Mitali Saha Assistant Relationship Manager, Corporate Division
Geotextiles are natural or polymer fabrics which are used in the construction of roads, drains, harbor works, breakwaters, land reclamation, and many other civil engineering purposes and have the ability to separate, filter, reinforce, protect, or drain when used in association with soil. It is made by natural fibers or manmade fibers and can also be created by blending both natural and manmade fibers. It is newly emerging in civil engineering and other fields, which offers great potential in varied areas of applications globally.
Concept and Different Categories of Geotextiles
Geotextiles were originally intended to be an alternative to granular soil filters for which it was also known as filter fabrics. The introduction of geotextiles was established in China and Kerala of this subcontinent. Woven mats made of reeds which were used in Babylonia was actually a geotextile. The mixing type or blending type of geotextiles began during the 1950’s after the invention of polymeric materials. To overcome the soil related problem, technologists thought of making fabrics from manmade materials such as polyamide, polyethylene to improve soil strength and behavior. Netherland was the first country to initiate the development of man–made geotextiles in 1953 through the “Delta” project to save the country from the ravages of floods generated from the North Sea. Other developed countries like the USA started using geotextiles especially to prevent soil erosion. Around the 1960’s manmade geotextiles started to become globally popular.
Types of Geotextiles
Typically geotextiles can be divided into two main categories: Fiber based geotextiles & Fabric based Geotextiles.
1. Fiber based Geotextiles:
Natural fibers have some properties which help in the making of geotextiles. They are collected from plant, animal, and mineral origins. They have high strength, high modulus, low breaking extension and low elasticity. The important natural fibers which are used in making geotextiles are jute, sisal, flax, hemp, abaca, ramie, and coir. Geotextiles which are produced from natural fibers are used mainly for temporary applications as they are biodegradable and of low cost.
The synthetic or man–made fibers used for geotextiles are called geosynthetics. The four polymeric families acknowledged as raw materials for geosynthetics are:
Polypropylene: The most used polymer for the manufacturing of geotextiles on account of its low cost, suitable tensile properties and chemical inertness is polypropylene. Polypropylene has low density that’s why it has low cost per unit of volume. The disadvantages of
polypropylene are, it is very much sensitive to UV rays and high temperature. It has poor creep and mineral resistance.
Polyester: Polyester is used as geotextiles because of its superior creep resistance and tenacity values. This is applicable when geotextiles require high stresses and bluff temperatures. The disadvantage of polyester is hydraulic degradation in soils over pH10. Polyester fabric is very cheap, and it is found from PET chips or plastics
Polyamide: Polyamide is essential for making traditional geotextiles. Nylon 6 and Nylon 6:6 are used to make it. The choice of polymers depend on strength, creep behavior, fabric structure & finishing parameters.
Polyethylene: Polyethylene is used in case of only woven coated geotextiles. It is UV resistant and has a great heat seaming resistance.
2. Fabric based Geotextiles
The most preferable geotextiles which is used in 70% of the cases is Woven geotextiles which are textile materials consisting of planar structure by using an interweaving number of threads (both warp and weft). It shows strong mechanical properties whose main functions are reinforcement, separation and filtration.
The demand of knitted geotextile is less but is increasing day by day due to its light weight. These geotextiles are easy to handle and their cost of transportation is low. The demand of knitted geotextile is increasing in our Asian subcontinent.
They are made by bonding synthetic fibers or materials together which is done by chemical or heat, needle punching or other methods. They are used in the separation and filter applications. When it is necessary to take pulling water, the nonwoven geotextiles are the best option.
Applications and Functions of Geotextile
Geotextiles are perfect materials for roads, landfills, ports, drainage structures, and other civil projects. Geotextiles are widely used in many common applications such as: on the airport runway uncovered and curved road, landfill and stone base on the road, build sidewalks and sand drainage layers, in the construction of parking lots and curved spaces, in green areas and in the construction of recreational spaces, in the construction of structure of the wall, construction of duct bank and pipe trench, construction of temporary or permanent roads and yards, reinforcement under tramways or railway ballast, etc.
Geotextiles are used in both large-scale civil engineering projects and small-scale hardscape projects to serve five main functions:
Geotextiles help to prevent two soil layers of different particle sizes from mixing with each other. Not only soil, but any material that must be separated without preventing water circulation. Separation is widely used in several ways such as landfill, road construction, making railroad lines and much more.
