Geosynthetics are synthetic products used to stabilize terrain. They are generally polymeric products used to solve civil engineering problems. This includes eight main product categories: geotextiles, geogrids, geonets, geomembranes, geosynthetic clay liners, geofoam, geocells and geocomposites. The polymeric nature of the products makes them suitable for use in the ground where high levels of durability are required.
According to marketsandmarkets.com, states that Geosynthetics Market is worth $15,403.7 Million by 2019. The geosynthetics market is segmented into six types: geotextiles, geomembranes, geogrids, geofoams, geonets and other. It is expected to show high growth owing to evolving environmental protection regulations and standards to boost future growth of geosynthetics. The market for geosynthetics is projected to reach $15,403.7 million by 2019, growing with a CAGR of 10.99% between 2014 and 2019. North America dominated the geosynthetics market in 2013. Asia-Pacific is projected to gain the major market size by value by 2019.Geotextiles is the major type of geosynthetics accounting for around 58% of the market in 2013, followed by geomembranes Geotextiles held the major share in the geosynthetics value market in 2013 and would remain the largest shareholder till 2019. The geomembranes held the second largest share for the geosynthetics market value, and projected to grow with a healthy CAGR, from 2014-2019.
According to futuremarketinsights.com, Geotextiles are anticipated to record substantial growth over the course of the forecast period because of their various applications, particularly in the construction industry. Furthermore, several local players have begun to offer application specific grade and size of geotextiles that could fuel the growth of the global geosynthetics market. Geotextiles had a market share of more than a third in the geosynthetics market in 2017 and this is predicted to rise to almost 40% by end 2027. Geotextiles are on track to gain a massive 390 BPS by then, at the expense of all other product types barring geogrid. The relatively lower cost of geotextiles compared to other products available in the geosynthetics market definitely works in their favour. The geomembrane segment has a volume share of 21% of the global geosynthetics market and is estimated to push past a value of US$ 6 billion by end 2027. Companies would also be advised to target the geogrid segment as they are used for both asphalt reinforcement and soil stabilization. Large construction activities in emerging economies such as Mexico and Brazil is poised to increase demand for geosynthetic products during the course of the forecast period. The Latin America geomembrane segment is expected to be worth US$ 125 million in 2017 alone.
www.gminsights.com reports that increasing demand for geotextiles based synthetic polymers including polyamides, polyesters, polyethylene and polypropylene in construction application owing to its cost-effectiveness and superior properties such as porosity, tensile strength, flexibility, compatibility and permeability should stimulate geosynthetic market demand. Global construction spending may exceed USD 12 trillion by 2024. Rise in infrastructure spending in India, China and Indonesia coupled with favourable regulatory norms pertaining to the usage of geotextiles based natural fibres such as jute and coir in promoting vegetative growth and mitigate soil erosion should enhance geosynthetics market demand.
Types and application
Geotextiles form one of the two largest groups of geosynthetics. They are textiles consisting of synthetic fibers rather than natural ones such as cotton, wool, or silk. This makes them less susceptible to biodegradation.
Geogrids are used to prevent sliding on long and steep slopes during installation and use of a landfill capping system. Geogrids represent a rapidly growing segment within geosynthetics. Rather than being a woven, non woven or knitted textile fabric, geogrids are polymers formed into a very open, gridlike configuration, i.e., they have large apertures between individual ribs in the transverse and longitudinal directions.
Geonets, and the related geospacers by some, constitute another specialized segment within the geosynthetics area. They are formed by a continuous extrusion of parallel sets of polymeric ribs at acute angles to one another.
Geomembranes represent the other largest group of geosynthetics, and in dollar volume their sales are greater than that of geotextiles. Their growth in the United States and Germany was stimulated by governmental regulations originally enacted in the early 1980s for the lining and sealing of solid-waste landfills.
Geosynthetic clay liners
Geosynthetic clay liners, or GCLs, are an interesting juxtaposition of polymeric materials and natural soils. They are rolls of factory fabricated thin layers of bentonite clay sandwiched between two geotextiles or bonded to a geomembrane and impermeable to water.
Geofoam is a product created by a polymeric expansion process of polystyrene resulting in a “foam” consisting of many closed, but gas-filled, cells.
Geocells (also known as Cellular Confinement Systems) are three-dimensional honeycombed cellular structures that form a confinement system when infilled with compacted soil.
