A MARINA SYSTEM

Abstract: A paving material, walkway (1) or marina system comprising a deck (3) and support means (2) for supporting the deck (3) characterised in that the paving material, walkway (1), marina system or deck comprises glass fibre reinforced concrete, and a process for the manufacture of a paving material or walkway comprising forming a deck (3) from glass fibre reinforced concrete and mounting the deck (3) on a support means (2).

Description: "A marina system" This invention relates to a walkway and more particularly to floating walkways, pontoons, marina systems and the like. Floating marina systems such as pontoons, walkways and finger pontoons for inland and coastal marina developments are usually made up of three primary structures namely, a structural frame, floatation devices for supporting the structural frame and decking disposed on the structural frame. The materials from which the components of marina systems are manufactured are critical and should be selected to optimise the durability, practicality, appearance and cost of the marina system. The decking used in a marina system is usually selected to optimise the strength, durability, non-slip nature, ease of cleaning and aesthetic appearance of the decking. A one piece reinforced concrete deck has been considered to satisfy the above requirements. However, a number of disadvantages are associated with such one piece reinforced concrete decks. A one piece concrete deck does not facilitate ease of access to facilities and services disposed or housed beneath the decking e.g. for maintenance purposes. In addition, reinforced concrete decking is extremely heavy whilst existing codes of practice for concrete demands a minimum coverage of reinforced concrete on steel reinforcements on the structural frame which further increases the weight of the decking. The additional weight of the reinforced concrete decking enhances the vertical stability characteristics of floating marina systems. However, the significant weight of such reinforced concrete decking also raises the centre of gravity of the one piece reinforced concrete deck which increases the instability of the floating system in wave induced roll. An object of the invention is to provide a floating marina system which overcomes the disadvantages of the prior art. A further object of the invention is to provide a strong and durable reduced weight decking for a marina system. Yet a further object of the invention is to provide a durable marina system having a non-slip surface. According to the invention there is provided a walkway comprising a deck and support means for supporting the deck characterised in that the deck comprises glass fibre reinforced concrete. Preferably, the deck comprises parallel slats. More preferably, the glass fibre reinforced concrete comprises a dye. Advantageously, the support means comprises floating means for supporting the deck on water. Preferably, the glass fibre comprises alkali resistant glass fibre. Suitably, the glass fibre comprises fibres 12mm to 30mm in length. Preferably, the glass fibre comprises fibres 25mm in length. Alternatively, the glass fibre comprises a glass fibre reinforced polymer rod. Suitably, the parallel slats comprise a reinforcing net. Advantageously, the reinforcing net comprises plastics. Suitably, the plastic comprises polypropylene. The invention also extends to a paving material characterised in that the paving material comprises glass fibre reinforced concrete. Preferably, the paving material is formed into a slat. Suitably, a plurality of slats is formed into a deck and preferably the deck is formed into a walkway. The invention also extends to a process for the manufacture of paving comprising forming the paving from glass fibre reinforced concrete. Preferably, the paving is formed into a deck and suitably the deck is formed into a walkway. Preferably, the deck is mounted on a support means and suitably the deck is formed into parallel slats. Advantageously, the slats are formed by spraying. Suitably, the glass fibre is alkali resistant glass fibre. Preferably, the glass fibre comprises fibres 12mm to 30mm in length. In an alternative embodiment of the invention the glass fibre comprises a glass fibre reinforced polymer rod. The invention also extends to the use of glass fibre reinforced concrete in the manufacture of a walkway. Preferably, the walkway comprises parallel slats while the walkway is preferably a floating walkway. The invention also extends to a marina system comprising a walkway and/or paving formed from glass fibre reinforced concrete. Glass reinforced concrete is an extremely strong material. No metal reinforcements are required with glass reinforced concrete unlike the reinforced concrete systems of the prior art thereby minimising the weight of the material. Accordingly, the glass reinforced concrete deck of the marina systems, walkways and paving of the invention can be comparatively thin compared with the prior art without compromising