A BAMBOO BASED CRASH BARRIER FOR ROADS OR HIGHWAYS

Abstract

A crash barrier for road highways is designed to provide a progressively increasing resistance to impact, which is designed with the sturdy fabrication of creosote-treated and HDPE-coated bamboo poles. Which is weatherproof and long-lasting, highly resistive against fungal, borer, termite attacks and working on using flexibility to dissipate the kinetic energy from a collision. In one embodiment a beam (2) comprising a club of three separate poles 2(a), 2(b), 2(c) is mounted on upright posts (1) consisting of three poles 1(a), 1(b), 1(c) placed triangularly at an angle of 60 with each other with connecting elements (3, 4). The rear elements (4) are of bamboo with node and are relatively stiff while the front elements (3) are hollow tubular and therefore more easily deformed. The deformable connections are fabricated with high tension GI wire rope 7, fixed with U clamps 9, and locked with crimping locks 8.

Claims

1. A crash barrier for roads or highways, comprising of: at least a horizontal beam (2) and a vertical post (1) connected with deformable components (4); wherein said horizontal beam (2) construction comprises a club of three separate poles (2(a), 2(b), 2(c)) supported on said vertical posts one above the other vide fabrication of creosote oil-treated bamboo poles through the vacuum pressure impregnation and coated with high-density polyethylene; wherein a front cushioning element (3) is provided an the front face of horizontal beam; wherein the assembly of said horizontal beam (2) and vertical post (1) is carried out with high tension MS bolts, struts, nuts, and washer connectors that has deformable components between beam (2) and posts (1); wherein the said connectors and spacer (4) elements are deformable components, thereby providing a progressively increasing resistance to impact by a vehicle on the said beam (2); and wherein said construction of the deformable components are fabricated with high tension GI wire rope (7) tightened with a winch, fixed with U clamps (9), and end locked with crimping locks (8).

2. The crash barrier as claimed in claim 1, wherein the bamboo poles used in said vertical post (1), beam (2), front cushioning element (3), and spacer (4), are treated with creosote oil through a vacuum pressure impregnation plant and coated with HDPE in order to make them weatherproof, and increase compressive strength of the crash barrier elements.

3. The crash barrier as claimed in claim 1, wherein the said beam and post are configured to dissipate the kinetic energy from a collision of a vehicle.

4. The crash barrier as claimed in claim 1, wherein the said beam (2) and post (1) is configured to allows the posts to move, flex, or even for beam (2) to bend enough to reform its original shape during the collision and cushion the vehicle.

5. The crash barrier as claimed in claim 1, wherein the fabrication of the crash barrier transfers the force of the vehicle to the front cushioning element (3), spacers (4), beam elements (2), posts (1), and finally to the end terminals or anchors.

6. The crash barrier as claimed in claim 1, wherein the creosote-treated and HDPE coated bamboo poles act as the main front cushioning (3) and said spacer (4) elements give cushion, flexures, and tension working and minimizes a vehicle snagging on the posts upon impact.

7. The crash barrier as claimed in claim 1, wherein the said beam (2) is made from three creosote treated and HDPE coated bamboo poles 2(a), 2(b), 2(c) joined on each other vertically with high tensile M10 bolts (14) with washer (12) and nut (11).

8. The crash barrier as claimed in claim 1, wherein the said post (1) is made from three creosote treated and HDPE coated bamboo poles 1(a), 1(b), 1(c) placed triangularly which makes an angle of 60 with each other joined with high tensile M10 bolts (13) with washer (12) and nut (11).

9. The crash barrier as claimed in claim 1, wherein each post (1) has deformable connections (4) between the beam (2) construction and the posts (1), which is more deformed than the other elements in a horizontal direction transverse to the length of the beam (2) construction.

10. The crash barrier as claimed in claim 1, wherein said horizontal beam (2) and cushion element (3) are reformable element set upon a post (1) parallel to the road.

11. The crash barrier as claimed in claim 1, wherein each deformable connection element-spacer (4), comprises a hollow tubular open-ended bamboo structure treated with creosote oil and coated with HDPE.

12. The crash barrier as claimed in claim 1, wherein beam (2) is mounted on deformable connecting elements (4) and acts as a semi-rigid crash barrier.

13. The crash barrier as claimed in claim 1, wherein said beam (2) is secured to each of said posts (1) by a bolt (6) traversing to beam 2(b) to post 1(c) through the spacer (4).

14. The crash barrier as claimed in claim 1, wherein the poles 1(a), 1(b), 1(c) constituting said post (1) and said beam (2) elements 2(a), 2(b), 2(c) have a constant diameter, the diameter of said beam elements being smaller than the diameter of the post elements and the spacer (4) and front cushioning element (3) diameter is greater than both beam and post elements.

