Colorful concrete pavers have begun to change the part of America on which people walk and ride. They are suitable for entryways, garden paths, patios, and swimming pool aprons. They are also being specified for urban redeveloment areas, historic restorations, city parks and plazas. These interlocking paving units provide an excellent cosmetic touch, but there are practical reasons as well why concrete pavers are gaining in popularity. Durability is one. Pigments are thoroughly dispersed throughout the strong concrete during mixing, and the color resists chipping, washing away and fading. Each unit securely interlocks with those around it, so no mortar or other binder is needed in laying the pavers.
Because there is no mortar or binder, pavers can easily be removed to gain access for repair or relocation of underground utility lines. When the service work is completed, the original stones can be readily replaced without regrouting or patching. The non-bonded friction joint between pavers permits drainage, eliminating ponds of water on the surface. It is also reported that there are no cracking problems because the pavers, which average about 5x9 inches in area, move independently instead of as a monolithic mass.
A solid, well-drained base is essential to good performance of the pavers. Differing soil and drainage conditions must be considered, and any applicable local codes and specifications must be complied with. If the existing soil is unsatisfactory, it must be excavated and a backfill of compacted dense aggregate installed. After the base is prepared, a layer of 1 « to 2 inches of sharp normal weight sand or limestone screenings is placed and leveled as a base for the paver stones. The pavers are then set in place by hand with open joints between them. Some specifications limit the joint width to 1/8 inch. Next the pavers are tamped with a mechanical vibrator until they are uniformly level, true to grade, and free of movement. This vibration forces sand into the crevices between the pavers, wedging them tightly together.