Description:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2005

COMPLETE SPECIFICATION
(See section 10, rule 13)

1. TITLE OF THE INVENTION:
METHOD OF CONSTRUCTION OF PAVEMENTS AND STRUCTURAL COMPOSITION THEREOF
2. APPLICANTS:
(a) Name Larsen & Toubro Limited
(b) Nationality An Indian Company
(c) Address L&T House, N. M. Marg, Ballard Estate, Mumbai - 400001, Maharashtra, India.

3. PREAMBLE OF THE DESCRIPTION:
PROVISIONAL
The following specification describes the invention. COMPLETE
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
The present invention relates to construction technology and more particularly, the present invention relates to the construction of pavements, specifically, to a structural composition and a method of construction of pavements, deploying drainage geocomposites.
BACKGROUND OF THE INVENTION
Roadways have served as a major way of transportation since ancient times. They provide a passage for the movement of people and vehicles. With ever-evolving technologies and new alternate pavement materials, methods of construction of the roadways have changed significantly, in terms of followed practices and materials deployed. As shown in Figures 1(a) and 1(b), in the case of the construction of different types of rigid pavements (100-a) and flexible (100-b) pavements a conventional step such as constructing a subbase layer (20) above the subgrade layer (10) is followed. The subbase layer (20) is covered with an aggregate base layer (60) when constructing the flexible pavements (100-b). The subbase layer (20) is covered with layers of stabilized subbase layer (30) and surface layer (50) made from pavement quality concrete in the case of rigid pavements (100-a). A separation layer (40) made of a polythene sheet is placed between the pavement-quality concrete (50) and the stabilized subbase layer (30) layers. For constructing flexible pavements (100-b) the base layer (60) made from aggregate is covered with a bituminous base layer (70), and a surface layer (80) made of bituminous material. The subbase layer (20) constructed from aggregate facilitates internal drainage and ensures rapid disposal of water, thereby protecting the pavement structure from water-related damages. However, for highways and expressways, a significant quantity of aggregate is required for the construction of the subbase layer in pavements. This depletes non-renewable natural resources, including quarried aggregate sources. Moreover, for projects with high aggregate lead, transportation of a large quantum of aggregate is always a big challenge that eventually increases the project cost.
Attempts have been made to overcome the issues related to high aggregate consumption in pavements by using drainage geocomposite in lieu of the subbase layer in rigid pavements as referred in IRC 58:2015. Reference may be made to guidelines published by the Indian Roads Congress (IRC: SP-59-2019) that elaborate on the properties and test methods as well as the use of geosynthetics such as geotextile, geonet, geomembrane, geocell, and geomat in road pavements and associated works. A geocomposite is a manufactured material consisting of two or more geosynthetic components. The application of geocomposite in pavements is specified in IRC 58. However, the suggested levelling layer (GSB) above the drainage geocomposite as mentioned in IRC 58 does not yield significant aggregate reduction. Additionally, drainage geocomposite laid according to published guidelines and specifications may result in damages due to construction activities like the movement of the paver and trucks during the construction of a roadway.
Reference may be made to a related art RU2006125460A that discloses a geocomposite interlayer for an earthen road. The document proposes the use of a geocomposite interlayer instead of a sand-draining layer. Moreover, the document elaborates on the structure of the geogrid with a provision of a geocloth from top and bottom and placement of additional watertight film between a lower plane of the geogrid and a lower layer of the geocloth. Deployment of the geocomposite layer results in improved quality of roadbed, and watertightness over the lower plane. The primary function of the geocomposite in this case is waterproofing to arrest capillary action.
Another related art US2001002497A1 discloses a geocomposite system for roads and bridges and a construction method. The geocomposite system includes a geomembrane disposed between two geotextile backings, a structural layer for supporting the geocomposite layer, and a base layer formed on top of the geocomposite layer. The geomembrane prevents the intrusion of liquids including deicing salts into the structural layers of roads. The geocomposite layer is bonded to the base layer by a tack coat of a suitable adhesive. Here the primary function of the geocomposite is waterproofing.
Accordingly, there exists a need to provide a method of construction of pavements by selecting a suitable drainage geocomposite system that can withstand construction-induced damages while ensuring an efficient drainage solution in pavements. Moreover, a method of construction of pavements is required that conserves depleting non-renewable natural resources such as quarried aggregate sources by eliminating the utilization of the same in pavement construction.
