News

Update: 4/10/07

Seems that there is some concern among folks with regards to the Laser Profiler. As noted in the forums, some folks don't trust the system. Personally, I think the system is pretty impressive and similar systems are in place nationwide. My concern is the implementation of an acceptance system using the profiler when it looks at conditions that far exceed those anyone is used to. I feel that we (contractors) can build roads that meet or exceed the specification requirements if we know how. The profiler takes elevation changes over a much larger distance than we are used to or can even see. In order to meet the rigorous requirements you would need a profile of the existing conditions prior to beginning any work. Then address the problem areas individually. I have requested that the department use the profile data that is collected when they do their planning surveys in the design process. The designers need to consider project phasing also. Larger projects that have traffic on structural asphalt for long periods or several pattern switches may need extra asphalt that can be profile milled prior to friction placement.

As with any new system, there is always a learning curve. The curve extends beyond the people doing the work and the department is going to have to make certain concessions. All things considered, I do believe this to be a system that can work. I also believe that the specs will change as everyone learns what is feasible and/or possible. Currently the departments designs have had a minimalistic approach to asphalt lifts/thickness'. The department is going to have to consider thicker courses with multiple lifts. That being said, Contractors are going to have to consider that the profiler will find the mistakes made. We are going to have to educate our paving crews on how to lay asphalt to meet the profiler. Pave slope, minimize roller heads, minimize hand work on the friction course, ensure paver screeds are in good shape, paver speed, starts and stops are minimized, structural course deficiencies are fixed PRIOR to friction and not with it, mix temps, and so on. Efficiency will lead to consistency, consistency leads to a better product

With all that said, I expect that the profiler itself will also be changing in the future. I have heard that the SMO is considering the use of a wider laser. The current laser only see about 2.5mm of the road surface in each location, which in my opinion is far to small to provide an actual assessment of a 200mm wheel path.

Consider that if you have a problem or a question with the profiler or any spec "SPEAK UP" your problems will remain yours unless you get involved enough to let others know. If you are uncomfortable questioning something to the FDOT or if you just need additional information feel free to use the forums here or call Jim Warren with the ACAF. There are folks in place to help fight the fight.

Update: 3/26/07

A couple of updates worth mentioning. All contracts let after January 1st this year will have the new Polymer modified binder index. Some of you may have already noticed the new index listed with the standard binders.

The SCO memo (03-07) outlining the changes to the IV procedures is posted for those of you interested in changing this portion of your ongoing projects. A simple letter requesting the change and referring to the memo should be all you need to do. This spec change will be official in the July '07 workbook.

Update: 3/15/07

The updated QC manager course is not all that different. I expected some substantial changes but there are not any. The one thing that alot of people are still confused about is the role of QC or maybe the responsibilities of the QC department. This is a topic for the forums and I intend to make a post about it today. All in all the only real differences are that the Contractors Monthly statement of compliance no longer requires that individual samples be listed when there are input but not complete, such as concrete cylinders that have not been broken yet. I have always felt that an "Exception" is something that is not in compliance with the specs not something that is in compliance but not finished, so it is a good change.

Update: Feb 19, 07

Profilograph based ride acceptance is here in full force. I know that most of you have had the Profilograph on your project and are probably pretty familiar with the RN (Ride number) concept. The new spec would provide an incentive disincentive based system that would pretty much eliminate the rolling straight-edge. I paid a visit to International Cybernetics Corp. to take a look at their products and try to understand the system and how it works. The folks at ICC were extremely friendly and help full with explaining all the inner workings of the systems and just what we should expect. ICC builds and supplies laser profilograph systems to companies worldwide but most importantly supply the systems that the FDOT currently use.

I learned that the profilograph is a very high tech system that takes continuous measurements and processes those measurements through a sophisticated software system. The software filters the data into several different output formats, one of which is ride number. The profilograph uses three distance measuring lasers and two accelerometers to create a continuous elevation profile. As the vehicle travels the road surface causes it to move up and down. The force exerted by the vertical movement is measured by the accelerometers and essentially subtracted from the laser measurements to create a profile. The vertical measuring lasers have a diameter of 2.5mm and in my opinion are quite small.

The biggest issue here is the change in surface evaluation. This new system takes into account surface elevation variations on a much larger scale than the current system. The measurements are done by measuring "wavelengths" of change. There are basically three different wavelengths that are measured, short, medium, and long. The rolling straightedge would be considered a short wavelength measurement device as it only accounts for changes that occur within 15 feet. So the profilograph is taking elevation changes into account that are not even visible and that occur over substantial distance.

The ride number is derived from running the raw data through software "filters" that should remove inaccurate data and average the readings. Since the profilograph is taking continuous readings, the software should average the reading to account for things such as an open graded friction course or variables such as a piece of debris in the road. There is an additional piece of equipment that can be added to the profilograph that measures cross slope. The slope measurements are taken by a separate system and are not used in the ride number calculation.

The department is intent on implementing some sort of profilograph acceptance system but further discussion is planned. The current spec is on hold. Updates to this topic will be posted here as they happen.

Update: Jan 31, 07

The department has sectioned off the specifications for the July '07 workbook on a different page. This page not only displays the specifications and the changes but it also notes any comments made and what the departments' response is. I cannot possibly stress how important it is to take the opportunity to comment and make suggestions about upcoming changes. As I read all the comments made about the changes for Sections 120,125,160, and 200 I counted about 5 people that made any suggestions. Out of the 5 only two to three represented the industry.

The department needs feedback from the people doing the work!

So many times someone will say how redundant a requirement is but never act on it. This page is where the department advertises the specs that are to be changed. No one is going to send you an email telling you that a spec is up for review (except for the FTBA if your a member) so it is up to you to check the site often and take the time to review the spec and suggest your ideas.

Update: Jan 26, 07

CTQP and FDOT have updated (changed) the QC Manager course. The QCM position has been restructured. I am not sure of all the changes but I will be attending the course in Clearwater Feb 6th and 7th. I intend to take notes and will write a summary to post here so that everyone can see what the changes are.

Update: Jan 25, 07

An updated Flexible Pavement Committee agenda is available for review HERE. If you have issues other than these listed please bring them with you to the meeting. Since this meeting is NOT at the SMO office, this map will help you find your way.

Update: Jan 15, 07

Final versions of Specification 234, 334, & 337 have been sent to FHWA for final review and implementation. The specification and all comments can be seen HERE.

Thought that this might be a good place for "Quotes of the week". Seems like someone is always saying something silly and why can't we all get a laugh out of it.

This one is related to earthwork.

A district earthwork representative to the road QC: "Just because the contractor is having difficulty achieving density is no reason to take another proctor." The new sample taken reduced the proctor value from 118 to 110 and resulted in passing tests.