Patent Application
20110064517
This invention relates to, in general, concrete for use in surfaces or pavements such as roads, sidewalks, driveways, bridges, and the like.
For decades, during significant rainstorms or snowmelt, cities and towns have experienced flooding of roads, streets, parking lots, etc. As recognized by the present inventor, what is needed is a new concrete structure that can be used to build roads, streets and other concrete structures while reducing flooding risks.
In light of the above and according to one broad aspect of one embodiment of the invention, disclosed herein are new methods and structures for forming concrete structures that can be used to make roads, sidewalks and other pavements or infrastructures. Specifically, embodiments of the invention utilize pervious concrete material with basalt reinforcement members (basalt rebar members, basalt mesh, or both) to form concrete structures or pavements that can be used for construction of roads, sidewalks and other concrete structures or infrastructure. Through the use of embodiments of the present invention, the concrete structures or pavements formed permit water and air to pass through the concrete structures, which provides various benefits, such as reducing the need for complex and expensive storm water runoff systems in flood prone areas.
In accordance with another broad aspect of an embodiment of the invention, disclosed herein is a pavement, comprising pervious concrete material and one or more basalt reinforcing members embedded in or positioned below the pervious concrete material. The one or more basalt reinforcing members may be basalt rebar rods, or basalt rebar rods having a Figure-Eight shape, or a mesh made of basalt strands. The one or more basalt reinforcing members add structural rigidity to the pervious concrete, making the pervious concrete capable or supporting loads as normally experienced on pavements. In one example, the pavement may also include a layer of filtration fabric positioned below the basalt reinforcing members.
In another embodiment of the present invention, the pavement may include a compacted soil layer; a layer of filtration fabric positioned above the compacted soil layer; and a layer of course aggregate material positioned above the layer of filtration fabric. The one or more basalt reinforcing members may be positioned above the layer of course aggregate material. In one example, the pervious concrete material forms the upper surface of the pavement.
In another example of the invention, the one or more basalt reinforcing members are positioned approximately two inches or more above the bottom of the pervious concrete material. The pavement may be used to form a road, parking lot, driveway, sidewalk or other structure as disclosed herein, which allows water or moisture to pass through the surface of the pavement and be filtered. Such a pavement reduces flooding and the need for complex storm drainage systems adjacent to the pavement.
In accordance with another broad aspect of an embodiment of the invention, disclosed herein is a method for forming a road. In one example of the invention, the method includes the operations of compacting a sub-base layer; installing a filtration fabric above the sub-base layer; installing a layer of aggregate material above the filtration fabric; positioning one or more basalt rebar reinforcement members above the layer of aggregate material; and pouring a layer of wet pervious concrete material above the one or more basalt rebar reinforcement members.
In another example, the method may also include leveling said layer of wet pervious concrete, and compacting said layer of wet pervious concrete. In another embodiment, the method may also include curing said layer of pervious concrete. The method may also include placing the one or more basalt rebar reinforcement members approximately two or more inches above the layer of aggregate material, and in another example, the method may include pouring a portion of said wet pervious concrete material below the one or more basalt rebar reinforcement members, so that the wet pervious concrete material embeds the one or more basalt rebar reinforcement members. In this manner, a road can be formed which allows water or moisture to pass through the road and be filtered, thereby reducing flash flooding and reducing or eliminating the need for complex storm drainage systems adjacent to the road.
The foregoing and other useful features and advantages of the invention will be apparent from the following more particular description of a various embodiments of the invention as illustrated in the accompanying drawings.
Disclosed herein are new methods and structures for forming concrete structures or reinforced pavements that can be used to make roads, sidewalks and other infrastructures. Specifically, embodiments of the invention utilize pervious concrete material with basalt reinforcement members (basalt rebar members, basalt mesh, or both) to form concrete structures or pavements that can be used for construction of roads, sidewalks and other concrete structures or infrastructure. Through the use of embodiments of the present invention, the concrete structures formed permit water and air to pass through the concrete structures, which provides various benefits, such as reducing the need for complex and expensive storm water runoff systems in flood prone areas.