OBJECTS OF THE INVENTION
An object of the present invention is to provide a method of construction of pavements.
Another object of the present invention is to provide a method of construction of pavements that embeds drainage geocomposite layer(s) in the pavement structure.
Yet another object of the present invention is to provide a method of construction of pavements that embeds an additional geotextile layer(s) along with the drainage geocomposite layer in the pavement structure.
Still another object of the invention is to provide a structural composition of the pavements deploying the drainage geocomposite layer.
SUMMARY OF THE INVENTION
This section is provided to introduce certain objects and aspects of the present disclosure in a simplified form that are further described below in the detailed description. This summary is not intended to identify the key features or the scope of the claimed subject matter.
The present disclosure generally relates to the construction of pavements, specifically, a method of construction of pavements and a structural composition thereof, deploying drainage geocomposites.
In an aspect, the present invention relates to a method of construction of pavements. The method includes providing a subgrade layer by compacting any one of soil, gravels, laterite, superior materials, or any combination thereof, with and without stabilizing materials. The method includes constructing rigid pavements by placing a drainage geocomposite layer on the subgrade layer, pegging the drainage geocomposite layer by suitable securing mechanisms to the subgrade layer, constructing a stabilized subbase layer on the drainage geocomposite layer, and covering the stabilized subbase layer with a surface layer. The method includes constructing flexible pavements by placing a drainage geocomposite layer on the subgrade layer, pegging the drainage geocomposite layer by suitable securing mechanisms to the subgrade layer, constructing a subbase layer on the drainage geocomposite layer, covering the subbase layer with a base layer, covering the base layer with a bituminous base layer, and covering the bituminous base layer with a surface layer. The method includes compacting the surface layer.
In another aspect, the present invention relates to the structural composition of pavements that includes one or more drainage geocomposite layers, overlaid with a sacrificial layer of geotextile sandwiched between any two layers of a rigid pavement or a flexible pavement. The structural composition of rigid pavements comprises the subgrade layer forming the lowermost layer, the stabilized subbase layer constructed above the subgrade layer, the surface layer forming the uppermost layer constructed on the stabilized subbase layer, and the drainage geocomposite layer sandwiched anywhere between the subgrade layer and the surface layer. The structural composition of flexible pavements comprises the subgrade layer forming the lowermost layer, the subbase layer constructed above the subgrade layer, the base layer constructed to cover the subbase layer, the bituminous base layer constructed to cover the base layer, the surface layer forming the uppermost layer constructed to cover the bituminous base layer, and the drainage geocomposite layer sandwiched anywhere between the subgrade layer and the surface layer.

BRIEF DESCRIPTION OF THE DRAWINGS
The objects and advantages of the present invention will become apparent when the disclosure is read in conjunction with the following figures, wherein
Figure 1(a) shows a cross-sectional view of a conventional rigid pavement structure;
Figure 1(b) shows a cross-sectional view of a conventional flexible pavement structure;
Figure 2 shows a flow diagram of the method of construction of pavements in accordance with an embodiment of the present invention;
Figure 3(a) shows a cross-sectional view of a rigid pavement in accordance with an embodiment of the present invention;
Figure 3(b) shows a cross-sectional view of a flexible pavement in accordance with an embodiment of the present invention; and
Figures 4(a), 4(b), 4(c), and 4(d) depict pictures of exhumed drainage geocomposites obtained from trial stretches (S1-S4) respectively examined for visual observations.
DETAILED DESCRIPTION OF THE INVENTION
The foregoing objects of the invention are accomplished and the problems and shortcomings associated with the prior art techniques and approaches are overcome by the present invention as described below in the preferred embodiment.
Throughout this application, with respect to all reasonable derivatives of such terms, and unless otherwise specified (and/or unless the particular context clearly dictates otherwise), each usage of:
“a” or “an” is meant to read as “at least one.”
“the” is meant to be read as “the at least one.”
Throughout this application, the terms “roads”, “roadways” and “pavements” are used interchangeably and mean “a surface built on land to travel along for vehicles and persons” and may include categories such as but not limited to highways, expressways, aircraft pavements, and road pavements in airports and other roads.
