---
category: literaturenote
citekey: harinderlaboratoryassessmentcoirgeotextile2022
title: Laboratory Assessment of Coir Geotextile Mats Under Wheel Load Conditions for Low-Volume Roads (LVRs)
authors: "Harinder, D; Shankar, S; Chandu, B"
year: 2022
date: 2022-09-00 2022-09
doi: 10.1088/1755-1315/1086/1/012027
publication: "IOP Conference Series: Earth and Environmental Science"
url: "https://doi.org/10.1088/1755-1315/1086/1/012027"
zotero_key: PJMVQSHF
zotero_storage: K635RKSC
collections: imporditud
folder: 001_artiklid
firstAuthor: "Harinder, D"
status: converted
---
![](_page_0_Picture_1.jpeg)

#### **PAPER • OPEN ACCESS**

# Laboratory Assessment of Coir Geotextile Mats Under Wheel Load Conditions for Low-Volume Roads (LVRs)

To cite this article: D Harinder et al 2022 IOP Conf. Ser.: Earth Environ. Sci. 1086 012027

View the [article online](https://doi.org/10.1088/1755-1315/1086/1/012027) for updates and enhancements.

### You may also like

- [Analysis on the Long Term Effect of Trial](/article/10.1088/1757-899X/136/1/012025) [Test Road Constructed on Batu Pahat Soft](/article/10.1088/1757-899X/136/1/012025) [Clay \(BPSC\) at Recess UTHM](/article/10.1088/1757-899X/136/1/012025) M M M Idrus, A E Edayu, Z Adnan et al. -
- [Effect of coir fibres on strength, thickness](/article/10.1088/1757-899X/1136/1/012042) [and cost of PMGSY roads](/article/10.1088/1757-899X/1136/1/012042) Ayush Mittal -
- [Effect on CBR Values with Addition of Coir](/article/10.1088/1755-1315/889/1/012005) [Geotextile and Marble Dust in Silty Sands](/article/10.1088/1755-1315/889/1/012005) Maninder Singh, Sachin Kamboj, Kunal Jain et al. -

# **Laboratory Assessment of Coir Geotextile Mats Under Wheel Load Conditions for Low- Volume Roads (LVRs)**

#### **D Harinder1 S Shankar2 and B Chandu3**

E-Mail: hariatnitw@gmail.com

**Abstract:**The present study brought out the effort and quantifies the use of geotextile in Low-Volume Roads over the weak subgrade. The Low-Volume Roads (LVRs) play a key role in the economic growth of rural area as well as helps in developing the country. The construction of these LVRs over the weak strength of soil subgrade is a challenging task for civil engineering to provide the safe and smooth flow of traffic, and such soil is revealed that the Black Cotton soil (BC). The weak soil subgrade consists the finer particles like clay and silt showing poor shear strength, bearing capacity, and California bearing ration values. It poses several serious problems to the LVRs. To arrest these problems many of the conventional techniques were adopted in pavement application. But these techniques are nor economical and neither eco-friendly. To reduce this problem, the cost of construction, and to provide a longer duration, geosynthetics are introduced as an alternate material in pavement application in the last few decades. In the umbrella of geosynthetics, the geotextile is gaining attention for its utilization in pavement constructions. The study found the coir composite mats performed better reinforcement and improved the strength of the pavements. This study concluded that the use of coir geotextile mats with appropriate of sub-base soil at the suitable position at H/4 with morrum soil improved the performance of the LVRs with 200mm thickness of mould over the 400 mm thickness of the mould. It is indicate a decrease in construction and maintenance costs of the LVRs.

*Key Words: Subgrade soil;Coir geotextile; reinforcement; Shear strength;WTT* 

#### **1.0 Introduction**

Last few decades, geosynthetic materials have been widely used to strengthen subgrade soil [1]. Especially, geogrid, geocell, and geotextile are commonly used to strengthen the pavement structure [2]. The geosynthetics materials are having more advantages and cost-effective materials to increase the performance of weak subgrade soil [3]. The utilization of geotextile causes additional confinement to the pavement structure, which is lead to strengthening the pavement structure. This controls the later movement of the weak soil and increases the overall stability and strength of the pavement structure. Its helps in tolerating the pavement failure criteria such as rutting and fatigue. The limitation and the failure criteria with reinforcement of pavement structure, along with the thickness of pavement layer (IRC: SP: 72-2018) is discussed [13]. Various research studies have demonstrated the advantages of geotextile [4]. Several kinds of research are also conducted to study the behaviors of the geotextile in the pavement structure. The behaviors of natural coir mats to reinforce the pavement section were studied by [5]. The polymeric geotextile studies were also noticed by [6] Perkins (1999) and Kim et al 2006 [7].

