TS006-Test Methods of Geotextiles

Test Methods of Geotextiles

Susmita Jagadale, Rahul Prasad

Department of Textile Chemistry

DKTE Engineering College ,Icchalkaranji, India

Abstract:

Technical textiles have the extreme range of products. but so many researchers are still carried out. Among various types of technical textiles, geotextiles possess very important class due to its versatile applications in roads, automobiles, dams and constructions industries. Geotextiles are the permeable textile materials which mainly used for filtration, drainage, separation, reinforcement and stabilization purposes. Geotextiles is the fastest growing industry and a promising field of technical textiles. Due to that need different properties of geotextiles plays very important role. In our research paper we highlight that need and also we explain that various live test methods so that proper selection of material is carried out.

Keywords: Technical textiles, geotextiles, non-woven, reinforcement.

INTRODUCTION:

In 1972, geotextiles were largely untested, and the site was set up as an accelerated field test to determine the comparative performances of several fabrics for use as a geotextiles.

As we know geotextile, geo, means earth and the ‘textile’ means fabric. Therefore, according to the definition of ASTM 4439, the geotextile is defined as follows: "A permeable geosynthetic comprised solely of textiles. Geotextiles are used with foundation, soil, rock, earth, or any other geotechnical engineering-related material as an integral part of human-made project, structure, or system."

Functions of geotextiles:

Separation: Geotextiles will prevent two soil layers of different particle sizes from mixing with each other, as is illustrated the image below.

Drainage: Geotextiles will efficiently collect superfluous water from structures, such as rainwater or surplus water, from the soil and discharge it.

Filtration: Geotextiles are an ideal interface for reverse filtration in the soil adjacent to the geotextile. In all soils 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. The complex needle-punched structure of the geotextile enables the retention of fine particles without reducing the permeability of the drain.

Reinforcement: Heavy geotextiles can be used to reinforce earth structures by means of fill materials. Thanks to their high soil fabric friction coefficient and high tensile strength, they are an ideal reinforcement solution.

Protection: Geotextiles are an ideal protection from 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. They can even easily be placed under water.

THE NEED TO GET IT RIGHT:

It may be argued that geotextiles are such a small part of a civil engineering project as to be financially insignificant and therefore not worth spending much time focusing on developing specs or seeking supply quotations. But the implications to long-term performance of a civil engineering structure are far greater than the initial cost of purchase of the geotextile. The failure of a roadway due to rupture of a geotextile or the erosion of a dam wall due to piping of embankment material through a geotextile filter are examples that clearly show the enormous potential financial impact that failure of a geotextile may have on a project.

Having many different specs in various States causes manufacturers to produce a host of different products unnecessarily. Setting uniform, consistent specs brings economies by allowing manufacturers to focus on producing and stocking fewer grades.

REINFORCEMENT:

The key difference between stabilization and reinforcement is that stabilization is accomplished by providing for drainage of water from the unstable soil, while in reinforcement the strength characteristics (stress–strain) of the geotextile provide added strength to the whole system. Another difference is that in stabilization the geotextile is placed on or around the area being stabilized and thereby also acts as a separator, whereas in the reinforcement application the geotextile is placed within the material being reinforced. This is in line with reinforcement concepts in concrete and other materials.

Concrete is used in innovative designs because of its many valuable properties such as high compressive strength, stiffness, low thermal, electrical conductivity, and low combustibility.
However concrete is brittle, weak and develops cracks during curing
The recent development of Fiber reinforcement in Concrete in various fields has provided a strong technical base for improving these deficiencies.

Why the Reinforcement of the concrete comes ?

Concrete plays important role in Construction line which is India’s second largest field in terms of Economy. Too improve the quality of construction we are enforcing the concrete with the textile fibers. To improve the some properties of that concrete.

How it come to know ?

Human being is motivated for fiber reinforcement from nature
Hornero bird native to South America builds nests out of straw and Clay.
Roman Colosseum built in 80 AD. stands strong This structure was built with horse hair as reinforced fibers and the structure is a glittering example of strength and durability.
Tipu Sultan’s palace at Srirangpattnam which still stands as it is after centuries was reinforced with Sheep’s wool.
A Pueblo house built in 1540 with straw reinforcement is the oldest house in USA.
The good example of it is we see mud wall in villages with straw reinforcement.

So where do we see cracks in Concrete All around us?

Parking area
Industrial flooring
Concrete terrace

Mechanics involved in fiber operation:

Damage of fiber matrix
Fiber/matrix debonding
Fiber bridging
Fiber failure
Fiber Pull-Out

Factors affecting fiber reinforcement in concrete:

Effect of Fiber Length
Effect of fiber volume fraction
Effect of fiber cross sectional shape Variation in the material
Variation caused by the test method
Environment
Type of instrument & its accessories
Conditions of testing such as speed, pressure and duration

Objective of fiber reinforcement in concrete :

Based on literature survey following objectives were finalized
To Prepare fiber reinforced concrete with natural and synthetic fibers in different proportions
To study effect of fiber type and fiber proportion on the characteristics of concrete.

