Geotextile grids are an innovative construction material used to stabilize subsoils. These grids are comprised of high-strength polymer mesh that is permeable, allowing soil particles to interlock within the grid structure.
When buried underground, geotextile grids reinforce and retain weak soils, providing subgrade stability without the need for heavy, expensive concrete or asphalt.
The woven geotextile material resists stretching and deformation, while the openings allow natural moisture and nutrient transfer. Geotextile grids require significantly less construction time and cost compared to traditional hardscape methods. While not as inherently strong as concrete, the tensile strength and friction properties of geotextile grids sufficiently support overlying structures and prevent differential settlement subsidence, pumping, and soil destabilization. When combined with proper soil compaction, these lightweight polymer grids offer an affordable, time-efficient solution for subgrade reinforcement, making them a versatile tool for paving, walkway, driveway, flatwork, site work, and civil engineering projects requiring structural stability.
Concrete is widely used in construction as a structural base material due to its high compressive strength and durability. However, producing and installing concrete requires substantial labor, transportation, and energy resources. When mixed properly, concrete cures into a solid mass as a result of a chemical reaction between the cement binder and water. This creates calcium-silicate-hydrate, glueing together fine and coarse aggregates into a rigid structure. A typical 3000 psi concrete mix has a high density around 150 pounds per cubic foot. To provide an adequate foundation for masonry paving, a 6” thick concrete subbase is often used, requiring over 500 pounds per square foot. With such heavy materials, transporting and manipulating concrete demands intensive equipment and manpower. Concrete transit trucks in the Washington D.C. area generally carry 10 cubic yards, weighing over 25 tons when full.
Moving these massive loads requires a heavy-duty truck chassis and 200-300+ horsepower diesel engine, consuming substantial fuel. With concrete costs extremely high and climbing, the materials alone for concrete are very expensive. Factor in driver wages, fuel usage, and equipment wear – it is extremely expensive to operate these vehicles.
Furthermore, once on site, concrete must be efficiently poured and finished before secondary curing begins. A 3 to 6 person crew is typical for managing the demanding logistics of unloading, wheelbarrowing, screeding, and trowel finishing the concrete, even for small jobs. The coordination and physical labor involved in placing wet concrete before it hardens comes at a significant man-hour cost. Concreting also uses energy and resources in the initial production. The cement alone requires immense heat up to 1500°C (2,732°F) to calcinate raw limestone and clay in a kiln. Overall, concrete’s weight and time-sensitive installation creates substantial costs for transportation, equipment, labor, and embedded energy usage. However, the resulting strength and longevity make concrete an economical foundation over the structure’s lifetime.
Though not directly applicable for masonry pavement subgrades, Department of Transportation (DOT) specifications provide a relevant reference for proper concrete subbase construction. For highway asphalt paving projects, DOTs commonly require a 6 inch thick concrete subbase meeting 3000 psi minimum strength. This must be poured over compacted and stable subgrade soils to minimize differential settlement. Proper concrete proportioning, mixing, placing, consolidating, and curing procedures are outlined to achieve optimal durability. Slump tests confirm appropriate workability for placing without segregation. The concrete must be thoroughly consolidated using vibrators to minimize voids and honeycombing.
Joints are scored at 15 foot intervals to regulate crack control. DOT specifications also dictate an appropriate smoothness and elevation tolerance not exceeding 3/8 inches over 10 feet. Curing must be initiated quickly using membrane compounds or moist burlap to develop strength. Following proper DOT protocols helps ensure the concrete slab resists freeze-thaw damage, provides uniform support, and lasts the pavement lifetime despite heavy traffic loading. Though masonry pavers have lower structural demands than heavy highway use, DOT standards remain a key reference for quality subbase work.
In contrast to concrete, geotextile grids provide a lightweight, rapid stabilization solution for subsoils supporting masonry paving. These polymer grids weigh just ounces per square foot, rather than hundreds of pounds for concrete. Geotextile rolls are easily transported in light trucks without excessive fuel consumption, using less than 50 horsepower engines. Installation also requires minimal manpower to unroll and secure the grids before backfilling with compacted soil. The porous woven material even allows in situ soil stabilization, avoiding excavation costs. Despite its light weight, high-strength geotextile with sufficient tensile modulus can provide comparable load distribution and stiffness as a concrete base. Engineers calculate the subgrade California Bearing Ratio and required increase in bearing capacity, then specify an appropriate geogrid strength and depth. Though not inherently as strong as solid concrete, the friction interaction between the grid and interlocked soil particles provides significant stability. Geotextile installation rates exceed 1000 square feet per man hour, drastically lower labor than necessary per square foot of concrete. With material, hauling, and construction costs roughly 1/4 that of concrete, geogrids offer engineers a rapid, resource-efficient subgrade stabilization solution prior to masonry paving.
In summary, proper structural design and construction techniques are essential to ensure that patio and masonry paving and other building elements can withstand lateral and compressive loads, and other environmental conditions, thereby ensuring the safety and stability of structures and paving in Washington DC and beyond.
Use a contractor who understands and cares about doing things right. Always, feel free to reach out to us here at Dupont Decks and Patios. You can find us online at https://dupontdeckspatiosdc.com/ and you can email us there as well!
