Patent Publication Number: US-2003223811-A1

Title: Modular exterior casing for crash barriers made of glass fiber reinforced concrete

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
     [0001] This application is related to my co-pending patent applications, namely:  
     [0002] Ser. No.—60/380,150—filed May 7, 2002, and No. 60/380,149—filed May 7, 2002. 
    
    
     
       FIELD OF INVENTION  
       [0003] This invention relates to crash barriers, specifically decorative exterior casing made of glass fiber reinforced concrete that can be placed manually to cover existing concrete barriers and provide energy-absorbing layer thereon.  
       BACKGROUND OF INVENTION AND PRIOR ART  
       [0004] U.S. Pat. No. 5,746,538 to Gunness is a concrete barrier having a plastic cladding that provides protection for the concrete against chemical deterioration.  
       [0005] U.S. Pat. No. 4,681,302 to Thompson shows a barrier comprising walls defining a container closed except for a fill opening to admit water.  
       [0006] U.S. Pat. No. 4,661,010 to Almer et al. is an improved concrete block intended to serve as a roadway-defining member. The block is in the shape of an elongate concrete body having an essentially triangular cross-sectional configuration with one bottom face and two preferably symmetrical side faces.  
       [0007] U.S. Pat. No. 5,651,635 to Nagle shows a special reinforcement basket of steel rebar for reinforcing concrete barriers. The invention is for precast concrete road barriers, which are manufactured in a plant and then brought to a site and anchored in place.  
       [0008] U.S. Pat. No. 5,720,470 to Johansson provides a barrier comprising of supports and impact-absorbing elements which extend between the supports. The impact-absorbing elements consist of tubes, rods or bars with mountings attached to the side of the tubes, rods or bars.  
       [0009] U.S. Pat. No. 6,340,268 to Alberson et al. is an impact-attenuating barrier wall. The wall comprises a fixed obstacle such as a concrete wall. A plurality of energy absorbing HMW/HD polyethylene cylinders is arranged in side-by-side position between the obstacle and the roadway.  
       [0010] U.S. Pat. No. 6,099,200 to Pepe et al. relates to an energy absorbing, retractable security barrier consisting of a reinforced telescoping bollard inserted into a foundation casing which is imbedded below ground.  
       SUMMARY OF THE INVENTION  
       [0011] Crash barriers, alternately called as concrete barricades, have come to widespread use in the United States and in many other countries. Typically poured in as one-piece slab of concrete or machine formed moveable elongated shapes, the barricades are from 2.5 to 3.5 feet in height and have a wider base portion, tapering up to a narrower top portion.  
       [0012] Concrete crash barriers provide a variety of features that are desirable as barricades, such as substance in weight and simplicity of manufacture. While providing a practical solution for many applications, concrete barriers also have several drawbacks. For example, heaviness of mass and special equipment required to move and install. It would be desirable to have a barrier that is light and easy to handle without the requirement of special equipment to be moved.  
       [0013] The style of barrier that has gained wider success has been the so-called “New Jersey” barrier (hereinafter referred to as jersey barrier). Commonly, the Jersey barrier is the device of choice whether used as a temporary road divider for a construction or permanently separating traffic lanes for roadways. This devise is also employed to control access to entranceways, driveways and to secure perimeter areas around buildings and objects requiring such protection.  
       [0014] Various security devices employed to control access to perimeter areas or entranceways have been proposed. Often seen are more complex devises that consist of an arm that is pivotally connected to a hydraulic base or cable operated beam barriers attached to motorized mechanism. The arm or beam when employed is then raised from a horizontal blocking position to a vertical open position. A disadvantage of such barrier is that they are not reinforced construction and as such cannot arrest the movement of a vehicle.  
       [0015] Other less complex and conventional barriers have been proposed like individual sawhorse type or collapsible V-shape barricades. Such designs, however, have limited use since they are generally lightweight and are thus easily tipped over or moved. Portable barricades often fail when a vehicle crashes through and continues on its way.  
       [0016] Concrete barriers were among the first to be developed. To resolve problems related to the weight of the concrete barriers, alternative lightweight barriers followed. Lightweight barricades are typically fabricated from synthetic materials, such as plastic, polyethylene or any other suitable material. These lightweight barriers are often times made of hollow structures that are easy to transport and manipulate, and do not need special equipment to be loaded or installed.  
       [0017] Unfortunately, these types of lightweight devises have the same break through problem that concrete barriers have. In particular, when a vehicle strikes a lightweight barricade it may push the barrier aside, enter another lane of traffic and cause an accident in the same manner that prior art concrete barriers did.  
       [0018] Recent concepts and inventions led to new and emerging functions of concrete barriers. Three-dimensional shapes are preferred compared to plain surface barriers used on highways made of steel-reinforced concrete. Designer barricades, camouflaged barriers and planter barrier systems are among these novel proposals that now finds a new niche in the market. 3D shapes are desired not only for its aesthetic significance but also because of its enhanced ability to create ‘progressive resistance’ or diversion upon impact of a moving vehicle.  
