Texas TXDOT Geotextile Fabrics

Solmax DOT Standard Specification Product Chart (click image to expand)

Texas TXDOT - Geotextile Uses

Texas projects cross expansive Blackland Prairie clays, caliche-rich alluvium in South and West Texas, coastal sands along the Gulf, and weathered rock in the Hill Country and Panhandle. Add extreme heat and UV, wide day–night temperature swings, hurricanes and tropical downpours on the coast, flash floods in the Hill Country, and localized freeze–thaw up north, and you get subgrades that can swell, soften, pump fines, rut, scour, or collapse when wetted. Geotextiles are the quiet engineering layer that helps pavements, structures, and drainage systems keep performing.

Separation and stabilization. On new lanes, widenings, and staged construction, a woven geotextile is placed between native soil and granular base. It keeps fine soils—expansive clays, silty caliche, and windblown sands—from migrating into the aggregate under traffic, spreads loads, and preserves base thickness. Where subgrades are very soft or moisture-sensitive (utility cuts, coastal lowlands, playa margins), crews often roll out geotextile to create a working platform so haul trucks and pavers don’t punch through. On exceptionally weak or highly plastic clays, the fabric is frequently paired with a geogrid to add stiffness and speed construction.

Filtration and drainage. Water management is critical in Texas, whether it arrives as a slow groundwater rise on the Coast or a sudden Hill Country cloudburst. Nonwoven geotextiles line underdrain trenches, wrap perforated pipes, and separate drainage stone from surrounding soils behind retaining walls and abutments. Matching pore size (AOS) and permittivity to local soils lets water move while fines stay put, reducing clogged outlets, wet spots, and shoulder failures. In colder districts, a nonwoven over open-graded aggregate also forms a capillary break, limiting upward moisture that weakens base layers during cold snaps.

Riprap underlayment and channel protection. Where flows concentrate—arroyos, culverts, storm outfalls, coastal inlets, and river bends—geotextiles serve as underlayment beneath rock riprap or gabions. A robust nonwoven filter is placed on the prepared bed or slope before stone. It prevents subgrade soils from piping through rock voids during high velocities, surge, and rapid drawdown, helping the armor “lock in” and protecting embankments at bridge approaches and channel transitions.

Structures and MSE walls. Across interchanges and urban corridors, mechanically stabilized earth (MSE) walls are common. Geotextiles act as joint and face filters, tucked behind panel or block joints so backfill fines don’t migrate to the face while drainage continuity is preserved. The same concept applies at wingwalls, backwalls, and around penetrations, where a filter layer keeps weeps functioning without trapping water.

Pavement interlayers and seal programs. Texas is a heavy user of chip seals and overlay preservation. Asphalt-impregnated nonwoven geotextile (a paving fabric) beneath overlays improves waterproofing and slows reflective cracking—vital where large thermal swings, high temperatures, and heavy axle loads age pavements quickly. Under seal coats, paving fabrics limit water intrusion into the base and subgrade with minimal added thickness.

Temporary erosion and sediment control. During construction, geotextiles appear in silt fence, curb socks, inlet protection, and check structures, filtering runoff while trapping fines—critical for stormwater compliance on long medians, steep cuts, and urban work zones. At site entrances, stabilized construction exits typically include a nonwoven geotextile beneath coarse rock; the fabric spreads wheel loads and prevents stone from punching into soft or freshly watered soils, reducing track-out and dust.

Liner protection and containment. Heavy nonwoven geotextiles cushion geomembranes in detention basins, lined ditches, salt- and sand-shed pads, and brine containment, protecting liners from puncture by angular aggregate and construction traffic.

Field practice. Performance hinges on basics: prepare subgrades smooth, avoid wrinkles, use proper overlaps or sewn seams, anchor with pins or the first lift, and cover promptly to limit intense UV. Selection is function-driven—woven for stabilization and tensile capacity; nonwoven for filtration, drainage, and protection—tuned to Texas soils, hydraulics, and traffic demands.

Texas TXDOT