Maryland MDOT Geotextile Fabrics

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

Maryland MDOT - Geotextile Uses

Separation and stabilization. On new lanes, shoulder widenings, and rehab projects, a woven geotextile is placed between native soil and granular base. It keeps fines from pumping into the aggregate under traffic, spreads loads, and preserves base thickness—critical on soft, saturated subgrades along the Chesapeake Bay and in flood-prone river valleys. Where subgrades are very weak, crews roll out fabric to create a working platform so trucks and pavers don’t punch through during staged construction; on extremely soft areas, it’s often paired with geogrid for added stiffness.

Filtration and drainage. Water drives many failures in Maryland: nor’easters, tropical remnants, spring snowmelt, and tidal backwater push moisture into the structure. Nonwoven geotextiles line underdrain trenches, wrap perforated pipes, and separate drainage stone from surrounding soils behind retaining walls and abutments. Matching pore size and permittivity to local soils—tight Piedmont clays versus cleaner coastal sands—lets water move while fines stay put, reducing clogged outlets, wet spots, and shoulder drop-offs. In freeze–thaw zones, a nonwoven over open-graded aggregate also forms a capillary break, limiting upward moisture that softens base layers in winter.

Riprap underlayment and scour control. Where flows concentrate—culverts, outfalls, stream realignments, tidal channels, and riverbanks—geotextiles serve as underlayment beneath armor stone. A robust nonwoven filter goes on the prepared slope before riprap. It prevents underlying soil from piping through rock voids during high velocities, storm surge, and drawdown, helping the rock “lock in” and protecting embankments at bridge approaches, causeways, and shoreline revetments from the Potomac to the Eastern Shore.

Structures and MSE walls. Maryland corridors contain extensive mechanically stabilized earth (MSE) walls and grade separations. Geotextiles act as joint and face filters 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 structural penetrations, where a filter layer keeps weeps working and fascia clean without trapping water.

Pavement interlayers. Asphalt-impregnated nonwoven geotextile placed beneath overlays improves waterproofing and slows reflective cracking—important on high-volume commuter routes subjected to deicing salts, wide day-night temperature swings, and heavy axle loads. On chip seals, paving fabrics limit water intrusion into the base and subgrade, extending service life with minimal added thickness.

Temporary erosion and sediment control. Geotextiles appear in silt fence, curb socks, inlet protection, and ditch checks. They filter runoff while trapping fines—vital for stormwater compliance in urban work zones, steep cuts, and long medians. At project entrances, stabilized construction exits typically include a nonwoven geotextile under coarse rock; the fabric spreads wheel loads and prevents stone from punching into wet soils, reducing track-out onto public roads.

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

Field practice. Performance hinges on basics: prepare subgrades smooth, avoid wrinkles, overlap or sew seams as required, anchor with pins or the first lift, and cover promptly to limit UV. Selection is function-driven—woven for stabilization and tensile capacity; nonwoven for filtration, drainage, and protection—tuned to Maryland’s soils, hydraulics, and traffic demands.

Bottom line: on MDOT projects, geotextile isn’t “landscape fabric.” It’s a purpose-chosen engineering layer that stabilizes soft ground, controls water and fines through coastal storms and freeze–thaw, protects structures and channels, and extends pavement life statewide.

Maryland MDOT