durability and strength. Moreover, glass fibre reinforced concrete is an inherently rough material thereby resulting in an non-slip surface without additional treatments being necessary to achieve a gripping surface. More particularly, glass reinforced concrete provides a non-slip surface without requiring texturing of the surface to achieve the non-slip characteristics. Accordingly, the non-textured surface of the decking 3 of the invention renders the decking 3 easier to clean than with textured systems of the prior art. In addition, the colour of the glass fibre reinforced concrete decking can be selected during manufacture according to individual requirements. An embodiment of the invention will now be described, by way of example only, having regard to the accompanying drawings in which: Fig. 1 is a perspective view of a marina system in accordance with the invention; Fig. 2 is a top plan view of a pontoon of a marina system in accordance with the invention; Fig. 3 is a side elevation of the pontoon of Fig. 2; Fig. 4 is a partial cross-section along the line IV-IV of Fig. 1; Fig. 5 is a top plan view of the support frame of the pontoon of Fig. 2; Fig. 6 is an end elevation of the support frame of Fig. 5; Fig. 7 is a transverse cross-section along the line VII-VI I of Fig. 5; Fig. 8 is a transverse cross-section along the line VIII- VIII of Fig. 5; Fig. 9 is a side elevation of the support frame of Fig. 5; Fig. 10 is a longitudinal cross-section along the line X-X of Fig. 5; Fig. 11 is a top plan view of an individual decking plank; Fig. 12 is a side elevation of the decking plank of Fig. 11; Fig. 13 is a transverse cross-section along the line XIII- XIII of Fig. 11; Fig. 14 is a top plan view of the floatation tank of the pontoon of the marina system of the invention; Fig. 15 is an end elevation of the floatation tank of Fig. 14, and Fig. 16 is a side elevation of the floatation tank. As shown in the drawings, a typical marina system in accordance with the invention is made up of a series of linked pontoons or walkways 1. Each pontoon 1 is made up of a support frame 2 having decking 3 mounted thereon. The support frame 2 is provided with an outer skin-like fender 4 typically of timber. The support frame 2 is substantially rectangular in shape and is made up of a first end member 5, a second end member 6, a first side wall 7 and a second side wall 8, all of which are provided with an outer fender 4. The decking 3 is made up of individual parallel transverse slats planks 9 disposed between the first and second side walls 7,8 of the support frame 2 as shall be explained more fully below. The support frame 2 together with the decking 3 is mounted on a series of floatation tanks 10 attached to the underside of the support frame 2. The floatation tanks 10 are substantially box-like in shape and are made up of a rear side wall 11, a front side wall 12, a base wall 13, a top wall 14, a first side wall 15 and a second side wall 16. The floatation tanks 10 are attached to the underside of the support frame 2 by floatation holders 32 which extend downwards from the support frame 2 as shall be explained more fully below. Figs. 4 to 9 show various views of the support frame 2 with the decking 3 removed for clarity. As shown in the drawings, the support frame 2 is provided with four elongate ribs 17 which extend parallel to the central longitudinal axis of the support frame 2 between the first and second ends 5,6 parallel to the first and second sides 7,8 of the support frame 2. The ribs 17 are supported at either end by the first and second end members 5,6 and are each made up of a gusset portion 18 and a channel portion 19. The elongate ribs 17 project upwards into the body of the support frame 2. As shown in Fig. 7, the first and second side walls 7,8 of the support frame 2 are contoured to define side flanges 20,21 respectively shaped to in turn define inwardly oriented grooves 41. The grooves 41 therefore face each other across the support frame 2. The ribs 17 are disposed such that the channel portion 19 of the two ribs 17 most adjacent to each side 7,8 of the support frame 2 are disposed to face the groove 41 of the respective side flange 20,21. The ribs 17 and the side flanges 20,21 together with the respective channel portions 19 and grooves 41 define two side channels 22,23 adjacent the side flanges 20,21 respectively and two intermediate channels 24,25 either side of a centre channel 26 disposed along the central longitudinal axis of the support frame 2. The support frame 2 is further provided with an end flange 31 similar to the side flanges 20,21 shown in Fig. 7 which also defines an end groove 42 for receiving the support frame 2. The channels 22,23,24,25 can serve as conduits as required through which pipelines etc. conveying services can be passed. A pipeline 27 is disposed within the channel 22 and serves to house necessary services such as plumbing and electricity along the length of the marina system of the invention. Screw holes 