Geotextiles will efficiently collect superfluous water from structures, such as rainwater or surplus water, from the soil and discharge it. It helps to flow water vertically and horizontally directly from the ground. The application of Drainage is more often used in sports stadiums, golf courses, airports and embankments to beach reclamation.
The function of the geotextile as filtration is to prevent the migration of particles from mud or soil coupled with water flow. Geotextiles are an ideal interface for reverse filtration in the soil adjacent to the geotextile. In all soil, water allows fine particles to be moved. Part of these particles will be halted at the filter interface; some will be halted within the filter itself while the rest will pass into the drain. Examples of applications are Revetment, Drainage pipes, Reclamation, Dredging and Groin.
Geotextile acts as a reinforcing element in a soil mass or combination with the soil to produce a composite that has improved strength and deformation properties. Heavy geotextiles can be used to reinforce earth structures by means of fill materials. Due to their high soil fabric friction
coefficient and high tensile strength, they are an ideal reinforcement solution.
The classic application of a Geotextile as a liquid barrier is paved road rehabilitation. It minimizes the vertical flow of water into the pavement structure. They are an ideal protection from the erosion of earth embankments by wave action, currents or repeated drawdown. A layer of geotextiles can be placed so as to prevent leaching of fine material. They can be used for rock beaching or as mattress structures and can even easily be placed under water.
Global Market scenario-At a Glance
On account of its functionalities and cost-effectiveness, geotextile is widely used in the field of construction. The market growth of geotextile is likely to accelerate by the growing demand for functional and high-performance textiles in agriculture, road construction and erosion control applications along with increasing development in construction industry.
According to Fortune Business insights, geotextile market size was USD 9,014.2 million in 2020 and is projected to reach USD 16,212.5 million by 2028 exhibiting a CAGR of 7.7% during the forecast period. The increasing demand for high performance and functional textile in road construction, erosion control, and agricultural applications, coupled with growing development in the construction industry is a primary factor driving the market growth. As per IndustryArc, in 2019 the largest share with 47% in Geotextile Market is held by The Asia Pacific (APAC). The market for geotextiles in the APAC region is mainly driven by the ongoing developments in the construction industry. China is expected to be the major market for geotextiles
in the region. According to the International Trade Administration, China spent USD 81.5 billion on urban rail transport construction in 2018, with an increase of 14.9% year-on-year and had a total of 6,370 km of new lines under construction. China has planned a total of 9,500 km expected in operation country-wide by 2021 with Jinan, Lanzhou, Changzhou, Xuzhou, and Huhhot planning to put new metro lines into operation. Also, according to the India Brand Equity Foundation, Indian Railways’ revenues increased at a CAGR of 6.20% during FY08-FY19 to US$ 27.13 billion in FY19, as well as the total national highways length increased to 122,434
km in FY18 from 92,851 km in FY14. Hence, leading construction activities of roads and railways will further drive the market in the forecast period.
Some of the key participants in the global geotextiles market are Royal Ten Cate (TenCate), Geosynthetic Lining Systems (GSE) Environmental, NAUE Gmbh & Co. KG, Propex Global, Fibertex Nonwovers, Fiberweb PLC, TENAX, Global Synthetics, etc.
Geotextile Market in Bangladesh-Industry Overview and Future Opportunities
Bangladesh is a low-lying, mainly riverside country located in South Asia with a coastline of 580 km on the northern littoral of the Bay of Bengal. As there are many low lying lands in our country, geotextile can be the best solution in this respect. The use of geosynthetics in Bangladesh was introduced back in 1989 through the production of the technical textile by DIRD Group. Although the production of geotextile in Bangladesh began many years ago, its use in different civil engineering and construction sector became popular over the past few years. Nowadays many textile industries of Bangladesh are producing geotextile commercially both for our in-house use and also export purpose. Some of the major geotex producers in our country are: Dird Felt Ltd., Nahee Geo-Textiles Industries Ltd., B.J. Geo-Textile Ltd., RM Geotex
Ltd., United Tex (BD) Int’l Ltd., etc.
