Geosynthetics Hold Key to Sustainable Future of Construction Industry

Feb 04,2020

Geosynthetics engineering has been undergoing radical transformation over several years in manufacturing as well as practical use cases. Abilities of geosynthetics to ensure enhanced performance of structures, and reduce the need for regular maintenance in civil engineering works further upholds their demand within the construction industry. Most importantly, they are increasingly being perceived as the cornerstone of sustainable infrastructure development. As innovative materials and products are coming on stage, the application of geosynthetics in geotechnical engineering continues to reach new heights.

Geosynthetics Replacing Conventional Aggregates in Construction of Roads

Geosynthetics in road construction can address the challenges associated with conventional road aggregates, at the same time, offering benefits of cost-cutting, enhanced performance, and reduced environmental impact. Moreover, they help decrease the width of road embankment layers and promote service life and speed of road construction. However, it is paramount to know the right product and specification for project requirement while making purchasing decisions regarding geosynthetics as they are not a one-size-fits-all approach. For each construction project and application, different specifications are required.

Stabilizing Road System with Geosynthetics

Emissions produced via extraction, transportation, and production of conventional aggregates pose an adverse impact on the environment. As such, construction firms are shifting towards a more sustainable option by opting for various types of geosynthetics including, geocomposites, and geotextiles. Owing to their excellent tensile strength, geosynthetics exhibit greater durability, particularly at lesser thickness, and higher resistance against ultraviolet (UV) rays.

Geosynthetics such as geogrids complement the overall rigidity of the pavement layers. Further, they avoid lateral expansion of the base, increase the confinement, and enhance vertical stress distribution on the subgrade. And these benefits, together, can boost the load carrying capacity of roads by more than 50%.

Unleashing Importance of Geosynthetics in Permanent Filter Applications

There are many geosynthetics which are being used in permanent filter applications. When compared with construction aggregates, geotextiles can developed as per the requirements of specific application, thereby delivering higher consistency during installation. As they are highly durable, they are less prone to separation during handling and placement, which is a usual problem with granular materials.

Geosynthetics ensure sufficient fluid flow throughout the plane of geotextiles. The apparent opening size (AOS) enables water to move freely from geotextiles in tandem with avoiding soil to pass through them. This is because of the smaller dimension of non-woven geotextiles’ AOS than that of finer soil particles.

Geosynthetics Allowing Adequate Liquid Flow Keeping Drainage Performance Intact

Installing conventional drainage solutions such as boulders and stones is a cost-prohibitive affair. Also, they get clogged in due course, thus, diminishing their efficiency. Geosynthetics have emerged as an economical solution for both horizontal and trench drains. They permit for a much thinner drainage layer, without compromising drainage effectiveness, along with a significant drop in installation time.

Non-woven geotextiles, given their high permeability, allow water to pass freely across their plane into the side ditches. This enables adequate flow of liquid without soil loss. Furthermore, geocomposites can do both filtration and drainage functions in road construction projects.

Preventing Base Material Contamination with Geosynthetic Separators

Contamination of aggregate base material with the bottom subgrade soil has been among the main reasons of failure of road systems built over soft foundations. Even a slight degree of contamination can have a negative effect on structural response such as hydraulic conductivity, and shear strength. As a result, it leads to early failure of roadways.

Placement of geosynthetic separators between the aggregate and the subgrade can effectively prevent the mixing of the subgrade and aggregate base material. In fact, in earlier times, the primary objective of using geosynthetics in road construction solely was to perform the application of separation. Geosynthetic separators are an inexpensive way and can assure considerable cost reduction over design longevity of roadways. Of all the geosynthetic types, geotextiles have normally been used for separation purpose.

Reinforcement Geosynthetics Avoiding Cracks in Asphalt Layers

Reflective cracking can occur in new pavement overlays wherein pre-existing cracks are present within the earlier paved roadways. It arises due to bending, and shear stress triggered by recurring traffic loads, as well as by tensile stress caused by heat variations. Reflective cracks propagate through new pavement overlays, as such, make them liable to early failure resulting from moisture penetration.

Reinforcement geosynthetics help mitigate the early formation of reflective cracking either by a single or a combination of functions such as separation, protection and barrier. Accordingly, these reinforcement geosynthetics perform by:

  • creating a layer that enables horizontal strains to make sure that large movements can occur without failure in the range of the pre-existing cracks. This mechanism is called stress absorbing membrane interlayer, and generally consists of bitumen-impregnated non-woven geotextiles.
  • developing tensile strength in the proximity of the crack tip, hence, curbing strain and stress in the bituminous material. This reinforcement mechanism can be performed using steel, polymeric or glass grids.
  • forming a hydraulic barrier to waterproof the road system, in spite of reoccurrence of cracks on the road surface. This function also includes using bitumen-impregnated non-woven geotextiles.

In the present scenario of increasing global focus on the adoption of bio-technical measures, jute geotextiles are grabbing huge attention owing to their umpteen benefits. Among the various components of natural geosynthetics, jute is showing up as a well-suited available fiber that allows customizations in the fabric material to cater to site-specific applications. Like any other product in the construction industry, geosynthetics are in a constant pressure to be on par with market landscape through innovations and ongoing trends.

Geosynthetics are a tipping point in road construction, provided, they are installed, handled and maintained properly. Although geosynthetics are in their earlier days in developing countries, they are garnering significant traction in the construction sector. This growing trend is attributable to the ability of geosynthetics to perform specific functions along with providing practical advantages such as, easy availability, rapid installation, prolonged service life if correctly chosen, and relatively lighter as compared to other construction materials.

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