28 are disposed along the first and second side walls 7,8 of the support frame 2 for attaching the fenders 4 to the support frame 2. As shown in Fig. 6, the support frame 2 is further provided with stiffeners 29 and stiffening plates 30 disposed and spaced apart along the length of the elongate ribs 17. The stiffeners and plates 29,30 respectively serve to reinforce the support frame structure 2. The float holders 32 extend downwards from the support frame 2 i.e. in a direction opposite to the decking 3 to support the floatation tanks 10. Figs. 10 to 12 show enlarged views of an individual plank 9 of the decking 3. As shown in the drawings, the plank 9 is rectangular in shape and is provided with screw holes 28 disposed along the plank 9 for attaching the plank 9 to the support frame 2. The screw holes 28 are located on the plank 9 to correspond to the location of the ribs 17 such that screws inserted through the screw holes 28 extend into the ribs 17. Internally, each plank screw hole 28 is made up of plastic tubing 33 disposed transversely within the plank 9 and a rebate 34 adjacent the surface of the plank 9 for receiving a self tapping screw. Each plank 9 contains a transverse sheet of polypropylene netting 35 disposed parallel to the top and bottom faces of the plank 9 such that the propylene netting is encased by the material of the plank 9 and is concealed within the plank 9. Figs. 13 to 15 show enlarged views of a floatation tank 10 of the pontoon 1. The floatation tank 10 is substantially box-like in shape and is made up of a rear side wall 11, a front side wall 12, a base 13, a top wall 14, a first side wall 15 and a second side wall 16 as previously described. An upwardly extending threaded fixing bar 36 is disposed adjacent each corner at the top face 14 of the floatation tank 10. The threaded fixing bar 36 is provided with a base plate 39 disposed within the top face 14 on which the floatation tank 10 is supported. Each wall of the material of the floatation tank 10 is reinforced with an inner aeroboard block to aid flotation 37. The aeroboard block 37 is shaped to define a corner recess 38 in which the base plate 39 is disposed adjacent each corner of the floatation tank 10. In addition, a polypropylene net 35 is disposed adjacent each threaded fixing bar 36 to reinforce the walls 11,12,13,14,15 and 16 of the floatation tank 10. The planks 9 used in the decking 3 of the marina system in accordance with the invention facilitate easy access to the support frame 2 and the pipeline 27 disposed within the support frame 2 by simple removal as required of individual planks 9 thereby providing easy access to the support frame 2. The planks 9 of the marina system of the invention are manufactured from glass fibre reinforced concrete. Glass Fibre Reinforced Concrete The walkways, pontoons, and marina systems of the invention are made of glass fibre reinforced concrete. Alkali resistant (AR) glass fibre is particularly preferred in the manufacture of the glass fibre reinforced concrete planks according to the invention. AR resistant glass fibre is advantageous as it is more resistant to attack from the alkali normally present in cement compared with normal glass fibre. Moreover, AR glass fibre has particularly good non-combustibility characteristics, is corrosion resistant, and has a high tensile strength similar to piano wire. Suitable glass fibres are available from NEG while a particularly preferred AR glass fibre reinforced concrete is also available from NEG. Further advantages associated with glass fibre reinforced concrete are: Flexibility of design; High impact strength; High bending strength; A high toughness and cracking resistivity; Light weight due to thin section, and Non-combustibility. The fibre lengths of the glass fibre can range from approximately 12mm to 30mm. A glass fibre length of 25mm is particularly preferred as it has been found that such a fibre length provides optimum length from both a workability and structural point of view and provides a glass reinforced concrete product having the desired structural integrity. Shorter glass fibres have been found to render the concrete mix more workable. However, excessively short glass fibre lengths have been found to slip excessively in the concrete. The percentage weight of glass fibre used in the concrete is varied according to the strength and workability required of the concrete. Typically, a glass fibre is used in a percentage rate of 0.5% to 5% by weight of the concrete. Excessively low percentages of fibre offer minimum strength advantage over plain concrete with the strength of glass fibre reinforced concrete increasing as the percentage of glass fibre is increased. However, excessively high amounts of glass fibre have been found to reduce the workability of the glass fibre reinforced concrete excessively. In an alternative embodiment of the invention, the glass fibre used in the concrete can be in the form of elongate rods or rebars inserted in the concrete during