Written by Sam Justice, P.E. Building roads, housing, and other critical infrastructure is a great responsibility taken on by engineers, architects and project owners. Ensuring that these structures are safe and reliable for years and decades is of the utmost importance at all stages of design and construction. The Challenge of Maintaining Quality in Construction The design team creates building plans and the associated specification that capture the essence of their vision as they work to write the guiding documents for their project. They make decisions about product types, grades, and take great pains to build into their documents citations of certifications and standards to assure only quality materials are allowed on the site. However, product competition and budget demands are a concern seen in many projects that can challenge the specifications intended to produce the best possible structure. Substandard “or equal” substitutions can be encountered in the critical moments between design, bid awards, and construction. It is up to the specifying engineers and architects to hold their spec in all phases of the process to ensure the right materials and installation procedures are used. The Bidding Process and Material Selection Contractors often produce bids with the materials indicated by the… Read more »
Yearly Archives: 2023
Why Geocells Outperform Geogrids for Road Construction
Geocells (cellular confinement system CCS) offer a more effective and practical 3D design solution to load support challenges than multilayered 2D geogrid efforts. Geocells transfer applied loads instantaneously, delivering practical soil stabilization in a product that is fast and easy to install. How do geogrids work? Geogrids rely on rutting, displacement and lateral movement of the road material to activate the load support reaction of the product. As shown below, failure of the driving surface must occur before the geogrid reacts. As a result, rutting and soil displacement is a prerequisite reality to the system. Since the geogrid is two-dimensional, material not located directly within the plane occupied by the geogrid is free to move, shift and displace. It is essential that geogrids are placed in a flat or a pre-tensioned manner—but that is not practical in a construction environment. It is common to see geogrids unrolled over a prepared grade with an undulating surface. As aggregate is placed over the top of the geogrid, the material kinks and waves, further warping the 2D plane. The geogrid is rarely pulled tight during installation which does not allow full tension under load. Geogrids are difficult to… Read more »
Geosynthetics and PFAS: Understanding the Role of Polymer Processing Aids in Geosynthetics
Written By: Michael Dickey, P.E., Director of Presto Geosystems Like many other industries, geosynthetics manufacturers are navigating the rapidly evolving landscape of new per- and polyfluoroalkyl substances (PFAS) regulations. However, in the case of geosynthetic products, an interesting and seemingly paradoxical question emerges: Is it possible that the same products that have been designed to solve complex environmental problems, and even contain pollutants, could also be a possible contributing source of PFAS? In this article, we explore this question and discuss the historic role of polymer processing aids (PPAs) in the production of geosynthetics. What Does Intentionally vs Unintentionally Added PFAS Mean? Since the discovery of PFAS in the 1930s, these compounds have been widely used in manufacturing operations worldwide—both intentionally and unintentionally. In a recent article published by the American Bar Association, the concept of intentional versus unintentional use of PFAS is discussed, and in the case of the latter, the use of fluorinated PPAS used in thermoplastics processing is highlighted as a well-known unintentional PFAS source. How this concept relates to traditional geosynthetics manufacturing is discussed further below. Eliminating Polymer Processing Aids (PPAs) from Geosynthetics Production of geosynthetic products such as geogrids, geomembranes, and geocells commonly involves sheet… Read more »
Meet the Presto Geosystems Team: Get to Know Lauren
Meet Lauren Armstrong, the newest member at Presto Geosystems, who joined the team in August 2023. Hailing from a small town near Chicago, Lauren has had quite the career journey. She began her career in IT in downtown Chicago, later transitioning to the Fiberglass Reinforced Plastic (FRP) industry, with her persistent passion for business development guiding her every step. Now at Presto Geosystems, she’s learning all about geosynthetics and facing new challenges head-on. Join Lauren as she shares insights from her past experiences, aspirations for the future, and the path that led her to Presto Geosystems. How long have you been with Presto Geosystems? I am pretty new to the crew—I started at Presto Geosystems in August 2023. Can you tell us a bit about your background? I have lived in a small town that is about 50 miles southwest of Chicago for my entire life. While it may not be the most exciting place in the world, I can’t imagine living anywhere else. I attended the University of Illinois at Urbana-Champaign and graduated with a degree in Marketing. My first job out of college was in downtown Chicago at an IT company working as an Account Manager. The idea… Read more »
Addressing Microplastics: How GEOWEB® Geocells Contribute to Eco-friendly Soil Stabilization Practices
