FIELD OF THE INVENTION

[001] The present invention relates to the field of a concrete panels precast pavement system. The invention, particularly relates to the precast pavement system wherein the reinforcement in the form of glass fiber reinforced polymer rebars have been placed in a particular manner inside the precast pavement panels and transfer precast panels has been placed for efficient load transfer.

BACKGROUND OF THE INVENTION

[002] Conventional concrete pavement construction involves preparing then positioning forms around an area proposed for pavement. The forms is having vertical inner surfaces to receive and contain poured concrete, further, the horizontal top surfaces, which usually are level with the surface of the poured concrete, or, once cured, pavement surface. The forms are having back surfaces that rest against appropriately-spaced stakes for holding the forms in place. Regardless of whether the structure and quality of forms, field chamferring requires considerable time for large pavement areas.

[003] In recent years, a number of field trials and research studies have been undertaken by various institutes and organization for developing a new kind of composite material. Glass Fiber Reinforced Polymer (GFRP) based construction become popular using dowel bars appear to be a promising alternative to conventional concrete pavement because of their non-corrosive properties and higher flexural strength. GFRP based construction includes a binder, a strong reinforcing element, inert materials and combination thereof. The binders can be selected from a group of a resin or polymer material such as, but not limited to, polyester, vinyl ester or epoxy and the like. The reinforcing material is used selected from a group of fiberglass, carbon fiber, or graphite fiber and combination thereof. The glass content not only provides the dowel good susceptibility to the corrosion; however, the glass type and resin type bases material do have a positive impact on the corrosion resistance. The glass content provides a positive effect on the mechanical properties (modulus, shear resistance, etc.) of the bars.

[004] There have been a number of researches provided for findings indicate the use of GFRP bars as dowel bars to overcome steel dowels in the pavement construction and enhances the bending strength of the placed members having various characteristics and few of them have been discussed below: [005] US 9458632 B2 discloses composite materials and methods thereof, making high temperature resistant composite materials. The composite materials of the present invention can be fabricated into landing pads, components used in landing pads to provide a structure to support the take-off and landing of aircraft, roadways or similar travel paths for heavy equipment, and/or components used in roadways or similar travel paths for heavy equipment. The composite material can also be comprised of an inorganic ceramic matrix having a top surface in facing opposition to a bottom surface and at least one side surface between the top surface and the bottom surface, a first open weave fabric comprising a plurality of fibers disposed in the matrix proximate the bottom surface of the matrix, and at least one additional open weave fabric comprising a plurality of fibers disposed in the matrix between the first open weave fabric and the top surface of the matrix, wherein the at least one additional open weave fabric is positioned closer to the bottom surface than the top surface of the matrix.

[006] A non-patent literature Glass Fiber-Reinforced Polymer Dowels for Concrete Pavements discloses results on the performance of GFRP dowel bars used in transverse joints of concrete pavements. The article includes static and cyclic laboratory testing in addition to field testing using the falling weight deflectometer. There are three types of GFRP have been tested in addition to epoxy-coated steel in the article. The article also provides information on load transfer in pavements and the feasibility of using GFRP in this application. A link is also given to study the article https://pdfs.semanticscholar.org/552b/d0e5da449accca1541902e 9cab4656c00fb5.pdf. The aforesaid documents and other similar solutions may strive to provide a precast pavement system, modular and removable maintenance; however, they still have a number of limitations and shortcomings such as, but not limited to, inability to modify without causing traffic jams and extensive use of resources for a longer period, the builder requires substantial amount of money and also high precision cannot be achieved as many uncontrollable factors are involved such as weather, workmanship, poor curing etc. The above mentioned prior arts can only perform certain aspects say for example provides a composite material structure having a various fixing and supporting member and further, the implementation of light weight and corrosion free materials with joint effectiveness or load transfer efficient structure.