References in the specification to “one embodiment” or “an embodiment” mean that a particular feature, structure, characteristic, or function described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
Hereinafter, embodiments will be described in detail. For clarity of the description, known constructions and functions will be omitted.
The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in brackets in the following description and a table below.
Reference No. Component
300-a Structural composition of a rigid pavement
300-b Structural composition of a flexible pavement
10 Subgrade layer
20 Subbase layer
30 Stabilized subbase layer
40 Separation layer
50 Surface layer
60 Base layer
70 Bituminous base layer
80 Surface layer
90 Drainage geocomposite layer

In an exemplary embodiment of the present invention, the method of construction of pavements involves placing layers of a plurality of materials constructed one above the other, such that it forms a unified structure of a roadway.
In an exemplary embodiment of the present invention, the method of construction of pavements deploys a layer of drainage geocomposite that may be covered by an additional layer of geotextile.
In an exemplary embodiment of the present invention, the method of construction of pavements deploys drainage geocomposite prepared by combining a plurality of layers of geotextiles with a core of geonet or any suitable material to facilitate drainage. The plurality of layers of geotextiles may include a top geotextile and a bottom geotextile, placed to hold a core therebetween. Throughout this application, the terms “geonet”, “a core of geonet” and “core” are used interchangeably and mean “geonet or any other suitable material to facilitate drainage”. The dimensions and physical characteristics of each layer in a geocomposite are subjected to variability as per the requirement.
In an exemplary embodiment of the present invention, the method of construction of pavements when implemented results in a structural composition of pavements with an elimination of one or more layers of one or more materials that are shown in Figures 1(a) and 1(b).
Figures 3(a), and 3(b) represent different embodiments of the present invention showing cross-sectional views of the pavements. Figure 3(a) represents a structural composition (300-a) of a rigid pavement. Figure 3(b) shows a structural composition (300-b) of a flexible pavement. The structural compositions (300-a, 300-b) of pavements are collectively referred to as “the structural composition (300)”. The structural composition (300) comprises layers of a plurality of materials constructed one above the other, such that it forms a unified structure of a pavement.
As shown in Figure 3(a), the structural composition (300-a) includes a subgrade layer (10) as the lowermost layer and a surface layer (50) as the uppermost layer that is in direct contact with traffic on the rigid pavement. The subgrade layer (10) is made from materials selected among soil, gravels, laterite, superior materials, or any combination thereof, with and without stabilizing materials. A drainage geocomposite layer (90) is placed on the subgrade layer (10) and pegged by suitable securing mechanisms such as ‘J’ pins thereto. The geocomposite is prepared by combining a plurality of layers of geotextiles with a core of geonet sandwiched therewithin. The plurality of layers of geotextiles may include a top geotextile and a bottom geotextile. The top geotextile and the bottom geotextile may have gsm (grams per square meter) in the range of 100-500 and may be made from polypropylene, polyester, nylon, polyethylene, polyvinyl chloride, or any other polymer or any combination thereof. The geonet may have a gsm in the range of 200-1500 and may be made from polyethylene resin, or any other polymer, or any combination thereof. Additionally/alternatively, the drainage geocomposite layer (90) may be covered with a sacrificial layer of geotextile. The sacrificial layer of geotextile may be made from polypropylene, polyester, nylon, polyethylene, polyvinyl chloride, or any other polymer or any combination thereof and may have a gsm in the range of 100-500. A stabilized subbase layer (30) is constructed on the drainage geocomposite layer (90). The stabilized subbase layer (30) is made of dry lean concrete. The stabilized subbase layer (30) is covered with a surface layer (50) that is made of pavement-quality concrete.
Figure 3(b) represents the structural composition (300-b) of the flexible pavement. The structural composition (300-b) includes a subgrade layer (10) as the lowermost layer and a surface layer (80) as the uppermost layer. The drainage geocomposite layer (90) that has earlier described composition is placed on the subgrade layer (10). A subbase layer (20) is constructed on the drainage geocomposite layer (90). The subbase layer (20) is made of materials selected among natural sand, gravel, aggregate, crushed stone, slag brick metal, kankar, crushed concrete, soil, brick aggregate, laterite, and recycled pavement material or any combination thereof with and without cement or cementitious materials. The subbase layer (20) is covered with a base layer (60). The base layer (60) is made of wet mix macadam. The base layer (60) is covered with a bituminous base layer (70) made from bitumen and aggregate. The bituminous base layer (70) is covered with a surface layer (80) which is made of aggregate and bitumen.
