Q: I am searching for data or specifications pertaining to long-term degradation resistance of geogrid exposures to cement—more specifically, cement-treated soils. Your assistance would be greatly appreciated.
A: Thank you for your question on geogrid durability in the presence of cement. This is not an issue for most polyolfin (polypropylene [PP] and polyethylene [PE]) geogrids. Such polymers are very resistant to the pozzolanic reaction by-products and the heat of hydration caused by curing cement in concrete. However, this is not the case for geogrids made of polyethylene terephthalate (polyester PET) yarns. A good reference for this is Hsuan and Koerner (2005). It might also interest you that with the rising quantity of plastic waste generation around the world, there has been growing attention regarding the consumption of waste materials in the production of construction materials such as concrete and asphalt. Due to the need and scale of this issue, there is a promising future in the utilization of recycled plastics from both a sustainability and a durability perspective.
Hsuan, Y. G., and Koerner, R. M. (2005). “Evaluation of the hydrolysis behavior of polyethylene terephthalate yarns.” Proc., GRI-18 Conf. on Geosynthetics R&D in Progress, GeoFrontiers, Austin, Texas, Paper no. 1.11.