moulding of the planks 9. An advantage to using elongate rods of glass fibre is that the rods help to resist breakages thereby reinforcing the planks 9 and obviating the requirement of the netting 35. A suitable rebar for the marina system of the present invention is a 6mm diameter glass fibre reinforced polymer rebar. In the present embodiment of the invention the netting 35 could be replaced by three such rebars spaced apart within the concrete of the planks 9. Suitable glass fibre reinforced polymer rods are available from Hughes Brothers Incorporated, Nebraska, United States. Dye is added in the glass reinforced concrete according to the colour required of the final plank 9. A wide range of colours may be utilized. Any kind of concrete dye may be used in the manufacture of the glass fibre reinforced concrete. Suitable dyes are available from Harcros Pigments Limited. An example of a glass reinforced concrete mixture suitable for use in the manufacture of the plank 9 is given by way of the following non-limiting example: EXAMPLE 1: MATERIAL WEIGHT Ordinary Portland Cement (OPC) 50Kg Sand 50Kg Water 17.5Kg Super Plasticiser .02Kg AR glassfibre 6.2Kg Colour dye As desired The glass reinforced concrete mix was mixed as follows: Equipment Required: A high shear mixer; a power sprayer which consisted of a spray gun connected to an air compressor which was fed by a grout hopper; a chopper for dosing glass fibre; and suitably shaped moulds. Method: Before production was begun the required moulds were cleaned, oiled and left ready for spraying. The required amounts of water and additive were released into the mixer and the mixer was started at a slow speed. The sand and cement were added to the mixing bucket of the mixer. The sand was added first, and the mixer was turned up to a high speed. The cement was then added. The constituents were left to mix for approximately 1 minute. At this stage dye was added to the mix if required and left to mix for a further 1 minute. The resulting grout was now ready for spraying. Before the grout is placed in the power sprayer, the sprayer is washed out thoroughly with clean water. The nozzle is lubricated with washing-up-liquid and placed on the sprayer. The hose is then connected to the nozzle and the spray gun is connected to the hose and air pipes. The compressor is started and all air pressures are checked. The glass fibre is typically in the form of a roll which is fed into the gun as will be appreciated by those skilled in the art. The gun is in communication with a chopper to control spraying of glass fibre portions chopped from the roll through the gun. The grout was then charged into the hopper. The moulds required to be sprayed were put into position. First of all a 3mm layer of grout was sprayed onto the bottom of the moulds, a layer of grout and fibre was then sprayed over the first layer using the gun. This layer was then compacted with the use of a roller. Another layer of grout and fibre was then sprayed and this layer was compacted as before. A strip of reinforcing/polypropylene netting was placed on top of this layer. The final layer of grout and fibre was then applied. This layer was compacted as before and then levelled and finished off using a steel trowel . The moulds were then stacked and new moulds put into position for spraying. When all the moulds required were filled and stacked, the stacks were covered and left to set. The moulds were stripped the following day and got ready for respraying. The floatation tanks 10 used in the marina system of the invention are typically manufactured from polystyrene aeroboard encased in concrete. An advantage of such floatation tank material is the high degree of durability and stability enjoyed by the floatation tanks 10. The floatation tanks 10 of the marina system of the invention are manufactured from a concrete having comparatively short glass fibre strands contained within the concrete. The purpose of the concrete casing of the floatation tanks is to protect the encased polystyrene material from damage. The concrete casing of the floatation tanks is not required to provide structural support unlike the glass fibre reinforced concrete of the planks 9. Accordingly, the structural strength requirements of the concrete of the floatation tanks are not as rigorous as those of the planks 9. A typical floatation tank concrete mix was as follows: EXAMPLE 2: MATERIAL WEIGHT Cement OPC 225Kg Sand 700Kg Water 150Kg Super Plasticiser 7Ltrs AR 12mm Chopped Glassfibre 4.5Kg Aeroboard The percentage rate of glass fibre utilised in the construction of the glass fibre reinforced concrete of the floatation tank is less than that required for the planks 9 as described in relation to Example 1. More particularly, a lower percentage is required as the skin of the floatation tank is non-structural while the purpose of the glass fibre in the skin is to reduce cracking of the skin. Accordingly, the percentage rate of fibre used in the manufacture of the skin was typically