I just wanted to move away again from the discussion Asphalt Conmpaction versus Coverage (that you can also find under Road Construction here) and discuss the basics again why we need a compaction system overall.

These are the facts and shortcomings of conventional compaction systems.:

• no real-time feedback
• predefined fixed numbers of passes
• higher risk of over- or undercompaction
• only spot testing of mat
• no data or analysis of data
• no detection of soft spots of underlying material

These are the facts and shortcomings of "Intelligent Compaction" systems:

• real time feedback and opportunity for correction
• mapping of underlying material and detecting of soft spots before paving; therefore compaction that can be corrected upfront
• passcounting with visualization through color display improves compaction process and awareness for compaction operator
• complete temperature profile of the whole mat
• data collection and analysis of data available to improve quality
• limits are the complexity of data and coming up with a useful data analysis
• costs that could be up to 30% of roller costs for an intelligent compaction system
• no strong correlation of measured stiffness with Intelligent Compaction and density

The Federal Highway Association defines the term "Intelligent Compaction" as a vibratory roller equipped with RTK, Integrated Measurement Computer, use of an accelerometer to monitor compaction and responses from layers underneath, temperature measurement tool, GPS based documentation system with continuous and real-time data, color coded display and a RTK base station.

I think we all agree that there is a need for a compaction system to improve quality. Question is what features are definitely mandatory to have to improve the quality of the compaction process or if all are needed? I am sure the research projects going on in the US and other countries and at the supplier site of compaction systems will bring some light to that.

What is your opinion?