Assistant Professor, Department of civil Engineering, VNRVJIET, Hyderabad, 500090,

Assistant Professor, Department of civil Engineering NIT-Waranagl,506004,

M.Tech Student, Department of civil Engineering VNRVJIET, Hyderabad, 500090,

 The coir geotextile mats are utilized for various applications with soil like reinforcement, drainage, filtration, separation, slope protection, interface in civil engineering aspects. It has been extensively used for slope protection and reinforcement of the soil in India [8-9]. The laboratory experiments studies reported that, coir mats in between the (interface) of base and subgrade levels [10]. It was noticed that the use of coir geotextile enhances the subgrade effectively, while considerably reducing the having and increasing the lateral confinement to the pavement [11]. The field test was also noticed on coir geotextile by [12]. The study concluded that obtained 50 percent of the CBR values with reinforcement of coir geotextile. In view of the above, the current experimental study was planned to conduct using the coir mats. Two types of mats were used and placed in a fabricated mould with different sub-base layers and subgrade. The bottom layer of both tank was field as subgrade with Black Cotton (BC) soil and compacted as per the modified CBR standards. Over the prepared subgrade, the geotextile was placed with appropriate anchoring. Further, the variable sub-base materials were placed over the coir mats. The below figure 1, show the placement position of the coir mats along with the height of the fabricated mould.

![](_page_2_Figure_6.jpeg)

Figure 1 Placement of coir mats in fabricated mould at different height

#### **2.0 Materials selected for the study**

The subgrade soil (BC) was collected from the lake nearby NITW. The basic tests on subgrade soil (BC) were tested in the laboratory, and the OMC, MDD, and CBR values are determined from the test. It evaluated the types and classification of soil. The laboratory study results are shown in Table 1.

IOP Conf. Series: Earth and Environmental Science 1086 (2022) 012027

doi:10.1088/1755-1315/1086/1/012027

Properties of Block cotton soil Value IS code Classification of soil CH IS 1498-1970 LL (Percentage, %) 56 IS 2720- 1985 (Part 5) PL ((Percentage, %) 26 IS 2720- 1985 (Part 5) PI (Percentage, %) 33 IS 2720- 1985 (Part 5) Specific gravity 2.6 IS 2720- 1980 (Part 3) OMC (Percentage, %) 16 IS 2720- 1980 (Part 7) MDD (gm./cc) 1.6 IS 2720- 1980 (Part 7) FSI(Percentage, %) 76 IS 2720- 1977 (Part XL) CBR value (Percentage, %) 2 IS 2720- 1987 (Part 16)

Table 1.BC soil test values

The sub-base materials were taken as sandy gravel (Poorly graded gravel) and morrum (well grade gravel) with different finer particles. The strength properties of the sub-base material were determined and presented in table 2. The OMC, MDD, and Shear strength (SS)- C and ϕ with the type of sub-base layer material.

| Sub- Base layer     | Gravel soil<br>properties | Morrum soil<br>properties |
|---------------------|---------------------------|---------------------------|
| OMC (%)             | 7.0                       | 11.0                      |
| MDD                 | 1.83                      | 1.90                      |
| SS (C and ϕ )       | 0, 32o                    | 5, 33o                    |
| CBR (%) - Un Soaked | 15                        | 23                        |
| Soaked CBR (%)      | 7                         | 11                        |

Table 2.Sub-baselayer material

The coir mats were manufactured from the coir fiber, which is available based on the field requirements. The experimental properties of the coir fiber were studied in the laboratory like length, diameter, specific gravity, etc.

The nomenclatures of the geotextile mats that are selected to conduct the study are coir composite mats and also woven coir mats denoted as CC and WCM respectively. Figure 2 (a) shows the CC and figure 2 (b) shows the WCM.

![](_page_4_Picture_5.jpeg)

Figure 2. (a) Coir Composite mats Figure 2. (b) Woven Coir Mat

## **3.0 Laboratory Setup**

The wheel rutting machine was utilized to perform the test in the laboratory by changing the height of the mould. The height of the load was lifted with the help of fabricated angles, which is enabling the loading on the fabricated mould. The maximum 15 kg load was applied to the prepared sample with a moving wheel width of 50mm and wheel diameter is 200mm. data were collected from the "Linear Variable Differential Transformer" (LVDT) along with the "Data Acquisition" DAQ system. The experimental setup along with the fabricated mould is shown in figure 3. The test samples are prepared based on the modified CBR standard. Figure 4 shows the tested sample and obtained rutting after the test with 400 mm height of fabricated mould filled with gravel materials.

