Patent Application
20060034652
The present invention relates generally to the construction of driveways and particularly to the construction of temporary driveways used in new home construction.
The driveway provides access to the construction site and is typically one of the first things constructed when a new home is being built. One option that may be used for a driveway in new home construction is to simply put the permanent driveway in place. However, installation of a finished surface such as concrete or blacktop prior to the construction is problematic because construction vehicles such as concrete trucks, hauling trucks, and other equipment can easily damage the finished surface of the driveway. For instance, a finished concrete driveway is typically only four inches thick. While this thickness is adequate for normal traffic associated with residential property, it is likely not sufficient for construction traffic.
Therefore, one form of temporary driveway used during building construction is a gravel driveway. Large gravel is typically poured from a dump truck and spread in a desired location. However, there are problems commonly associated with this form of driveway. One problem is that the placement of the gravel can be time consuming. The gravel must first be poured in place and then spread to form a relatively flat surface.
Another significant problem is water drainage. The surface of a finished driveway is contoured to control water drainage. However, a gravel drive cannot be similarly prepared. If water drainage is not controlled, water that pools on the surface can wash away gravel. Moreover, improper water runoff often creates serious problems including flooding in areas that are not capable of handling the excess water.
Another common problem of gravel driveways is keeping the gravel in the temporary driveway during heavy construction traffic. Traffic over the gravel can cause the gravel to disperse and spill past the boundaries of the driveway into the yard. Keeping the gravel in its intended location can be a time consuming and labor intensive job. Gravel that has been displaced into the yard can pose a hazard where gravel is buried when the lawn is prepared.
The removal of the gravel after it is no longer needed poses another problem. Most homeowners prefer to replace the gravel driveway with a finished concrete or blacktop driveway after construction. In this case, some or all of the gravel will have to be removed and the driveway re-graded to prepare for the new concrete or asphalt driveway which adds time, labor, and expense to the construction process.
Similar problems arise in other construction projects where a temporary driving or parking surface is needed. For instance, some larger construction projects, such as a housing subdivision, include a central office with adjacent parking. Other construction projects require a staging area for temporary retention of building materials. In most cases, a temporary gravel surface is prepared, which poses the problems mentioned above.
What is needed is a temporary driveway that eliminates the problems associated with driveways that are traditionally used during new home construction.
In order to address these needs, the present invention contemplates a temporary driveway for use during new home construction. The temporary driveway is placed on a new home lot at the start of construction and is removed when construction is completed. According to one embodiment of the invention, the temporary driveway comprises one or more pre-cast planks dimensioned to accommodate the passage of vehicles.
According to one form of the invention, the temporary driveway is in the form of a pre-cast reinforced concrete panel or plank. The concrete plank is formed in a casting bed which consists of a pair of end abutments with a fixed flat surface between them on which the concrete is poured, and with fixed side forms that extend the full length of the flat surface to contain and shape the concrete. In one embodiment, a continuous length of concrete is cast and then cut to a desired length. For a typical driveway plank, the pre-cast concrete plank is cut to a twelve foot length.
In one embodiment, a concrete reinforcement is placed in desired locations before the concrete is poured. In some embodiments of the present invention, rebar can be used to reinforce the concrete. Preferably, the concrete reinforcement takes the form of pre-stressed cables. When using pre-stressed cables, the end abutments are anchorages used to anchor the ends of the cables. The cables are preferably ½″ diameter steel cables stretched between the two anchorages to a predetermined tension. In a specific embodiment, the cables are stressed to 31,000 psi.
In a most preferred embodiment, two rows of pre-stressed cables are provided, one row adjacent the top and bottom surfaces to prevent warping of the slab. With the cables under stress, the concrete is poured, encasing the cables. After the concrete has cured, the cables are released from the anchorages. As each length of plank is cut, the cable tension pulls the plank into compression, which increases the strength and durability of the plank.
According to another form of the invention, the pre-cast temporary driveway is in the form of a pre-cast polymer concrete body. The polymer casting material consists of a polymer binder and a filler. In accordance with one aspect of the invention, the filler is composed of recyclable materials such as waste rubber particles, fiberglass, and/or plastic. The recyclable materials are processed into pellets before being combined with the polymer binder to form the casting material. Alternatively, other fillers such as sand, crushed stone, gravel, and other aggregates may be used. Generally, any dry, non-absorbent, solid material can be used as a filler. The pre-cast polymer body can be reinforced with any materials or methods as are known in the art.
In a further feature of the invention, the temporary driveway is provided with a lifting system. The lifting system facilitates transport and placement of the temporary driveway at desired locations, without obstructing the top surface of the temporary driveway. Preferably, the lifting system includes at least two lifting points at a front portion of the pre-cast plank and at least two lifting points at a rear portion of the body. In this way, the temporary driveway can remain level and balanced as it is lifted, transported, or lowered.