[007] Accordingly, there remains a need in the prior art to have a concrete panels pre- casted in a factory or workshop of rectangular cross section reinforced with glass fiber reinforced polymer bars as per their requirement with the reduced thickness and C&D waste management, therefore overcome the aforesaid problem and shortcomings. OBJECTS OF THE INVENTION

[008] Some of the objects of the present invention satisfied by at least one embodiment of the present invention are as follows:

[009] An object of the present invention is to provide an alternative to the conventional method of paving in the form of precast pavement system -AgrPath. [010] Yet another object of the present invention is to reduce the time of construction of pavement using precast technology.

[011] Another object of the present invention is to increase the flexural strength of the pavement which helps increase the life of the pavement and reduce the thickness following have been done.

[012] Still another object of the present invention is to provide the pavement panels which can be used for retrofitting, i.e. panels which can replace faulty slabs if required. These and other objects and advantages of the present invention will become more apparent from the following description, when read with the accompanying figures of drawing, which are however not intended to limit the scope of the present invention in any way.

SUMMARY OF THE INVENTION

[013] In the view of the foregoing disadvantages inherent in the known types of system, wherein the construction of pavements with the use of concrete (cast in situ), dowel bars are embedded in the pavement to transfer loads across a transverse joint from one slab of concrete pavement to the next, now present in the prior art, the present invention provides a pavement system having high precision during manufacturing and use of alternative reinforcement in the form of glass fiber reinforced polymer rebars in the lower section of concrete panels helps achieve high flexure strength without increasing but rather decreasing the quantity of material used and hence resulting in higher flexure strength as compared to the conventional counterpart and saving on material as well. As such, the general purpose of the present invention to provide the longevity of the pavement and reduces the need of maintenance and repair, which will be described subsequently in greater detail, is to provide a new and improved, which has all the advantages of the prior art and none of the disadvantages.

[014] In accordance with an aspect of the present invention, a system without pre stressing, which implies that AgrPath is having the better flexural strength and life to the pavement at a lesser cost in less time.

[015] In accordance with another aspect of the present invention, a precast pavement system enables the panels to be directly installed at the site by manufacturing the panels in a controlled environment. As the project time period is cut short the resources will be spent for a shorter period resulting in a reduction in the resources consumed as well which will eventually lead to reduction in capital expenditure. Another very useful advantage of the system is that if the pace of construction of roads in the country is increased manifold then it will definitely prove to be a boon to the economy of the country as roadways provide mobility and connect people which for sure will enable those in remote areas get opportunities they’ve till now been deprived of.

[016] In accordance with another aspect of the present invention, a concrete panel pre-casted in a factory or workshop of rectangular cross section reinforced with glass fiber reinforced polymer rebars. Further, Reinforcement placed in the lower most fibers of concrete panel, so that reinforcement takes the flexural loading, and eventually reduce the thickness of the precast panel.

[017] In accordance with another aspect of the present invention, the precast panels are laid on site and then installed. There might be a problem of edge cracking at joints to eliminate which another structural element called transfer precast panels have been introduced. [018] In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.

[019] These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[020] The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:

[021] FIG. 1 illustrates a cross section view of a various layers of the pavement in accordance with an embodiment of the present invention;

[022] FIG. 2 illustrates a cross section view of dowel slots of the pavement in accordance with another embodiment of the present invention;

[023] FIG. 3 depicts a top plan view of dowels in accordance with another embodiment of the present invention;

[024] FIG. 4 & 4A depicts bottom reinforcement and a top reinforcement of the pavement in accordance with another embodiment of the present invention; [025] FIG. 5A & 5B depicts cross-section view of transverse and longitudinal sides in accordance with another embodiment of the present invention;

[026] FIG. 6 depicts side view of Dowel Slots in accordance with another embodiment of the present invention; [027] FIG. 7 depicts longitudinal joints in precast panels in accordance with another embodiment of the present invention; and

[028] FIG. 8 depicts top view of the pavement in accordance with another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION [029] In the following detailed description, reference is made to the accompanying drawings which form a part thereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that the embodiments may be combined, or that other embodiments may be utilized and that structural and logical changes may be made without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims and their equivalents.

