A basic categorization of concrete curbing choices includes:
1. Common Concrete Curbs:
Barrier or Straight curbs are used along roads that need to keep vehicles from crossing over into a pedestrian walkway or any outdoor area that needs to keep vehicles out of. Basically, they are meant to keep vehicles from going over it without doing possible damage to your car. These are used mostly in high pedestrian frequented areas, and they use the straight up and down edge, 90 degree, because they are less likely to be tripped-over by pedestrians.
Mountable or Roll Curbs are designed to be driven over slowly as the edges are rounded with a sloping curb face. These are used to reduce your vehicles speed, or to bring you up to a higher pavement without damaging your alignment- such as going up a driveway or over a speed bump.
Mower curb a ribbon of concrete designed with a narrow ledge alongside a barrier curb used to border flowerbeds, gardens, and ponds. With one side of the mower’s wheels riding the flat boarder of concrete, one can cut the grass all the way to the narrow ledge with having to use a weed-whip, or causing mower damage, while the upper barrier edge keeps the mower from going into the protected area.
2. Monolithic Curbs:
Monolithic or Integral curbs are designed with the idea that the joints between curbs cast onto concrete slabs cause water penetration, or planes of weakness which results in a shortened life span, meaning fractures, so the need for one smooth transition from curb to sidewalk is realized in the integral curb as no joints appear- just one smooth ribbon of concrete.
3. Decorative Concrete Curbing
Many shapes are possible with decorative curbing using various colors, stamps, additives to the cement- your imagination is the limit. These are used to create a focal point in an outdoor setting or to act as barriers for flower beds, gardens, and ponds. Homeowners can even have a Slanted or Angled curb where the slanted edge is painted a different color than the straight edge of the curb- it is used for purely aesthetic reasons.
Curb Product Mix Design : The concrete mix consists of a standard 3 to 1 mix, 3 parts washed mortar sand, washed sand has a more consistent color, to 1 part Type II Portland Cement. Shrinkage and hairline cracking will be retarded by the addition of half inch polypropylene fiber (Fibermesh) mixed into each batch at the ratio of 1.6 oz per cubic yard. Color should also added in a measured repeatable fashion so there is conformity throughout the curbing in your yard. Residential curbing does not need rebar since it will not have heavy trucks driving over it.
The best method to control random cracking in concrete curbs is to place control joints in the concrete surface at specific locations such as 3 to 4 feet apart to create weakened planes where the concrete can crack in a straight line below the surface joint which leaves a finished concrete surface free of cracks.