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OF THE INVENTION
1. Field of the Invention
The present invention relates generally to slip-form construction involving wet concrete and, more particularly, to slip-form construction of concrete drains.
2. Description of the Related Art
Slip-form construction is a method of building involving wet concrete. The name refers to the moving form or mold the concrete is poured into, which moves along the project as the previously poured concrete hardens behind it. Slip-form relies on the quick-setting properties of concrete requiring a balance between early strength gain and workability. The technique has been applied to large buildings and to road construction.
In recent years, the drainage or lack of drainage on United States roadways has come under close scrutiny as related to the affect of the drainage on the roadway itself. It has been found that proper drainage can be a key factor in extending the life of the roadway. The Federal Highway Administration (FHWA) and others have done extensive research, over multiple States, into proper drainage techniques. These studies have established the need for installation of proper subsurface drainage systems along America's highways. U.S. Dep't Fed. Highway Admin., Summary of Federal Highway Administration's Drainage Efforts, Feb. 5, 2002, http://www.fhwa.dot.gov/Pavement/drain.cfm.
The current installation of subsurface drains along roads in the United States is a complicated and labor intensive process. It involves many steps, many of which must be completed or finished by hand.
Initially, the drain area is trenched to sufficient depth and width so as to act as a form for wet concrete. Then, metal pipes or other types of conduit are placed in the trench. These conduits can have prefabricated down spouts and grating which are generally positioned directed above the center of the drain. Once in the trench, the conduit must be set in the proper location within the trench. This time consuming step is accomplished by leveling the conduit by hand using various sized shims.
Once properly positioned, small amounts of concrete are poured at certain intervals along the conduit to act as anchors, holding the conduit in place and ensuring that the conduit will not become dislodged in subsequent steps. These anchors are loosely poured and are not tightly packed, potentially trapping air in the finished product which can lead to points of structural instability. Finally, additional concrete is poured around and along the entire conduit. In addition to directing the concrete around the conduit by hand, the drain is also finished to grade by hand while the concrete is still wet. In some cases, reinforcing iron bars or rebar are shaped and placed under and around the proposed drain or conduit as well.
Because the subsurface drains typically include downspouts and grating centered over the pipe, the typical subsurface drain can not function as foundation for other structural components, for example curbs or barrier rails. If the project calls for an additional structural component, the drain is completed in a first phase of construction and the additional component is fabricated adjacent to the drain in a separate, second phase of construction.
There are currently three typical conventions for placement of subsurface slotted drains. They may be installed along a roadside. They may be installed next to a barrier rail or wall. Or they may be installed next to a curb. In each case, the drain installation is generally independent from the installation of other features such as the mentioned road, barrier rail, wall, curb, etc.
A typical installation of a drain with an adjacent curb is therefore a minimum of a five phase process. In the first phase, the area is prepped for the drain including trenching, laying rebar in the trench and laying the drain conduit over the rebar. In the second phase, the position of the drain conduit is fixed by hand, shimming the conduit along the length of the drain and periodically anchoring it with plugs of concrete. In the third phase, another pass along the drain is made where concrete is poured over the conduit and is distributed by hand and hand finished to grade. The poured concrete is then left to dry. In the fourth phase, the adjacent area is prepped for the curb. In the fifth phase, a slip-form machine forms the curb along the adjacent drain. The process requires multiple passes and time consuming, labor intensive steps.
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OF THE INVENTION
For the reasons including those discussed above, there exists a need for improved systems, molds and construction methods for installing subsurface drains and slotted drains that can, for example, reduce cost, reduce the amount human labor required for installation, reduce the number of steps required, simplify the process and reduce redundancies.
In some embodiments, a system for making slotted drains of slip-formed concrete can comprise concrete, a block, a drain path forming structure, a hopper and a mold. The hopper can be configured for receiving concrete and for providing concrete to the mold for molding concrete. The mold can comprise a drain member guide, a topper, a first side and a second side. The drain member guide can be configured to slide over the drain path forming structure and the hopper can be configured to provide concrete around the drain member guide. The topper, first and second sides can be for molding the top, first and second sides of the slotted drain respectively as they are passed along the area intended for the drain. The second side can also be configured to create a slot in the slotted drain and to selectively hold the block, the slot configured to selectively receive the block.