In the preferred embodiment of the present invention, the structural composition (300) of pavements comprises one or more drainage geocomposite layers (90), overlaid with or without a sacrificial layer of geotextile sandwiched between any two layers of the rigid pavement and/or the flexible pavement. The structural composition (300-a) of rigid pavements comprises the subgrade layer (10) forming the lowermost layer, the stabilized subbase layer (30) constructed above the subgrade layer (10), the surface layer (50) forming the uppermost layer constructed on the stabilized subbase layer (30), and the drainage geocomposite layer (90) sandwiched anywhere between any two layers of the rigid pavements. The rigid pavements may be bonded/unbonded, short panel, reinforced, or plain jointed. The structural composition (300-b) of flexible pavements comprises the subgrade layer (10) forming the lowermost layer, the subbase layer (20) constructed above the subgrade layer (10), the base layer (60) constructed to cover the subbase layer (20), the bituminous base layer (70) constructed to cover the base layer (60), the surface layer (80) forming the uppermost layer constructed to cover the bituminous base layer (70), and the drainage geocomposite layer (90) sandwiched between any two layers of the flexible pavement structure. The flexible pavement may have different materials for subbase layer (20) and the base layer (60) such as granular subbase/granular base layer, cementitious subbase/cementitious base layer, emulsion/foam bitumen stabilized reclaimed asphalt pavement/virgin aggregate base layer or any combination thereof.
The drainage geocomposite and additional sacrificial layer may have gsm values that may go beyond the ranges mentioned earlier.
The invention envisages a reduced consumption of the material required for constructing the subbase layer (20) in conventional rigid pavements by the deployment of a drainage geocomposite layer (90). In flexible pavements, the invention provides the enhancement of the drainage characteristics of the pavement when subbase material with low horizontal permeability is constructed.
Figure 2 represents a preferred embodiment of the present invention illustrating a method of construction of pavements (200) (hereinafter referred to as “method (200)”). The method (200) when performed results in a structural composition (300) of pavements. The method (200) comprises steps from 201-204.
At step 201, the method (200) involves providing a subgrade layer (10) by compacting (201) any one of soil, gravels, laterite, superior materials, or any combination thereof, with and without stabilizing materials.
At step 202, the method (200) involves constructing rigid pavements by placing a drainage geocomposite layer (90) on the subgrade layer (10), pegging the drainage geocomposite layer (90) by suitable securing mechanisms to the subgrade layer (10), constructing a stabilized subbase layer (30) on the drainage geocomposite layer (90), covering the stabilized subbase layer (30) with a surface layer (50).
At step 203, the method (200) involves constructing flexible pavements by placing a drainage geocomposite layer (90) on the subgrade layer (10), pegging the drainage geocomposite layer (90) by suitable securing mechanisms to the subgrade layer (10), constructing a subbase layer (20) on the drainage geocomposite layer (90), covering the subbase layer (20) with a base layer (60), covering the base layer (60) with a bituminous base layer (70), covering the bituminous base layer (70) with a surface layer (80).
At step 204, the method (200) involves compacting (204) the surface layer (50, 80).
The steps 202 and 203 of placing a drainage geocomposite layer (90) on the subgrade layer (10) may further include placing an additional sacrificial layer of geotextile on the drainage geocomposite layer (90).
In an exemplary embodiment of the present invention, field trials were undertaken by constructing four trial stretches (S1, S2, S3, and S4). Each trial stretch (S1, S2, S3, and S4) was fixed as 50m in length and 3.5m in width. Each trial stretch (S1, S2, S3, and S4) was constructed with a subgrade layer and different specifications of drainage geocomposite systems as explained below.
