through the subbase lift of interest. The DCP seating requirement serves little purpose for a subbase lift that will be covered by subsequent lifts. The acceptable range of moisture contents during DCP testing of granular subbase should be capped at 10%. A sufficient amount of data exists to create an LWD trial specification for granular subbase. A mass of 10 kg, drop height of 50 cm, and plate diameter of 20 cm are recommended. It is also recommended that the LWD specification include three seating drops followed by three data drops at each new height.