By embedding basalt reinforcement members within pervious concrete, the PSI rating level of the pervious concrete structure formed is believed to be sufficient to withstand traffic loads and other weight bearing loads because basalt reinforcement members both reinforce the pervious concrete material and the basalt reinforcement members can be exposed to water without rusting or being weakened by rust over time. Through the use of pervious concrete combined with one or more basalt reinforcement members, roads and streets can be formed so that the amount of rainwater runoff in flash flood prone areas is reduced. Instead, rainwater or other moisture passes through the pervious concrete surface and down below the grade of the concrete surface.
Through the use of embodiments of the present invention, during rain or snow or other moisture conditions, the groundwater aquifers can be more readily replenished because the water/moisture passes through the pervious concrete to the aquifers located below such pervious concrete. Moreover, through the use of embodiments of the present invention, several environmental constraints typically experienced by impervious or traditional concrete can be avoided or minimized while serving many of the same purposes as standard concrete. For instance, pervious concrete allows water to pass through it and seep into the soil therefore becoming instrumental in recharging groundwater and reducing large amounts of stormwater runoff. Because pervious concrete allows water and air to pass through the concrete structure, there is a large reduction in the need for complex and expensive storm water runoff systems in flood prone areas.
Many characteristics of basalt materials have been recognized by the present inventor as useful when combined with pervious concrete. Basalt is a naturally occurring volcanic rock that employs a variety of benefits when compared to steel reinforcement typically used for reinforced concrete. It is believed that basalt materials have a higher tensile strength than fiberglass or possibly steel. Basalt is a naturally occurring rock which means it can resist rust or any type of corrosion and does not absorb any amount of water. Basalt rebar is also about ¼ of the weight of steel rebar, which makes basalt rebar much easier to transport and assemble on the job site. Also, basalt rebar can be easily cut and shaped using common tools in the field.
If desired, the basalt rebar members 54 may be temporarily held together in a desired patters using coated wire twist ties, also known as bar ties (not shown), which temporarily can affix rebar members to one another. The bar ties can be, in one example, 16 gauge, 6 inch steel ties if desired.
Pervious concrete 52 is commercially available from many concrete companies, such as Lafarge North America, Inc. Basalt rebar and basalt mesh may be available from Raw Energy Materials, Inc. of Pompano Beach, Fla. In one example, the basalt rebar members 54 can be rods made of a unidirectional composite of basalt fibers.
In one example, to construct a surface such as a road or sidewalk or other concrete structure using an embodiment of the present invention, after the sub-grades and sub-bases have been prepared, one or more basalt reinforcement members (e.g., 54, 62) are positioned along the surface as desired to achieve the required structural integrity or PSI ratings. Pervious concrete material 52 is poured on top of such basalt reinforcement members, and the top of the pervious concrete material is compacted (in one example, the top half inch of pervious concrete material may be compacted). The surface of the pervious concrete material can be covered with plastic, ply, or a tarp to keep the pervious concrete moist during curing which may take a number of days for the pervious concrete to fully cure. In one example, joints between pervious concrete members can be placed for instance, every twenty feet, and it is believed that expansion joints would not be needed since pervious concrete material does not expand or contract in the same manner as impervious concrete. The plastic/ply/tarp also functions to keep rainwater out of the pervious concrete material while the pervious concrete material is curing.
Embodiments of the invention may be used to form roadways 70 (FIG. 4)(compare to
In one example of the present invention, pervious concrete 52 may be formed in a manner that is thicker in consistency compared to regular concrete 74, as pervious concrete 52 can be formed as a mixture of cement, coarse aggregates (i.e., ⅜″ gravel or limestone), water, and little or no sand. Pervious concrete 52 may be formed so that it has a large volume (e.g., approximately 15-30%) of interconnected voids 100 (
In one example, pervious concrete 52 may be delivered to a job site in a conventional ready-mix concrete truck, and can be poured within one hour of being initially mixed. Pervious concrete 52 may be poured into standard concrete forms using 2″×4″ wood forms or other conventional forms or related techniques, in one example.
