Performance comparison of conventional biplanar and low-cost alternative geocomposites for drainage

ABSTRACT: Geocomposites for drainage are easy to transport and install in the field. These advantages are particularly important in regions of the world with poor transportation infrastructure and less specialised labour. However, the cost of geocomposites for drainage can limit their use in such regions. In this context, alternative materials can be used for the production of low-cost and environmentally friendly geocomposites for drainage. This paper compares the performance of some types of conventional biplanar low-discharge geocomposites and alternative geocomposites in transmissivity tests. The conventional geocomposites had a geonet or a geospacer as drainage core, whereas the alternative geocomposites had drainage cores made of bottle caps or tyre strips. The results showed similar performance for conventional and alternative geocomposites. It was also observed that for the discharge capacity of the geocomposites, a sand layer over 0.8 m thick would be required in most cases for normal stresses up to 100 kPa and under confined flow conditions. The results validated the use of alternative core materials, which may reduce the cost of geocomposites for drainage, particularly in regions where these products are not available or are expensive.