Destabilized bituminous bonding layer

Abstract

A method of applying a new surface to an existing surface. The method comprises applying a bituminous emulsion bonding layer to the existing surface; destabilizing the bituminous emulsion bonding layer; and applying a bituminous mixture to the bituminous emulsion bonding layer.

Description

CROSS REFERENCE[0001]Not Applicable.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]This invention relates generally to a method of applying a bituminous mixture to an existing surface, and more particularly, but not by way of limitation, to a method of applying a bituminous emulsion bonding layer and a thin layer of cold-applied bituminous mixture to an existing surface by destabilizing the bituminous emulsion bonding layer immediately before applying the bituminous mixture.[0004]2. Description of the Related Art[0005]It is often desirable to place a new layer on an existing surface, such as a road, to improve the ride and serviceability of the surface. The dominant materials of choice for the construction, repair, and maintenance of roads are hot mix bituminous mixtures.[0006]Hot mix bituminous mixtures are generally produced in a central location and transported to the application site. As any hot bituminous products are transported, they lose heat. If the tempera...

AI Technical Summary

Benefits of technology

The invention is about a method for applying a new surface layer to an existing surface using a bituminous emulsion bonding layer and a bituminous mixture. The bituminous emulsion bonding layer is applied to the existing surface and then destabilized, which causes the layer to separate from the surface. The bituminous mixture is then applied to the destabilized layer, resulting in a new surface layer. The method can be used to create new roads, repair potholes, or seal surfaces. The bituminous emulsion bonding layer can be destabilized using various methods, such as adding a destabilization agent or changing the pH or temperature of the layer. The resulting surface layer has improved properties, such as increased strength and durability.

Problems solved by technology

As any hot bituminous products are transported, they lose heat.

If the temperature of a hot mix bituminous mixture becomes too low, the mixture becomes difficult to handle and place and it becomes difficult to achieve a durable surface.

Thus, there are limits as to how far hot mix bituminous mixtures can be transported.

However, there is an effective upper limit on mixture temperatures, either due to the cost to heat the mixture or the degradation of the hot bituminous product.

Areas beyond the maximum haul distances for hot mix bituminous mixtures have few options for the construction, repair, and maintenance of roads.

Cold-applied bituminous mixtures are much more difficult to apply to a surface, such as a road, than hot mix bituminous mixtures.

The disadvantage to increasing solvent is that it results in a tender mixture until a sufficient amount of solvent evaporates.

Also, solvent emissions produce a negative environmental impact.

Although handling and laydown may be enhanced, however, the ultimate rheological properties of the mixture may be compromised.

The tires of these vehicles tend to adhere to the bituminous bonding layer and transport it to undesirable adjacent areas.

This loss of bituminous bonding layer may degrade the desirable bond between the surface and the bituminous mixture.

A bituminous emulsion bonding layer tends to be extremely slick or slippery when first applied to a roadway.

However, the apparatus of the '578 patent is not as successful with cold-applied bituminous mixtures.

The '578 spray paver does not allow the bituminous emulsion bonding layer to partially or completely dry before application of the bituminous mixture, which is applied within five (5) seconds of the application of the bituminous emulsion bonding layer.

The use of a cold-applied bituminous mixture with the '578 spray paver is more problematic.

This slippage is a result of the high shearing forces required to apply the cold-applied bituminous mixture and the low frictional component of the slick bituminous bond layer.

Thus, cold-applied bituminous mixture may be successfully applied at high application rates, but extra material is costly.

Increasing the thickness of the cold-applied bituminous mixture is valuable for remote areas not suitably served by central bituminous hot mix plants, but the cost of the resulting surface is excessively high.

Additionally, when a cold-applied bituminous mixture is applied while the bituminous emulsion bonding layer is not sufficiently coalesced, the mixture may move under post placement compaction.

This pushing and shoving may produce a surface that is not sufficiently dense and the desired thickness and smoothness may be compromised.

Combining the '578 spray paver with either the '520 patent or the '962 patent does not remedy the application inabilities.

The problem is a combination of the slick bituminous emulsion bonding layer and the stiff cold-applied bituminous mixture, which tends to slide on the slick bituminous emulsion bonding layer.

Applying a greater shearing force to the bituminous mixture only increases the slippage and creates greater tearing of the cold-applied bituminous layer.

The drawback is the excessive amounts of materials that are required to produce a paved surface that can be applied without tearing, shoving, or sliding either during application by a spray paver or by post placement compaction.