A Comprehensive Guide on What is Jute Geotextile

Jute is a rain-fed crop long used for sacking and wrapping. Its fibre is strong, absorbent and biodegradable, and those properties have opened up uses well beyond packaging. Jute Geotextile (JGT) is one of them, used in civil engineering, soil erosion control, road pavement construction and riverbank protection.

JGT does many of the same jobs as synthetic geotextiles (geosynthetics) made from petrochemical polymers: separation, filtration, drainage and short-term reinforcement. The difference is that it biodegrades, so it suits jobs where it is needed only until soil and vegetation can take over. Its use in rural roads in India is covered by the Indian Roads Congress guideline IRC:SP:126-2019, on low-volume rural roads using jute geotextiles.

As JGT biodegrades it merges into the soil. On bare slopes it acts as a mulch: it holds moisture, protects seeds and creates a microclimate that helps vegetation recover. This makes it a common choice for bioengineering on exposed soil.

Biodegradability is sometimes seen as a drawback. In practice, JGT typically lasts about two seasons, which is usually long enough for the soil it protects to consolidate or for vegetation to establish. In filtration uses the soil next to the fabric forms its own natural filter layer (a “filter cake”) during that time, so it keeps working after the jute has gone. That is why JGT is used in road construction as well as on slopes.

Geotextiles are technical textiles used to solve soil problems in civil engineering. They are made from synthetic polymers (petrochemical compounds) or from natural fibres such as jute and coir.

Benefits of using jute geotextiles

(i) Jute geotextiles usually cost less than synthetic geotextiles for short-term uses.
(ii) Jute is an agricultural crop, so jute geotextiles break down into the soil and leave no plastic residue.
(iii) They are easy to lay; semi-skilled workers can install them.
(iv) They help turn bare or degraded land into productive, vegetated land.
(v) They reduce the need for repeated repairs on road and railway slopes in problem soils.
(vi) They do not pollute water or air.
(vii) By cutting erosion and silt inflow, they help dams and reservoirs keep their storage capacity at low cost.

Potential application areas for jute geotextiles

(i) Soil erosion control
In the monsoon, rain and runoff strip particles from the soil surface. Erosion is worst on steep slopes, where the protective vegetation has been removed, and wherever the force of rain and wind is greater than the soil’s resistance.

A geotextile laid over the soil holds the particles in place. Jute degrades within a few seasons, so its own erosion-control life is limited, but it does not stop plants growing through it. It helps them establish, and the vegetation then provides the long-term erosion control and slope protection. In this way jute geotextiles help prevent surface slips, reduce soil erosion and add organic matter to the soil.

(ii) Reinforcement
Laid in weak soils, jute geotextiles add tensile strength while they last, which increases bearing capacity and reduces uneven settlement during the period when the soil is consolidating.

Jute geotextiles can help stabilise soils prone to dispersion and shallow rotational slips by taking up some of the tension that would otherwise lead to shear failure. They are also used to support tree planting in semi-arid areas.

In paved roads, the main reinforcement function of a geotextile is lateral restraint of the base course. When traffic loads the road surface, the base aggregate spreads sideways, away from the wheel. That lateral movement creates tensile strains at the bottom of the base and leads to vertical strain, which shows up as permanent rutting in the wheel path.

With a geotextile at the bottom of the base, friction develops between aggregate and fabric when the base tries to spread, and the geotextile is put in tension. The stiffness of the geotextile limits the lateral strain in the base near it. The result is less lateral spreading of the base aggregate and less rutting at the surface. With jute, this benefit lasts while the fabric is intact, by which time the subgrade beneath has usually consolidated and gained strength.

(iii) River & canal bank protection
Jute geotextiles protect hill slopes, road and railway embankment slopes, bridge approaches, reservoir slopes, viaducts and the banks of water bodies. Their flexibility and permeability let water flow across them, which suits riverbanks and embankments exposed to floodwater. Because jute degrades fastest when constantly wet, banks in permanent contact with water usually need a planting scheme or a longer-lasting coir or synthetic layer to take over. On these slopes the fact that jute leaves nothing behind in the water is a real advantage.