A Case Study on Upgradation of Road using Full Depth Reclamation (FDR) under Pradhan Mantri Gram Sadak Yojana (PMGSY-III)

  

[Paper ID - IIMS2025104]

 

A Case Study on Upgradation of Road using Full Depth Reclamation (FDR) under Pradhan Mantri Gram Sadak Yojana (PMGSY-III)

Shailendra Pradhan (0009-0004-1120-1008)¹, Bablu Kirar (0000-0002-8707-2538)², Pradeep Muley (0000-0001-5031-3783)³

¹M.Tech. Student, Department of Civil Engineering, SATI, Vidisha (M.P.), shailendra22mt15@satiengg.in

²Assistant Professor, Department of Civil Engineering, SATI, Vidisha (M.P.), bablukirar.civil@satiengg.in

³Assistant Professor, Department of Civil Engineering, MMMUT, Gorakhpur (U.P.), pmce@mmmut.ac.in

  

ABSTRACT

 

This research focuses on the upgradation of roads using the Full Depth Reclamation (FDR) method, specifically the case study during and after construction phase of road, "T-08 Nasirabad to Babhanpur via Rajapur Garha" in Uttar Pradesh. Under Pradhan Mantri Gram Sadak Yojna (PMGSY) for low volume roads. The study aims to analyses the factors that affect FDR during and after execution and identify necessary steps to control these factors. The research follows a methodology that includes the collection of existing road samples, gradation analysis, and the preparation of a Job Mix Formula (JMF) as per IRC:SP:89-2018 using cement and chemical additives “Terrasil & Zycobond”. The FDR process involves pulverizing the existing pavement, blending it with stabilizing agents such as cement, lime, or chemical additives “Terrasil & Zycobond” and then compacting the mixture to form a strong, durable base. This newly formed base layer can be topped with suitable bearing course, such as asphalt overlays or chip seals, to restore the road’s surface. The technique also offers environmental benefits by reducing the demand for new aggregate and energy consumption, lowering greenhouse gas emissions associated with material production and transportation, and minimizing construction waste. The main concern for this case study is to analysis all the factor which effects FDR during and after execution, by conducting laboratory and field test. Laboratory test include gradation, liquid limit, plastic limit, modified proctor, unconfined compressive strength test, flexural strength test and field test include natural moisture content, gradation, field dry density, falling weight deflectometer. List what are the necessary steps required to control these factors.

KEYWORDS:  Full Depth Reclamation (FDR), Job Mix Formula (JMF), Falling Weight Deflectometer (FWD)

 

1.         INTRODUCTION

Due to rise in awareness in society towards the bed effects of the mining burden on natural resources, Environment friendly recycled or existing/waste material use in construction technology incorporates in reduce demand for virgin aggregate leading to cost saving and energy conservation, comparative to conventional technology for conservation of natural resources. The use of Full Depth Reclamation (FDR) stabilized base constructed along with cement binder using Terrasil and Zycobond additives result in enhance strength, reduces water susceptibility, and increases pavement flexibility. The main important objective of this research paper is to study all weather road ordinary district road connecting rural areas with major cities and market by upgradation of road through FDR technology to reduce the environmental impact Construction of conventional pavement adversely affects the environment in terms of use of natural resources, energy consumptions, emission of greenhouse gases etc. Hence, there is a need to adopt innovative technologies which are not only cost effective but also make rural road construction more economical and environmental friendly. FDR being an innovative mythology, will improve the quality of road works constructed and promote speedy construction. Cement binder and chemical additives Terrasil & Zycobond treated base using FDR will be helpful in conservation of natural resources as this technology focuses on recycling of existing pavement materials. The study analysis in laboratory with varying cement content and chemical additives (Terrasil & Zycobond) dosages to find the optimum dosages through hit and trail method for field implementation FDR base layer as per IRC: SP: 89-Part-II,2018. Utilizing FDR in flexible pavement for base layer construction improves cost-effectiveness, durability, and pavement strength. However, thicker wearing course is required to prevent rutting and cracking. FDR implementation in low volume roads under Pradhan Mantri Gram Sadak Yojna (PMGSY) results in cost reduction of 30-40% as compared to conventional method.