According to one form of the invention, the lifting system takes the form of lift inserts recessed into the top surface of the pre-cast plank. The lift inserts can be embedded in the casting material or attached to the reinforcement. Preferably, the lift inserts have an opening at one end allowing the pre-stressed cables, rebar, or metal rods to be fed through. The lift inserts are placed at desired lifting points and positioned so that the lifting portions of the inserts are adjacent to or just below the top surface of the pre-cast plank. A cap covers the lifting portion of the insert. Once the casting material has been poured and set, the cap is removed exposing the lifting portion of the insert. Preferably, the lift inserts are dogbone inserts. Alternatively, other forms of lift inserts may be used such as anchor, coil, or plug type lifting inserts. In other embodiments, the lifting system can be lifting rings embedded in the sides of the pre-cast plank or threaded into embedded thread cores.
The present invention further contemplates a method for constructing a temporary driveway for a new home construction site. The method comprising the steps of:
It can be appreciated that the present invention contemplates a temporary driveway that can be used for new home construction sites. The temporary driveway is reinforced to endure the heavy traffic associated with new home construction. In addition, the temporary driveway includes features that facilitate transportation to and from a desired location. These features of durability and portability allow the temporary driveway to be used, stored, and reused as needed. This greatly simplifies and hastens the process of constructing a driveway. When a new home is being constructed, the temporary driveway can be transported and placed at the construction site at the start of construction, and removed when construction is completed.
It is, therefore, an object of the present invention to provide a novel, efficient, and economical apparatus and method of forming a temporary driveway. It is a further object of the present invention to provide a temporary driveway that alleviates problems associated with the driveways that are traditionally used in new home construction. For instance, the temporary driveway eliminates the hassles of a gravel driveway including: placing the gravel, keeping the gravel in its intended location, and removing the gravel after it is no longer needed.
Another object of the present invention is to provide a temporary driveway that is sturdy enough to handle heavy equipment and high traffic volume associated with new home construction. Yet another object of the present invention is to provide a temporary driveway that can be pre-cast off-site before construction begins with the capability of being lifted and transported to and from a construction site when needed.
These and other objects and benefits of the invention will be readily discerned from the following written description, taken together with the accompanying figures.
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the invention is thereby intended. It is further understood that the present invention includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the invention as would normally occur to one skilled in the art to which this invention pertains.
Referring to
Referring now to
In one embodiment, the pre-cast plank 12 is formed of portland cement concrete. In order to increase the tensile strength of the pre-cast portland cement concrete plank 12, reinforcements are used. Referring to
It can be appreciated that the concrete reinforcements can be rebar or other suitable materials or methods that are used to reinforce concrete. However, pre-stressed cables are preferred because they tend to place the concrete plank in compression along its length. The pre-stressing improves the compression strength and creep deformation properties of the concrete.
In another embodiment, the pre-cast plank 12 is formed of polymer concrete. Polymer concrete has good mechanical properties, such as high compression strength, and high durability in terms of fatigue, corrosion and freeze-thaw resistance. Polymer concrete consists of a polymer or resin binder component and a filler or aggregate component. Typical resins used in polymer concretes are polyester, epoxy, and acrylic thermoset resins. Preferably, polyester resin is used, mainly for economic reasons.
In accordance with one aspect of the invention, the aggregate or filler used in the polymer concrete consists of recyclable materials such as waste rubber particles, fiberglass and/or plastic. The waste rubber particles may be derived from waste vehicle tires. Alternatively, other fillers such as sand, crushed stone, gravel, and other aggregates may be used. Generally, any dry, non-absorbent, solid material can be used as a filler. The recyclable materials or other materials used for the filler are preferably processed into pellets of a desired size before being combined with the polymer binder to form the polymer concrete. The size and quantity of the pellets can be readily determined by a person of ordinary skill in the art based on the strength requirements for a particular pre-cast plank construction.
In another embodiment of the invention, the polymer concrete may also include fibrous reinforcement material to increase the impact strength, modulus, and overall mechanical properties of the polymer concrete. The most common types of fibers used are fiberglass, aramid, and carbon. Preferably, the fibrous reinforcement is fiberglass, chopped or milled. The fiber reinforcement material is added to the mixture with the filler material in a known manner.
Other forms of reinforcement may be used to increase the tensile strength of the polymer concrete such as steel bars. In general, polymer concrete may be reinforced using any conventional concrete reinforcement method as are known in the art.
The polymer concrete compositions also preferably include at least one catalyst as is known in the polymer art. Catalysts are added to the binder before mixing with the filler, in order to initiate the polymeric curing. Suitable catalysts include conventional free radical polymerization initiators, such as organic peroxides, hydroperoxides, and azo compounds. The polymer concrete compositions also preferably include at least one promoter or accelerator to modify (i.e., increase or decrease) the gel time, cure time, cure rate, and/or cure temperature. A variety of other additives may be used in the polymer concrete composition to improve the material properties, aesthetics, manufacturing process, and performance such as, for example, cross-linking agents, coupling agents, initiators, solvents/heat dissipators, surfactants, accelerators, and viscosity control compounds.
To produce the polymer concrete, the polymer binder and catalyst are mixed with the filler and fibrous material. Mixing conditions typically involve room temperature, a dry environment, and standard concrete mixing equipment. The curing time and temperatures can be adjusted to any length or temperature as needed.
