Tack Coat Massachusetts

As a state of Massachusetts tack coat contractor that places tack coat for paving contractors we comply with the state specifications out lined in the document titled “Mass DOT SUPPLEMENTAL SPECIFICATIONS”. Our tack truck distributor services for pavement contractors here in the greater Boston area and Western Massachusetts depends on providing and applying the right product that is always on spec for our customers.

The State of Massachusetts tack coat specifications and details are lined out at the bottom of this page. Reading all the details of the specifications can be confusing and detailed. The bottom line is the material used with in the state and that we supply and install is an asphalt emulsion that is defined as RS-1 tack coat.

Tack Coat Asphalt Emulsion Droplet

RS-1 tack coat is an anionic rapid setting asphalt emulsion that is used to bond two layers of asphalt together to produce a durable roadway and prevent slippage of the two layers. It works by combining two opposite contents like oil and water that are held in suspension as it is stored and handled.  The emulsion has in the formulation dispersants that keep it from settling when in storage so that it does not harden or settle out prior to usage. The asphalt cement component is emulsified in water so it can be sprayed well and not be too thick. RS-1 is a rapid setting anionic asphalt emulsion designed to break and cure quickly and destabilize instantly on contact with aggregate surfaces after it has been applied.

The varieties of asphalt emulsions are divided up according to the electric charge that surrounds the asphalt particles. They are either cationic, or anionic emulsions reflecting the electronic charge. Then these tack coat emulsions or subdivided by how quickly the suspended asphalt particles break. By break we mean how fast the water will evaporate from the emulsion leaving behind just the asphalt cement. The term RS-1 rapid setting emulsion means that will it will break quickly when the emulsion is sprayed from the distributor truck onto the aggregate. The actual setting speed or time it takes to break varies by job site conditions such as temperature, wind and humidity. To speed the process of breaking our trucks are heated so it speeds it up and the paving crews can proceed quickly with the paving project. This is usually especially important at the start of a pass. This enables the paving machine to get started and not have water trapped between the existing layer and the new hot mix layer being installed. All contractors know that efficiency is important to get the tonnage of asphalt placed per shift is important.

Tack Coat – Asphalt Emulsion Terms

Tack coat status changes and what the terms mean. The transition from a spray-able asphalt emulsion to an asphalt glue is called a couple of things When a tack coat emulsion is first applied from our distributor trucks onto the pavement it has a brownish color and is a little runny. The tack starts to dry and will change to a shiny black color due to the water evaporating from the emulsion. This is called breaking and it is not as runny.

There is one more physical status to go. At the point of breaking some water is still present at this point. Later on, depending on environmental conditions the exact time will vary but when the entire water content has evaporated the emulsion has “set.” So, by definition it is no longer an emulsion since the water is gone. Anyone who has installed a paving fabric and tried to pull it up after the emulsion has set and the fabric soaked it up the chances of getting it free is slim to not likely.

Riverside Asphalt Services Distributor Trucks

R Model Mack Truck asphalt distributor

Our fleet of asphalt emulsion distributor trucks are set up during the paving season to service paving contractor’s needs whenever they need the work scheduled. The tack is loaded from our tankers that hold an ample supply of tack on site to efficiently supply paving projects in Western Massachusetts. Becket burners keep the material heated to optimum temperature to help the tack break. The spray booms are controlled from the cab so the application is safe and efficient.

The control of each nozzle can produce a pattern as narrow as about an inch to over 12 feet wide and any increment in between. Each job is different and the spray pattern can be adjusted to what pattern is being paved at the time.

A Tack Coat Supplier

Riverside asphalt handles large volumes of tack coat and is also geared to supply pavers with asphalt emulsion in various quantities based on their volume needs. Some of the scenarios we help with are larger parking lot repave projects. We can spray parking lots before paving let it break, block it off and it is ready for paving. This way the efficiency of a spray truck is much better than hand spraying from a tack trailer. Or a truck can be available for a longer period on the job if needed. The job constraints will dictate how the application is scheduled and what it will take on each project.

Tack Trailers filled

For smaller parking lot projects, we can fill on demand tack trailers so that buying quantities of tack in pails and then transfer the tank up and into the trailer is avoided. As anybody knows who has handled much tack the greater the distance from the person handling it and the tack is appreciated since it just wreaks gloves and cloths if it gets on it.

Five Gallon Pails of tack

5 Gallon Pail of Tip Top Tack Coat

Our tack coat is also packaged in 5 gallon pails so it can be handled and stored in smaller quantities. To hand carry on a job site and apply tack as needed in smaller areas like utility cut repairs. The material is “Best By Test” what we mean by this is nothing is diluted or changed from the plant on to the user. It is the same as what is used on the state paving projects.

State of Massachusetts tack coat specifications

For a person, not familiar with state of Massachusetts specifications for tack coat or wanting to confirm what it is we have put together references to the places the specs are listed. The short answer is the state is are calling out Rapid Set -1 asphalt emulsion.

Page subsection specifically SUBSECTION 460.62 Tack Coat page 53 bottom of the page they describe the following.

The requirement of when tack coat should be used is stated as follows “All pavement surfaces shall be tack coated immediately prior to placing each HMA lift. HMA placed over milled surfaces shall be tack coated at an application rate of 0.07 gallon per square yard (0.28 L/m2 ). HMA placed over smooth pavements (unmilled) shall be tack coated at an application rate of 0.05 gallons per square yard (0.2 L/m2 ). Tack coat shall meet the requirements of M3.11.06. The existing surface shall be cleaned of all foreign matter and loose material and shall be dry before the tack coat is placed.”

Basis of Tack Coat Payment

The basis in payment is lined out in section to be “Asphalt emulsion as specified herein to be paid for as tack coat, if required, will be paid for at the contract unit price per gallon under the item for Asphalt Emulsion for Tack Coat, complete in place.

Definition of What Material to Use

In sub section SUBSECTION M3.11.03 Tack Coat. page 212 of the PDF they specify that the tack coat to be used shall be tack coat. The Item is labeled as  d) Tack coat – Asphalt Emulsion, RS-1 when needed, applied at the rate of 0.05 gallons per square yard (0.25 L/m2)

The next section that specifies Tack Coat is is the SUBSECTION M3.11.04 Mineral Aggregate section for SUBSECTION M.3.11.06 Bituminous Materials.

They again call out the tack coat material to be used as the following “Bituminous material for the tack coat on the existing surface, where required and specified, shall be emulsified asphalt, grade RS-1 conforming to M3.03.0.

The details on what they call out for specifications is in the document titled “Massachusetts Highway Department 2005 Quality Assurance Specifications for Hot Mix Asphalt Pavement” The section is M3.D3.0 Asphalt Emulsions. It calls out ”

“These materials shall be homogeneous and shall show no separation after mixing within thiny days after delivery. They shall conform to the requirements of AASHTO-MI40 with the following exception: Viscosity determination will not be required for material sampled at point of delivery.”

Riverside Asphalt Services an Experienced Emulsion Contractor

Since 1989 Riverside Asphalt Services has been applying RS-1 tack coat.  We been learning all the nuances needed to efficiently work as a tack coat application contractor here in Massachusetts. We know what to do and how to go about it on a all sizes of paving projects.  You can sub contract the work to us and focus on the placement of the asphalt. If you have any questions at all regarding this service please call us 781-254-2773 for application details. For the company information, and billing please call the office at 781-320-0913. We hope we can be of service to you and your company.