 

2.      METHODOLOGY

Full Depth Reclamation process done with cement and Zydex industries chemical additives Terrasil & Zycobond in pavement rehabilitation improves pavement’s structural capacity at reduced costs by restoring the existing pavement layers with little use of new materials. Typically, FDR road execution is carried out at various locations across India under PMGSY for low volume roads, where layer thickness ranges from 210 to 250 millimeters. FDR is a pavement rehabilitation method that recycles existing asphalt and base materials to create a stabilized foundation, offering a cost-effective and sustainable alternative to full reconstruction. The correct proportioning of materials is important for the production and quality of FDR mixes. The Job mix formula (JMF) should be carried out with a scientific and systematic approach that balances the existing and desired engineering properties, constructability, durability, and economics. Methodology consist of two part, first part is JMF, which involve data analysis and sample collection from existing road for laboratory testing to determine optimum binder content and chemical additives dosage to obtained, design mix established as per IRC: SP: 89-Part-II, 2018 The Job mix design should be carried out with a scientific and systematic approach that balances the existing and desired engineering properties, constructability, durability, and economics. Second phase construction process start after finalized JMF, which involve execution of FDR base layer on the field.

2.2 Material

Reclaimed Pavement Materials (RPM) were collected from the site for the testing in the laboratory of M/s Sri Bhawan, After ensuring proper quartering of the samples, materials were tested for Gradation, UCS, Durability and Residual strength so as to evaluate the suitability of the RPM for road construction. 

2.2.1 Source of Material

i.    Existing crust materials collected from the site.

ii.   Ordinary Portland cement (OPC) of grade 43.

iii.  Terrasil & Zycobond stabilizer from Zydex Industries Pvt. Ltd, Vadodara, Gujarat.

2.2.2 Mechanism of Acceptance of Additives & Binder

2.2.2.1. Terrasil

Terrasil is a reactive soil modifier that permanently modifies the soil surface, making it hydrophobic. Terrasil is a non-Leachable and safe chemistry, and works with all soil types. Brownish liquid in appearance and Soluble in water. Confirming to Commercial Chemical Stabilizers as per IRC SP 89 Part II 2018. Terrasil has Forms 4-6 nm reactive alkyl-siloxane surface to create hydrophobic soils, Imparts charge shield and oil lubricity to soil particles, UV & heat stable, Non-leaching. It reduces permeability from 10-5 to 10-7 cm/sec, Reduces Expansivity (FSI), compacted bases are dimensionally stable, Prevents Freeze Thaw, Improves Compaction Density, Increases Load Bearing Capacity.

2.2.2.2. Zycobond

Zycond is 80-90 nm flexible acrylic co-polymer that has a very high surface area available for bonding. The higher number of contact points ensure flexible bonding at a nano level, leading to improved fatigue resistance in stabilized soil. Zycond in combination with Terrasil imparts higher strength and enhanced flexibility. Whitish liquid and dispersible in water. Confirming to Commercial Chemical Stabilizers as per IRC SP 89 Part II 2018. Zycobond has  80-90 nm acrylic co-polymer, UV & heat stable, cross linkable soil modifier, chemically binds soil particles into a flexible cross-linked matrix. Imparts flexibility & bonding to the treated bases, Higher Fatigue Resistance, Prevents propagation of cracks to the top when used with cement.

2.2.2.3. Cement

Cement is a key construction material used globally for building infrastructure, from homes and roads to bridges and skyscrapers. It acts as a binding agent when mixed with water, aggregates, and other materials to form concrete or mortar, which then hardens into a solid, durable mass.

 

2.3 Job Mix Formula (JMF) Preparation

The correct proportioning of materials is important for the production and quality of FDR mixes. The objective is to establish the combination of Reclaimed Pavement Materials (RPM) in conjunction with Cement and Zydex nanotechnology additives, to suit the road construction employing Full Depth Reclamation Technique. Design mix established as per IRC: SP: 89-Part-II, 2018 guidelines and gradation of the FDR mix is carried out as specified in MoRTH clause Table 400-4. The general steps is followed for the mix design is listed as:

Step 1.  Sample collection of existing roads. Obtain the field samples from every 500 meter for determining the variability in the material for deciding the number of mix designs to be carried out. Sampling was done on 18h Aug 2022. Example of sample collection shown in Table 3.

Table 3 Site Sampling for JMF

Step 2. Determine the gradation of the reclaimed material sample. For gradation of collected sample theoretical calculation is done to make the FDR gradation mix while incorporating width and depth of proposed roads. Step 3. If necessary, additional materials may be added to satisfy the gradation requirements. Additional material is provide only in case if in aggregate and fine ratio, Aggregate is less than 40% of FDR mix. Step 4. For mix design, three different cement contents testing may is selected.

