Patent Application
20180119366
Not Applicable.
The present disclosure relates generally to systems for creating a durable seal between adjacent panels, including those which may be subject to expansion and contraction or mechanical shear. More particularly, the present disclosure is directed to an expansion joint design for use in surfaces exposed to impact or transfer loads such as foot or vehicular traffic areas.
Construction panels come in many different sizes and shapes and may be used for various purposes, including roadways, sideways, and pre-cast structures, particularly buildings. Historically, these have been formed in place. Use of precast concrete panels for floors, however, has become more prevalent. Whether formed in place or by use of precast panels, designs generally require forming a lateral gap or joint between adjacent panels to allow for independent movement, such in response to ambient temperature variations within standard operating ranges, building settling or shrinkage and seismic activity. Moreover, these joints are subject to damage over time. Most damage is from vandalism, wear, environmental factors and when the joint movement is greater, the seal may become inflexible, fragile or experience cohesive and/or adhesive failure. As a result, “long lasting” in the industry refers to a joint likely to be usable for a period greater than the typical lifespan of five (5) years. Various seals have been created in the field. Moreover, where in a horizontal surface exposed to wear, such as a roadway or walkway, it is often desirable to ensure that contaminants are retarded from contacting the seal and that the joint does not present a tripping hazard, whether as a result of a joint seal system which extends above the adjacent substrates or as a result of positioning the joint seal system below the surface of the substrates. This may be particularly difficult to address as the size of the expansion joint increases.
Various seal systems and configurations have been developed for imposition between these panels to provide seals or expansion joints to provide one or more of fire protection, waterproofing, sound and air insulation. This typically is accomplished with a seal created by imposition of multiple constituents in the joint, such as silicone application, backer bars, and elastically-compressible cores, such as of foam. While such foams may take a compression set, limiting the capability to return to the maximum original uncompressed dimension, such foams do permit compression and some return toward to the maximum original uncompressed dimension.
Expansion joint seal system designs for situations requiring the support of transfer loads have often required the use of rigid extruded rubber or polymer glands. These systems lack the resiliency and seismic movement required in expansion joints. These systems have been further limited from desirably functioning as a fire-resistant barrier.
Other systems have incorporated cover plates that span the joint itself, often anchored to the concrete or attached to the expansion joint material and which are expensive to supply and install. These systems sometimes require potentially undesirable mechanical attachment, which requires drilling into the deck or joint substrate. Cover plate systems that are not mechanically attached rely on support or attachment to the expansion joint, thereby subjecting the expansion joint seal system to continuous compression, expansion and tension on the bond line when force is applied to the cover plate, which shortens the life of the joint seal system. Some of these systems se an elastically-compressible core of foam to provide sealing, i.e. a foam which may be compressed by has sufficient elasticity to expand as the external force is removed until reaching a maximum expansion. But these elastically-compressible core systems can take on a compression set when the joint seal system is repeatedly exposed to lateral threes from a single direction, such as a roadway. This becomes more pronounced as these elastically-compressible core systems utilize a single or continuous spine along the length of the expansion joint seal system—which propagates any deflection along the length. The problems and limitations of the current elastically-compressible core sealing cover plate systems that rely on a continuous spline are well known in the art.
These cover plate systems are designed to address lateral movement—the expansion and compression of adjacent panels. Unfortunately, these do no properly address vertical shifts—where the substrates become misaligned when the end of one shifts vertically relative to the other or longitudinal shifts between panels. In such situations, the components attached to the cover plate are likewise rotated or elevated in space causing a pedestrian or vehicular hazard. The current systems do not adequately address the differences in the coefficient of linear expansion between the cover plate and the substrate or allow for curved joint designs. The inability of the current art to compensate for the lateral or thermal movement of the cover plate results in failure of attachment to the cover plate or additional pressure being imposed on one half of the expansion joint system and potentially pulling the expansion joint system away from the lower substrate. Current systems do not sufficiently address the potential impact or shock to the cover plate from vehicular traffic over time or by a snowplow or other.
The present disclosure therefore meets the above needs and overcomes one or more deficiencies in the prior art by providing an expansion joint system which includes a cover plate, a plurality of ribs, an elastically-compressible core having a core bottom surface, and a core top surface, wherein each of the plurality of ribs pierces the elastically-compressible core at the core top surface, and a flexible member attached to the cover plate and to each of the plurality of ribs, wherein at least one of the plurality of ribs remains rotatable in relation to the cover plate. The disclosure also provides an expansion joint seal which includes a cover plate, a plurality of ribs, an elastically-compressible core having a first layer and a second layer, a plurality of ribs between the first layer elastically-compressible core and the second layer core, and a flexible member attached to the cover plate and to each of the plurality of ribs, wherein each of the plurality of ribs remains rotatable in relation to the cover plate.
