Abstract:
This research paper describes a laboratory-based unpaved pavement model study incorporating new types of jute geotextiles (JGTs) intended for low-volume roads under static loading. Tests on the pavement models were carried out to evaluate the performance of four types of JGTs, viz. (1) grey (untreated) JGT, (2) rot-proof treated JGT (using reasonably eco-friendly chemicals) and (3) two types of jute–polypropylene (PP) blended geotextiles laid in between a modelled Wet Mix Macadam layer and a suitably compacted subgrade layer. Three types of subgrade soils were used from different geo-climatic regions of the Indian subcontinent including Black Cotton soil. Model tank preparation was done by judiciously selecting some combinations of JGT and subgrade soil based on the outcome of a fundamental study on biodegradability behaviour of these JGTs in the experimental saturated soils. Model tanks were water-treated for different durations up to six months to keep the subgrade soil and the JGT 100% saturated uninterruptedly before testing to study the effect of time-dependent biodegradability behaviour of the pavement models with and without JGT both. Experimental results clearly indicate that there is a substantial improvement in stress–strain behaviour of the pavement models due to incorporation of any type of the experimental JGTs over control models. The time-dependent model study reveals improvement in stress–strain behaviour of the system in spite of degradation of the JGTs, and jute–PP blended JGT is most effective in improving the pavement models. This indicates that consolidation of subgrade has occurred within a period of 3–6 months.