Table I
Property Minimum average roll value
Mass per unit area (gsm) 710
Thickness of drainage geocomposite (mm) 4.5
Tensile strength (kN/m) 16
In-plane
permeability
(l/m/s) Hydraulic gradient, i=1 at
100 kPa pressure 0.55
Hydraulic gradient, i=1 at
200 kPa pressure 0.45
The deployed drainage geocomposites differed in specifications of constituent layers thereof as described below:
For S1, the drainage geocomposite constituted a top geotextile and a bottom geotextile of 130 gsm each, holding a geonet of 450 gsm therebetween with the specification as per Table I.
For S2, the drainage geocomposite constituted a top geotextile of 200 gsm and a bottom geotextile of 130 gsm, holding a geonet of 450 gsm therebetween.
For S3, the drainage geocomposite constituted a top geotextile of 250 gsm and a bottom geotextile of 130 gsm, holding a geonet of 450 gsm therebetween.
For S4, the drainage geocomposite constituted a top geotextile and a bottom geotextile of 130 gsm each, holding a geonet of 450 gsm therebetween. The layer of geocomposite was overlaid with a sacrificial layer of geotextile of 200 gsm at the top.
In pavement construction, the pavement layers (stabilized subbase, granular base) are constructed using pavers. The construction trucks and pavers travel directly on the underlying layers. Hence, to simulate field construction, a 150mm thick layer of wet mix macadam (WMM) was constructed with a paver over the drainage geocomposite system in all stretches S1, S2, S3 & S4.
Visual inspections and laboratory tests of exhumed drainage geocomposites from the trial stretches (S1, S2, S3, and S4) were carried out for both, along the wheel path of paver and away from the wheel path.
Table II summarizes the findings of visual observations of various drainage geocomposite /geotextile samples. Throughout this document, ‘OWP’ stands for ‘outer wheel path’, ‘IWP’ stands for ‘inner wheel path’, ‘MWP ‘stands for ‘middle of wheel paths/away from wheel path’, and ‘MORTH’ stands for ‘Ministry of Road Transport and Highways’.
Table II
Stretch Drainage Geocomposite layer details Remarks Overall condition
of
the drainage geocomposite
S1 • Top geotextile: 130 gsm
• Bottom geotextile: 130 gsm
• Geonet: 450 gsm • Major punctures in larger area in OWP and IWP
• Minor tears
• Major wrinkles in MWP Poor
S2 • Top geotextile: 200 gsm
• Bottom geotextile: 130 gsm
• Geonet: 450 gsm • Minor punctures
• Minor wrinkles in OWP Fair
S3 • Top geotextile: 250 gsm
• Bottom geotextile: 130 gsm
• Geonet: 450 gsm • Very minor punctures
• Geonet is intact with no damage Fair
S4 • Top geotextile: 130 gsm
• Bottom geotextile: 130 gsm
• Geonet: 450 gsm
• A sacrificial layer of geotextile of 200 gsm at the top of the drainage geocomposite • No damage to the drainage geocomposite and it is intact.
• Punctures observed in the top 200 gsm geotextile sacrificial layer Good
In an exemplary embodiment of the present invention, figures 4(a), 4(b), 4(c), and 4(d) show pictures of exhumed drainage geocomposites obtained from trial stretches (S1-S4) respectively that were examined for visual observations. Figure 4(a) shows major punctures and wrinkles in the drainage geocomposite. As the gsm of the top geotextile increases from 200 to 250 in the deployed drainage geocomposites in S2 and S3 respectively, minor punctures to very minor punctures were observed in the drainage geocomposite, as represented in Figures 4(b) and 4(c). In the case of S4, wherein, the drainage geocomposite was overlaid with an additional sacrificial layer of geotextile, the deployed drainage geocomposite was observed to be intact as represented in Figure 4(d).
In an exemplary embodiment of the present invention, tests to measure tensile strength and in-plane permeability were carried out at a Bombay Textile Research Association (BTRA), Mumbai laboratory to ascertain the installation damage of drainage geocomposite and compared with control samples from fresh rolls.
Table III shows the tensile strength data of the exhumed drainage geocomposite samples from the trial stretches (S1, S2, S3, and S4).
