Development of New Jute Geotextiles for Use in Roads Ghosh Mahuya1, Pal Ayanjyoti, Uma1, Sarma Sankar1, Rao G. Venkatappa2, Banerjee Prabir K.3 1Indian Jute Industries’ Research Association 2Advisor, MoT Sponsored R&D Project: “Development of Standards for Use of Jute Geotextiles (JGTs) in Rural Roads” at IJIRA and Former Professor and Head, Dept of Civil Engineering, IIT, Delhi 3Former Professor and Head, Department of Textile Technology, IIT, Delhi Online published on 8 April, 2019. Abstract This research paper describes parts of two separate research works carried out for development of new types of jute geotextiles (JGTs) for road applications. The first part is on the laboratory-based pavement model study incorporating JGT as ‘separator’ geotextile for rural roads. Loading tests on the pavement model tanks were carried out to evaluate the performance of three types of jute geotextiles (JGTs), viz., (i) grey JGT, (ii) rot-proof treated (IJIRA developed formulation) JGT and (iii) jute-polypropylene (PP) blended geotextile laid in between a modelled Wet Mix Macadam (WMM) layer and the subgrade layer. Three different types of subgrade soils were selected from different geo-climatic regions of India including Black Cotton Soil. Model tank preparation was carried out by selecting judiciously some combinations of JGT and type of subgrade soil based on the outcome of a preliminary experimentation on biodegradability test of these JGTs in the mentioned types of 100% saturated soil media. Model tanks are water cured for different durations up to six months before testing to study the time-dependent behaviour of the pavement models. Test results clearly indicate that there is significant 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 that jute-PP blended JGT is most effective in improving two layer model pavement system. In the second part, two design concepts of developing 100% jute-based asphalt overlay (A/O) fabric suitable for mitigating reflection cracks in low traffic road are described. In the first approach, a lenobased construction (responsible for ‘reinforcement’) combined with plain woven portions (act as ‘asphalt absorbent’) was selected for the purpose. Comparative in-situ performance of the newly developed jute asphalt overlay (JAO) fabric within pavement and other two commercial A/O fabrics with different constructions was studied. Both the dry and hygrally treated samples of asphalt concrete beams (ACBs) with and without A/O fabrics were subjected to accelerated cyclic mechanical loading simulating the vehicular traffic. A comparison of crack propagation established the efficacy of JAO though it is weaker in respect of strength and modulus than one of the commercial A/O fabric used. An analysis of the fabrics exhumed from the tested ACBs revealed that JAO having grid like structure with suitable opening size help in creating proper interlocking among aggregates of the overlay and voids of the old pavement surface across the fabric within pavement and thereby the two layers of the pavement acts as a single body which resists crack growth much better beyond its level than sheet like A/O fabrics. To overcome a few constructional limitations of JAO, another structure, namely, Mod JAO was developed which was basically a leno woven jute grid and needed to be attached with a layer of very light weight jute non-woven fabric. Mod JAO showed much better mechanical properties than JAO due to better yarn strength realization. Evidently, it is expected that it would perform more efficiently inside pavement than JAO. Top Keywords Jute Geotextiles (JGTs), rural road, biodegradability, pavement model test, stress-strain behaviour, Asphalt overlay fabric, asphalt concrete beam, leno weave, plain weave, grid like structure, cyclic mechanical loading. Top |