Patent Application
20190096200
The invention relates to pedestrian warning devices, particularly those that are incorporated into roadway corners or sidewalks for pedestrian use.
Sidewalks are well known structures that provide a walking surface for pedestrians, and that are frequently used on the sides of roads, parking lots, and other similar areas where pedestrians and vehicles are both routinely present. Such sidewalks are typically made from a form of pavement and are typically anywhere from 4 to 8 inches above the road surface.
To make sidewalks safer, particularly for users with disabilities, ramps are used to create a sloped transition from the sidewalk to the road surface. These ramps and associated landings are subject to numerous government regulations, particularly under the Americans with Disabilities Act, that are intended to ensure that the surface is safe for use by pedestrians and disabled persons.
In general, these ramps or landings have a concrete base, similar to the sidewalk itself, that is covered with a tactile panel, such as the Universal Radius Tactile Warning Surface Product (U.S. Pat. No. 9,365,985 B2), which is a glass and carbon composite panel that is enhanced with fiberglass truncated domes. Traditionally, tactile panels are either cast-in-place or surface applied.
Although cast-in-place tactile panels are easy to install in fresh concrete, they are difficult and costly to replace because once the concrete is set, the underlying substrate must be at least partially destroyed in order to remove and replace the tactile panel. One variation of cast-in-place tactile panels features spaced honeycomb-like lower walls. However, because of the nature of the honeycomb, air can become trapped between the lower walls, creating areas that lack support from the underlying substrate. This trapped air can result in a lack of support that can lead to fatigue, and cracking failure of the tactile panel due to repetitive and heavy loading.
Surface applied tactile panels are tactile panels applied to a finished substrate. Surface applied tactile panels are typically mechanically fastened and adhered to the underlying substrate. In addition, in order to compensate for irregularities in the substrate and minimize water intrusion that would otherwise damage the tactile panel, the surface applied tactile panels require additional caulking around the perimeter. Because surface applied tactile panels are mechanically fastened, they are easier and cheaper to remove than cast-in-place tactile panels. Once the fasteners are removed, the panel is heated to break the adhesive bond then stripped away from the underlying substrate. As a result, the underlying substrate remains intact, reducing the cost and time associated with replacing the tactile panel.
Although the surface applied tactile panel improves upon the cast-in-place tactile panel, both cast-in-place and surface applied tactile panels suffer from similar shortcomings. Both fail to remove the potential for air and water infiltration, which in turn compromises the structural integrity and functionality of the tactile panels.
These shortcomings are particularly problematic because the intersections of pedestrian ramps and sidewalks and street gutters are often locations where it is difficult to drain away standing water that remains after a rain or snow-melt event. Frequently there is insufficient pitch in these areas to provide positive drainage relief and puddles and ice may form resulting in hazards to pedestrians. If water is able to enter around the tactile panel at such a location or between the panel and the concrete slab, over time it will expand or contract, thus causing numerous problems to the long-term safety and stability of the ramp. To address these issues, ramp manufacturers go to great lengths to create water-tight or water-resistant tactile panels to prevent water from entering the ramp system. However, with a water tight ramp, pools of standing water may form at the base of the ramp during times of rain or melting snow or ice, causing puddles to form in the roadways and often back up the ramp, thus introducing a new hazard.
Porous concrete, also known as porous pavement, is distinguishable from traditional or non-porous concrete due to its high porosity, which allows for stormwater to infiltrate back into the ground naturally by passing directly through the concrete. Porous concrete has the ability to reduce pavement runoff and prevent pooling in areas that lack adequate drainage. As a result, porous concrete slabs allow water, whether the water comes from rain, melting snow or ice, or general road cleaning activities, to drain through the porous concrete and infiltrate back into the ground. However, current tactile panels do not allow water flow, thereby negating the benefits of using porous concrete as an underlying substrate.
What is needed, therefore, is a tactile warning device that is able to reduce the pooling or collection of water on or around the ramp and does not suffer structural degradation due to air and water infiltration.
The present invention solves the problems associated with tactile warning devices by providing tactile warning devices that effectively handle air and water infiltration.
The present invention is directed to a tactile warning device that effectively handles air and water infiltration. The perforated tactile warning device comprises a porous concrete slab and a tactile panel comprising a plurality of domes and a plurality of perforations, wherein the tactile panel is secured to the porous concrete slab via a plurality of anchors such that a space is created between a substantial portion of the tactile panel and the concrete slab.
The present invention is also directed to a tactile warning device that utilizes channels to effectively handle air and water infiltration. The perforated tactile warning device comprises a porous concrete slab having one or more channels and a tactile panel comprising a plurality of domes and a plurality of perforations, wherein the tactile panel is secured to the porous concrete slab via a plurality of anchors.
The present invention is also directed to a tactile warning device that utilizes nonporous concrete to effectively handle air and water infiltration. The perforated tactile warning device comprises a nonporous concrete slab having one or more channels and one or more drainage holes and a tactile panel comprising a plurality of domes and a plurality of perforations, wherein the tactile panel is secured to the nonporous concrete slab via a plurality of anchors.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description, appended claims, and accompanying drawings where:
The present invention will now be described more fully in detail with reference to the accompanying drawings, in which the preferred embodiments of the invention are shown. This invention should not, however, be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be complete and will fully convey the scope of the invention to those skilled in the art.