![](_page_4_Picture_10.jpeg)

Figure 3. Experimental used for the study Figure 4. Tested sample

IOP Conf. Series: Earth and Environmental Science 1086 (2022) 012027

doi:10.1088/1755-1315/1086/1/012027

### **4.0 Data Analysis and Discussions**

The samples were prepared in the mould (mould of size height of 400 mm), which consists of the bottom layer as black cotton soil subgrade over that geotextile is anchored with corner anchoring. The sub-base layer material was placed over the anchored geotextile and compacted as per the modified California bearing ratio test. It was prepared with different heights of soil subgrade. In order to find the effective position of coir mats with the proper layer material, the geotextile was placed at variable heights. So that the confinement of the weak soil improves the later stability. The study was conducted to evaluate the better reinforcement among CC and WCM.

![](_page_5_Figure_7.jpeg)

Figure 5.Rutting along with wheel passes of gravel soil at H/2 position

Figure 5 indicated the inclusion of coir geotextile mats at a position of H/2 in 400 mm height of the manufacturing mould. It was noticed that the maximum wheel passes are noted as 850 repetitions with the reinforcement of the CC material. The position of coir mats at this location concern the maximum thickness of the sub-base layer. It also fails in shear strength, due to lower values of C and ϕ in table 2. The lower numbers of passes are noticed for un reinforcement section. Figure 6 showed the number of passes at the position of H/4 with mould size of 400 mm.

![](_page_6_Figure_5.jpeg)

Figure 6. Rutting along with wheel passes of gravel soil at H/3 position

The coir geotextile was placed at a position of H/3 to reduce the layer thickness in a similar mould with similar types of soil. While placing coir geotextile material at H/3 position, it is noticed that similar types of failure with lower repetition. The obtained repetitions are noticed as 580 and 340 with and without reinforcement to the pavement structure respectively. Figure 6 showed the relation between repetitions and obtained rutting at a height of H/3 in 400 mm thickness of mould.

![](_page_6_Figure_8.jpeg)

Figure 7. Rutting along with wheel passes of gravel soil at H/4 position

The current study was carried out with the placement position of coir geotextile materials at the H/4 (130mm) position. The geotextile is placed near to the wheel load with gravel as a sub-base layer material. It is noticed that maximum of 780 passes and minimum of 560 passes respectively. The position of coir geotextile mats at H/4 height is noticed as appropriate with gravel material when compared with other positions like H/2 and H/3 positions. Figure 7 showed the relation obtained from the wheel track test passes and rutting. The placement of coir mats plays a vital role to control the failure sub-base layer and improved the performance of the LVRs.

Further, the tests were performed with the replacement of the gravel material with morrum soil using the 200 mm thickness of moulds. It was indicate the decreases of the subbase layer material thickness compared over 400 mm thickness of mould. The coir geotextile is positioned in between two-layer material.

![](_page_7_Figure_7.jpeg)

Figure 8Rutting with wheel passes at H/2 height of coir mat

In this case, the deformation was noticed in terms of rutting with more passes using the morrum (M) soil. The measured rutting was observed with and without reinforcement under the traffic loading categories (T1 = 30000) as per the IRC: SP: 72-2018. Obtained more passes were noticed with the morrum soil as a sub-base layer material. The observed rutting with the gravel soil rutting was noticed with un-reinforcement and reinforcement sample is 15 mm and 4 mm respectively. The included CC mats decrease the rutting up to11mm, due to its tensile strength. The number of passé and the rutting are shown in figure 8.

![](_page_8_Figure_5.jpeg)

Figure 9Rutting with wheel passes at H/3 height of coir mat

The laboratory test at H/3of coir geotextile showed the maximum and the minimum rutting deformation as 27 mm and 8 mm with and without reinforcement of CC mats respectively. It was observed that the CC mat is suitable with morrum soil and improved the confinement to the material and enhances the strength of the pavement structure. It is also noticed that among the types of geotextile mats the CC mat is more effective to offer reinforcement to the pavement structure. The WCM is suitable for providing the appropriate separation between the two different layers. Figure 9 shows the rutting and the passes at H/4 positions in the fabricated mould of 200 mm height.

![](_page_8_Figure_8.jpeg)

Figure 10Rutting with wheel passes at H/4 height of coir mat

Similarly, the coir materials are placed with a reduction of sub-base layer thickness at H/4 positions and observed that rutting deformation and the number of passes. It was found that 37 mm is the maximum and 11 mm minimum rutting of the coir geotextile respectively, with and without the inclusion of the coir geotextile. It is revealed that the morrum soil content cohesive fine improved the confinement to the coir geotextile and increases the passes. The study indicated the use of coir with morrum soil showed improved performance than, other positions and other types of soil. The figure10 showed the rutting performance of the coir geotextile along with passes.