15. The crash barrier as claimed in claim 1, wherein the said crash barrier beam and post-assembly consist of hydraulic jaws for bamboo poles fixing and fixed drills for joining works.

Description

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

[0009] FIG. 1 is a front elevation of a crash barrier according to the invention,

[0010] FIG. 2 is an end view of a crash barrier,

[0011] FIG. 3 is plan views of a crash barrier,

[0012] FIG. 4 is a backside view of a crash barrier,

[0013] FIG. 5 is a perspective view of a crash barrier, &

[0014] FIGS. 6(a) and 6(b) illustrates the real time picture of the bamboo crash barrier before and after a crash and corresponding test results thereof furnished as an example.

DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention provides a method of making a crash barrier as used on motorways and motor roads of the type comprising a generally horizontal beam supported by upright posts which is made from creosote-treated bamboo through a vacuum pressure impregnation plant, with HDPE coating and fabricated with high tension GI wire ropes which are long-lasting, all weatherproof, and strong enough to prevent vehicles from leaving the road in the event of an incident while dissipating some of the impact energy. Here we have described the detailed process of making a crash barrier.

[0016] There are 1250 listed species of bamboo in the world and more than 125 species are found in India alone. Each has its characteristics and mechanical properties. In this application, mechanical properties are the most important thing. We have selected Bambusa Balcooa and Bambusa Bambos. Both species are known for their naturally woven solid strands, high wall thickness, and good mechanical properties. Both species grow up to a height of 20-25 meters with 10-15 cm diameter and 20-30 mm wall thickness.

[0017] Bamboo is known for its strength and it comes from the naturally woven solid strands structure. From day one the new bamboo shoots convert into mature bamboo with proper strands structure, which takes the time of 2.5-3 years. The harvesting method ensures the harvesting of matured clumps with desired specifications. Cutting the clumps in the required size from 12-28 feet with a high accuracy cross-cutter machine for further processing. The cutting process is inspected by trained people.

[0018] Split and cracked pieces shortened in bundles and marked as rejected. Bend pieces get bundled for the straightening process. The straight pieces go into the next process. This is a very important process because the strength of bamboo depends on its diameter and natural structure and maturity. Every piece goes through an inspection process and is sorted into different categories. Then they are to be set into different racks. The diameter vise-shortened bamboos are transported for further use.

[0019] After cutting and sorting, the bent pieces are taken for the straightening phase. Bamboos are straightened using a conventional process with the help of some mechanization. The system has 4 furnaces to heat the bamboo. Before heating, every bamboo is passed through a manual coating process of a mixture of sodium hydroxide and mustard oil. These materials help bamboo in the heating and seasoning process. 400-500 C. temperature is provided to bamboo for a specific time focused on the area that needs to be straightened. After heating, appropriate bending force is given manually or by the hydraulic jacks in the opposite direction of the bent area. This opposite force removes the bend and straightens that particular section.

[0020] At the time of harvesting, bamboo contains up to 25-30% moisture. The best tensile strength of bamboo is obtained with low moisture content (likely 10-13%). So the excess moisture is removed by the specialty-designed seasoning chamber. This chamber works with the biomass-based boiler system. The boiler generates the required steam and the steam passes through the pipes of the chamber. Meanwhile, the normally dry air flows by crossing the pipes. The dry heated air gradually removes the moisture from the bamboo strips. Specific temperature of chamber stage 1(25 C. for 0-24 hrs)-stage 2 (40 C. for 24-48 hrs)-stage 3 (60 C. for 48-72 hrs) and stage 4 (70 C. for 72-96 hrs).

[0021] Bamboo is known for very good strength but it has known issues with several types of attacks like fungal, borer, termite, etc. Which reduces the longevity of bamboo. There are several treatment methods for its protection, but the most scientific and engineering method is VPI-Vacuum Pressure Impregnation. The oil-based or solvent-based solution is used in this process. The treatment solution is selected as per the application and raw material type. An oil-based treatment Creosote oil, which contains a very good quantity of bitumen and naphthalene with IS 2018:1983 code is injected into every pore of bamboo strips by the VPI plant at the temperature of 50 C. The main treatment chamber is filled with strips. The vacuum pump creates the vacuum in the treatment chamber to suck out the air and moisture via the vacuum chest. Then it sucks creosote oil into the full vacuum. Bamboo strips in the chamber where bamboo strips absorb the creosote oil. The pressure pump injects the creosote oil into the pores of the bamboo strips. In another solvent-based treatment, CCB (Copper-Chrome-Boron) solutions with IS 9096:2006 code is used with a ratio of (1.5:3:4) with the same method solution and is injected into strips of bamboo by using a VPI plant.

