The new norm in asphalt mix and sealcoating
By Jeff Winke
When people talk about living in the “new normal” it is often referred to as the reality of the aftermath period of a major crisis or the result of evolutionary change brought on by technology or different circumstances. The norms and expected patterns are different from what they used to be–thus, a new version of what is known to be normal. Life is different.
In the world of asphalt paving, new normals seem to emerge frequently as new technology and practices change and improve. One area of paving which appears to have experienced a new normal is with additives. Additives have always been seen as something added to enhance or refine. But today, more and more they are a part of the asphalt mix or sealcoat.
“In a highly competitive environment, contractors need to have assurance that the additives they use in their mix designs will add value to the quality of their asphalt mixes, both in terms of added durability and easier constructability,” stated Brad Gibbs, commercial manager with Arkema-Road Science, a division of ArrMaz, Tulsa, Okla. “When they approach a bid situation with greater confidence that the final product will go down without problems, their risk factor goes down and so does the contingency line item on their bid sheet. They have a better chance to win the bid and the agency or owner benefits from the resulting cost savings. Adding additives with proven performance, becomes a win-win for all parties involved.”
Similar concerns for durability and ease of application are found with sealcoating.
Jack Moltz, with Southern Emulsions Inc., Tuscaloosa, Ala., said: “Not all sealcoating projects are the same. The condition of the pavement surface, how the pavement is used, weather conditions, etc. will all play into the decision of what sealcoat to select. The use of additives enables the formulation of sealcoat mix designs to address these conditions and therefore becomes an essential part of the sealcoating process.”
Contractors can use additives as a marketing tool to gain and retain a customer base. By adding around 10- to 15-percent to the material cost, the life of sealcoating is said by experts to be allegedly enhanced by 50-percent or more.
“Sealcoating, like every other product, has a certain limitation of protecting the asphalt pavement,” stated Nihal Pandrapragada, research chemist at STAR Seal, Inc., Columbus, OH. “Additives can be used to go beyond those limitations and boost sealcoating performance in terms of protection and preservation. Today, with the majority of sealcoating contractors using additives, it is no longer an option to exclude the use of additives if you are looking to stay competitive within your market area.
“Additionally, the use of additives becomes imperative while sealcoating in less-than-ideal conditions. Those conditions include challenging weather which can be found in early spring, late fall, or night time when you want to ensure optimum drying and cure.”
For the contractor, there is power in additives… the power of providing greater options that are not afforded otherwise.
“Additives allow contractors to stay more competitive by giving them the power to create flexible solutions, a more controlled job, a higher quality coating, and a better customer experience,” stated Rick Poole, president of Diamond Shield Fortifier LLC, Alexander, Ark. “A contractor can tailor the job for a customer, such as a quicker dry/cure time, a blacker appearance, and increased bonding and resistance all while having more control over the environmental conditions the coating will be placed in. This in turn reduces liability, damage to the coating integrity, and appearance.”
Poole continued: “Many jobs require additives to ensure a successful outcome. For example, night work, projects with super-tight schedules and early or late season work–all of which may not allow for the 24- to 48-hours of cure time.
“Saying ‘Time is Money’ about additive use is cliché, but without an additive to accommodate for the initial cure time of a coating, you must stop and wait to come back another day to finish. Additives greatly reduce this waste of time and resources with fewer trips back to finish jobs. In return more work is completed with the same hours each month, which means more profitability, and less wear and tear on equipment.”
Clearly, additives in sealcoating is designed to help shorten cure time.
“There are several key advantages when additives are included in sealcoats,” stated Woodrow Adams, operations manager at STAR Seal. “These are performance improvements with greater resistance to chemicals, deicing salts, oil, jet fuel, etc. and greater resistance to water and weather elements–as well as improved abrasion resistance. There is, of course, reduced drying time by 25- to 30-percent and uniform drying in less-than-ideal conditions and uniform dry color under shade or direct sunlight. Also, sealcoat additives keep sand/aggregate uniformly suspended in the mix, thus eliminating settling in the bottom of the tank. They help distribute sand/aggregate evenly throughout the sealcoating and produce a uniform textured and streak-free appearance of the finished job.”
Adams added that sealcoat additives provide a number of benefits compared to sealing without:
• Extends sealer durability and longevity
• Improves flexibility to help prevent cracking
• Improves adhesion and cohesion properties of sealer
• Increases resistance to extreme temperatures
• Increases resistance to chemicals
• Increases color retention
• Shortens the time between coats or re-opening to traffic when a fast-drying additive is used
• Adds a degree of cost that may be offset by allowing for a greater amount of dilution
Pavement failures across the nation are visible to anyone who uses our road systems. From rutting to cracking to potholes, poor pavements aren’t just a nuisance, they’re a significant safety hazard.
Gibbs pointed out that additives to the asphalt mix such as adhesion promoters and warm-mix additives are designed to prevent the stripping of asphalt from the aggregates used in the mix, and are designed to provide protection against pavement distresses.
“The results are safer pavements and extended road life, helping to mitigate the potentially dangerous hazards of potholes and rutting, which saves owners and agencies significant money over the lifetime of the pavement. Also, as we become more environmentally conscious, additives that help utilize a higher percentage of recycled asphalt pavement (RAP), are designed to reduce production and compaction temperatures, while helping the road building industry control waste, costs and energy efficiency. When roads are milled up, the ability to reuse the previous pavements on new roads is a tremendous benefit to sustaining our natural resources,” Gibbs said.
“Proven performance additives can be injected directly in-line with the asphalt either through blending at the asphalt terminal or in-line at the mix plant. This direct injection is an alternative to the added hassle, time, footprint, equipment, expense and safety concerns of coating the aggregates with lime dust, and eliminates additional steps in the process to ensure adequate aggregate asphalt coating and adhesion. Also, mixes that are more workable and easier to compact can drive construction costs down by reducing the equipment needed in the field.”
Asked to encapsulate the advantages of additives to pavement mixes, Gibbs named three:
1. Extend the life of the pavement, which saves taxpayers money over the long-term.
2. Create safer roads by preventing potential distresses that cause dangerous driving conditions for motorists.
3. Facilitate improved mix and reduced construction costs, adding value to all stakeholders.
Additives are designed to enhance and strengthen the qualities of both asphalt mixes and sealcoating. In many respects, additives are being expected and a part of asphalt paving and maintenance today. Additives are becoming the new normal!
Jeff Winke is a business and construction writer based in Milwaukee, Wisconsin. He can be reached through firstname.lastname@example.org