The space 130 solves several of the problems inherent in prior art devices. Infiltration of air and water both result in the degradation of existing devices through erosion of both the tactile warning panel and the underlying concrete substrate. The presence of space in these existing devices is eliminated in order to avoid air and water infiltration that would exacerbate an already significant weakness in the system. Air and water infiltration not only increase the degradation rate of the existing devices, resulting in rusted, warped and cracked tactile panels, but attempting to avoid air and water infiltration creates new hazards such as pooling around the warning devices. In colder climates, when pooling occurs around a warning device, the pooled water may freeze, creating a further hazard. In contrast, the combination of the space 130 and the porous concrete slab 120 in the perforated tactile warning device 100 addresses both of these problems by serving as a reservoir for the water that flows freely through the perforations 112 and also enabling effective management of the water via percolation through the underlying porous concrete slab 120. This passage of water through the perforated tactile warning device 100 is in stark contrast to prior devices and allows the perforated tactile warning device 100 to withstand stormwater runoff, melting and other water-related concerns, without compromising the structural integrity of the perforated tactile warning device 100.
Ideally, the perforations 112 are holes with diameters between about 0.125 inches and about 0.5 inches, preferably about 0.1875 inches. The perforations 112 are sized large enough to allow water to flow through the tactile panel 110, yet not so large as to compromise the structural integrity of the tactile panel 110. The size and number of the perforations 112 can be adjusted to ensure that the perforated tactile warning device 100 is capable of handling the anticipated volume of stormwater.
The perforations 112 may be evenly distributed across the tactile panel 110 so as to allow water to pass through the tactile panel 110 regardless of where the water contacts the tactile panel 110. For example, the perforations 112 may be centered between the domes 114 as shown in
While the porous concrete slab 120 is at least the size of the tactile panel 110, the porous concrete slab 120 may also be larger than the tactile panel 110 in one or more dimensions, creating a border of porous concrete in the perforated tactile warning device 100. In addition, the porous concrete slab 120 may include one or more lifting points 124 as known in the art in order to allow the perforated tactile warning device 100 to be lifted, removed and replaced as necessary. Where lifting points 124 are utilized within the porous concrete slab 120, there will be corresponding holes in the tactile panel 110 to allow access to the lifting points 124.
Turning to
The channels 230 in the porous concrete slab 220 may be oriented and sized based on the expected amount of water infiltration and the structural requirements of the porous concrete slab 220. For example, the channels 230 may be arranged substantially parallel to one another as depicted in
While the porous concrete slab 220 is at least the size of the tactile panel 210, the porous concrete slab 220 may also be larger than the tactile panel 210 in one or more dimensions, creating a border of porous concrete in the perforated tactile warning device 200. In addition, the porous concrete slab 220 may include one or more lifting points 224 as known in the art in order to allow the perforated tactile warning device 200 to be lifted, removed and replaced as necessary. Where lifting points 224 are utilized within the porous concrete slab 220, there will be corresponding holes in the tactile panel 210 to allow access to the lifting points 224.
Turning to
The presence of the channels 330 and drainage holes 340 allows the tactile panel 310 to be secured to a nonporous concrete slab 320 via one or more anchor points 325, with limited space between the tactile panel 310 and the nonporous concrete slab 320. In some embodiments, the space between the tactile panel 310 and the nonporous concrete slab 320 can be eliminated such that a substantial portion of the tactile panel 310 is in direct contact with the nonporous concrete slab 320. To allow the water to drain through the tactile panel 310, the tactile panel 310 includes perforations 312. The perforations 312 may be arranged about the tactile panel 310 in a manner that positions the perforations 312 substantially above the one or more channels 330 in the nonporous concrete slab 320, such that surface water may drain through the perforations 312, collect in the channels 330, and then pass through the nonporous concrete slab 320 via the drainage holes 340.
While the nonporous concrete slab 320 is at least the size of the tactile panel 310, the nonporous concrete slab 320 may also be larger than the tactile panel 310 in one or more dimensions, creating a border of nonporous concrete in the perforated tactile warning device 300. Alternatively, while the perforated tactile warning device 300 may utilize a nonporous concrete slab 320, porous concrete may be poured adjacent to the perforated tactile warning device 300 to increase drainage capacity.
Similar to the porous concrete slabs 120, 220 detailed above, the nonporous concrete slab 320 may include one or more lifting points 324 in order to allow the perforated tactile warning device 300 to be lifted, removed and replaced as necessary. Where lifting points 324 are utilized within the nonporous concrete slab 320, there will be corresponding holes in the tactile panel 310 to allow access to the lifting points 324.
It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to exemplary embodiments, it is understood that the words, which have been used herein, are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.
This application claims the benefit of U.S. Provisional Patent Application 62/563,668, filed Sep. 27, 2017, the disclosure of which is herein incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62563668 | Sep 2017 | US |
