By Bob and George Koerner
This, our 24th annual conference, was a great success, according to the 160 persons in attendance on March 16, 2011, in Dallas, Texas. Inasmuch as it was the last day of the Geo-Frontiers Conference, the topic kept interest high thanks to the 20 authors making presentations of their respective papers.
While the topic of sustainability, per se, was on our minds as a theme for years, it was the issuance and distribution of a report from the United Kingdom under the acronym WRAP (Waste & Resources Action Program), which opened the door to the relative ease of calculating carbon footprints of various construction projects. This report was distributed to GSI members and 12 of them responded with calculation papers comparing the CO2 generated from a traditional (soil-related) solution with that of the equivalent geosynthetic solution.
The other eight papers at GRI-24 were sustainability projects in their own right, all of which are based on a major use of geosynthetic materials.
Papers with CO2 comparisons
Russell Jones of Golder opened the conference describing the background and details of the WRAP report. In it there were several wall, slope, and bund case histories with detailed analyses. (See this paper in magazine format.)
Thomas Egloffstein of ICP Engineering Co. compared a traditional road base with one having geogrid reinforcement, which resulted in a profound CO2 footprint decrease. Richard Goodrum of Colbond presented CO2 calculations with turf reinforcement mats the lowest of three levee armoring alternatives. Garry Gregory of Gregory Geotechnical and Oklahoma State University showed a low carbon footprint case history involving fiber reinforced soil.
George Koerner of the Geosynthetic Institute reported on the carbon footprint of five different drainage pipe materials. Sam Allen of TRI Environmental evaluated carbon footprints of two channel erosion control designs. River dike comparisons were presented via a case history in Taiwan by Wayne Hsieh of the National Pingtung University.
Seven different stormwater retention systems were compared for their carbon footprints by Archie Filshill of CETCO Contracting Services Co. Don Hullings of Jones Edmunds Inc. compared an exposed geomembrane landfill cover to a traditional soil-related one with excellent results. Doug Brown of Tensar International Inc. used the CO2 model to compare earth vs. geogrid reinforced landfill berms.
Christos Athanassopoulos of CETCO compared compacted clay liners to geosynthetic clay liners with results that were highly dependent on natural clay borrow sources. Bob Koerner of GSI revisited exposed geomembrane landfill covers with results similar to those of Don Hullings.
The net effect of these 12 papers was to make 25 comparisons of traditional vs. geosynthetic solutions arriving at the outstanding conclusion shown in the following table. Here, we see that the geosynthetics solutions represent an average 63% reduction in CO2 generated in comparison to traditional soil-related solutions. That’s profound!
That said, sustainability goes further than making a comparison with traditional systems since geosynthetic materials allow for entirely new and different applications. In this regard, there were eight additional papers.
Michael Samuelson of TenCate described the use of recycled fibers in textile itnerlayers for asphalt road resurfacing. Kent von Maubeuge of NAUE described the reduction of climate damaging gases on the environment using geosynthetic solutions.
Archie Filshill of CETCO Contracting used nanocomposites to improve the physical and mechanical properties of recycled polyethylene materials. Allan Wingfield of Colbond described the optimization of sustainability by way of several interesting green roof examples.
Paul Oliveira of Firestone selected several small, unique projects to exemplify the favorable use of geomembranes. Boyd Ramsey of GSE Lining Technology illustrated the reduced CO2 emissions and energy consumption during geosynthetic installation situations.
Michael Ayers of Closure Turf described several case histories of developing final landfll covers using structured geomembranes and sand-ballasted synthetic turf. Lastly, Grace Hsuan of Drexel University illustrated the possible use of geomembranes in algae production (for production of diesel fuel) at landfills.
All 20 papers stemming from this GRI-24 Conference are available on CD from the IFAI Bookstore.
In closing, perhaps the following graphic from Christos Athanassopoulos’ paper on CCL (150 trucks)-to-GCL (1 truck) transportation comparison should become the “poster child” for the use of geosynthetics in the reduction of carbon footprint as we hopefully move into a more sustainable future.