[0022] In VPI treatment, some excessive solvent or oil is soaked by strips and it has to be removed. Poly seasoning chamber with auto temperature-air control system is used in this process. Airflow with 25 C. for the first 24 hrs-20 C. up to 48 hours-15 C. up to 72 hrs is set during the operation. In the case of creosote oil, it solidifies the fuming elements into naphthalene which lasts longer into the strips. In the case of CCB solution, the outer surface of excessive water is dried at the required temperature.

[0023] The treated and seasoned Bamboos are ready for the next HDPE coating operation. The system has an extrusion unit where the raw bamboo pieces are connected to the cap by a pneumatic stapler machine on the feeding table. Specifically designed connecting caps maintain feeding sequence and distance between bamboos. The Haul-off (Traction) machine pulls the bamboo towards the extrusion head. Haul-off speed is controlled by a plc system with servo-gearbox. The extrusion unit has several parts like a screw barrel, head, hopper, and heater.

[0024] The raw HDPE granules are sucked through the pipe and heated to 80 degrees Celsius in the hopper for 90 minutes. Preheating process removes moisture from granules. The granules are fed into the screw barrel, which is covered by heaters. The heaters are covered with an insulation chamber. There are five heating zones in the barrel and the granules are heated at temperatures of 150-170-180-205-215 degrees to melt the HDPE granules. The temperature of the screw barrel is maintained by the auto-cut thermocouple control panel and cooling system. The melted HDPE plastic comes out from the extrusion head while the bamboo simultaneously passes through the inner side of the HDPE layer through the coating head. So the bamboo passes through the head by stretching the HDPE layer.

[0025] At the very next point, a cooling system shrinks, the hot melted plastic and the HDPE coating get the shape of bamboo. 4 cooling zones bring down the coating temperature gradually by 150-120-80-40 degrees. The second Haul-off (traction) machine pulls the coated bamboo and forwards it towards the cutting table. Once cooled, the bamboo is further cut to the appropriate size. Capping is done with a Capping machine working on the same principle of extrusion.

[0026] Precise quality checkpoints ensure the quality of HDPE coating on the Bamboo pole. The auto-laser-operated surface check QC machine is used in this process. Defective and punctured coating pieces are separated and tested and approved coated bamboo poles are selected for the fabrication of the crash barrier.

Crash Barrier Fabrication Unit

[0027] The fabrication table is designed for both beam and post. The fabrication table consists of hydraulic pressure-operated jaws to fix the HDPE-coated bamboo poles and a computer-controlled 5-axis drill machine that drills with high accuracy. A tensioner machine with a gear ratio of 1:10 is used for GI wire rope clamping and fabrication.

[0028] Referring first to FIGS. 1 to 4, a crash barrier comprises a series of upright posts 1, preferably of clubbing of three creosote treated and HDPE coated bamboo poles 1(a), 1(b), 1(c) placed in a triangle shape set into soil or concrete bases. The actual crash beam 2 may be of various different designs, but in this particular example, it is clubbing of three creosote treated and HDPE coated bamboo poles 2(a), 2(b), 2(c) placed on each other vertically and parallel to the road.

[0029] On the front side of each beam 2 the front cushioning element 3, a creosote-treated and HDPE coated bamboo pole with a hollow tubular structure with naturally woven nodes is placed transverse direction on the roadside which is connected with high tension wire rope 7 tightened at the rear side of post 1 with u-clamp 9 and aluminum ferrule 8 joint. These wire rope connections bind the front cushioning element 3, beam elements 2, spacer 4 and post elements 1 very tightly. Thus it will be seen that this front cushioning element 3 is deformed by a vehicle impact and if the crash barrier is struck by a light vehicle the force will be absorbed by the crushing of the front cushioning element 3. This collapsing may be sufficient to absorb most of the energy of an impact from a light vehicle.

[0030] Referring to FIG. 2, At each upright post 1, beam 2 is supported by a connection which includes front and rear connecting element spacer 4. Creosote treated and HDPE coated bamboo piece which has a hollow tubular structure with or without node is used as a spacer element. Spacer element 4 is a deformable connection between beam elements 2 and post elements 1 which is connected with M10 head bolt 6 passes securely to the beam 2(b) and tightened rear side to the post 1(c) with washer 12 and hex head nut 11.

[0031] Thus if the beam is struck by a heavy vehicle the spacer element will be fully flattened and the heavy impact will then be absorbed by deforming and crushing the spacer.

[0032] FIG. 4 also illustrates an important feature of the invention concerned with the attachment of beam structure 2 to the vertical posts 1. In the system illustrated, for example in FIG. 3, four heavy-duty M10 hex head bolts 5 are secured to the post element 1(a) and a(b). To fix the spacer 4 the M10 head bolt 6 passes securely to beam 2(b) and through the post 1(c).

