Improvement Projects
Click on the links below for information on specific projects.
Road & Drainage Improvement Projects
The Engineering Division manages a variety of projects in it's long term Capital Improvement Program (CIP).
Roadway Resurfacing
County Roads are resurfaced annually as part of the Prescription for Progress road improvement program. The resurfacing projects include dirt and gravel road paving, pavement recycling, full-depth patching, surface treatment, chip seal, and conventional asphalt overlay. The 2001-2002 resurfacing contract pioneered the use of rubberized asphalt overlay on selected roads. Roads are selected for resurfacing based on pavement condition evaluations by geotechnical consultants. Roads with the lowest Overall Condition Index (OCI) are added to the paving list. The type of resurfacing option(s) to be used on selected roads is determined after further investigation of the existing pavement thickness, subgrade condition, traffic use, and other factors.
Resurfacing Options
A number of methods and processes are used for resurfacing County roads. Listed below are descriptions of some of the methods and processes.
Pavement Recycling
Pavement recycling in its simplest form involves milling the existing asphalt, mixing the milled asphalt with a binding agent, and compacting the mixture by rolling. A significant advantage of the process is that it saves on raw material costs. The process is well-suited for thin or average depth asphalt roads with extensive alligator cracking, which are not suitable for full-depth patching. There are two methods; Cold Process recycling and Hot In-Place recycling. The cold process recycling method uses cold binding agents or emulsions; this method usually requires a couple of weeks after milling and compacting for the road to set up. The hot in-place recycling method employs an extensive system of heaters, milling heads, spray bars and screeds which remove and replace up to 2" of asphalt surface in a continuous process. At the present time, the County only uses cold-process recycling.
Full Depth Patching
Full-depth patching refers to saw cutting and replacing segments of the existing pavement to its full depth, as opposed to an overlay which only replaces the top portion of the pavement. One of the most important steps in the patching process is to provide a weatherproof seam. This is done by saw cutting a clean edge and applying liberal amounts of asphalt tack to the face of the joint or laying a geotextile fabac before paving. Full-depth patching is done on roads that are in relatively good shape except for isolated areas which need patching.
Surface Treatment
Surface Treatment refers to the application of a geotextile fabric to increase the shear strength of the overlaid surface. The fabric helps to reduce a condition known as reflective cracking in thin asphalt overlays. It is commonly used for roads which are to receive a thin asphalt overlay but which have widespread, moderate cracking (not severe enough to warrant recycling). The process begins with a binding agent being applied to the road to anchor the geotextile fabric. After the fabric is laid and the binding agent is set, (This takes approximately 24 hours), the road receives a surface coat of 1-1/2" to 2" of asphalt.
Surface Treatment
Surface Treatment refers to the application of a geotextile fabric to increase the shear strength of the overlaid surface. The fabric helps to reduce a condition known as reflective cracking in thin asphalt overlays. It is commonly used for roads which are to receive a thin asphalt overlay but which have widespread, moderate cracking (not severe enough to warrant recycling). The process begins with a binding agent being applied to the road to anchor the geotextile fabric. After the fabric is laid and the binding agent is set, (This takes approximately 24 hours), the road receives a surface coat of 1-1/2" to 2" of asphalt.
Chip Seal
Chip seal is sometimes employed as a maintenance measure to prolong the service life of a roadway or to enhance vehicle traction. However, it is not intended as a replacement for more effective and long-lasting repair methods since the process does nothing to improve the structural qualities of the roadway. The first step in the chip seal process is the application of hot liquid or cold emulsion binding agent to the roadway surface. A thin layer of crushed stone is then applied to the binder. Traffic over the stone layer helps to anchor the stone, although motorists usually complain during the first week or so about excess stone coming off the road as they drive on it.
Rubberized Asphalt Overlay
Rubberized asphalt technology holds promise for enhancing the structural qualities of asphalt while also providing a way to recycle tons of discarded tires. In its upcoming 2002 paving program, the County will be using a new process administered through the Asphalt Rubber Technology Service (ARTS) by Clemson University to produce and install a 2" thick rubberized asphalt overlay on approximately 4 miles of roadways. For more information about ARTS, go to www.ces.clemson.edu/arts, or telephone them at (864)-656-6799. The e-mail address is arts@ces.clemson.edu