Jointing

Pavement Design Engineer:
Michael Davy
321-432-1489
email: mdavy@rinker.com

Concrete is unique in that immediately after laying it, the structure must be jointed (cut) into smaller units to function properly. Concrete pavements need these joints to maintain their ride quality, good looks, and structural soundness over their design life.

These guidelines will help ensure a successful concrete paving project.

Prepare a jointing plan. This plan should indicate the location and each type of joint in the pavement.

Prepare jointing details. The paving contractor must know how to build the joints before starting construction. Jointing details should be included in the construction drawings.

Determine if joint sealants are necesary, and if so, what type. Sealant selection should be based on traffic and environmental conditions. For light duty parking lots in clean areas, sealants may not be necessary. For heavy trucking facilites in cold climates, sealants are a must.

Think about the edges. Pavement stresses are highest at the edges. Details for integral curbs or thickened edges should be considered to provide the necessary support around the perimeter of the pavement. Consider these areas in the jointing plan as well.

Cut panels should be square

Joints should be cut radial to curves at the pavement edge

Joints should intersect at 90° angles

Jointing Tips

Designing a jointing plan for a pavement application is more of an art than a science. An ideal jointing plan should be economical to build, provide sensible locations for the pavement to crack, and look good.

• Cut panels should be square
• Joints should be cut radial to curves at the pavement edge
• Joints should intersect at 90° angles
• Spacing between joints should not exceed 15 feet

A sound jointing plan can help a concrete pavement reach its full design life. On any concrete paving project, the jointing plan should be designed in conjunction with the pavement geometry. This will allow the designer to identify any difficulties in jointing prior to construction.

Why Saw Cut?

One guarantee of concrete is that it will crack; joints provide a controlled location for that crack to occur. Saw cuts provide a perfect way to tell the concrete where to crack by creating a plane of weakness in the concrete. Other methods such as tooling or inserting a premolded filler strip may be as effective in controlling the crack, but are not as economical as sawing.