Pub. 1 2018-2019 Issue 2

I magine driving down a beautiful asphalt road. The ride is quiet and smooth and you don’t feel any unpleasant jarring or annoying repetitive joint noise caused by the pavement. Youmay not consciously appreciate the quality of the asphalt pavement you’re traveling on, but it affects your overall feeling of well-being. Now start to imagine a little damage as you drive down that same road and start encountering occasional potholes or transverse cracking. The more damaged the road becomes, the more dissatisfied you feel. Now that you have this imaginary experience in mind, let’s talk about the art of paving. It is an art that consists of build- ing roads that are beautifully paved, have no apparent joints, and no changes in the ride profile. Froman owner’s perspective, asphalt is an economically sound way to pave a road. Fromthe public’s perspective, asphalt roads provide a superior traveling surface that can be installedmore quickly than other paving materials. From a contractor’s per- spective, many paving companies in the intermountain area are highly qualified to install asphalt, but doing the job right takes advance preparation and commitment throughout the entire building process in order tomake a reliable, low-mainte- nance road that will continue to provide a good surface for its entire life cycle. The contractor has to use the right processes to minimize potential problems and must also be committed to building a quality product. The process of building a good road requires choosing a good specification. If you are looking for a good public specifica- tion, the 2017 version of the APWA specification is a superior choice that has corrected many of the shortcomings of the previous versions. This specification can easily be adopted by any city as the default specification in order to achieve the goal of a well-built pavement. After you have the specification, you also need to choose the contractor. Durable, high-quality roads that last a long time are built as a result of good engineering and good specifica- tions, but creating them also requires having the work done by a quality contractor who can demonstrate the value of thoughtful processes and a skilled work force. The contractors in the intermountain area have become very proficient about the way they place and compact the base layers. However, I’ve also noticed that many of the projects don’t use quality control testing throughout the process. The contractors have become reliant on just doing the quality assurance testing at the end that gives them their construc- tion quality feedback, but testing just at the end isn’t enough. Installing these types of materials involves a lot of variability, and smaller localized deviations in uniformity are as likely to fail as the larger ones. That’s why it isn’t enough to check on quality only once. In contrast, a good quality control program can help you better understand and compensate for the actual variability throughout the process. You should always choose the contractor who understands the art involved in building a good road and will do the work to build all the layers correctly. PAVING By Doug Watson, CMT Engineering Laboratories THE ART OF continued on page 18 17