Often, we go to these conferences and retain only a small amount of information because of how jam packed the conferences are. But how much do we retain after three months have gone by?
Katherine Au, Materials Manager at OMEGA & Associates, attended the conference in February, and here’s what she has to say three months later.
Walking into the convention center was overwhelming. There were rows upon rows of construction equipment and machinery. Around every turn was a new paving innovation or construction technology. My first thought was, “how long did it take them to get all these massive things in here?” I decided to take a loop around the whole place first before deciding which booths to visit. With so many new technologies, it’s hard to list all that had an impact on me, but below are a few that I found most interesting, even three months later.
Oscillating rollers seemed to be popping up at more booths than I expected. More companies are interested in this technology because they help improve productivity and create a smoother finish on mixes that can otherwise be a bit challenging. It’s also a great technology for tender mixes or when working in tight spaces.
I was exposed to this new type of roller a couple of years back and saw promising results. This roller is sold as a better way of achieving density for hot-mix asphalt. Instead of the up and down movement of the vibratory rollers, this was more of a “massaging” movement which allows the drum to stay in constant contact with the material. The oscillation allows contractors to achieve higher density numbers which is important when working with a strict timeline as many of us do.
The oscillating rollers require fewer passes than vibratory rollers to achieve the same density which in turn leads to saved time, and as we all know, time is money. I’ve mentioned this to some of our clients as a new technology that should be used on systems where possible. I received positive feedback from another colleague who said Wisconsin has been using it for some time and loves it. Several clients haven’t had any experience with the technology, with more time, effort and research, clients likely will start to adopt the technology.
Another new technology that stuck with me were spray pavers which are pavers with built in spray bars. This technology is helpful to the asphalt industry because it saves an extra step. Normally when paving, there is a separate truck that carries the tack coat in a tank and sprays the tack coat down before the paver comes in to lay down the asphalt. The tack coat needs time to “cure” before the asphalt is applied so the asphalt can adhere to the tack coat.
The spray paver combines the paver and tack truck into one by adding tack spraying equipment to a paver. On these vehicles, the spray bar gets placed about a foot in front of where the paving material gets distributed. This allows the pavement to immediately get placed behind the tack and eliminates any driving over the tack which can damage both the wheels of the vehicle and the effectiveness of the material.
With this built in spray bar it saves time from having to wait for a tack coat to be applied and cure time before being able to place the hot-mix asphalt. Additionally, you eliminate the need of having another driver for the tack coat truck. The room for error is also lessened with this approach because when paving in separate steps as a standard, sometimes improper application or damage after application of the tack can occur. That will cause issues with bonding and can cause potholes or cracking. The spray pavers eliminate the extra step and allow for improved bonding between the tack coats and new pavement layers.
In April I attended the ICAT (Innovations in Construction, Asphalt & Transportation) conference. During one of the asphalt sessions, the topic was about spray pavers. Chris Ingram with Roland Machinery spoke about his experience with the 1800-3 SprayJet. It was good for me to learn more in detail about how the technology worked—the heat from the hot-mix asphalt that is placed over the tack coat steams the water out of the tack coat which causes the emulsion to get draw up into the mat to improve the bonding to the layer below. In speaking with some IDOT Materials Engineers, they mentioned that IDOT is already planning to use spray pavers for some thinlay projects for pavement preservation. Hopefully we’ll see the spray pavers becoming more commonly used by other agencies.
From a testing point of view, the asphalt analyzer was the hot new item advertised. IDOT already incorporated as an acceptable test method for determining the asphalt binder content in asphalt mixtures It’s an automated and enclosed system, making it safer and more accurate when it comes to testing.
This machine “washes” the hot-mix asphalt sample and keeps the trichloroethylene solvent enclosed within the system so none of the harmful fumes escape. The machine works by inserting a sample into the washing chamber, and once all chambers are locked, the extraction procedure, number of washing and dry cycles is selected by the built-in PC, depending on the sample type and size.
It’s a much faster way of extracting the liquid asphalt from the hot-mix asphalt vs the other methods of extraction so we can determine that we are getting the correct amount of liquid asphalt required for that specific mix design.
Overall this conference was geared towards contractors looking to buy new equipment, but it was interesting looking inside some of the machines while they weren’t moving or filled with asphalt. As a Materials Manager at a construction-focused firm, I haven’t had the opportunity to look inside of these machines and new technologies because I usually see them when in action. It was beneficial because I gained a better understanding of how the machines work and are built, as well as new technology to advance the work we do.