As shown in
A cross section of a lifting point 30 is shown in
The dogbone insert 22 has an attachment portion 24 embedded within the casting material. In one approach, the attachment portion 24 defines an opening 24a sized to snugly receive a cable 19 from the upper row 20 of cables before the plank 12 is formed. This method of attaching the lift insert 22 ensures that the lift point 30 is capable of withstanding the weight of the pre-cast plank as it is lifted. As an alternative, the attachment portion 24 can be configured in two pieces to allow attachment to the cable after it has been pre-stressed. In other embodiments, the lift insert 22 can be embedded without attachment to the reinforcements. It can also be appreciated that other forms of lift inserts and methods of lifting the planks as are known in the art may be used. By way of non-limiting examples, anchor, coil, and plug type inserts recessed into the top surface 13 or lifting rings embedded into the sides of the pre-cast plank 12 may be used.
Referring now to
The pre-stressed cables 19 are stretched between the two abutments 26 and are anchored to the abutments to maintain their tension. Preferably, the cables 19 are stressed to approximately 31,000 psi. It can be appreciated that as the cables 19 are stretched across the casting bed 25, the cables 19 may be threaded through the opening 24a in the lift inserts 22 at desired locations for placement of the lifting points 30 for each pre-cast plank 12. As mentioned above, a cap 29 covers the lifting portion of the insert 22. The top of the cap (not shown) should be positioned so as to be exposed after the concrete is poured. The cap can then be removed after the concrete has set to provide access to the lift insert 22 within the recess 25.
As mentioned above, the extruder 31 is disposed in the casting bed. The extruder 31 is operable to traverse the length of the bed between the abutments 26. In a preferred embodiment, the extruder 31 is equipped with a guide plate to guide the movement of the extruder 31 down the length of the bed 25. The guide plate has holes through which the pre-stressed cables 19 are fed before the cables 19 are anchored to the abutments 26. As is conventional in the art, the extruder 31 is equipped with a trough that extends from an opening at the top of the extruder to an area adjacent the casting bed. The extruder moves along the length of the casting bed along the pre-stressed cables as concrete is poured into the trough. The concrete flows from the back of the extruder into the casting bed in an even distribution across the width of the bed.
Before the concrete has cured, the top surface 13 is preferably provided with a surface treatment that can enhance the frictional resistance of the surface. In the preferred embodiment, the top surface 13 is given a brush-textured finish or broom finish. Alternatively, other types of finishes and surface treatments may be used as are known in the art such as a float or trowel finish. The finish gives the top surface 13 a rough texture that provides traction. Optionally, drainage grooves or other gross features can be formed in the surface. It is understood that similar features can be incorporated into a pre-cast polymer plank.
After the concrete has cured, the cables 19 are released from the abutments 26 and the cast length of concrete is cut into planks of desired length. The pre-cast planks 12 are then removed from the bed 25.
Prior to installation of the temporary driveway 10, the driveway location is prepared in accordance with known construction methods. For instance, the location is cleared and then graded and compacted to provide a relatively smooth flat surface on which the planks are laid.
As can be seen from
Once construction of the house or building is completed or the temporary driveway is no longer needed, each pre-cast plank 12 can then be lifted by engaging the lifting points 30 again as shown in
It is also contemplated that a pre-cast plank already in position in a temporary driveway can be removed and replaced if the plank becomes damaged. The placement of the lifting points for access at the top surface of the plank allows any plank to be removed without disturbing adjacent planks in the temporary driveway.
As described above, the location for the temporary driveway is preferably graded in preparation for receiving the planks. The location can be graded as if in preparation for a standard poured drive. However, one benefit of the pre-cast planks is that the location need not be ideally graded and prepared. In other words, the planks can be positioned over a rough graded location that may not be entirely uniform. The weight of the planks will tend to smooth out some of the roughness and unevenness of the rough grade. However, the resulting driving surface does not need to be residential grade since it will only be subject to construction traffic while the house is being built.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same should be considered as illustrative and not restrictive in character. It is understood that only the preferred embodiments have been presented and that all changes, modifications and further applications that come within the spirit of the invention are desired to be protected.
Thus, while the present invention contemplates a temporary driveway, other uses requiring a temporary surface capable of supporting heavy loads and/or vehicle traffic are contemplated. By way of non-limiting examples, the present invention can be used for a temporary parking lot, a staging area, and load storage. In addition, the size of the pre-cast planks can be altered for particular uses. However, the overall dimensions of the planks are preferably dictated by the impact on the transportability of the planks. For instance, the present invention contemplates that the planks can be easily transported using standard hauling vehicles, such as a flat bed trailer. Moreover, it is contemplated that the weight and inertia of the planks are amenable to be lifted by a conventional crane used at a residential construction site.
This is a continuation-in-part of application Ser. No. 10/917,969 filed on Aug. 13, 2004.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10917969 | Aug 2004 | US |
| Child | 10998114 | Nov 2004 | US |