Methodology:

Mixing of fibers
Preparation of Fiber Reinforced concrete blocks
Testing of Fiber Reinforced concrete Blocks

Experimental Work:

Polyester fibers, Polypropylene fibers, Banana fibers, Coir fibers is taken for test
Fibers were dispersed in water by continuous stirring. This water in which fibers were dispersed was used for forming the concrete.
The proportion of fibers in concrete used was 0.25 % - 1 % on weight of cement

Preparation of Moulds and Testing of Fiber Reinforced Concrete:

Compressive Strength
Tensile Strength
Moisture Absorption Test
Slump Test
Setting Time of concrete

Tensile Splitting Strength:

As per ASTM C 496 standard Tensile splitting strength test was performed using cylindrical specimen.
In determining the modulus of rupture by a beam specimen the upper, part of the specimen is in compression while the lower part is under tension, therefore it gives a better idea about the tensile strength of concrete.

Compressive Strength

As per TS EN 12390-3 Standard compressive strength test was performed.
The most important property of concrete is the compressive strength which was determined by loading the molded and cured specimens.
The testing machine used had sufficient capacity which provided the required rate of loading.

Moisture Absorption:

As per ASTM C 140 moisture absorption of concrete was performed.
The concrete cube was kept in oven; so that the moisture present in the concrete cube will evaporate then the oven dried cube were kept in water for 24 hours.
Then the water absorbed by concrete was found by weighing the block.
Amount of moisture in concrete, was known as the moisture content and was expressed as a percentage on the mass of the concrete.

Slump Test (Workability):

As per ASTM C 143 standard test method for slump of concrete was carried out.
Slump test was performed to check the workability and consistency of the fresh concrete with fibers.

Setting Time:

As per ASTM 403 standard test method for setting time of concrete was carried out.
This test was done using Vicat’s needle apparatus.
In this test a needle was tried to penetrate on a concrete mould.
The time at which needle ceases to penetrate gives the Setting time.

RESULTS:

Effect of fiber type and proportion on Compressive Strength of concrete

Effect of fiber type and proportion on Tensile Strength of concrete

Effect of fiber type and proportion on moisture absorption of concrete

Effect of fiber type and proportion on Slump (Workability of Concrete)

Effect of fiber type and proportion on Setting time

CONCLUSIONS

Test methods are a means to understand the product
Test results give a true picture of the product
Test results are dependable when conducted exactly as per the standard test methods
Compressive strength of fiber reinforced concrete has improved significantly, especially in case of Polypropylene fibrillated and banana fiber at 0.25%.
There is no effect on Moisture absorbing property of concrete reinforced with polypropylene fibers at all four levels of fiber volume fraction,
Polyester, banana fiber, coir there is significant effect on moisture absorbing, also with polyester and both the natural fibers the moisture absorbing has reduced significantly.
Workability for all the fibers is satisfactory at low fiber volume fraction, but in case of banana & coir at 1% workability is poor.
Setting time is not affected for PP fibers at all levels of fiber volume fraction, but for Polyester, banana fiber, coir there is significant effect on setting time.
Finally it can be concluded that fibrillated polypropylene fiber gives best results in terms of strength and has no adverse effect on moisture absorbency So if proper fiber reinforcement techniques used one can improve the life of concrete structures.

REFERENCES:

Kaniraj, S. R. & Rao,G. V.(1994) Trends in the use of geotextiles in India,Geotextiles and Geomembranes,13(6-7):389 402.Doi:https://doi.org/10.1016/0266-1144(94)90004-
Sarsby, W. R. (2007).Geosynthetics in civil engineering. Woodhead Publishing, Abington, Cambridge.
Ingold, T. S. (2013). Geotextiles and Geomembranes Handbook, Elsevier, Amsterdam, The Netherlands.
Samrat Mukopadhyay, Raul Fangueiro, “Banana Fibers- Variability and Fracture Behavior”, Portugal, Journal of Engineering Fiber & Fabrics Vol 3 Issue 2, August 08 .
F.Pacheco Torgal1, Said Jalali “Vegetable Fibre Reinforced Concrete Composites: A Review” 1C-TAC Research Unit, University of Minho, , Portugal
“Secondary Reinforcement Fiber for Concrete”, Buckeye Building Fibers Tillman Memphis, www.ultrafiber500.com
Grand View Research Forecasts Global Geotextiles Market (https://www.estormwater.com/grandview-research-forecasts-global-geotextiles-market) (access date: 13/10/2017)
M.Y. Gudiyawar and A. V. Mahajan, “Application of Fibers in Fiber Reinforced Concrete” www.fibre2fashion.com
M. A. Erki, S. H. Rizkalla, “Fiber reinforcement polymer Reinforcement for concrete” , Concrete international Journal, June 1993, Page no 48.
Indrajit Patel and C D Modhera , Study Basic properties of fibers reinforced high volume fly ash concrete” Journal of Engineering research and studies.
H. Jia and C. Vipulanandan, “Nondestructive Evaluation Of Fiber Reinforced Polyester Polymer Concrete” , Department of Civil and Environmental Engineering University of Houston, Houston
Bruce Perry, “Effective use of Polypropylene fibers in concrete” , Engineering Service group seminar November, 2004.
http://www.ril.com/html/business/recron_3s.html
http://en.wikipedia.org/wiki/Fiber-reinforced_concrete
Journal of Scientific and Engineering Research