The disclosure also provides an expansion joint seal including a cover plate, a plurality of ribs, an elastically-compressible core having a core bottom surface, and a core top surface, a plurality of ribs extending through the elastically-compressible core at the core top surface, the rib extending to the core bottom surface, and a flexible member attached to the cover plate and to each of the plurality of ribs, wherein each of the plurality of ribs remains rotatable in relation to the cover plate.
Additional aspects, advantages, and embodiments of the disclosure will become apparent to those skilled in the art from the following description of the various embodiments and related drawings.
So that the manner in which the described features, advantages, and objects of the disclosure, as well as others which will become apparent, are attained and can be understood in detail; more particular description of the disclosure briefly summarized above may be had by referring to the embodiments thereof that are illustrated in the drawings, which drawings form a part of this specification. It is to be noted, however, that the appended drawings illustrate only typical preferred embodiments of the disclosure and are therefore not to be considered limiting of its scope as the disclosure may admit to other equally effective embodiments.
In the drawings:
An expansion joint seal system 100 is provided for imposition in a joint, such that a portion remains above the joint, i.e. partial imposition. The joint is formed of a first substrate 102 and a second substrate 104, which are each substantially co-planar with a first plane 106. The joint is formed as the first substrate 102 is separated, or distant, the second substrate 104 by a first distance 108. The first substrate 102 has a first substrate thickness 110, and has a first substrate end face 112 substantially perpendicular to the first plane 106. Likewise, the second substrate 104 has a second substrate thickness 114, and has a second substrate end face 116 substantially perpendicular to the first plane 106.
By selection of the properties of its various elements, the expansion joint seal system 100 may provide sufficient fire endurance and movement to obtain at least the minimum certification under fire rating standards. The selection of fire retardant components permits protection sufficient to pass a building code fire endurance protection, such as for one hour under ASTM E 1399 requiring pre-test cycling or EN 1366 with joint cycling during the fire endurance testing. Moreover, the expansion joint system 100 may reduce the damage from impact of external components.
Referring to
The cover plate 120 is preferably made of a material sufficiently resilient to sustain and be generally undamaged by the surface traffic atop it for a period of at least five (5) years and of a material and thickness sufficient to transfer any loads to the substrates which it contacts and may have limited compressibility. The cover plate 120 may be provided to present a solid, generally impermeable surface, or may be provided to present a permeable surface. The cover plate 120 has a cover plate width 122. To perform its function when positioned atop the expansion joint, and to provide a working surface, the cover plate width 122 typically is greater than the first distance 108. In some cases, it may be beneficial for a hinged ramp 144 to be attached to the edge of the cover plate 120. A ramp 144, hingedly attached to the cover plate 120 may provide a surface adjustment should the substrates 102, 104 become unequal in vertical position, such as if one substrate is lifted upward. A ramp 144 ensures that a usable surface is retained, even when the substrates 102, 104 cease to be co-planer, from the first substrate 102, to the cover plate 102, through to the second substrate 102. In the absence of such a ramp 144, movement of one substrate would result in the edge of the cover plate 102 being rotated upward presenting a hazard to vehicular and pedestrian traffic. Alternatively, rather than being positioned atop the expansion joint, the cover plate 120 may be less than the first distance 108 and installed flush or below the top of substrate 102 and/or installed flush or below the surface of substrate 104. The contact point for cover plate 120 may be the deck or wall substrate or may be a polymer or elastomeric material to reduce wear and to facilitate the movement function of the cover plate 120. Regardless of the intended position, the cover plate 120 may be constructed without restriction as to its profile. The cover plate 120 may be constructed of a single plate as illustrated in
Referring to
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The force transfer plate 226 need not retard the movement of each rib 124 as the movement of each rib 124 will be retarded by the elastically-compressible core 128. Flexible attachment of the ribs to the cover plate 120 and to the force transfer plate 226 permits multi-axis movement of the ribs 124 and the flexible member 134 in connection with cover plate 120. The flexible member 134 may be connected to the cover plate 120 with components intended to sever the connection upon a strike to the cover plate 120. This may be accomplished with breakaway shear pins connecting the flexible member 134 to either, or both of, the cover plate 120 and the ribs 124. The force transfer plate 226 may be composed, or contain, hydrophilic or fire-retardant or other compositions that would be obvious to one skilled in the art. In the event of a failure of the elastically-compressible core 128 to retard water or to inhibit water penetration, a hydrophilic or hydrophobic composition on the force transfer plate 226 may react to inhibit further inflow of water. Additionally, the three transfer plate 226 may contain or have an intumescing agent, so that upon exposure to high heat, the force transfer plate 226 may react, and provide protection to the expansion joint.