Written by: José Pablo George, M.S., CPESC-IT, International Business Manager Microplastics, tiny plastic particles smaller than five millimeters, present a potential hazard to both wildlife and marine organisms. As revealed by a global microplastics database provided by the National Centers for Environmental Information (NCEI) and published by the National Oceanic and Atmospheric Administration (NOAA), plastic is the dominant type of marine debris in the ocean and the Great Lakes. These microplastics, usually originating from single-use, disposable plastics on land, are transported via rivers and wind into global circulation systems where they accumulate. International Measures and Guidelines: A Proactive Response to Plastic Pollution The United Nations Environment Programme´s Intergovernmental Negotiating Committee and Environment Assembly have adopted an international legally binding instrument on plastic pollution to address plastic pollution throughout its life cycle. Given the array of different types of plastics, the Sea Studios Foundation, in conjunction with Earth911.org, the Institute of Agriculture and Trade Policy, the WHO International Programme on Chemical Safety, and the US EPA, has published a Smart Plastics Guide. This guide outlines seven commonly used plastic types and their potential health hazards. There are some plastics (often used for disposable packaging) that are not easily recycled and may contain… Read more »
Ballast Stabilization Using Geocells
The Often Overlooked Importance of Junction Efficiency as a Key Design Consideration A significant number of research studies have been carried out to investigate the benefits of using geocells in railway track bed applications. Combined with an ever-expanding list of successful projects from around the world, the benefits of using geocells in rail ballast stabilization is well-documented. Rail operators understand that durable track geometry starts with a solid foundation, and geocells have emerged as a powerful value engineering tool for reinforcing ballast and sub-ballast layers while optimizing layer thicknesses. Many practitioners may not be aware of the critical role that geocell junctions (both mechanical and internal) play in ensuring that the installed system performs in a uniform and consistent manner. In track bed stabilization applications, non-uniform junction performance can lead to differential settlement and localized subsidence—which in turn can lead to serviceability issues, damage to the overlying structure/pavement, and a reduction in overall design life. In essence, poor junction performance can nullify all the intended benefits of a geocell system. This article will succinctly discuss the different types of junctions present in geocell systems, failure mechanisms and test methods, and the concept of junction efficiency as a performance parameter. Types… Read more »
“Or Equal” Substitutions in Geosynthetics: Evaluating the Contractor’s Proposed Alternative Amidst Global Supply Chain Disruptions & Rising Costs
As supply chain issues and project delays continue to wreak havoc in the global geosynthetics industry, Presto Geosystems has prepared this “reboot” of our tips for evaluating “or equal” substitutions to help you navigate the decision-making process when confronted with a proposed alternative geosynthetic product. According to a recent special feature article from Geosynthetic News Alerts (GNA), more oversight and diligence is needed—now more than ever—as deceptive products and inferior raw materials continue to find their way into global markets. According to GNA “Distributors and installers that place orders in good faith—particularly with overseas vendors—may wind up with rolls of geosynthetics they can’t use, and no wriggle room in compressed delivery timelines to find alternatives or otherwise rectify errors.” To protect against this, GNA goes on to emphasize the importance of vetting geosynthetics suppliers to maintain quality metrics. In light of this, Presto offers this reboot of our five tips for evaluating “or equal” substitutions to help you keep your project on the path to success amidst the chaos. Tip #1: Review Product Datasheets Closely (Be Wary of Disclaimers) Many design professionals tend to focus on the numbers shown on a product datasheet and may even have an implicit trust… Read more »
Conserving Natural Resources Using Geosynthetics
Written By: Cory Schneider, Environmental Scientist, Presto Geosystems Natural resources are finite, or at a minimum, can easily be consumed faster than they can be replaced. As such, the conservation of natural resources is a pragmatic endeavor. Geosynthetics—widely available materials used in construction, civil engineering, and environmental protection—can be useful in promoting the conservation of these resources. When used as intended, geosynthetics can enhance soil properties and reduce the demands placed on natural resources. Types of Geosynthetics Geosynthetics are typically made from synthetic polymers, such as polyethylene, polypropylene, and/or polyester, and are designed to be durable and resistant to weathering and other environmental factors. General groupings of geosynthetics include: geotextiles, geogrids, geomembranes, geocells, erosion control blankets (ECBs), and turf reinforcement mats (TRMs). Geotextiles (permeable) and geomembranes (impermeable) provide separation, while geogrids and geocells provide varying degrees of stabilization and confinement. ECBs and TRMs, made with a combination of natural and synthetic fibers, resist surficial erosion by preventing seed washout prior to germination. Application areas where these geosynthetic materials are used typically include: load support, slope, shoreline, and channel protection, and earth retention. Using Geosynthetics in Load Support Applications to Conserve Natural Resources In load support applications, geogrids, geotextiles, and geocells… Read more »
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