Coquina Based Underwater Mitigation Reef and Method of Making Same
A method of forming a concrete block embedded with coquina stone comprising the steps of positioning a layer of sand on the bottom surface of a concrete block form, then positioning a layer of coquina stone above the layer of sand positioned on the bottom surface, then pouring concrete over the layer of sand and the layer of coquina stone, thereafter allowing the concrete to harden to form a concrete block which is then removed from the concrete block form.
This application claims priority to U.S. Provisional Application Ser. No. 61/125,803 filed Apr. 29, 2008 entitled “Coquina based underwater mitigation reef and method of making same” that is herein incorporated by reference in its entirety.
FIELD OF THE INVENTIONThis present invention relates to artificial underwater reefs replicating a habitat for underwater plant and animal wildlife in general, and in particular, to a mat of concrete blocks that are embedded with coquina or similar rock and a method of construction thereof.
BACKGROUND OF THE INVENTIONIn the past, there have been attempts made to create underwater reefs to attract marine animals and plant life. For example, ships have been sunk in the ocean to attract fish and marine life. Similarly, other man-made structures have been used often anchored to the ocean bottom to provide a habitat for fish and marine life. In addition, attempts have been made to recreate habitat following damage to underwater reefs caused by hurricanes. Moreover, when real estate development projects are undertaken on the ocean coasts, many areas require mitigation in the form of creating artificial reefs to compensate for the dredging and removal of hardbottom areas. In the past, boulders or other rocks have been used to create what some refer to as a mitigation reef. However, such prior mitigation reefs have been used but found to provide inadequate habitat for aquatic and marine life. Thus, there is a need to provide an artificial mitigation reef that provides suitable habitat for underwater marine and fish populations.
SUMMARY OF THE INVENTIONNow, heretofore, a product referred to as cable concrete has been used in erosion control applications. Cable concrete comprises mats of concrete blocks where the concrete blocks are held together through ropes, including nylon or metal ropes, and placed over areas where erosion may occur, including stream beds, culverts, etc. Cable concrete is used in a variety of applications including Channel and Slope Protection. It has been used in sewage treatment plant applications and low water crossing applications. It has been used for boat ramps, lakeshore protection, tank crossings, and channel protection for storm sewer outlets. Further, cable concrete mats have been used for storm water management ponds, and access road overflows. Other applications include lakeshore protection, bridge abutment protection, bridge and/or pier protection, as well in landfill applications, and to form access roads. The cable concrete mats have also been used in underwater applications to prevent scour.
In addition, it is well known that natural reefs made of coquina rock provide a desirable habitat for underwater marine life and fish life. Coquina rock or stone contain fragments of shell and sand which protrude from the surface. Raw coquina stone from a quarry looks similar to a clump of sand tightly packed with tiny shells and larger shell fragments. Natural coquina reefs are said to exist off the coast of North Carolina and Florida, as well as Barbados. On-shore quarries where coquina stone may be found are known to exist in Florida.
It has been posited that mats of cable concrete where the concrete blocks have been embedded with coquina stone, or other suitable stone such as coral stone may serve as useful artificial mitigation reefs. Testing to determine whether coquina rock embedded in the concrete blocks of cable concrete would serve as suitable artificial mitigation reefs has been undertaken. It is believed that a suitable artificial mitigation reef requires that the coquina rock stay sufficiently embedded in the concrete, with substantial coverage by the coquina rock over the concrete, and that the underwater marine life grow on the coquina-embedded concrete blocks of the mats of cable concrete.
There are a number of potential different ways to construct coquina stone embedded concrete blocks. For example, 32″ by 32″ inch concrete blocks may be poured and coquina stone placed on top of the wet concrete. Of course, many different size and shaped concrete blocks may be used. The coquina stone may be pushed into the concrete with a flat board or possibly vibrated into the concrete. Using this method, the coquina stone did not embed as well as other methods or provide coverage of the concrete as well as other methods. An alternative method of embedding the coquina stone into the concrete blocks was devised. In this alternative method, 32″ by 32″ open top boxes were constructed that had an interior sidewall height of between 8.5″ and 9″. Again, different size and shaped blocks could be used. Prior to the pouring of concrete into the open top boxes, an inch of sand was evenly spread on the bottom surface of the box. Next, a layer of coquina stone was placed on top of the sand. Next, the concrete was poured over the coquina stone and sand and allowed to harden. When the concrete blocks were removed from the open top boxes, the excess or loose sand came free exposing the coquina stone embedded into the concrete. Experimental tests have been undertaken to determine whether mats of cable concrete that include coquina stone embedded concrete blocks will serve as a suitable artificial mitigation reef. Further, an alternate method to make the coquina stone embedded concrete blocks could be done without the use of sand in the bottom, although it is believed that this would not provide as good of a coquina embedded stone compared to when the sand is used in the process.
The present embodiments are illustrated as exemplary embodiments that disclose a method of embedding coquina stone into concrete blocks that used in mats of cable concrete that are used to create artificial mitigation reefs.