In one example, a surface or pavement 110 such as a road, sidewalk, driveway, parking lot, or the like, can be formed using pervious concrete 52 reinforced with basalt rebar 54.
One example of a method of forming a pavement using pervious concrete 52 and basalt rebar members 54 is illustrated in
At operation 122, a non-woven, geotextile filtration fabric 114 is placed to cover the compacted soil and acts as a silt catcher in use, when the water percolates into the soil below. The geotextile fabric 114 also functions as a weed blocker to prevent any unwanted growth that could disrupt the pervious concrete layer 52.
At operation 124, coarse aggregate material 116, such as limestone, crushed glass, superheated clay, is placed on the filtration fabric 114. In one example, more than 6″ of coarse aggregate 116 is placed on top of the geotextile fabric 114 which in use increase the storage capacity, as well as provide a secondary filtration layer to capture pollutants before they enter storm drains or compacted soil 112 below.
At operation 126, basalt rebar members 54 are placed on the coarse aggregate 116. In one example, the basalt rebar members 54 are placed in 1′×1′ grids covering the entire area where the pervious concrete will be installed. The grid may be formed using basalt rebar members 54 that are held together in the grid through the use of wire ties. In one example, each basalt rebar rod 54 may have a diameter of approximately ⅝″, although the dimensions of the basalt rebar members will vary depending upon the needs of a particular application. Concrete chairs or support blocks 118 may be used to support the basalt rebar, for instance 2″ above the layer of coarse aggregate 116. This will allow the rebar 54 to become embedded in the pervious concrete 52 about 2-2½″ from the bottom of the pervious concrete layer. In one example, for each 8′ span of rebar, three chairs or support blocks can be evenly installed underneath the rebar grid for support.
At operation 128, the pervious concrete 52 is poured over the basalt rebar 54. In one example, the pervious concrete 52 is poured such that there is a sufficient amount ready for compaction, for example 6″ for sidewalks and driveways, 10-12″ for streets/roadways.
At operation 130, the pervious concrete layer 52 is leveled and compacted while still wet. In one example, a vibrating mechanical screed is used to level off the pervious concrete 52, wherein the screed is a flat board or tool used to smooth concrete after it has been placed on a surface.
In one example, at least ½″ of the pervious concrete layer 52 may be striked-off above the form to allow for compaction. Operation 130 may also include compacting the pervious concrete, for instance, through the use of a heavy steel roller to compact the pervious concrete layer. This operation creates a pervious concrete slab where the top approximately 1½″ has smaller voids to trap pollutants captured from substances like oil and grease. Edges near the forms may be compacted using a small, hand-held press to prevent raveling of the edges.
After placement of the pervious concrete layer, at operation 132, a mist of water can be applied to the pervious concrete 52, and the pervious concrete 52 may be protected by covering it with plastic sheeting (e.g., a 6 mil polyethylene cover such as Visqueen), and kept damp for 5 to 7 days until full hydration has occurred in the pervious concrete. In one example, the curing process begins within approximately ten minutes of the initial placement of the pervious concrete layer 52, and continues for at least 7 days. In one example of the invention, the pervious concrete layer is believed to reach its maximum strength after 28 days of curing.
In another embodiment of the invention, a pavement surface 110 such as a road, sidewalk, driveway, parking lot, or other surface can be formed using pervious concrete 52 with one or more basalt rebar reinforcement members 140 that have a “Figure Eight” shape.