[0033] The beam elements 2 are joined together as shown in FIG. 4 on the fabrication table. Elements 2(a), 2(b), and 2(c) are set vertically upon each other, and two vertical and two horizontal hydraulic jaws fix the elements. Drilling and M10 boult 14 passed through 2(a), 2(b) and 2(c) tightened at another end of 2(c) joining all elements rigidly.

[0034] The post elements 1 are joined together as shown in FIGS. 3 & 4 on the fabrication table. Elements 1(a), 1(b), and 1(c) are set vertically in a triangle shape at a 60 angle with each other and making a tangent with the road. Two axial and two horizontal hydraulic jaws fix the elements. Drilling and two M10 boult 13 passed through 1(a) and 1(b) horizontal direction. Simultaneously two M10 boult 13 passed through 1(a) to 1(c) and 1(b) to 1(c) tightened axial direction and joined all elements rigidly.

[0035] Crash barrier made from Creosote treated and HDPE coated bamboo poles perform better comparted to metal W beam and C post. As per the bending test conducted at VNIT, Nagpur accordance to IS 516-1959 reaffirmed in 2004. The maximum loads reported in the table below are corresponding to the deflection of 150 mm.

TABLE-US-00001 Sr. Span No. Specimen Details (m) Maximum Load (KN) 1 Beam - Three Bamboo Cluster 2 30.95 2 Post - Four Bamboo Cluster 1.8 40.95 3 Metal W section 2 17.77 4 Metal C section 1.8 34.00

DRAWINGS REFERENCE NUMERICALS

[0036] 1. Post elements

[0037] 2. Beam elements

[0038] 3. Front cushioning element

[0039] 4. Spacer

[0040] 5. M10 boult (beam-post connector)

[0041] 6. M10 boult (beam-spacer-post connector)

[0042] 7. High tension wire rope

[0043] 8. Wire rope loop with aluminum ferrule

[0044] 9. U-clamp (wire rope)

[0045] 10. Night reflectors

[0046] 11. Hex head nut

[0047] 12. Washer

[0048] 13. M10 boult (post)

[0049] 14. M10 boult (beam)

EXAMPLE

TABLE-US-00002 TEST DETAILS Test Standard EN1317-1&2 Test type TB Test product Bamboo Crash Barrier Date of Test Dec. 5, 2022 Date of Report Feb. 6, 2022 Client details M s B ya S ti Pvt Ltd. Target impact speed 100 + 7% kmph Target impact angle 20 (+1.5/1) Target test weight of vehicle 900 40 kg TEST ARTICLE DETAILS Name of the manufacturer M s B ya S ti Pvt Ltd. Name of test item Bamboo Crash Barrier (Kooch K ch) Total length of test item in metres 51.2 m. Total length of end terminals 24 m. (12 m each) Height of the test item in the 0.85 m. impact area Post spacing and/or unit length in metres Middle Beam Section 1.6 m COMPONENTS OF THE TEST ARTICLE (Middle SECTION) Sr. No Component Description Dimensions 1 Post 90 10 mm, Length 1800 mm 2 Beam 80 10 mm, Length 4800 mm 3 From Cushioning 100 10 mm, Length 1422 mm Element 4 Spacer 110 10 mm, Length 300 mm 5 Beam - Post Co M10, Length 360 mm 6 Beam - Post - Spacer M10, Length 280 mm Connector 7 Wire Rope 5 mm, length 1700 mm 8 Wire Rope 8 mm, length 52000 mm 9 Post Bolts M10, length 190 mm 10 Beam Bolts M10, length 250 mm indicates data missing or illegible when filed

TABLE-US-00003 TEST VEHICLE DETAILS Vehicle identification number MP0 C 3653 Vehicle make/model Hyundai 10 mag Vehicle model year and/or initial registration 2010 Vehicle mass 97 kg Added ballast weight Yes Ballast type/description| Instruments Total ballast mass 23.2 kg Total test mass in kilograms (kg) 920.2 kg RESULTS TEST CONDITION Actual impact speed in kilometres per hour (km/h) 102 kmph % Difference from nominal speed +2% Actual impact angle in degrees 19 Difference from nominal angle in degrees TEST ITEM Dynamic deflection (dm) in metres 0.8 Normalised dynamic deflection (d ) in metres 0.81 Working width (w ) in metres 1 Normalised working width (w ) in metres 1.01 Class of normalised working width W3 Lengths of contact in meters 8 m Actual impact point location Between Post 19.sup.th indicates data missing or illegible when filed

TABLE-US-00004 IMPACT TEST ACCEPTANCE CRITERIA Actual impact speed and angle within tolerance limits? Yes Actual impact speed and angle combination within the tolerance Yes envelope. During and after the impact no more than one wheel of the Yes vehicle passes over the rearmost part of the deformed system? Vehicle rolls over during the test? No Vehicle within exit box? No indicates data missing or illegible when filed