[030] Referring now to the drawings, there is illustrated, in FIG. 1 , a precast pavement system (100) constructed from a plurality of precast pavement panels. The system is comprised of a top precast panel (105) and a transfer precast concrete panel (110). The top precast panel is having reinforcement in the form of a plurality of glass fiber reinforced polymer (GFRP) rebars, and the transfer precast concrete panel (1 10) connected with a plurality of dowel bars (135) along the length of a pavement for providing a load transfer mechanism. The top precast panel (105) is further comprising a plurality of glass fiber strands in a lower section of the precast pavement panels. Further, the Load transfer mechanism at transverse joints, as shown in FIG. 2 & 3 is provided using the conventional method used for the approved AgrPath system not describing for the sake of brevity of the present invention. For repair / retrofitting applications, dowels are drilled and installed in the existing pavement.

[031] In accordance with an embodiment of the present invention, the transfer precast concrete panel (110) is laided across a base layer (125) and a bedding layer (115) and further, placed on a sub-base layer (120), wherein the base layer (125) is a Graded Construction & Demolition Waste layer. Further, the bedding layer (115) with the approved bedding material, as required, and comprised of Bituminous foam, fly ash paste, marble dust paste or a combination thereof.

[032] In accordance with another embodiment of the present invention, the required material for the sub-base layer (120) is selected from a group of Bitumen macadam, Dry Lean Concrete (DLC), Fine graded sand, mixture of some inert wastes with sand or a combination thereof. The various composition of the composite material is prepared in the amount and other parameters says for example grade of concrete, compressive strength, thickness etc., which can be further evaluated while constructing the pavement according to the environmental and other condition. The existing base to be left in place may be a granular base or a stabilized base. If the existing base is a granular base, the base shall be regraded and compacted using vibratory roller compaction in accordance with. The moisture content in the upper granular base can be adjusted, as necessary, to allow the compacted base to achieve dry density of, but not limited to, 92% of the maximum dry density for that material. [033] As required by the project plans and/or the approved AgrPath system requirements, the preferable treatments can be applied to the compacted granular base or an existing stabilized base includes the steps: Fine-grained granular bedding, applied, the bedding material can be compacted and graded; Cementitious material bedding, applied, the cementitious material may be placed directly over the soil compacted existing base (130) before panel placement.

[034] The fine-grained granular and the cementitious bedding material, if placed directly over the base, can be finished to the required grade and compacted to provide a smooth surface for panel placement. A fine-grading trimmer is used to trim the granular bedding surface to ensure that the panels can be placed at the correct surface elevation. Cementitious bedding material placed directly over the existing base shall be finished to the designated grade using concrete-finishing tools.

[035] The finished bedding surface have no areas in excess preferably of, but not limited to, 1800 cm ² at the bedding surface that exhibit low spots in excess preferably of, but not limited to 3 mm. The prepared bedding surface should not be disturbed before placement of the panel.

[036] Further, a new base can be constructed as required by the project plans. The new base can be constructed to the width and thickness designated in the project plans. The new base surface can be finished to ensure that the panels are placed at the correct surface elevation. The finished base surface have no areas in excess preferably of, but not limited to, 1800 cm ² at the bedding surface that exhibit low spots in excess preferably of, but not limited to, 3 mm. The prepared bedding surface not to be disturbed before placement of the panel. [037] In accordance with another embodiment of the present invention, the precast panels is placed directly over the granular or cementitious bedding material, all panels will be underseal using the preferred cementitious undersealing grout material. Grout ports (140) are uniformly distributed across the panel area as shown in the FIG. 3. Preferably, a minimum of four grout ports is used per panel.