One example of a method for forming a pavement surface 110 using pervious concrete 52 with a reinforcement of basalt rebar members 140 having a “Figure Eight” shape is illustrated in
At operation 144, basalt rebar members 140 having “Figure Eight” shapes are placed on the coarse aggregate. In one example, these basalt rebar members 140 are placed in 1′×1′ grids covering the entire area where the pervious concrete will be installed. The grid may be formed using basalt rebar members that are held together in the grid through the use of wire tires. In one example and as shown in
At operation 125, the pervious concrete is poured over the shaped rebar. In one example, the pervious concrete is poured such that there is a sufficient amount ready for compaction, for example 6″ for sidewalks and driveways, 10-12″ for streets/roadways.
At operation 126, the pervious concrete layer is leveled and compacted while still wet. In one example, a vibrating, mechanical screed is used to level off the pervious concrete, wherein the screed is a flat board or tool used to smooth concrete after it has been placed on a surface. In one example, at least ½″ of the pervious concrete layer may be striked-off above the form to allow for compaction. Operation 126 may also include compacting the pervious concrete, for instance, through the use of a heavy steel roller to compact the pervious concrete layer. This operation creates a pervious concrete slab where the top approximately 1½″ has smaller voids to trap pollutants captured from substances like oil and grease. Edges near the forms may be compacted using a small, hand-held press to prevent raveling of the edges.
After placement of the pervious concrete layer, at operation 127, a mist of water can be applied to the pervious concrete, and the pervious concrete may be protected by covering it with plastic sheeting (e.g., a 6 mil polyethylene cover such as Visqueen), and kept damp for 5 to 7 days until full hydration has occurred in the pervious concrete. In one example, the curing process begins within approximately ten minutes of the initial placement of the pervious concrete layer, and continues for at least 7 days. In one example of the invention, the pervious concrete layer is believed to reach its maximum strength after 28 days of curing.
In another embodiment of the invention, a pavement surface 110 such as a road, sidewalk, driveway, parking lot, or other surface can be formed using pervious concrete 52 with a reinforcement of basalt geomesh or mesh 150.
One example of a method for forming a pavement surface using pervious concrete 52 with a reinforcement of basalt geomesh 150 is illustrated in
At operation 154, a basalt geomesh 150 is placed directly on top of the coarse aggregate without the use of concrete chairs or steel substitutes. In one example, a basalt geomesh 150 is a mesh or basalt strands having a plurality of approximately 1″ by 1″ squares of basalt strands.
At operation 155, once the basalt geomesh 150 has been installed over the coarse aggregate, pervious concrete is poured over the geomesh 150 until the desired thickness of concrete has been reached.
Operations 156-157 may be similar to operations 130-132 of
In one example, at least ½″ of the pervious concrete layer may be striked-off above the form to allow for compaction. Operation 156 may also include compacting the pervious concrete, for instance, through the use of a heavy steel roller to compact the pervious concrete layer. This operation creates a pervious concrete slab where the top approximately 1½″ has smaller voids to trap pollutants captured from substances like oil and grease. Edges near the forms may be compacted using a small, hand-held press to prevent raveling of the edges.
After placement of the pervious concrete layer, at operation 157, a mist of water can be applied to the pervious concrete, and the pervious concrete may be protected by covering it with plastic sheeting (e.g., a 6 mil polyethylene cover such as Visqueen), and kept damp for 5 to 7 days until full hydration has occurred in the pervious concrete. In one example, the curing process begins within approximately ten minutes of the initial placement of the pervious concrete layer, and continues for at least 7 days. In one example of the invention, the pervious concrete layer is believed to reach its maximum strength after 28 days of curing.
If a pothole 160 (
Referring to
At operation 162, one or more holes 163 are drilled into or about the collapsed section of the pervious concrete, wherein the hole(s) are drilled deep enough to allow a sand slurry injection 164 of operation 165 to reach underneath the pervious and fill the void created by the loss of compaction in the subgrade.
At operation 165, sand or a slurry of sand 164 is injected into the drilled hole(s) 163, which fills the void(s) in the subgrade or sub-soil below the pothole. The injected sand slurry 164 provides for both long term stable subsurface conditions by restoring the level of the compacted soil or course aggregate underneath the pervious concrete 52, and also retains an effective permeability through the repaired subsurface beneath the repaired pothole. Once completed, the rebar 54 and the pervious concrete 52 returns to their original position, and hence the pervious concrete has been repaired.