![](_page_9_Figure_5.jpeg)

Figure 11, function of coir mats to the pavement with and without reinforcement

The two-layer model section of the pavement with reinforcement and without reinforcement is shown in figure 11. Figure 11A shows the un-reinforcement pavement model. Figure 11B shows the showed significant reinforcement and separation with the coir composite mats. Figure 11C shown the reinforcement only, the improper separation between the bottom of the soil layer. The composite mats give the multi-function such as reinforcement as well as separation of weak subgrade pavement structure and it is clearly shown in figure 11B, the placement of coir geotextile at appropriate sub-base layer help in improving performance of the pavement.

#### **5.0 Conclusion**

The shows the following conclusion, the study is limited to a few of the coir mats with two types of sub-base materials. The coir mats are placed at different heights, and the position of the coir mats near the wheel is show a significant reduction in deformation. The study results can be utilized for particular soil used in the study. The following are the major conclusions are found as:

- The maximum passes are noted with morrum soil (T1= 30,000) repetition with higher rutting of 37mm at the H/4 position. It was reduced up to 7 mm using the CC mats. It was indicated the use of effective soil with geotextile enhances the strength of the pavement structure.

- - In the case of 400mm size mould, the included coir mats at the H/4 height have the maximum passes. It occurs due to the thickness of the sub-base layer with appropriate material over the Composite geotextile mats. This is lower with the WCM than the CC.
- - In the case of a 200mm size mould, the deformation (20mm) at height of H/4 is greatly reduced with Composite material. The inclusion of coir geotextile is enhancing the performance with the well-graded sub-base layer material.
- - The study indicates the utilization of coir mats is suitable near the wheel load with morrum as the sub-base layer material.

#### **Reference:**

- [1] Han, B., Ling, J., Shu, X., Song, W., Boudreau, R. L., Hu, W., & Huang, B. (2019).Quantifying the effects of geogrid reinforcement in unbound granular base. *Geotextiles and Geomembranes*, *47*(3), 369-376.
- [2] Altay, G., Kayadelen, C., Taşkıran, T., & Kaya, Y. Z. (2019). A laboratory study on pull-out resistance of geogrid in clay soil. *Measurement*, *139*, 301-307.
- [3] Visvanathan, A., Velayudhan, S., & Mathew, S. (2022). Field evaluation of coir geotextile reinforced subgrade for low volume pavements. *Journal of Natural Fibers*, *19*(2), 597-609.
- [4] Khan, A. J., Huq, F., &Hossain, S. Z. (2014). "Application of jute geotextiles for rural road pavement construction". In *Ground Improvement and Geosynthetics* (pp. 370-379).
- [5] Subaida, E. A., Chandrakaran, S., &Sankar, N. (2009). "Laboratory performance of unpaved roads reinforced with woven coir geotextiles". *Geotextiles and geomembranes*, *27*(3), 204-210.
- [6] Perkins, S. W. (1999). "Mechanical response of geosynthetic-reinforced flexible pavements". *Geosynthetics international*, *6*(5), 347-382.
- [7] Kim, W. H., Edil, T. B., Benson, C. H., &Tanyu, B. F. (2006). "Deflection of prototype geosynthetic-reinforced working platforms over soft subgrade". *Transportation research record*, *1975*(1), 137-145.
- [8] Rao, G. V., Sheela, E. Y., &Sayida, M. K. (2020). "Application of coir geotextiles in rural roads of India". *Indian Geotechnical Journal*, *50*(2), 172-183.
- [9] Sridhar, R., &Prathap Kumar, M. T. (2018). Experimental investigation of load settlement behavior of coir mat and coir fiber reinforced sand. *Journal of Natural Fibers*, *15*(3), 452-463.
- [10] Subaida, E. A., Chandrakaran, S., &Sankar, N. (2009). "Laboratory performance of unpaved roads reinforced with woven coir geotextiles". *Geotextiles and geomembranes*, *27*(3), 204-210.
- [11] Rao, G. V., and R. K. Dutta. 2005. Characterization of tensile strength behaviour of coir products. Electronic Journal of Geotechnical Engineering 10. (Bundle B), pp. 0520
- [12] Sayida, M. K., Evangeline, S. Y., &Girish, M. S. (2019). "Coir geotextiles for paved roads: A laboratory and field study using non-plastic soil as subgrade". *Journal of Natural Fibers*.
- [13] IRC: SP: 72-2015. Guidelines for the design of flexible pavements for low volume rural roads. New Delhi, India: Indian Roads Congress.