An Introduction to Interlocking Pavers

The Minoans designed the first segmental roadways around 5,000 years ago. The Romans built the first interstate segmental system, which was longer than the new interstate highway system in the United States. Most would agree that paving stones offer the beauty and charm of a “Old World,” but North America often overlooks the strength and longevity of interlocking pavers. This article explains the fundamentals of interlocking pavers, and addresses common misconceptions about pavers.Get info LA Paver and Remodeling Group

It is important to understand that an installation of paving stone is an engineered system; pavers are simply a part of that system. From the bottom up, the components of a paving stone construction are: compacted subgrade (or soil layer), geotextile cloth, compacted base aggregate, bedding sand, edge protection, pavers, and joint sand. Unlike concrete cast in place, the interlocking pavers are a flexible pavement. It is this versatility that enables the transfer and distribution of point load from a truck or car tire to the subgrade through the base layer. The load was distributed over a wide area by the time the load hit the subgrade, so the subgrade will not deform.
Concrete, by comparison, is a rigid pavement. Its simple function is to bridge soft spots in the ground. Poured concrete can crack and break because of the sub-grade loads, shrinkage, soil expansion, and frost heaving. Concrete is one of the most important building materials but poured concrete in place makes a poor paving surface. This is due to its relatively inability to flex and low tensile resistance. Fiber reinforcement and rebar will improve concrete’s tensile strength but cracking and breaking is unavoidable.
Modular paving stones are typically made of precast concrete or kiln-fired clay which is hardened. Properly mounted pavers are interlocked, thus distributing a load on one paver between multiple pavers and ultimately moving it via the base layer. Factors that influence interlock are the thickness of the paver, the form of the paver, the height of the paver, the width of the joints, the pattern of the laying and the restriction of the edges. Most paver manufacturers offer lifetime warranty on professional installation of their products. Natural stone such as Flagstone and Bluestone is not ideal for versatile paving, and is usually placed on a concrete slab with mortar. Since interlocking pavers are joined to sand (instead of mortar), they can be uplifted and replaced cheaply. For example, when work is complete, pavers can be uplifted to access underground utilities and reinstated.
The design of the Paving system is dependent on variables including soil composition, expected load stress, atmosphere, water level, and rainfall. The materials used for foundation and bedding sand aggregates are geographically variable. Soils rich in clay and loam are unsuitable for compaction and can not be used as the base material; a graded crushed stone is substituted in such situations. Proper compaction of the subgrade and base material is essential for a paving system’s long-term performance, and the compacted base depth can exceed 12 inches in vehicular applications. To ensure interlocking and avoid lateral creep, the edges of a paver system have to be restrained. Staked-in plastic edge restraint, precast concrete curb, and cast-in – place concrete are the most common kinds of edge restraint. Sand bedding products include angular sand, fabricated sand, and polymeric sand.