       [0019] In a backlash against flat surface barriers, decorative barricades faced a growing demand brought about by current state of events. Temporary concrete barriers popped up in front of government buildings after a terrorist attack against the U.S. Federal agencies are now seeking alternatives to concrete barricades. Corporate executives and even homeowners have been asking about ‘less-jarring’ barriers that do not clash with the aesthetics of the building structure.  
       [0020] Regardless of shape or construction, most such type of barriers is made non-resilient, massive and heavy. This is potentially very dangerous to the vehicle occupants. There are some prior art designed to progressively absorb kinetic energy and thereby gradually decelerate the vehicle, such devises however are relatively complex and expensive. Some are built with internal chambers filled with liquids or other fluid materials. Others comprise of springs or internal shock absorbers.  
       [0021] While addressing some of the issues related to barriers systems, prior art failed to provide a barrier system which is lightweight and easy to place by hand without special equipment. When restoring the barrier after a collision, it may be necessary to replace the barrier elements and in certain cases even the entire chunk of concrete. In serious cases, there is a risk that the articulated attachments connecting the barriers will break in case of high impact, which can cause the barrier elements to separate from each other diminishing to a considerable extent its collision protecting properties. It can also be extremely dangerous in that they are rigid and non-forgiving.  
       [0022] Generally, any impacting object possesses energy in motion also known as kinetic energy. The faster an object goes the more kinetic energy it has. The way crash barriers works is to take away the kinetic energy out of the moving vehicle. It can do this by soaking up the kinetic energy, like a sponge. This means the crash barrier does not need to be nearly as strong and rigid as it stops the vehicle by a plowing action. In many instances, the impacting vehicle will be unharmed, as the barrier itself will do all the work. Consequently, a correctly designed energy absorbing crash barrier must be resilient yet permits itself to deform readily. This keeps the reaction forces relatively low in contrast with rigid type barriers that do not absorb much energy. The impact force is extremely large in rigid type barriers as the vehicle absorbs its own kinetic energy by deforming itself.  
       [0023] Accordingly, it is an object of the present invention to provide an improved devise, which is relatively light for ease in transport and positioning. It also relates to an energy-absorbing barrier, particularly an energy-absorbing barrier designed for dissipating kinetic energy upon impact.  
       [0024] The invention described herein is considered an improvement over prior proposals in that it relies on the novel construction of modular exterior casing made of composite cement and graded stone with countless strands of embedded alkaline resistant glass fibers, also known as glass fiber reinforced concrete (hereinafter referred to as GFRC). It does not have the graded rock aggregates or steel-reinforcing bars commonly associated with concrete barricades.  
       [0025] The present invention also aims to obviate the drawbacks of prior-art cement barriers by providing an added exterior layer to existing concrete barriers comprising of unique resilient GFRC material mixture that will yield accordingly upon impact, thereby lessening the damage to the colliding object by readily deforming and absorbing the force of the kinetic energy.  
       [0026] Another object of this invention is to enhance protection to perimeter areas without sacrificing aesthetics of the improvement in the immediate vicinity. Its physical properties depend heavily on fiber content, quality of mix and manufacturing process. The result is a composite that combines the strength and lightweight characteristics of conventional fiberglass with the durability and longevity of cast stone. Glass fiber reinforced concrete is the ideal material because of the relative ease of creating three-dimensional shapes that can also be pre-finished and shipped to the job-site economically because of their lightweight construction.  
       OBJECTS OF THE INVENTION  
       [0027] Accordingly, the objects and novel advantages of the present invention are:  
       [0028] 1) to provide an exterior casing to cover existing concrete barriers.  
       [0029] 2) to provide a protective layer to concrete barriers that is engineered to absorb a progressive impact.  
       [0030] 3) to provide a barrier devise that is relatively light for ease in transport and positioning.  
       [0031] 4) to provide a modular enclosure to concrete barriers made of glass fiber reinforced concrete.  
       [0032] 5) to provide a protective shell that does not have steel-reinforcing bars and graded rock aggregates commonly associated with concrete barriers.  
       [0033] 6) to provide a barrier cover that has three-dimensional shape and decorative appearance.  
       [0034] 7) to provide an exterior casing that is pre-finished and can be shipped economically because of its lightweight construction.  
       [0035] Other objects of the invention will become apparent from a consideration of the drawings and subsequent description.  
     