[038] Preferably, the undersealing grout (140A) attain a compressive strength of, but not limited to, 3.4 MPa at the time of opening to traffic. When the grout (140A) is pumped, the grout flow rate should be within the pre-determined range. The grout is mixed in a batch pump in batches and pumped continuously from a grout hopper. The undersealing grout ports is filled to mid-depth with the undersealing grout (140A). The rest of the port depth is filled with the slot patching grout or patching material or other approved higher-strength rapid-setting patching material.

[039] In accordance with another embodiment of the present invention, as shown in the FIG. 4 & 4A the precast pavement system where reinforcement in the form of glass fiber reinforced polymer rebars has been placed in a particular section of precast pavement panels so that the depth of the panels get reduced. Further, a new sort of element has been integrated with the system which is called transfer precast panel, this element is placed beneath the ending of one panel (the top precast panel) and beginning of the other (the top precast panel) with the sole purpose of increasing load transmission efficiency. The precast pavement system where panels of reduced thickness are precast without pre-stressing and then installed directly in the desirable location. The longevity of the pavement is helped by the use of transfer element as well as alternate reinforcement. [040] In accordance with another embodiment of the present invention, the precast panel is constructed in a factory or workshop, preferably but not limited to, of rectangular cross section reinforced with glass fiber reinforced polymer rebars, wherein the reinforcement is placed in the lower most fibers of concrete slab so that reinforcement takes the flexural loading. This also helps to reduce the thickness of the precast slab. The precast slabs are laid on site and then installed. There might be a problem of edge cracking to eliminate which another structural element called transfer precast panel has been introduced.

[041] In accordance with another embodiment of the present invention, referring to FIG. 2 the precast panels is placed so that the width of the transverse joints incorporating the panels preferably not exceed, but not limited to, 10 mm, and further, the width of the longitudinal joints preferably set to be within, but not limited to, 3 mm of the width. If the precast panels are opened to traffic before the dowel slots (135A) are grouted or patched, shims is used at the approach joint side of the panels to prevent forward drift of the panels under traffic.

[042] In accordance with another embodiment of the present invention, preferably, the vertical elevation difference at the transverse joints between the precast panels and the existing pavement or another panel is not exceed, but not limited to, 5 mm. If the elevation difference is larger, the joint areas can be ground full width to bring the repair area under compliance.

All transverse and longitudinal joints (155) of the pavement shall be sealed. Joint widths will vary from site to site and repair areas, and joint widths may range from 8 to 12 mm or more. This variation should be kept in mind if polyurethane rods (150) are used as part of the joint sealing operation with other relevant sealant (145). [043] In accordance with another embodiment of the present invention, the transfer precast panel (110) is a slab placed beneath the linkage of alternate panels. These panels help the load to transmit gradually from one panel to other. The panels are connected with dowel bars (135) along the length of the pavement and tie bars along the width of the pavement. The dowel bars (135) and tie bars are used to connect the panels to each other firmly.

[044] In accordance with another embodiment of the present invention, the dowel slots (135A) shall be patched or grouted as shown in FIG. 2 & 3. For AgrPath systems with dowel slots at the precast panel bottom, the approved rapid-setting dowel slot grout (140A) is poured through grout ports (140) into each slot.

Whether a grout material or a rapid-setting patching material is used for the dowel slots (135A), the material attain the required compressive strength preferably of, but not necessarily limited to, 21 .90 MPa before opening the repair area to traffic. The grout material or the dowel patching material or other approved material is used to fill the anchor ports and to repair any surface damage to the panel.

[045] In accordance with another embodiment of the present invention, the various panel hardware is embedded in the precast pavement panels, which may include Reinforcement placed in a single direction or both directions and in one or two layers; Block-outs provided for Dowel bars (135) and any other load transfer devices; Grout ports for Dowel bar slots; Anchors (160) as shown in FIG. 8; and Panel setting bolt hardware, if required.