around 0.5%. The length of fibre utilised in the production of the glass fibre reinforced concrete floatation tank was typically 12mm. The floatation tank mixture was formed into a floatation tank as follows: A floatation tank mould was employed which consisted of two main parts - an upper steel shutter and concrete base of the following fixed dimensions: 3000 x 1500 x 150mm. The steel shutter was interchangeable and could be increased or decreased in length or width depending on production requirements. When production was due to begin, the mould was cleaned oiled and squared. The floatation tank was cast upside-down. Four holes were predrilled in the slab to receive threaded bars which were anchored in the blocks using reinforced netting. The threaded bars were used to connect the walkways to the floatation tanks. The aeroboard 37 was then chamfered and four holes cut out of each corner with the aid of a template. The glass fibre reinforced concrete mix was transported from the mixer to the moulds. The base was poured first and levelled off to a depth of about 20mm. The aeroboard 37 was then placed in the mould and spacers fixed around the sides. Clamps were placed across the top of the mould to hold the aeroboard down during pouring. The sides were then filled, the spacers were removed and the sides topped off with concrete. The sides were compacted lightly. After an initial set the clamps were lifted and the top was screeded to the required depth. The edge was chamfered off with a bull -nose trowel. The mould was then covered. The following day the moulds were stripped. After a few days drying time the floatation tanks were turned, right-side-up fitted with nuts and washers. The floatation tanks were then stacked and ready for delivery. In use, a marina system as shown in Fig. 1 is assembled from pontoons 1 as previously described. A typical marina system is provided with a primary walkway or pontoon 1 and secondary walkways or pontoons 43 attached to the primary pontoon 1. Each pontoon 43 is provided with floatation tanks 10 also as previously described. Mooring mountings 44 are disposed on the support frame 2 for mooring boats etc. The pontoons 1,43 are connected by connecting frames 45 to secure the secondary pontoons 43 to the primary pontoon 1 at the support frame 2 of the primary pontoon 1 and secondary pontoon 43. The primary pontoon 1 and the secondary pontoons 43 are provided with upstanding service posts 46 so that boats etc attach to moorings 44 can receive electrical power, water and other services from the service posts 46. The service posts 46 are mounted on the planks 9 and are in communication with the service pipe 27 disposed beneath the planks 9 as previously described. The marina system of the invention is held in place by mounting posts 47 inserted in the sea, river or lake bed. The primary pontoon 1 is attached to the mounting post 47 by brackets 48 which enjoy a sliding relationship with the upstanding mounting posts 47 so that the marina system of the invention can ride upwards and downwards on the mounting posts 47 as the water level rises and decreases. Typically, the glass fibre reinforced concrete decking is manufactured in plank form with a standard plank width of 300mm. The plank 10 can be attached to the support frame 2 with stainless steel self tapping screws through the holes 28 cast in the plank. The use of the plastics tubing 33 in the screw holes 28 avoids stresses experienced the support frame 2 in use from being transmitted to the plank 10. In addition, the use of separate plank 9 facilitates replacement of individual plank 9 should damage occur. The use of a polypropylene net in the glass fibre reinforced concrete material used in the marina system of the invention enhances the structural integrity of the glass fibre reinforced concrete and prevents complete separation of a plank 9 should a plank 9 become fractured. However, where glass fibre reinforced polymer rebars are employed no netting is required. The support frame 2 is manufactured from galvanised steel or any other suitable material. An advantage of galvanised steel is that galvanised steel provides flexibility to the support frame 2 which is advantageous during the twisting load experienced by a support frame on waves etc. Galvanised steel is also highly compatible with glass fibre reinforced concrete decking 3. The threaded fixing bar 36 and backing plate 39 are suitably manufactured from stainless steel bolts cast into the glass fibre reinforced concrete. The marina system of the invention is stable under off-shore weather conditions and is suitable for use in the assembly of elongate finger piers. The colour adaptability of the marina system of the invention ensures that a wide variety of colours can be used or blended in the manufacture of marina systems to render the marina system compatible with local and environmental surroundings. Alternatively, the marina system can be coloured to reflect or portray corporate or club colours etc.