    
    
     DESCRIPTION OF DRAWINGS  
     [0036] In the drawings, reference numerals are supplied for purposes of detailed discussion.  
     [0037]FIG. 1 is a front elevational view showing the facade of the exterior casing as separate components.  
     [0038]FIG. 2 shows a plan view comprising of modular segments of the enclosure shell.  
     [0039]FIG. 3 reveals a partial cross-section of the barrier shell from the end side. A side view illustration of the outer layer shape is shown.  
     [0040]FIG. 4 presents a cross-sectional isometric view exposing the various elements of the invention comprising of an existing concrete barrier and the outer barrier casing. The Jersey barrier is shown in broken lines for illustrative purpose.  
     [0041]FIG. 5 illustrates a side sectional view demonstrating the internal construction that does not include steel reinforcing bars and rock aggregates.  
     [0042]FIG. 6 is a cross-sectional view of alternative barrier designs as an optional variation to the objects of the invention. The concrete barriers are represented by means of broken lines for illustrative purpose.  
     [0043]FIG. 7 demonstrates an example how glass fibers are dispersed and laid randomly in all directions as revealed from the interior portion of a longitudinal wall segment.  
     [0044]FIG. 8 provides a broken section of composite cement and embedded glass fibers.  
     [0045]FIG. 9 presents a photomicrograph of alkaline resistant glass fibers in cement mortar matrix showing random fiber distribution. 
    