Table III
Stretch Location of Sample collection Average Tensile Strength (kN/m) % Retained Strength
Machine Direction Cross Machine Machine Direction Cross Machine
Minimum values (As per MORTH /
IRC) 16.00 16.00 - -
S1 OWP 15.05 10.71 94% 67%
IWP 15.00 13.00 94% 81%
MWP 17.25 11.70 108% 73%
S2 OWP 20.80 11.10 130% 69%
IWP 19.75 11.05 123% 69%
MWP 19.95 14.95 125% 93%
S3 OWP 14.80 15.70 93% 98%
IWP 17.60 11.21 110% 70%
MWP 16.10 15.35 101% 96%
S4 OWP 17.70 14.90 111% 93%
IWP 18.43 15.73 115% 98%
MWP 18.15 15.05 113% 94%
As presented in Table III, there was a reduction in the tensile strength of the exhumed products because of installation damage during construction. In the machine direction, the tensile strength was not affected significantly with a minimum retained strength (in percentage) observed as 93%. However, in the cross-machine direction, a significant reduction in tensile strength was observed with most affected in S1 and less affected in S4.

Table IV shows the in-plane permeability data of the exhumed drainage geocomposite samples from the trial stretches (S1, S2, S3, and S4).
Table IV
Stretch Location of Sample collection Average In-plane Permeability (l/m/sec), hydraulic gradient
i =1
100 kPa 200 kPa
Minimum values as per MORTH/IRC specifications 0.55 0.45
S1 OWP 0.22 0.15
IWP 0.20 0.13
MWP 0.27 0.19
S2 OWP 0.20 0.13
IWP 0.22 0.15
MWP 0.24 0.17
S3 OWP 0.20 0.13
IWP 0.24 0.17
MWP 0.18 0.12
S4 OWP 0.267 0.2
IWP 0.41 0.27
MWP 0.28 0.22
As illustrated in Table IV, the horizontal permeability/in-plane permeability of the drainage geocomposite was significantly reduced by more than 50% as against the MORTH specified value of 0.55 l/m/sec at 100 kPa.
In general, the stress levels at the drainage geocomposite level in rigid pavements are less than 25 kPa. Additional testing was done at a pressure level of 50 kPa for the drainage geocomposite exhumed from S4 and an average horizontal permeability of 0.3 l/m/sec was observed. Moreover, it was found that the top and the bottom geotextiles of the drainage geocomposite had permanently elongated within the aperture size of the geonet. The permanent elongation of geotextiles has resulted in reduced water pathways within the cross-section of the drainage geocomposite. The elongation in the geotextile may be a result of the aggregate in the overlying WMM layer during compaction.
ADVANTAGES OF THE INVENTION
1. The method (200) and the structural composition (300-a) eliminate the need to use the subbase layer composed of the aggregate, replacing the same with a drainage geocomposite, which is easy to install and time-saving.
2. The method (200) and structural composition (300-b) improve drainage characteristics when subbase materials composed of locally available resources are used in construction projects with low horizontal permeability.
3. The method (200) and the structural composition (300) result in the conservation of the fast-depleting natural resources.
4. The method (200) and the structural composition (300) deploy drainage geocomposite, being a factory-manufactured product, ensuring high quality and contributing to a durable pavement.
The foregoing objects of the invention are accomplished and the problems and shortcomings associated with prior art techniques and approaches are overcome by the present invention described in the present embodiment. Detailed descriptions of the preferred embodiment are provided herein; however, it is to be understood that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure, or matter. The embodiments of the invention as described above and the methods disclosed herein will suggest further modification and alterations to those skilled in the art. Such further modifications and alterations may be made without departing from the scope of the invention.

, Claims:We claim:
1. A method of construction (200) of pavements, the method (200) comprising :
providing a subgrade layer (10) by compacting (201) any one of soil, gravels, laterite, superior materials, or any combination thereof, with and without stabilizing materials;
constructing rigid pavements (202) by,
placing a drainage geocomposite layer (90) on the subgrade layer (10);
pegging and securing the drainage geocomposite layer (90) to the subgrade layer (10);
constructing a stabilized subbase layer (30) on the drainage geocomposite layer (90);
covering the stabilized subbase layer (30) with a surface layer (50);
constructing flexible pavements (203) by,
placing a drainage geocomposite layer (90) on the subgrade layer (10);
pegging and securing the drainage geocomposite layer (90) to the subgrade layer (10);
constructing a subbase layer (20) on the drainage geocomposite layer (90);
covering the subbase layer (20) with a base layer (60);
covering the base layer (60) with a bituminous base layer (70);
covering the bituminous base layer (70) with a surface layer (80); and
compacting (204) the surface layer (50, 80).
