FIELD OF INVENTION:

[0001] This invention relates to the field of hardware - mechanical engineering, in the field of roadside guardrail / Highway safety application. More particularly, a process and a system to make passenger and vehicle safety crash barriers made from creosote-treated bamboo through a vacuum pressure impregnation plant, coated with high-density polyethylene, and fabricated with high tension GI wire ropes.

PRIOR ART AND PROBLEM TO BE SOLVED:

[0002] Vehicles leaving roadways, particularly at high speeds, are extremely dangerous and represent a threat to life for not only those traveling in the vehicle but to anyone in the vicinity too. A two-ton lump of metal traveling at 70mph is going to damage or destroy almost anything it contacts, including buildings, which is why such effort is taken to contain vehicles in the event of this happening. So crash barriers of the appropriate type are installed at accident-prone locations, especially at locations like valley sides of hilly roads, high embankments, sharp/blind curves, etc. It prevents vehicles from leaving the road in the event of an incident while dissipating some of the impact energy and minimizing the chance of fatalities. The use of concrete barriers, W-beam metal barriers, and rope barriers are common nowadays. Rope barriers are very flexible so it is very little area for the application. The same as with concrete barriers, it's a very time-consuming process with high costs. So metal W- beam crash barriers are most familiar but again, considering the cost of the metal barriers and sustain ability of the material, it has come to think of alternatives for safety crash barriers.

[0003] In India, around 1.5 lakh people die every year in close to 5 lakh road accidents. Over one -third of those accidents happen on highways. India's socio-economic cost of road traffic accidents for the year 2019 was in the range of $15.71 billion to $38.81 billion, which amounts to 0.55-1.35% of the GDP, revealed a study by Bosch India. And the reason behind all the losses is the lack of infrastructure of bumps, lanes, side -marking, reflectors, and safety barriers. There are so many pockets on Indian highways where safety barriers are not installed. So currently, India is engaged in a project to remove accident-prone “black spots” and rectify road designs on highways. But it has some limitations with production facilities of conventional barriers, and also the cost factor is also playing an important role. Some low-cost solutions for highway side safety barriers are yet to be found.

[0004] To resolve the above problems, a crash barrier is designed with the sturdy fabrication of VPI-treated and HDPE-coated bamboo poles. The bamboo- made roadside safety barrier is working on the principle of using flexibility to dissipate the kinetic energy from a collision. This solution of crash barrier is available at half price as compared to metal barriers. Bamboo has a naturally constructed hollow cylindrical structure with a high wall thickness which allows it to absorb the impact of a vehicle and slow down its velocity at the time of the crash. HDPE coating enhances the shear strength of the bamboo which protects the joineries during crashes. Here in this invention, all bamboo poles are treated with creosote oil through a vacuum impregnation plant which protects it against any fungal, borer, or termite attacks and enhances the longevity of bamboo.

THE OBJECTIVES OF THE INVENTION:

[0005] The principal objective of the invention is to design a crash barrier that is made from VPI-treated bamboo poles coated with High-density Polyethylene (HDPE) and fabricated with high-tension GI steel ropes. Which absorbs the impact energy of the hitting vehicles and reduces the severity of the accidents. To design the extremely strong beam and the post, they are attached with high tension GI wire rope. This combination allows for the posts to move, flex or even for the beam to break free in a collision and cushion the vehicle - slowing it down while not catapulting it back across the roadway. [0006] Another objective of the invention is to fabricate the crash barrier, which functions as a system with the beam, posts, connection of the beam to the posts and each other, and the end anchors (or terminals) all playing an integral role in how the crash barrier will function upon impact. It is effectively one strong band that transfers the force of the vehicle to the beam elements, posts, and finally to the end terminals or anchors.

[0007] The further objective of this invention is to use the good mechanical properties of bamboo in designing a low-cost crash barrier that is efficient to protect the vehicle and passenger during crashes. Bamboos are used as the main cushion, flexural and tension element. All the bamboos are treated with creosote oil through the VPI plant, which protects them against fungal, borer, or termite attacks. Bamboos are coated with HDPE to make them weatherproof and to enhance their shear properties of it. All the elements are fabricated with high-tension GI wire ropes. The design has a bamboo-made spacer which also reduces or minimizes vehicle snagging on the posts upon impact. In addition, a spacer may be used to increase the offset of the beam with an obstacle such as a curb.

SUMMARY OF THE INVENTION:

[0008] There are a considerable number of reasons for choosing bamboo-made crash barriers over flexible steel ones. Bamboo-made crash barriers are suitable for Indian narrower roads, more effective against heavier vehicles. It reduces damage suffered by vehicles colliding with them and also eliminates headlight dazzling as there are no gaps for light to shine through. Its smooth, flush surface is less likely to cause injury to motorcyclists with more resistance to damage from impacts, and the single barrier can perform all functions, including single barrier medians.

BRIEF DESCRIPTION OF ACCOMPANYIMNG DRAWINGS:

[0009] FIG. 1 is a front elevation of a crash barrier according to the invention, FIG. 2 is an end view of a crash barrier, FIG. 3 is plan views of a crash barrier,

FIG. 4 is a backside view of a crash barrier,

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

Fig 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

[0010] 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.

[0011] 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.

[0012] 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. [0013] 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.

[0014] 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.

[0015] 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 - 24hrs) - stage 2 (40°c for 24 - 48hrs) - stage 3 (60°c for 48 - 72 hrs) and stage 4 (70°c for 72 - 96hrs).

[0016] 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 solventbased 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.

[0017] 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.

[0018] 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 pic system with servo-gearbox. The extrusion unit has several parts like a screw barrel, head, hopper, and heater.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] Crash barrier fabrication unit

The fabrication table is designed for both beam and post. The fabrication table consists of hydraulic pres sure -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.

[0023] 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. [0024] 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.

[0025] 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 MIO 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.

[0026] 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.

[0027] 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).

[0028] 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. [0029] The post elements 1 are joined together as shown in FIG 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 MIO boult 13 passed through 1(a) and 1(b) horizontal direction. Simultaneously two MIO boult 13 passed through 1(a) to 1(c) and 1(b) to 1(c) tightened axial direction and joined all elements rigidly.

[0030] 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.

DRAWINGS REFERENCE NUMERICALS:

1. Post elements

2. Beam elements

3. Front cushioning element

4. Spacer

5. MIO boult (beam - post connector)

6. MIO boult (beam - spacer - post connector)

7. High tension wire rope 8. Wire rope loop with aluminum ferrule

9. U - clamp (wire rope)

10. Night reflectors

11. Hex head nut

12. Washer

13. MIO boult (post)

14. MIO boult (beam)

[0031] Example