In recent years, in our country natural fiber based textile especially jute geotextile is becoming popular day by day. Even though jute is a seasonal agricultural crop, it still widely grows in the South Asian subcontinent particularly in Bangladesh. The demand of jute geotextile in foreign market is increasing rapidly as the importers are showing interest to buy jute geotextile because of its eco-friendly characteristics and cheap cost. Despite most of the jute industries in our country being export oriented (who are exporting raw fibers, jute yarn, and packaging material ;) some jute industries are now exporting jute geotextile, but in small quantity. At present, Latif Bawany Mills under state-owned BJMC is exporting 5000 MT, Janata Jute Mills Ltd. is exporting 2000-2500 MT and some others are exporting jute geotextile every year. But this amount is very little compared to the demand and opportunity. Global demand is remarkably high and the factories cannot meet the demand. Most of the export oriented jute mills are busy producing and exporting jute yarn and packaging material. But by exporting jute geotextile, they can earn more within using the same amount of raw material, labor and capital.
Prospects and Policy Development
There are huge opportunities of the geotex industry in Bangladesh. Every year Bangladesh Government allocates huge budget to build or renew roads in rural areas. If
geotextiles are used, then the life span of those roads will be many times more than, if the roads are built without it. Management of wet/soft soil or slurry can be another significant application in Bangladesh. Lots of ETPs are installed in our country but none of them can manage their sludge easily and effectively. The main problem is separation of solids from liquids. By using geobags one can easily separate the solid waste from the slurry leading to an excellent, easier and safer environmental solution. These types of applications can also be used by the city corporation people during clearing mud clogged drains to separate solids from liquid. There are a vast amount of low lying lands in the south of Noakhali and Lakshmipur where the lands are not suitable for cultivation or are only useable for one season leaving it under water for the rest of the year. If in these cases, geo bags damns made from slurry to encircle the area (like DND project in Dhaka) are used, then the lands can be utilized for cultivation round the year. Using geotextile can be very effective and long lasting (totally unaffected by flood and cyclone), damns can be produced leading to socio economic growth of the concerned population and the country as a whole. Erosion control can be another very important application of geotextiles. Every year lots of river bank dwellers suffer from erosion problems leading to absolute loss of their land and property. Geotextiles can be the easiest and cost effective solution to this humanitarian problem of mass destruction.
Despite the huge demand of geotex in world, we cannot utilize the opportunity to export this in bulk quantity dueto some reasons as lack of variations and diversification of products for using outdated machineries, low investment and research capacity, administrative inefficiency, no policy/guidelines designed specifically for this sector etc. To accelerate the export, government should acknowledge and recognize geotextile as a growth and economic sector and start an office/section run by textile engineers under the Ministry of Textiles. For the development of technical textile sector, apart from government, both BUET and BUTEX have very important role to play as they have to work together. In some applications, like erosion control jute based geotextiles can be used effectively. This is because in case of erosion control, we need geotextile for a limited period of time and after a certain time it is totally degraded which then acts as a fertilizer. We also need to develop our weaving, non-woven and warp knitting capability and have to master these skills to manufacture these fabrics of varying specifications and properties for
the progression of geotextile sector.
Real estate sector: Thriving against all odds since its inception
The real estate sector of Bangladesh started its journey in the 1970s, with the concept of developing apartments, and has been climbing up the ladder ever since. At present, developing apartments has stretched to model cities, shopping malls, and commercial set-ups making the sector one of the key drivers of economic growth. The sector has managed to make a sizable impact in employment generation and directly adds on average nearly BDT 5.0 million to government revenue per annum.
The spiraling growth in population has made Dhaka and Chittagong into two of the most populous metropolitan cities in Bangladesh, for which they attract most of the projects. Bangladesh Bank estimates the housing finance demand for the fiscal year 2020-21 to rise compared to that of the previous year, with private banks holding the lions share in outstanding housing loans as of end of June 2020. The nationwide lockdown last year, acted as an obstacle to the growth of this sector, from which it is gradually recovering because of the enormous support from the government. Moreover, high liquidity which drove the lower interest rate in the banking sector also played a vital role here.
Many doors have opened for the booming real estate sector, for example, the development of new and spacious areas outside of Dhaka which calls for urban infrastructures in order to develop.The construction of new roads and railways will provide them with an opportunity to consider regions apart from the mainstream ones. The increasing rate of lower-middle-class people has led to a rise in demand for their homes. In addition to that as mentioned above support from the government, banks and NBFIs are also contributing immensely.
Unfortunately, the pandemic is not the only hurdle faced by the real estate. Mismanagement caused by few developers sometimes result in customer dissatisfaction. Minimal coordination between development authorities and disorganized urban planning exacerbates the situation. As a result, joint efforts from the government and industry players
are required to cater to the needs of the people. In addition, real estate should start stressing over lowcost affordable housing in order to accommodate the influx of lower-middle-income families.
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