[046] In accordance with another embodiment of the present invention, the longitudinal and transverse cross-section view of the top reinforcement (165, 165A) and bottom reinforcement (170) is being casted in the concrete for the top precast panels, as shown in FIG. 5A and 5B. Some extra top reinforcement (165A) has to be given for the safety of the anchors. They define the minimum percentage of reinforcement that can be used for the top precast panels in either side independent of panel size and loading conditions. [047] In accordance with another embodiment of the present invention, the profile of the longitudinal edge (155) of the top precast panels, as shown in FIG. 7. They are a kind of interlocking joint provided on both the panels that are locked at the time of installation to perform as a transfer joint along the longitudinal side of the pavement. The dimensions are dependent on the loading and thickness of the panel. [048] In accordance with another embodiment of the present invention, the precast pavement panels can also include a surface texture. The surface texture is applied while the concrete is still in a plastic state, but without damaging the surface of the concrete and before application of any membrane curing compound. The surface textures to the top surface of the precast panel can be selected from Transverse tining; or AstroTurf drag.

Method and Operation

[049] In the practice of the method of the present invention, the work include, but is not necessarily limited to, the steps: Saw-cutting and removal of existing pavement; existing or new base preparation; Installation of approved bedding material, as required; Fine grading of the base and bedding; Placement of Precast Panels; Installation of load-transfer devices at transverse joints; Placement of precast panels; Panel undersealing; Patching of load-transfer device; Grinding; and Joint sealing of the precast pavement panels. [050] In accordance with another embodiment of the present invention, the precast pavement panels which can be used for retrofitting i.e. panels which can replace faulty slabs if required. The precast pavement system is fabricated and installed in accordance with the demand of the traffic load intensity and stretch of the road for a complete and new construction of pavement. Also these specification details for materials and processes for fabrication and installation of AgrPath to be used for continuous rehabilitation of existing asphalt and concrete pavements.

[051] In accordance with another embodiment of the present invention, the precast panels is stripped of formwork after the concrete has attained a minimum compressive strength to ensure that the concrete would not be damaged during the stripping process and to allow for lifting of the panels. The stripped panels may be moved to other areas within the plant to take care of the panel finishing details. These finishing details may include Clean-up of the block-outs; Installation of foam strips (gaskets) along the bottom edges of the panel and along the preferred perimeter of the dowel slots (135A) as shown in FIG. 6; Applying project and panel-specific marking on each panel; Checking for any damage to the panel, repairing minor surface damage, and filling small surface voids using a sand-cement paste or an approved proprietary patching material; Rounding the top edges of the panels with a hand stone to prevent chipping during handling and installation; Checking for dowel bar alignment; and Checking for dimensional tolerances. All forms and casting-bed areas should be cleaned after each use.

[052] The above-mentioned precast pavement system opened to the traffic only after the following applicable conditions are met, which includes: At the end of the first lane closure when a system with slots at the panel bottom is used or narrow-mouth surface slots are used, the repair areas can be opened to traffic even if the slots have not been grouted or patched; At the end of the next lane closure after the panels with the bottom slots are grouted, or the narrow-mouth slots are patched and the panels are undersealed and the materials have reached the minimum acceptable strength. Work should be scheduled to minimize the exposure of precast panels to traffic prior to patching or grouting the dowel slots (135A). Panels without effective load transfer at transverse joints or without panel undersealing (for panels placed directly on the bedding) shall not be exposed to traffic for a pre-determined period. Further, the system helps with cutting on the depth of the pavement, along with adding to the longevity as well as pace of pavement construction. [053] It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-discussed embodiments may be used in combination with each other. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description.

[054] The benefits and advantages which may be provided by the present invention have been described above with regard to specific embodiments. These benefits and advantages, and any elements or limitations that may cause them to occur or to become more pronounced are not to be construed as critical, required, or essential features of any or all of the embodiments.

[055] While the present invention has been described with reference to particular embodiments, it should be understood that the embodiments are illustrative and that the scope of the invention is not limited to these embodiments. Many variations, modifications, additions and improvements to the embodiments described above are possible. It is contemplated that these variations, modifications, additions and improvements fall within the scope of the invention.