Installation of a geocomposite drain. Geocomposite drains are often used on steep slopes of landfill capping systems. A geocomposite consists of a combination of geotextiles, geogrids, geonets and/or geomembranes in a factory fabricated unit. Also, any one of these four materials can be combined with another synthetic material (e.g., deformed plastic sheets or steel cables) or even with soil.
Geosynthetics are generally designed for a particular application by considering the primary function that can be provided. As seen in the accompanying table there are five primary functions given, but some groups suggest even more.
Separation is the placement of a flexible geosynthetic material, like a porous geotextile, between dissimilar materials so that the integrity and functioning of both materials can remain intact or even be improved. Paved roads, unpaved roads, and railroad bases are common applications.
Reinforcement is the synergistic improvement of a total system’s strength created by the introduction of a geotextile, geogrid or geocell (all of which are good in tension) into a soil (that is good in compression, but poor in tension) or other disjointed and separated material. Applications of this function are in mechanically stabilized and retained earth walls and steep soil slopes; they
can be combined with masonry facings to create vertical retaining walls. Also involved is the application of basal reinforcement over soft soils and over deep foundations for embankments and heavy surface loadings.
Filtration is the equilibrium soil-to-geotextile interaction that allows for adequate liquid flow without soil loss, across the plane of the geotextile over a service lifetime compatible with the application under consideration.
Drainage is the equilibrium soil-to-geosynthetic system that allows for adequate liquid flow without soil loss, within the plane of the geosynthetic over a service lifetime compatible with the application under consideration. Geopipe highlights this function, and also geonets, geocomposites and very thick geotextiles. Drainage applications for these different geosynthetics are retaining walls, sport fields, dams, canals, reservoirs, and capillary breaks.
Containment involves geomembranes, geosynthetic clay liners, or some geocomposites which function as liquid or gas barriers. Landfill liners and covers make critical use of these geosynthetics. All hydraulic applications (tunnels, dams, canals, surface impoundments, and floating covers) use these geosynthetics as well.
Tackling flood management
In late July 2018, severe flooding affected the Indian state of Kerala due to unusually high rainfall during the monsoon season. It was the worst flooding in Kerala in nearly a century,in which over 373 people died within a fortnight, while at least 280,679 people were evacuated, mainly from Chengannur,Pandanad, Aranmula, Aluva, Chalakudy, Kuttanad and Pandalam. All 14 districts of the state were placed on high alert. According to Kerala government sources, one-sixth of the total population of Kerala had been directly affected by the floods and related incidents.Thirty-five out of the forty-two dams within the state were opened for the first time in history. All five overflow gates of the Idukki Dam were opened at the same time, for the first time in 26 years. Heavy rains in Wayanad and Idukki have caused severe landslides and have left the hilly districts isolated.The situation was regularly monitored by the Prime Minister and the National Crisis Management Committee coordinated the rescue and relief operations.
In this regard Geosynthetic could have been a great tool to balance this hassle. Geosynthetics offer many benefits over traditional methods of construction in the water industry where structural drainage, flood management, erosion control and soil reinforcement are required. Geo-synthetic materials can be utilized for all stages of construction to strengthen infrastructure by improving road design, preserving water, controlling evaporation, limiting erosion, and enhancing the longevity, resilience and safety of structures. Most importantly, they protect the environment and promote a stronger planet by conserving energy and the earth’s resources through the production of durable and sustainable structures. The benefits of geosynthetics are prominent in the design and construction of all types of roads, highways and yards. Threatened by lateral displacement and weakening of base course aggregate, structures deteriorate prematurely. Geogrids are the ideal option for base reinforcement and pavement optimization, both on weak and stable subgrades. They promote aggregate interlock as well as confinement, increase bearing capacity, and distribute load for-ces, by creating a stable foundation. Ultimately, geosynthetics improve the roadway structure, reduce maintenance cycles and increase its lifespan. Process such as structural drainage and soil reinforcement management a full fledged flood management system could be developed. Creation, repairs and reinforcement of flood embankments which act both as erosion protection against flood water and for flood water storage could be used a tool to tackle this.There had been several case studies across the globe.
Info and Sources
- http://www.abg-geosynthetics.com/ market-sectors/water.html
- Giridhar Techfab Private Limited
- Manufab India