Porphyry Pavers and Sustainability
Posted by Roger Murphy on Mon, Oct 03, 2011 @ 11:49 AM
Porphyry Pavers
The primary Porphyry paving stone in use today is the product of stratified porphyry. This stone’s first ancient building use was as roofing material in Northern Italy. Porphyry is quarried in vertical stratified slabs or in monolithic blocks. We will focus at a later date on how monolithic blocks get fabricated and the building products that come about from these blocks. Stratified porphyry occurs when there are frequent fractures of tectonic origin or fracturing during cooling in this igneous rock 260 million years ago. These parallel strata, from 1cm to 50cm, make the Porphyry easily worked in open cast quarries. It also contributes to the workability of the stone into a finished product.
Breaking of the stone both at the quarry face and in the production operation
are closely related to the fabric and structure as well as its’ hardness. A characteristic of this type of porphyry is that is splits along natural parallel planes. Of equal importance, it can also be easily split along planes that are perpendicular to the stratification. When the slab of porphyry comes down from the quarry face, it has two natural surfaces that do not need to be reworked. Working pieces by creating four sides through the paver fabrication process instead of six, adds to the low overall impact of these quarries on the environment and the use of energy and water to produce finished and semi finished products.
Once, this stratified porphyry was found only in Italy's Trentino-Alto Adige porphyry platform, but now primary sources can be found in the Puerto Madryn-Chubut area of Argentina and in Mexico’s San Juan De La Paz-Guanajuato region.
Looking at porphyry from a geological point of view makes it easy to understand the qualities of this material and the reasons why it is by far the best for street paving and in general, the building sector. It is a material with an extremely long life and is quarried in a low impact method.
Porphyry's composition determines its high compression strength, resistance to stains, slip resistance, and high freeze/thaw ratings. The stone is the most popular paver inEurope, and is favored for its flexibility in design, beauty, durability and low maintenance requirements. The stone is by far one of the most durable pavers in the world. These materials are available through Milestone Imports - www.milestoneimports.com