Table 5 Cement content and Terrasil + Zycobond dosage combination

Step 5. Determine optimum moisture content and maximum dry density of mix using each estimated cement/CCS content. Modified compaction tests were carried out on existing crust materials with cement, Terrasil & Zycobond stabilizer in accordance with IS 2720 (Part-VIII).

Step 6. For each cement content, 150 mm cubical specimen may be prepared at maximum density and optimum moisture content for determination of unconfined compressive strength (UCS) at 28 days. SP: 89 (Part II): 2018 adopted. Step 7. 12 cycles of Wet-dry durability test on each specimen at the estimated cement content to be conducted. In order to check the durability of the stabilized mix, wetting and drying test was carried out on laboratory casted 150x150x150 mm cube moulds with combination of % cement and stabilizer dosage of Terrasil 0.75 kg/m3 & Zycobond 0.75 kg/m3. Test was got conducted in accordance with IRC: SP: 89 (PART II): IS 4332 (Part IV). Step 8. Plot the unconfined compressive strength and wet-dry durability test results on a graph to determine the desired cement content. Step 9. Create a mix design report with the established cement content and Terrasil & Zycobond while incorporating moisture/density information.

 

2.4 Construction Process of FDR Base

                                                                                                   

Full-depth reclamation (FDR) is a rehabilitation method that recycles existing pavement into a new stabilized base layer. This process involves pulverizing the pavement and blending it with stabilizing materials like cement and additives. The stabilized material is compacted with rollers, creating a stiff, stable base ready for a new surface course. The process involves profiling the existing road, trenching and widening the road, determining required moisture content, grading the road, and spreading cement. The process of execution of FDR technology during upgradation of road “T-08 Nasirabad to Babhanpur via Rajapur Garha” road length 7.30 km is described below:

Step. 1 Profiling of existing road. The gradation, thickness and width of road is measured at every 100 meter interval and report is prepared after incorporating design thickness and width to identify the need of aggregate/soil to match the JMF gradation. Step. 2 Trenching and widening of road. Existing road is 3.75 m Width and proposed width is 5.5 m for bearing course, so 38 cm trench is dug at both side of existing carriageway and material is loosen with backhoe and spread in 5.65 meter width and rolling is done with soil compactor while maintain 3.5% camber. Step. 3 Required moisture content (RMC) of carriageway is done at interval of 30 to 50m distance in middle, left side and right side by making a 0.5 m X 0.5 m X 0.25 m pit, material obtained from pit is transferred in enamel trays and mix thoroughly and approx. 1 kg sample is take from mix and heating it on gas stove or by Rapid Moisture Meter (RMM) to determine the NMC of carriageway. To determine RMC formula is given is [RMC = OMC – NMC]. Step. 4 Gradation of carriageway is done by taking sample from 0.5m X 0.5m X 0.5m Pit at an interval for 250m as per NIRRDA FDR Booklet Guideline’s. Step. 5 Cement Spreading is done by the truck mounted automatic cement spreader. The rate of cement spreading is maintained as per JMF. In order to check the rate of cement spreading 0.5m X 0.5m metal tray is placed before spreading and weight of cement is determine by weighting the amount of cement obtained in metal tray. The spreading of width of Spreader is 2.4m, and it is divided in three segment, so it takes three strips to cover 5.65m width. Step. 6 Chemical dosing is done in water tanker after measuring the amount of water required for cover the specific length. Amount of chemical is determined by volume of FDR mix multiple by 0.75 time to get the Terrasil and Zycobond quantity in Kg.  Step. 7 Pulverization of carriageway is carried by reclaimer while maintaing the RMC to achieve the desire OMC. The width of reclaimer is 2.4 m, it take 3 strip to cover 5.65m width. Step. 8 Material sample is taken just after pulverization for gradation, cube casting and finer material hives are made alongside the carriageway for surface finishing after compaction. Step. 9 Rolling of pulverized carriageway is done why sheep foot/ pad foot roller. Minimum of 8 Passes of rolling. Step. 10 After completing 8 passes of sheep foot/ pad foot roller grading of carriageway is done by motor grader, by maintaing 3.5% chamber. Step 11 Once grading is done than rolling is carried out by soil compactor, 8 passes is done but after 3 to 5 passed finer material is spread on rough patch or small marked made due to aggregate to make the surface smooth. Step. 12 PTR roller is used to make final surface the smooth, by making 8 passes of PTR roller. Step. 13 After completing smoothing of surface, Field density test of finish stretch is done by sand replacement method and thickness check of pulverized carriageway is also carried by using phenolphthalein indicator to find out the penetration of cement up to desire depth 250mm. Step. 14 Curing of finish FDR base is done form next day after construction for the periods of at least 10 days and more.