In one example, the methods disclosed herein for forming a pavement or surface 50, 60, 70, 80, 90 or 110 (such as a road, alley, parking area, sidewalk or other surface) may include forming the surface through the use of one or more basalt reinforcement members combined with pervious concrete, without the need for installing stormwater pipes or other stormwater drainage.
Embodiments of the invention can be used to make or repair various pavements surfaces or roadways, such as but not limited to streets, sidewalks, driveways, parking lots, highway shoulders, non-vehicular bridges, lightweight vehicular bridges, heavy highways, and lightweight structural components such as parking garage floors, curbs, or other floors, for example.
Through the use of embodiments of the present invention, streets or other structures can be created with significantly reduced or zero runoff, meaning that streets or other structures such as parking lots, sidewalks, etc. can be formed without the need for underground pipes or catch basins, which can result in a significant cost savings when building or maintaining such streets or other infrastructure. Embodiments of the present invention may also eliminate the need for rainfall stormwater management or portions thereof, as well as pumps which are used in cities such as New Orleans.
In another embodiment, where existing streets or infrastructure already have storm systems in place, the streets, roads, sidewalks and other infrastructure can be replaced with streets, sidewalks or other structures utilizing embodiments of the present invention. In repairing an existing road, the processes described above could also include an operation of removing the existing pavement and/or other materials present, until the soil layer is exposed.
In one example, a concrete structure using pervious concrete may be formed using construction techniques that are used with impervious concrete; and in other embodiments, different construction techniques are used for forming concrete structures using pervious concrete. For instance, in accordance with an embodiment of the present invention, the basalt rebar members combined with the pervious concrete material can be configured by placing the basalt rebar members in a pattern that is specially adapted or designed to increase the structural integrity of the pervious concrete structure.
In another embodiment of the present invention, a method is disclosed for planting of trees, shrubs or other vegetation along sidewalks or roadways. In one example, the method includes identifying a location for having the tree, shrub or vegetation planted, providing pervious concrete material with basalt reinforcement members around the desired location for the tree, shrub or vegetation, and allowing the pervious concrete to form. The tree, shrub or vegetation can then be planted after the pervious concrete cures. Because of the pervious nature of the concrete, water will drain through the concrete structure (sidewalk, road) and provide water and nutrients to the tree, shrub or vegetation. Therefore, the tree, shrub or vegetation will not have a tendency to uproot the sidewalk, road, or other concrete structure, as typically happens with sidewalks or roads that utilize impervious concrete. Moreover, the roots of tree, shrub and other vegetation will receive more water and air through the use of pervious concrete than with conventional impervious concrete.
While the methods disclosed herein have been described and shown with reference to particular operations performed in a particular order, it will be understood that these operations may be combined, sub-divided, or re-ordered to form equivalent methods without departing from the teachings of the present invention. Accordingly, unless specifically indicated herein, the order and grouping of the operations is not a limitation of the present invention.
It should be appreciated that reference throughout this specification to “one embodiment” or “an embodiment” or “one example” or “an example” means that a particular feature, structure or characteristic described in connection with the embodiment may be included, if desired, in at least one embodiment of the present invention. Therefore, it should be appreciated that two or more references to “an embodiment” or “one embodiment” or “an alternative embodiment” or “one example” or “an example” in various portions of this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined as desired in one or more embodiments of the invention.
Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects.
While the invention has been particularly shown and described with reference to various embodiments thereof, it will be understood by those skilled in the art that various other changes in the form and details may be made without departing from the spirit and scope of the invention.
This application claims priority to and the benefit under 35 U.S.C. 119(e) to U.S. Provisional Patent Application No. 61/211,396 entitled “Reinforced Pervious Concrete” filed Mar. 25, 2009, the disclosure of which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61211396 | Mar 2009 | US |