    
     REFERENCE NUMERALS IN DRAWINGS  
     [0046]                               REFERENCE NUMERALS IN DRAWINGS                                        9   Lateral casing component       10   Longitudinal casing component       11   Top lip radius       12   Upper recessed wall       13   Upper-mid lump       14   Lower-mid lump       15   Base lump       16   Lower recessed wall       17   Lateral quarter segment       18   Longitudinal wall segment       19   Wall thickness detail       20   Base recessed wall       21   Metal pin dowel       22   Soil back fill       23   Jersey barrier       24   Loop anchors and steel wiring       25   Randomly laid glass fibers       26   Embedded glass fibers       27   Composite cement mix                    
     DETAILED DESCRIPTION  
     [0047] A typical embodiment of the present invention is best illustrated in FIGS.  1  and FIG. 1, the exterior casing comprise of modular units consisting of four lateral casings  9 , each part is represented by a lateral quarter segment  17  adjoining four longitudinal casing components shown in FIG. 2. These lateral and longitudinal wall segments may vary in tenns of plurality and positioning depending on the desired length, width and number of concrete barriers to be covered. As a result, it fits generally any type of concrete barrier design as it virtually expands in all direction (see FIG. 6). FIG. 2 shows an ideal setup for standard stand-alone Jersey barrier. Longitudinal and lateral wall segments  17  &amp;  18  may be added up to a preferred quantity of connections on a given situation. FIG. 4 demonstrates a single detached application of the invention covering an existing concrete barrier represented by a broken line  23 .  
     [0048]FIG. 3 in part reveals a section of the longitudinal segment relative to the thickness of the wall  19 , preferably about 0.5 to 0.75 inches wide and the three-dimensional shape of the exterior facade  11 - 16  &amp;  20 . Accordingly, the present invention provides an innovative exterior casing that has a decorative appearance wherein the upper portion consist of a top lip radius  11 , an upper recessed wall  12  and an upper-mid lump  13 . The lower portion down to the base form shows a lower-mid lump  14 , a base lump  15 , a lower recessed wall  16  and a base recessed wall footing. Numerals  11  to  16  and  20  represent the preferred shape of the enclosure shell not only for its aesthetic purpose but also for its ability to generate progressive resistance upon impact of a moving vehicle. The lateral and longitudinally walls segments therefore were designed in slightly reversed sloped face, about 75 to 85 degrees oblique from the top lip radius  11  tapering down to the base recessed wall  20 . Upper, mid and lower lumps are radius design primarily to add strength and support around the wall segments.  
     [0049] The principal material asset of this invention underneath its three-dimensional characteristic is its novel construction of composite cement and graded stone ( 27 , FIG. 8) embedded with long strands of alkaline resistant glass fibers ( 26 , FIG. 8). It has a tensile strength or the ability to have strength when stretched. This tensile strength also creates dramatically enhanced impact strength generating virtually the dual qualities of conventional concrete, which are compressive strength and longevity. FIG. 7 demonstrates an example how glass fibers are dispersed and laid randomly in all directions as revealed from the interior portion of a longitudinal wall segment.  
     [0050]FIG. 9 presents the alkaline resistant glass fibers in cement mortar mix showing random fiber distribution thereby creating uniform, omni directional strength characteristics of glass fiber reinforced concrete. This material technology has the desirable trait of “ductile failure mode” which minimizes the ballistic debris produced by an impact event. Unlike conventional concrete, that has the characteristic known as ‘brittle failure’ because of its semi-crystalline structure that tend to shatter on impact, glass fiber reinforced concrete holds the material together because the fibers are dispersed randomly and lay in all directions within the material matrix  26 ,  27 .  
     [0051] One preferred embodiment of this invention is to provide a barrier shell that does not include steel-reinforcing bars and rock aggregates commonly associated with concrete barriers. Accordingly, another aspect of this invention is to provide a protective layer to concrete barriers that is economical to ship because of its lightweight construction. FIG. 5 demonstrates the internal construction of the barrier casing in relation to an existing barrier wherein the enclosure shell is attached by means of metal loop anchors and graded steel wires  24 . The gap between the casing&#39;s lateral and longitudinal walls and the existing concrete barrier  22  (FIG. 4) are back filled with commercial planting medium to camouflage the existing barricade giving it a less jarring look. By means of this technique an alternative object is achieved wherein the exterior casing back filled with graded soil creates a planting compartment.  
     [0052] With specific reference to FIG. 6, it is stressed that the particular alternative variations shown are by way of example and for purposes of illustrative discussion of optional embodiments. FIG. 6 is presented in the cause of providing what is believed to be useful description of the conceptual aspects of the invention. Each unique barrier design claims variable strength and energy absorbing features that were tested according to the U.S. Army Corp of Engineers.  
     [0053] While the above description contains a number of advantages, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of one preferred embodiment thereof. Other optional variations are found in FIG. 6.