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 »
Posts By: Ashley Beyer
Seven Key Factors to Choosing the Right Geocell
Written by William G. Handlos, P.E. Choosing the Right Geocell Does excellent quality and support matter to you? Of course it does. But, you are smart enough to know that there is no free lunch. Low cost alternatives are less expensive for a reason. So, what do you need to look for to recognize the right geocell for your project? 1. Quality Feedstock Insist upon verifiable proof that your geocell is manufactured only with virgin high density polyethylene. While it is possible to achieve poor weld strength with virgin materials, it is impossible to achieve consistently excellent weld strength unless only virgin high density polyethylene is used. 2. Integral Components Choose a geocell that offers connection components, tendons, stakes, load transfer clips and installation tools that are specifically tailored for the system. Using rope, staples, bent rebars (J hooks) and zip ties that are not specifically designed for use with a geocell engineered solution is unwise and potentially catastrophic. Use only designs that recognize the critical nature of these components to the overall success of the project. 3. Experience and Warranty Choose a manufacturer who has thousands of projects and decades of experience. It is shocking how little some manufacturers… Read more »
A Simple Question
How long does it take to install? It is a question we hear every day. When it comes to cost and installation rates for geosynthetic construction products, there are no simple answers to what seems like simple questions. In fact, beware of those who try to simplify determination of installation costs for their products with quick answers or charts and tables to determine construction rates. Experienced project managers and site supervisors of the crews charged with installation are in the best position to estimate productivity rates. They know best their crew’s capability and the characteristics of the site involved. The variables that need to be considered include: Crew size, talent, work ethic and workday length Temperature, precipitation and length of day (sunlight) Experience with product class Size of the project Site Access Site Conditions (see weather) Crew The optimum crew size is important. Too small and you may lose the benefits of assembly line productivity. Too large and you will find that you fall over each other and pay for extra “inspectors”. All crews are not created equally. The familiarity with tools and techniques vary greatly as does the work ethic both between crews and by region and country. Weather… Read more »
Impervious Gravel vs. Porous Aggregate Paving Systems
Written by William G. Handlos, P.E. For two decades, I held the position of City Engineer and frequently had to explain to disbelieving homeowners, developers and elected officials – that gravel driveways and parking lots were not porous. I would explain that for purposes of stormwater runoff, such gravel pavements must be treated exactly as we would concrete and asphaltic pavements. They often bristled at the idea that gravel did not percolate water and were upset to find that their gravel driveway, lots and roadways were assumed to shed 100% of rainwater. So it is with more than a dose of irony that I now have found myself in the position of regularly explaining to local and state officials that aggregate pavements are not necessarily impervious. Stakeholders are so accustomed to repeating the impervious gravel mantra…that they forget to notice that porous aggregate is not the same thing as gravel. I think it is best to start with a primer on the vernacular. A “good” gravel (Image 1) should have 40 to 70% stone, well-graded from 1/4” to 2-1/2” diameter; 20 to 50% sand; and 10% +/- fines. It should resist abrasion, shed water and be capable of being compacted. A… Read more »
Porous Pavement Systems in Extreme Weather
Porous Pavements Customers are always coming up with new applications for our GEOBLOCK® Turf Protection System, but the University of Wisconsin-Madison just took it to another level. In early 2014, their Space Science and Engineering Center purchased the GEOBLOCK® Pavers to aid in staging their ice coring drills in Greenland and Antarctica. The GEOBLOCK System was utilized for two specific applications. The first application was for a footer under the frame of the drill tent(s). This application allowed the weight of the drill tent building to be distributed across the snow’s surface and provide support. Due to the GEOBLOCK System’s rigid design and load transfer tabs, the same characteristics that make it a strong, durable turf protection system, also delivered value over snow. In the second application, the GEOBLOCK Units served as a flooring system inside the drill tent. Researchers liked the grid surface as it provided a non-skid surface and easy installation at sub-zero temperatures (-40°F). The rigid design also wasn’t affected by on-site drilling fluids (due to the non-reactive and inert polyethylene construction). Researchers also capitalized on the light-weight design and reusability. The remote location required air-lifting the material and hand construction. The GEOBLOCK® system proved it can… Read more »
The Market for Lightweight Construction Mats
Written by William G. Handlos, P.E. Lightweight Construction Mats Construction access in soft soils present a common challenge engineers and project managers face while attempting to complete a project on-time and within budget while avoiding scheduling delays and associated costs. These soft soil sites may also be located in remote, difficult to access areas making construction impossible without a good site access system. Popular construction mat systems are made out of a range of materials including timber, laminate, steel and composite mats. They can be effective, but are also costly. They can also put laborers at risk as they require heavy equipment to install. The ideal mat system for access road construction would be designed to have a high utility-to-weight ratio and would deliver an eco-friendly alternative to current technology. A lightweight construction mat system made from high density polyethylene (HDPE), GEOTERRA®, was created by Presto Products in 2003 to meet the needs of major oil and gas companies working in remote areas of the Amazon jungle. Transporting materials to these sites by helicopter precipitated the need for light, yet strong mats for work platforms and roadways. As the first of its kind, the mats capitalize on the sustainable characteristics of… Read more »
800.548.3424
