By Richard Bodie, Vice President Commercial Sales Pavestone Company

Permeable pave stone systems can provide a high traffic pavement, reduce stormwater runoff and improve stormwater quality. Photos courtesy of Pavestone

In the past, the landscape industry has predominantly based its product and service offering on plant materials?EUR??,,????'??? installation and their subsequent maintenance. Along with the installation of trees, shrubs and ground cover plantings, occasionally came a need for a either a bed edging or for a retaining wall structure. What was originally an occasional ?EUR??,,????'??non-green?EUR??,,????'?? requirement for landscaping contracts has now grown into a multi-million-dollars industry.

Enter today?EUR??,,????'???s world of ?EUR??,,????'??hardscaping.?EUR??,,????'?? Hardscape, which was once handled by stone masons, has now become the normal trade for today?EUR??,,????'???s full-package landscape firm.

The introduction of new stone color blends along with the increased variety of shapes delivers a more aesthetically pleasing and natural stone look to residential and commercial wall installations.

Generation One

Two major elements of the hardscape offering are segmental retaining walls and pave stones made of concrete. As any product is introduced, used and evaluated, a predictable product life philosophy emerges. Segmental concrete retaining walls and pavers are no exception. While these products have not reached a ?EUR??,,????'??commodity?EUR??,,????'?? status, there has been a categorical evolution of product types. The original wall products were basically one size fits all. The paver products consist primarily of rectangles, squares and various interlocking shapes. In some circles these original products have earned a title of ?EUR??,,????'??Generation One?EUR??,,????'?? category products. These products have and continue to serve the industry with the majority of sales and customer satisfaction.

Four distinct shapes that can be modulated together to create a variety of design possibilities?EUR??,,????'??+either a random or set pattern?EUR??,,????'??+are used in this project. Some manufacturers provide up to six stone variations. With a compressive strength greater than 8,000 psi and a water absorption maximum of five-percent, these stones can be used for either a patio or driveway.

Generation Two

As with any product proliferation, the evolutionary process continues and now a ?EUR??,,????'??Generation Two?EUR??,,????'?? category product has materialized. These products consist of Generation One products with a new twist as well as expanded product multiple piece counts and increased dimensional scales. The primary divergence has been the introduction of the tumbling process. Tumbling is an additional manufacturing process that ?EUR??,,????'??antiques?EUR??,,????'?? the product appearance by distressing the surface and edges. The architectural finish emulates the old world character that designers, contractors and end users alike have been fabricating into their landscape already. The newer Generation Two also offers an expansion of shapes, colors and textures not seen before in the previous product lines. This overall Generation Two product progression fastens the use of concrete segmental walls and pave stones use in future landscape design packages.

Tumbling is an additional manufacturing process that ?EUR??,,????'??antiques?EUR??,,????'?? the product appearance by distressing the surface and edges.

Different Dimensions

Concrete segmental retaining wall shapes consisted primarily in a six or eight inch vertical height, 18 inches in horizontal dimension and have been 12 to 24 inches in depth. They have been manufactured with a split either in a convex or straight manner. Overall, the facing of the product was and is an assembly of identical shapes in appearance. These Generation One ?EUR??,,????'??single?EUR??,,????'?? shape products have been and currently are the mainstay of concrete segmental retaining wall structures due to the ease-of-installation of pinless/mortarless systems and low-maintenance factor. As with the entrance of Generation Two segmental retaining walls come into view, there are many stirring changes to note. The most notable difference is the introduction of multiple sizes ?EUR??,,????'??? both in vertical and horizontal dimension. What was once a fascia of consistently sized units is now a combination of horizontal and vertical units that modulate together. This departure from a uniform sizing bestows an entirely new look and feel for concrete segmental retaining walls. When you add the tumbled appearance, a whole another aspect of design capability for the landscape designer, the contractor and end user comes to life. The introduction of new stone color blends along with the increased variety of shapes delivers a more aesthetically pleasing and natural stone look. These new systems are attractive and affordable structures for both residential and commercial applications.

An additional new trend of pave stone products that fit into the Generation One and Two philosophies are the permeable or porous concrete pavers. Originally turf block products ?EUR??,,????'??? open cellular grids ?EUR??,,????'??? have been successfully used for slope surface stabilization, overflow parking and even fire lane pavements. The products are capable of providing a pavement and a greenbelt solution for various site work treatments. Although they are somewhat limited in use due to the fact they are not intended for high traffic applications. As a result, the introduction and use of permeable paver systems ?EUR??,,????'??? paving units with small geometric surface voids ?EUR??,,????'??? are fast becoming a component of stormwater control best management practices. Now is it not only possible to mitigate stormwater run off quantity but the also product?EUR??,,????'???s water infiltration, according to research, reduces the amount of pollutant load previously in the raw stormwater. These pave stone systems (an engineered pavement section) can provide a high traffic pavement, reduce stormwater runoff and improve stormwater quality.