 

3.     RESULTS AND DISCUSSION

3.1. Laboratory test

3.1.1. Combined Gradation of RPM

The gradation of the existing materials of Chainage 7+000 per MoRTH Table: 400-4 (IS 2720 Part-4) is given in table 2 and the gradation envelope shown in Fig.1. The proportion of aggregate to finer material ratio is 51:49. 

Fig.1 Particle Size distribution for combined reclaimed pavement material

3.1.2. Proctor Compaction Test

Modified proctor compaction tests were carried out on existing crust materials with Cement, Terrasil & Zycobond stabilizer in accordance with IS: 2720 (Part-8). The MDD and OMC with different combinations given in Fig. 2. 

Fig. 2 Result of compaction test for the FDR mix. Cement content and Terrasil + Zycobond combination.

3.1.3. Durability Test (Wetting and Drying Test)

To check the durability of the stabilized mix, wetting and drying test was carried out on laboratory casted 150x150x150 mm cube moulds with combination of 5.0% cement and stabilizer dosage of Terrasil 1.0 kg/m3 & Zycobond 1.0 kg/m3. Test was got conducted in accordance with IRC: SP: 89 – 2018 (IS: 4332 Part IV). The test specimens were subjected to the wetting and drying test for 12 cycles and the test results summary averaged of three sample is presented in Table 6.

Table 6 Result of durability Test (Wetting & Drying Test)

3.1.4. Unconfined Compressive strength (UCS) Test

Existing crust materials samples were carried out in accordance with IRC: SP: 89 Part II 2018

(IS 2720 Part-10). In order to assess the gain in compressive strength due to stabilization,        150 mm x 150 mm x 150 mm cubes were cast with FDR mix, Cement, Terrasil and Zycobond stabilizer and compacted to 97% of MDD at its corresponding OMC. The specimens were cured for a period of 7 and 28 days. The 7 days and 28 days UCS results are given in Fig. 3.

Fig. 3 Result of UCS test for 7 and 28 days for JMF

3.1.5. Residual Strength

Residual strength of the stabilized mix, wetting and drying 12 cycles was carried out on laboratory casted 150x150x150 mm cube moulds with combination of 5.0% cement and stabilizer dosage of Terrasil 1.0 kg/m3 & Zycobond 1.0 kg/m3. Then UCS test was got conducted on the conditioned samples in accordance with IRC: SP: 89 – 2018. The UCS test results summary averaged of three samples is presented in Table 7. 

Table 7 Residual strength test

3.1.6. Flexural Strength

Flexural Strength of the stabilized mix, test was carried out on laboratory casted 500x100x100 mm beam moulds with combination of 5.0% cement and stabilizer dosage of Terrasil 1.0 kg/m3 & Zycobond 1.0 kg/m3. Test was got conducted in accordance with IRC: SP: 89 – 2018, (ASTM D 1635, 9.0) test results summary averaged of three sample is presented in Table 8. 

Table 8 Result of flexural strength test

3.2. Field Test

The successful construction of FDR with cement/CCS relies on the control of depth and uniformity of pulverization, strength of compacted subgrade, cement content and placement moisture content of reclaimed mix, and compaction of reclaimed layer.

 

3.2.1. Test Frequency

It is prudent to conduct periodic testing during construction to confirm that the properties of materials being used are within the range of value anticipated during the design. Quality control tests and their minimum desirable frequency are as given in Table-3 FDR booklet By NRIDA

 

3.2.2. Natural Moisture Content (NMC)

Moisture content or natural moisture content is amount content present in the existing pavement and subgrade till the required depth for reclamation, before pulverization. To ensure FDR layer stabilization at optimum moisture content it is crucial to determine NMC to add required moisture content for FDR layer during pulverization.

 

3.2.3. Spreading Rate of Cement

Spot check-In this, a sheet of canvas, usually 1 m² in area, is placed ahead of the cement spreader. After the spreader has passed the canvas, the cement is carefully picked up and weighed. Overall check-The distance or area is measured over which a truckload of cement of known weight is spread. This actual area is then compared with the theoretical area, which the known quantity of cement should have covered.

