Pervious concrete is a type of concrete that is highly porous to allow water, for example from precipitation, to pass through the concrete. The use of pervious concrete will reduce runoff from a site. As such, the use of pervious concrete is consistent with ecologically sustainable construction practices. Pervious concrete may be used for parking lots, sidewalks, driveways, and roadways, as a few non-limiting examples.
The porous nature of pervious concrete is achieved by the materials that are put into the concrete. Specifically, pervious concrete is a mix of course aggregate, cement, water, chemicals or “add material,” and little to no sand. This mixture creates an open-cell structure in the concrete, which allows water to filter though the pervious concrete.
Pervious concrete is typically used in a “ready mix” fashion, delivered to a jobsite and poured into an on-site form. Pervious concrete is unique in many ways including the long cure time to reach maximum strength; due to the makeup of pervious concrete, the cure time required to reach full strength is typically 28 days or longer. The pervious concrete material must be covered and controlled during the cure time. During this cure time the product does not provide maximum protection and is prone to dilution from water, cracking from stressing or reduced ultimate strength due to temperature.
The present invention relates to pervious concrete, and more particularly to precast pervious concrete panels. The panels comprise elements such as at least one lifting member or pocket to promote easier lifting for transporting the panel and at least one aperture for insertion of a connector used to join panels together.
Furthermore, the present invention may be used in association with non-pervious surfacing material as part of a drainage system.
It is further contemplated by the present invention that various ratios of sand and various aggregate sizes may be used for applications requiring different strength characteristics.
One aspect of the invention provides a preformed pervious concrete panel including a concrete mix having an aggregate size in the range of about one-eighth inch to about three-quarters inch and a sand content ratio in the range of zero percent to ten percent, a peripheral surface, at least one lifting member at least partially integrated into the peripheral surface, and at least one aperture located in the peripheral surface.
The aggregate size may also be in the range of about one-eighth inch to about one-half inch.
The sand content ratio may also be in the range of 1 percent to 7 percent.
The sand content ratio may also be zero percent.
The pervious concrete panel may also include a void ratio in the range of 16 percent to 22 percent.
The void ratio may also be in the range of 18 percent to 22 percent.
The at least one lifting member may also be a female connector.
The at least one lifting member may also be a steel cable loop.
The at least one aperture may extend continuously linearly through the panel.
Another aspect of the invention provides a pervious concrete system including at least a first and a second preformed pervious concrete panels, each of the preformed pervious concrete panels including a concrete mix having an aggregate size in the range of about one-eighth inch to about three-quarters inch and a sand content ratio in the range of zero percent to ten percent, a peripheral surface, at least one lifting member at least partially integrated into the peripheral surface, and at least one aperture located in the peripheral surface; at least one connector having a first and a second oppositely disposed ends; and wherein the first end of the connector is received in an aperture of a first panel and the second end of the connector is received in an aperture of the second panel, thereby joining the first and second panels.
The pervious concrete system may also include a piece of strip material placed underneath the panels at the joint.
The at least one connector may have a hard-stop to provide a gap between the panels.
Another aspect of the invention provides a method for producing a pervious concrete panel including providing a pervious concrete mix having a an aggregate size in the range of about one-eighth inch to about three-quarters inch and a sand content ratio in the range of zero percent to ten percent, providing a containment vessel having a shape defining the peripheral surface of the panel, providing at least one lifting member, introducing the pervious concrete mix into the containment vessel, forming at least one aperture in the peripheral surface, arranging the lifting member in the mix at a predetermined location in the peripheral surface prior to the mix fully curing, allowing the pervious concrete mix to cure for a predetermined amount of time, and separating the panel from the containment vessel.
The aggregate size may also be in the range of about one-eighth inch to about one-half inch.
The sand content ratio may also be in the range of 1 percent to 7 percent.
The sand content ratio may also be zero percent.
The method for producing a pervious concrete panel may also include a pervious concrete panel with a void ratio in the range of 16 percent to 22 percent.
The void ratio may also be in the range of 18 percent to 22 percent.
Another aspect of the invention provides a method for producing a pervious concrete panel including providing a pervious concrete mix having a an aggregate size in the range of about one-eighth inch to about three-quarters inch and a sand content ratio in the range of zero percent to 10 percent, providing at least one lifting member, forming the panel having a peripheral surface with a continuously moving form, forming at least one aperture in the peripheral surface, arranging the lifting member in the mix at a predetermined location in the peripheral surface prior to the mix fully curing.
