Setting the Application – Right
By: Eric Reimschiissel
A typical asphalt seal coat material is usually classified as a mineral filled asphalt emulsion or clay based mineral filled asphalt emulsion seal coat. Some names like clay based, clay emulsion or high mineral, mineral filed asphalt emulsion are asphalt seal coat applications and not true asphalt slurry seal seals. Seal coats are typically machine squeegee applied and thinner seal coat materials are spray applied. The existing asphalt surface is covered with a thin coating of sealant material.
A true asphalt slurry seal material is an RTC, Clark County, City of Las Vegas, City of Henderson specification material. Asphalt slurry seals are applied on millions of square yards of residential streets in Southern Nevada, by far, more than asphalt seal coats. Asphalt slurry seal is the most versatile and cost effective way to preserve and protect your asphalt paving investment. Over time it will significantly extend the life of existing pavements by protecting the asphalt surface from the effects of aging, the environment and the hot summer suns destructive rays and most importantly add a surface for the elements and traffic to wear on instead of the existing asphalt dense grade.
Slurry seal is a mixture of latex modified asphalt, rock aggregate, fillers and other component materials machine applied on the asphalt pavement surface with a spreader box. The asphalt slurry seal has three classifications and rock sizes, Type 1 which is a 1/8 inch minus aggregate, is applied to newer residential streets and parking lots in good condition, Type 2 which is a 1/4 inch minus aggregate is applied on older residential streets and collectors and a Type 3 which is a 3/8 inch minus aggregate is a high traffic highway application.
Slurry seals last much longer that seal coats. Do not let some ones marketing efforts to sell seal coating convince you otherwise, it is not true. Seal coat materials that are squeegee applied are about 2 -3 lbs. per square yard whereas a Type 1 slurry seal is 10 lbs. per square yard or more and a Type 2 is 12 lbs. per square yard or more. Commons sense tells you that fine mineral seal coating applied at 2 lbs. will not last as long as an application of rock and asphalt slurry seal at 12 lbs. Slurry seals actually provide a new surface of asphalt on the pavement. The new asphalt slurry surface is not comparable to a 2 inch thick hot mix overlay but can provide an aggregate surface to fill voids etc. and provide a wearing surface on the street which seal coating cannot.
Seal coating applications do not last as long as slurry seal but the initial seal application will look nice with a uniform dark black color. Slurry seal applications are similar to regular asphalt application that are not as black and will turn gray with time just like our typical roadways. Slurry seals are somewhat irritating due to the shedding of some fine aggregate in the short term. There are some tradeoffs of appearance for a slurry seal application that will last over 3 times as long as a seal coat. When considering an asphalt pavement application consider the cost over the life of the asphalt pavement surface and really what is best for the condition of the pavement.
In summary, it is our goal to educate and provide information. Our goals are providing the “Right Treatment, on the Right Road at the Right Time”. We extend this statement to include the “Right Price” as we all need to consider our budgets with the application we use.