According to some embodiments, a mold for use with a slip-form machine can comprise a drain member guide, a first portion, and a second portion. The first portion can be configured to receive concrete and direct the concrete around a portion of the drain member guide. The second portion can be configured to shape the concrete to a desired shape. The second portion can comprise a top portion, a first segment and a second segment. The top portion can be configured to shape a top of the concrete in a flat linear manner. The first segment can be connected to the top portion and can be configured to shape a first side of the concrete. The second segment can be configured to shape a second side of the concrete with a slot along the second side of the concrete. The second segment can also be connected to both the top portion and the drain member guide. According to some embodiments, the mold can further comprise one or more rebar guides.
Additional embodiments of a mold for slip-forming a concrete slotted drain can comprise a cylindrical metal pipe and a forming apparatus. The forming apparatus can comprise a top member and a side member. The top member can be configured to be above a part of a top of the cylindrical metal pipe. The top member can have a flat bottom surface parallel with the axis of the pipe and the top member can be configured to substantially block concrete from flowing over the bottom surface and can direct concrete between the bottom surface and the top surface of the pipe. The side member can be connected to and, in some embodiments, at an angle from the bottom surface of the top member. The side member can have a portion formed by or attached to a side of the cylindrical metal pipe and can have a closed end. According to some embodiments, the side member can be further configured to hold an elongated block.
Some embodiments of a mold for use with a slip-form machine can comprise an outer housing, a drain member guide and a void forming projection extending outwardly from the drain member guide. Some embodiments may further comprise one or more dropdown side shields.
A method of laying slip-formed concrete, according to some embodiments, can comprise laying a main drain portion which can define an outer surface, and positioning a guide member around the main drain portion. The guide member can comprise a void generating outward projection. The method can further comprise initiating the flow of concrete onto the guide member, encouraging the concrete to shift around substantially all of the outer surface of the main drain portion and moving the guide member along the main drain portion. The method can include the step of generating a void in the concrete along a predetermined portion of the main drain portion. The void can expose the outer surface of the main drain portion to the atmosphere.
The method according to some embodiments can include the step of selectively inserting a secondary material into the void as the guide member moves along the main drain portion. The method can also include a guide member further comprising a rebar guide and the step of selectively inserting rebar along the rebar guide into an outer surface of the concrete. In addition, where at least a portion of the rebar extends above the outer surface of the concrete, the method can further comprise forming a concrete barrier over and connected to the rebar.
In some embodiments, a combination curb and slotted drain is prepared in two phases. In the first phase, the area is prepped for the drain including trenching, laying rebar in the trench (if required) and laying the drain conduit over the rebar. In the second phase, a single pass of the slip-form machine properly positions the conduit, forms the concrete drain around the conduit, allows the placement of downspouts as needed and forms the finished curb above the drain. In the same phase, holes can be hand finished as needed as the machine passes along the drain area.
These and other objects of the present inventions will become readily apparent upon further review of the attached drawings and specification.
BRIEF DESCRIPTION OF THE DRAWINGS
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The features and advantages of the inventions, and the manner of attaining them, will become apparent by reference to the following description of preferred embodiments of the inventions taken in conjunction with the accompanying drawings.
FIG. 1 is a perspective front view of an embodiment of a system to create a drain by slip forming concrete.
FIG. 2 is a perspective rear view of an embodiment of a system to create a drain by slip forming concrete.
FIG. 2A is a rear end cross-sectional view of the slip form mold of FIG. 2.
FIG. 3A is a cross-section of a drain showing the placement of rebar which will serve as a foundation for another structure.
FIG. 3B is a cross-section of a drain-foundation with a barrier wall being slip formed on top and with a void filler still in place.
FIG. 3C is a cross-section of a curb with a drain and drain opening.
FIG. 3D is a cross-section of a drain with a vertical down-spout.
FIG. 4 a schematic view of concrete being poured into a hopper of a slip form mold, showing a general overview of the position and location of a slip form mold in a trench with relation to rebar and a conduit, according to some embodiments.
FIG. 5 is a rear view of an embodiment of a slip form mold with a conduit shaped guide around a balloon in a trench.
FIG. 5A is a rear view of an embodiment of a slip form mold with a conduit shaped guide around a steel pipe in a trench.
FIG. 6 is a rear view of an embodiment of a slip form mold beginning to form a concrete drain in a trench.