Masonry Magazine October 1994 Page. 15
Paving stones are often chosen only for their aesthetics and disregard the fact that paving stones are a totally functional form of pavement.
Paving stones today are manufactured on a precision mold which guarantees exact dimensions. Many of the paver shapes come with spacing bars along the sides to insure precise joint spacing and also allow the stones to be placed with the use of a mechanical installation machine. Modern pavers have a compressive strength of over 9000 psi, an absorption rate of only three to four percent and are available in a large variety of shapes and colors.
Clay paving stones have been used over the years without many changes, but over the past five-to-ten years the clay brick manufacturers have realized that they haven't enjoyed the increased sales that the concrete pavers have experienced. With an increased market share as their goal, the clay brick manufacturers have developed a variety of clay pavers that are truly innovative. These new products include sand cast pavers, extruded pavers, re-pressed pavers and even pavers with spacer bars, all of which have very consistent and uniform characteristics. The new clay pavers include many new shapes and colors. With the many different modern paving stones that have evolved, the technology for the installation of these products has likewise continued and advanced through the cooperation of industry professionals who have dedicated their efforts to establish standards of both manufacturing and product installation. Paving stones today are currently being used in streets, airports, port authority yards, industrial work areas, drive ways, walkways, and many other areas of indoor and outdoor paving.
Segmental retaining wall systems are a relatively new concept in concrete products that was born in North
SOUTHERN BRICK'S pavers line the streets and courtyards of Underground Atlanta.
America. The earliest wall system in segmental retaining walls as we know them today developed in Canada in the mid-1970's in the form of cast units that were just done in basic molds. From that beginning the many different wall concepts developed into the thirty-plus wall systems that are currently available across the United States and the entire world.
Our most modern retaining wall stones are manufactured on both block and paving stone machines. The stones are produced in precision molds into the different shapes and engineered to lock together with different means.
Stones are dry stacked
The principle behind the different wall systems is such that most walls can be constructed on a compacted roadmix base and without a concrete footing. The stones are dry stacked on top of each other and lock together with pins, clips, or mechanical block design. The various systems can be built to different heights according to their specific engineered design, and many of the systems can be built to heights in excess of twenty feet with the addition of different engineered tie back systems.
The interlocking paving stone and segmental retaining wall industries have been enjoying outstdanding success, thanks to the establishment of stringent manufacturing and product installation standards.
The manufactured retaining wall stones being produced today represent a highly technologically advanced product that eliminates the destruction of forests, offers a much longer serviceable life expectancy and certainly provides beauty for all to enjoy.
Like the interlocking paving stone industry, the segmental retaining wall industry has found extreme sucess from the efforts of industry professionals who helped to establish both manufacturing and product installation standards. Retaining wall systems, from small non-load bearing garden type walls to massive highway projects, continue to become a part of our everyday surroundings.
Both paving stones and segmental retaining walls are a flexible systems that are able to move with freeze/thaw cycles with no adverse effects. They are proven systems that offer many years of functional serviceability and distinct beauty. We will welcome the day when pavers are recognized for their functionality as well as their beauty and become the norm rather than the exception when considered with other forms of pavement.
As industry professionals we are very fortunate to have the availability of a tremendous selection of pavers and wall systems and our own industry installation standards. Both the paving stone and segmental retaining wall industries are in an infancy stage of development here in the United States, but in the years to come you can expect to see a dramatic continued growth pattern.
MASONRY-SEPTEMBER/OCTOBER, 1994 15