The method for producing a pervious concrete panel may include forming the panel with a slip-forming machine.
The method for producing a pervious concrete panel may include forming the panel with an extruding machine.
The aggregate size may also be in the range of about one-eight inch to about one-half inch.
The sand content ratio may also be in the range of 1 percent to 7 percent.
The sand content ratio may also be zero percent.
The method for producing a pervious concrete panel may also include a pervious concrete panel with a void ratio in the range of 16 percent to 22 percent.
The void ratio may also be in the range of 18 percent to 22 percent.
Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.
The precast pervious concrete panels 10 are preferably sized and configured to be connected to one another. The precast pervious concrete panels 10 may be connected using any methods known in the art. One such method is shown in
The connecting member 22 may take any form known in the art and may be made of any material known in the art. In the illustrated embodiment of
A panel of strip material 24 may be provided under one or more joints between adjacent precast pervious concrete panels 10. The use of the strip material 24 under the joints will reduce stress concentration at the joint connection by dissipating the load bearing, ensure debris is not pinched between panels 10, and allow the panels 10 to slide easily together. If used, the strip material 24 may take any form known in the art and may be made of any material known in the art. In the illustrated embodiment the strip material 24 is generally rectangular and is made of Korlath.
As shown in
For example, as shown in
As shown in
It is further contemplated that the precast pervious concrete panels 10 may be formed using any means known in the art. For example, and not by way of limitation, the precast pervious concrete panels could be formed on a slip-forming or extruder machine. This would produce a precast pervious concrete panel 10 with multiple hollow channels running through the panel 10 as shown in
It is further contemplated that precast pervious concrete panels 10 may be used as inserts to be used in combination with traditional concrete or asphalt as shown in
It is further contemplated that the precast pervious concrete panels 10 could be reinforced using any means known in the art including, but not limited to, embedding rebar, fibers or mesh in the precast pervious concrete panels 10.
It is further contemplated that the precast pervious concrete panels 10 may be connected in a manner as shown in
The profile of the connectors 50 may substantially match the cores of the panels 10; they may be round or any other shape used to make the panel's core. For example, the connector 50 in
As outlined above, pervious concrete is a mix of course aggregate, cement, water, and little to no sand. It is further contemplated that the precast pervious concrete panels 10 may be cast using any combination of such materials known in the art. However, it is contemplated that the pervious concrete mixture may be designed to meet the specified strength and permeability of the intended application. Typically, the stronger the precast pervious concrete panel 10, the more material required which reduces the permeability, therefore each application may have a unique mix. The mixes will be classified based off their aggregate size and their sand content. Preferably the pervious concrete material will have a range of aggregates typically varying from about ⅛-¾″ in size and sand content ratios up to 10%. For example, a mix for a sidewalk or patio according to the present invention may utilize an aggregate size of about ⅛″-⅜″ and include up to approximately 7% sand content. This mixture would provide a minimum strength of 3,500 psi, an 18-22% void ratio, and infiltration rates exceeding 500 inches/hour. Alternatively, a mix for a highway shoulder or parking stall may employ an aggregate size of about 5/16″-½″ and up to approximately 7% sand content. This mixture would provide a minimum strength of 4,000 psi, a 16-20% void ratio, and infiltration rates exceeding 500 inches/hour.
A method for producing a pervious concrete panel 10 comprises: providing a pervious concrete mix having a predetermined aggregate size and percentage of sand; providing a means for forming the pervious concrete panel; providing a means for lifting the pervious concrete panel; introducing the pervious concrete mix into the forming means; incorporating the lifting means; and curing the pervious concrete mix.
The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.
This application claims the benefit of co-pending U.S. Provisional Patent Application Ser. No. 61/658,625, filed 12 Jun. 2012; co-pending U.S. Provisional Patent Application Ser. No. 61/659,726, filed 14 Jun. 2012; and co-pending U.S. Provisional Patent Application Ser. No. 61/761,564, filed 6 Feb. 2013, all entitled Precast Pervious Concrete Panels.
Number | Date | Country | |
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61658625 | Jun 2012 | US | |
61659726 | Jun 2012 | US | |
61761564 | Feb 2013 | US |