 

3.2.4. Gradation After Reclamation/Pulverization

The gradation of the existing materials as per MoRTH Table: 400-4 (IS 2720 Part-4), the gradation envelope shown in Fig. 4. The proportion of aggregate to finer material ratio is varies at different chainages this indicates aggregate soil ratio is not uniform across road length.

Fig. 4 Particle Size distribution of pulverized material at different chainages.

3.2.5. Field Dry Density

Sand replacement method is used. The density of the layer should not be less than 100% of the maximum density of the cement treated mix as determined in the laboratory.

 

3.2.6. Unconfined Compressive Strength (UCS) for Cube

Fig. 5 Result of UCS test for cube at 7 and 28 days for executed FDR base 

Reclaimed/Pulverized crust materials samples were carried out in accordance with IRC: SP: 89 Part II 2018 (IS 2720 Part-10). In order to assess the gain in compressive strength due to stabilization, 150 mm x 150 mm x 150 mm cubes were cast with FDR mix, Cement, Terrasil and Zycobond stabilizer and compacted to 97% of MDD at its corresponding OMC. The specimens were cured for a period of 7 and 28 days. The 7 days and 28 days UCS results are given in Fig 5. Shows UCS value of cube is well within the desire limits.

 

3.2.7. Unconfined Compressive Strength (UCS) for Core

An Extracted core specimen for the determination of compressive strength. As per IRC: SP: 89 Part II 2018. The length of the specimen, when capped, shall be as nearly as practicable twice its diameter. Therefore, it is recommended ≥ 150 mm diameter. Cores is taken after seventh day completion of the FDR layer for in-place compressive strength testing.

 

Table 9 Result of UCS test for core of extracted from FDR base layer after execution.

3.2.8. Falling Weight Deflectometer test

The deflection bowl data for pre and post monsoon seasons are shown in Fig. 6 (a) and               Fig. 6 (b), respectively. The average deflection values recorded at D0 before and after the monsoon were 0.406 mm and 0.477 mm, respectively, showing a slight increase due to moisture effects during the monsoon. Pre mansoon and post mansoon test conducted on July 2^nd 2024 and September 26^th 2024 respectively.

Fig. 6 Falling weight deflectometer test result pre and after mansoon.

4.    CONCLUSIONS

The UCS strength obtained for 7 and 28 days for combinations tested with Cement 5% + Terrasil 1 kg/m³ + Zycobond 1 kg/m³ meets the desired criteria for JMF. And Average flexural strength is 1.17 MPa. During execution FDR base gradation after pulverization varies across entire length, this indicate non-uniform laying of GSB, WBM in the existing road. UCS value of cube uniform as comparted to core UCS value it may be due to varying mixing uniformity of pulverized FDR mix. FWD evaluations showed a marginal increase in deflections post-monsoon due to moisture-induced effects.

 

5. ACKNOWLEDGEMENT

I take this opportunity to express my thanks to Dr. Rajeev Jain, Professor and Head, Department of Civil Engineering for extending every possible help and support during the experimental work.. I am especially thankful to Dr. Y.K. Jain, Director, SATI, Vidisha for his kind cooperation and rendering me all possible facilities.

List of References

Haifang Wen and Bruce Ramme (2008), “Performance of an asphalt pavement with a Class C fly ash stabilized FDR base: A case Study”. Airfield and Highway pavements. doi:10.1061/41005(329)36

Maurizio Bocci, Andrea Grilli, Fabrizio Cardone & Gilda Ferrotti (2012), “Full-Depth Reclamation for the Rehabilitatdion of Local Roads: A Case Study” International Journal of Pavement Engineeringh. doi:10.1080/10298436.2012.657196

Afreen Abulkasim Mulla & K. G. Guptha (2019), “Comparative Study and Laboratory Investigation of Soil Stabilization Using Terrasil and Zycobond”. Sutstainable Construction and Building Materials, Springer Singapore, doi: 10.1007/978-981-13-3317-0_68

Dr. G.D. Ransinchung R.N. (2022) “Full Depth Reclamation for Rehabilitation of Low Volume Roads” Published by National Rural Infrastructure Development Agency, New Delhi, India

IRC: SP: 89-2010 “Guidelines for soil and granular material stabilization using cement, lime and fly ash”. Published by Indian Roads Congress, New Delhi, India

IS4332-Part 5 “Methods of test for stabilized soils: Determination of unconfined Compressive Strength of stabilized soils”. Published by Bureau of Indian standard, New Delhi, India 

IS2720-Part 4 “Methods of test for soils: Grainsize analysis”. Published by Bureau of Indian standard, New Delhi, India