In the preferred embodiment, 32″ by 32″ concrete blocks were formed having a height of 8.5″ to 9″. The cable concrete mats of the present invention are not limited to this size block however. Smaller or larger sized blocks including 16″ by 16″ blocks could also be used. To construct the concrete blocks that are embedded with coquina stone, a preferred method of construction has been devised which preferably includes the steps of positioning about one inch of sand spread evenly over the bottom surface of a concrete forming box, next adding a layer of coquina stone on top of the sand, the layer of coquina stone being of one to two inches thick, and finally, pouring concrete over the layers of coquina stone and sand. Once the concrete has sufficiently set, the concrete blocks are removed and sand in the bottom of the concrete forming box is removed, leaving a layer of exposed coquina stone embedded in the concrete blocks.
In forming a mat of cable concrete where the concrete blocks used in the cable concrete mats are embedded with the coquina stone, it is useful to set up series of concrete forming boxes, that are adapted to allow nylon or steel rope, most preferably polyester rope, to extend into the concrete blocks and connect one concrete block to the next to form a mat of concrete blocks, referred to as cable concrete upon hardening of the concrete.
An even more detailed explanation of a preferred method of construction is set forth below herein. There are at least two suitable ways to position the connecting rope in the blocks for use in creating a mat of cable concrete. The first way is to create a mold that resembles an oversized ice cube tray as shown in
The second procedure entails just a single mold (referred to as a cube although not required to be a cube in the geometric sense, much like ice cubes of varying geometry are referred to as cubes). The sand and stone is placed in the cube in the same manner as the full mold (ice cube tray style in
Normally a 4,000 psi concrete is used but different applications, engineers, or specifications may require concrete of varying strengths. The setting time before the blocks can be removed from the mold is approximately 12 hours but this is determined by the location and temperatures that molds are poured in. The time for placement is a minimum of seven days after the concrete blocks are manufactured. A number of mats of cable concrete may be connected together as desired. The cable concrete mats can be connected together with stainless steel clamps, any type of crimping sleeves that are used in saltwater, and stainless steel straps. The standard connecting distance is every 4 feet on centers, around the perimeter of the mats. It should be noted that it may not always be necessary to connect the mats together once installed.
The claims should not be read as limited to the described order or elements unless stated to that effect. Therefore, all embodiments that come within the scope and spirit of the following claims and equivalents thereto are claimed as the invention.
Claims
1. A method of forming a concrete block embedded with coquina stone comprising the steps of:
- positioning a layer of sand on a bottom surface of concrete block form;
- positioning a layer of coquina stone above the layer of sand positioned on the bottom surface;
- pouring concrete over the layer of sand and the layer of coquina stone;
- allowing the concrete to harden to form a concrete block;
- removing the concrete block from the concrete block form.
2. The method of claim 1, wherein the layer of sand is approximately one inch deep.
3. The method of claim 2, wherein the layer of coquina stone is approximately one to two inches deep.
4. The method of claim 1, further including the step, prior to the step of pouring the concrete, of positioning a rope or cable within the concrete block form that extends from a point within the concrete block form to a point outside the concrete block form.
5. The method of claim 4, wherein the cable or rope extends through two sidewalls of the concrete block form.
6. The method of claim 5, wherein the cable or rope is comprised of polyester.
7. A method of making a mat of cable concrete including a plurality of concrete blocks embedded with coquina stone, comprising the steps of:
- preparing a plurality of concrete block forms to be poured with concrete;
- positioning a layer of sand on a bottom surface of the plurality of concrete block forms;
- positioning a layer of coquina stone above the layer of sand positioned on the bottom surface of the concrete block forms;
- positioning a rope or cable within the plurality of concrete block forms that extends from a point within the concrete block forms to a point outside the concrete block forms;
- pouring concrete over the layer of sand and the layer of coquina stone and the rope or cable in the plurality concrete block forms;
- allowing the concrete to harden to form a plurality of concrete blocks;
- removing the concrete blocks from the plurality of concrete block forms.
8. The method of claim 7, wherein the layer of sand is approximately one inch deep.
9. The method of claim 8, wherein the layer of coquina stone is approximately one to two inches deep.
10. The method of claim 7, wherein the rope or cable extends from one concrete block form into an adjacent concrete block form.
11. The method of claim 7, wherein the connecting step is performed by having a cable or rope extend from one concrete block form into an adjacent concrete block form such that when the concrete hardens, the adjacent concrete blocks are connected by the rope or cable.
12. The method of claim 1, further including the step, prior to the step of pouring the concrete, of positioning a first plastic or metal tube within the concrete block form that extends all the way through the concrete block form.
13. The method of claim 12, further including the step, subsequent to the step of positioning the first plastic or metal tube, of positioning a second plastic or steel tube within the concrete block form that is perpendicular to the first plastic or steel tube and that extends all the way through the concrete block form.
14. The method of claim 12, further including the step of threading rope or cable through the first plastic or metal tube.
15. The method of claim 12, further including the step of threading rope or cable through the first and second plastic or metal tubes.
16. The method of claim 15, wherein the concrete block is connected to an adjacent concrete block that was made in accordance with the same process as the concrete block.
17. The method of claim 15, wherein the concrete block is connected to other concrete blocks made in accordance with the same process as the concrete block to form a cable concrete mat.
18. The method of claim 1, wherein the coquina stone comprises coral stone.
19. The method of claim 7, wherein the coquina stone comprises coral stone.
Type: Application
Filed: Apr 29, 2009
Publication Date: Oct 29, 2009
Inventors: Louis Arvai (West Lorne), Charles Chase (Rodney)
Application Number: 12/432,321
International Classification: E02B 3/04 (20060101);