2. The method (200) as claimed in claim 1, wherein, constructing rigid pavements (202) and constructing flexible pavements (203) comprises placing the drainage geocomposite layer (90) anywhere between the subgrade layer (10) and the surface layer (50, 80).
3. The method (200) as claimed in claim 1, wherein, constructing rigid pavements (202) and constructing flexible pavements (203) further comprises overlaying a sacrificial layer of geotextile on the drainage geocomposite layer (90).
4. A structural composition (300) of pavements, the structural composition (300) comprising:
one or more drainage geocomposite layers (90) overlaid with a sacrificial layer of geotextile, the one or more drainage geocomposite layers (90) overlaid with a sacrificial layer of geotextile sandwiched between any two layers of a rigid pavement or a flexible pavement, wherein
a structural composition (300-a) of rigid pavements comprises:
a subgrade layer (10), the subgrade layer (10) forming the lowermost layer;
a stabilized subbase layer (30), the stabilized subbase layer (30) constructed above the subgrade layer (10);
a surface layer (50), the surface layer (50) forming the uppermost layer constructed on the stabilized subbase layer (30); and
the drainage geocomposite layer (90), the drainage geocomposite layer (90) sandwiched anywhere between any two layers of the rigid pavement;
a structural composition (300-b) of flexible pavements comprising:
a subgrade layer (10), the subgrade layer (10) forming the lowermost layer;
a subbase layer (20), the subbase layer (20) constructed above the subgrade layer (10);
a base layer (60), the base layer (60) constructed to cover the subbase layer (20);
a bituminous base layer (70), the bituminous base layer (70) constructed to cover the base layer (60);
a surface layer (80), the surface layer (80) forming the uppermost layer constructed to cover the bituminous base layer (70); and
a drainage geocomposite layer (90), the drainage geocomposite layer (90) sandwiched anywhere between any two layers of the flexible pavement.
5. The structural composition (300) as claimed in claim 4 wherein the subgrade layer (10) is made by compacting materials selected from soil, gravels, laterite, superior materials, or any combination thereof, with and without stabilizing materials.
6. The structural composition (300) as claimed in claim 4 wherein the drainage geocomposite is prepared by combining a top geotextile and a bottom geotextile, each having grams per square meter (gsm) in the range of 100-500, with a layer of geonet or any other suitable core to facilitate drainage of grams per square meter (gsm) in the range of 200-1500 sandwiched therebetween.
7. The structural composition (300) as claimed in claim 4 wherein the drainage geocomposite layer (90) is overlaid with a sacrificial layer of geotextile having gsm in the range of 100-500.
8. The structural composition (300) as claimed in claim 4 wherein the stabilized subbase layer (30) is made of dry lean concrete in the rigid pavements.
9. The structural composition (300) as claimed in claim 4 wherein the surface layer (50) is made of pavement-quality concrete in the rigid pavements.
10. The structural composition (300) as claimed in claim 4 wherein the subbase layer (20) is made of materials selected among natural sand, gravel, aggregate, crushed stone, slag brick metal, kankar, crushed concrete, soil, brick aggregate, laterite, and recycled pavement material or any combination thereof with and without cement or cementitious materials in the flexible pavements.
11. The structural composition (300) as claimed in claim 4 wherein the base layer (60) is made of wet mix macadam in the flexible pavements.
12. The structural composition (300) as claimed in claim 4 wherein the bituminous base layer (70) is made from bitumen and aggregate in the flexible pavements.
13. The structural composition (300) as claimed in claim 4 wherein the rigid pavement may include categories such as bonded/unbonded, short panel, reinforced, and plain jointed.
14. The structural composition (300) as claimed in claim 4 wherein the flexible pavement may have different materials for the subbase layer (20) and the base layer (60) such as granular subbase/granular base layer, cementitious subbase/cementitious base layer, emulsion/foam bitumen stabilized reclaimed asphalt pavement/virgin aggregate base layer or any combination thereof.
Dated this on 1st July 2025

Prafulla Wange
Agent for applicant
IN/PA/2058