Claims: CLAIMS: 1. A walkway (1) comprising a deck (3) and support means (2) for supporting the deck (3) characterised in that the deck (3) comprises glass fibre reinforced concrete. 2. A walkway (1) as claimed in Claim 1 characterised in that the deck (3) comprises parallel slats (9). 3. A walkway (1) as claimed in Claim 1 or Claim 2 characterised in that the glass fibre reinforced concrete comprises a dye. 4. A walkway (1) as claimed in any of Claims 1 to 3 characterised in that the support means (2) comprises floating means (10) for supporting the deck (3) on water. 5. A walkway (1) as claimed in any of Claims 1 to 4 characterised in that the glass fibre comprises alkali resistant glass fibre. 6. A walkway (1) as claimed in any of Claims 1 to 5 characterised in that the glass fibre comprises fibres 12mm to 30mm in length. 7. A walkway (1) as claimed in any of Claims 1 to 6 characterised in that the glass fibre comprises fibres 25mm in length. 8. A walkway (1) as claimed in any of Claims 1 to 5 characterised in that the glass fibre comprises a glass fibre reinforced polymer rod. 9. A walkway (1) as claimed in any of Claims 2 to 8 characterised in that the parallel slats (9) comprise a reinforcing net (35) . 10. A walkway (1) as claimed in Claim 9 characterised in that the reinforcing net (35) comprises plastics. 11. A walkway (1) as claimed in Claim 10 characterised in that the plastics comprises polypropylene. 12. A walkway (1) as claimed in any of Claims 1 to 11 characterised in that the support means (2) comprises a support frame (2) for supporting the deck (3). 13. A paving material characterised in the paving material comprises glass fibre reinforced concrete. 14. A paving material as claimed in Claim 13 characterised in that the paving material is formed into a slat (9). 15. A paving material as claimed in Claim 14 characterised in that a plurality of slats (9) is formed into a deck (3). 16. A paving material as claimed in Claim 15 characterised in that the deck (3) is formed into a walkway (1). 17. A process for the manufacturer of paving comprising forming the paving from glass fibre reinforced concrete. 18. A process as claimed in Claim 17 characterised in that the paving is formed into a deck (3). 19. A process as claimed in Claim 18 characterised in that the deck (3) is formed into a walkway (1). 20. A process as claimed in Claim 19 comprising mounting the deck (3) on a support means (2) . 21. A process as claimed in Claim 20 characterised in that the deck (3) is formed into parallel slats (9). 22. A process as claimed in Claim 21 characterised in that the slats (9) are formed by spraying. 23. A process as claimed in any of Claims 17 to 22 characterised in that the glass fibre is alkali resistant glass fibre. 24. A process as claimed in Claim 23 characterised in that the glass fibre comprises fibres 12mm to 30mm in length. 25. A process as claimed in Class 23 characterised in that the glass fibre comprises a glass fibre reinforced polymer rod. 26. Use of glass fibre reinforced concrete in the manufacture of a walkway (1) . 27. Use as claimed in Claim 25 characterised in that the walkway (1) comprises parallel slats (9). 28. Use as claimed in Claim 26 or Claim 27 characterised in that the walkway (1) is a floating walkway (1). 29. A marina system comprising a walkway (1) as claimed in any of Claims 1 to 12 or a paving material as claimed in any of Claims 13 to 16.

Inventors: LIM CHONG JIN, LIM, CHONG, JIN
Applicants: BANAGHER CONCRETE LIMITED, LIM CHONG JIN, LIM, CHONG, JIN
Application year: 1998
Main classification: E02B3
IPC codes: E02B3