The force transfer plate 226 is maintained in position at least by attachment or contact with the elastically-compressible core 128. The force transfer plate 226 may be positioned so as to contact and be adhered only to the core bottom surface 132 of the elastically-compressible core 128. Alternatively, the force transfer plate 226 may be positioned within the elastically-compressible core 128 so that the edges of the force transfer plate 226 may extend into the elastically-compressible core 128 and be supported from below by the body of an elastically-compressible core 128. Preferably, the force transfer plate 226 is positioned within the lowest quarter of the elastically-compressible core 128 for maximum load force absorption. The force transfer plate 226 may be positioned higher in the elastically-compressible core 128 in lighter duty or pedestrian applications.
The force transfer plate 226 does not attach to either of the substrates 102, 104 and is maintained in position by connection to the body of an elastically-compressible core 128. The force transfer plate 226 may provide support from below for the ribs 124 which are not otherwise supported from below by the body of an elastically-compressible core 128. Beneficially, the force transfer plate 226 maintains the each of the ribs 124 in position whither the ribs 124 have support from below or not. In high cover plate shear conditions, the force transfer plate 226 supports a joint system which is wider or which uses a narrow depth, and uses the resistance to compression to retard each of the ribs 124 from shifting and delivering all of the compressive force to the trailing edge side of the expansion joint seal system 100. This reduces the ultimate force and the amount of compression by applying the compressive force over a larger area of the elastic-compressible core 128 and at a 90-degree angle to the direct compressive force which adds longevity to the useful life compared to the prior art.
Preferably, the fore transfer plate 226 is sufficiently wide to maximize load transfer. The force transfer plate 226 can be up to or greater than 50% of the width of the expansion joint in seismic applications requiring +/−50% movement. Referring to
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The cover plate 120 may be detachably attached to the flexible member 134. Expansion joint seals are often installed under conditions where mechanical strikes against the cover plate 120 are likely, such as roadways in locales which use snow plows. When used, snow plows employ a blade positioned at the roadway surface to scrape snow and ice from the roadway for removal. Any objects which extend above the roadway surface sufficient to contact the plow are likely to ripped from the roadway surface. It may therefore be preferable or the cover plate 120 to be detachably attached magnetically to the flexible member 134 and retained with a tether 180 to prevent the cover plate 120 from falling into the joint between the substrates 102, 104. This embodiment permits snow plow strikes on the cover plate 120 without permanent damage to the elastically-compressible core 128 or the balance of the expansion joint seal system 100. The tether 180, which may be also attached to the elastically-compressible core 128, may further prevent the elastically-compressible core 128 from sagging away from the cover plate 120, a problem known in the prior art. The tether 180 may be highly flexible, resilient material sufficient to sustain the impact load and sufficiently durable to do so the life of the joint system 100. The support of the elastically-compressible core 128 is of particular (or increased) importance where the elastically-compressible core 128 is in a width to depth ratio of 1:1 or less. Alternatively, the cover plate 120 may be detachably attached to the flexible member 134 using screws, bolts or other devices prepared to break-away in the event of a strike. The flexible member 134 may also be constructed to break apart in the event of a strike, such that flexible member has a tensile strength not in excess of 344.7 kPa. Where the flexible member 124 is provided as a hinge, the first member 302 of the flexible member 124 may be constructed of a high strength polymer, but which is still weaker than the associated second member 304.
Referring to
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When an elastically-compressible core 128 is produced from foam, the pore sizes are preferably 90-200 pores per linear inch, a measurement typically referenced as “pores per inch,” and abbreviated as PPI. Such a value is desirable for low viscosity, under 220 Cp, minimally-filled, or those using nanofillers such as clay, aluminum trihydrate, and microspheres. As the PPI is decreased, the pore size is increased, permitting thicker or larger fillers. Where a higher viscosity impregnate and/or larger particle size functional fillers are used, and when a vapor-permeable elastically-compressible core is desired, a foam of 25-130 PPI is preferred.
The elastically-compressible core 128 may contain hydrophilic, hydrophobic, conductive, or fire-retardant compositions as impregnates, or as surface infusions, as vacuum infusion, as injections, full or partial, or combinations of them. Moreover, the elastically-compressible core 128 may be caused to contain near the core top surface 130, such as by impregnation or infusion, a sintering material, wherein the particles in the impregnate move past one another with minimal effort at ambient temperature, but form a solid upon heating. Once such sintering material is clay. Such a sintering impregnate would provide an increased overall insulation value and permit a lower density at installation that conventional foams while still having a fire endurance capacity of at least one hour, such as in connection with the UL 2079 fire endurance test. While the cell structure, particularly, but not solely, when compressed, of an elastically-compressible core 128 inhibits the flow of water, the presence of an inhibitant or a fire retardant may prove additionally beneficial. The fire retardant may be introduced as part of the foaming process, or by impregnating, coating, infusing, or laminating, or by a functional membrane.
The elastically-compressible core 128 may be treated with, or contain, liquid-based fire-retardant additives, by methods known in the art, such as infusion, impregnation and coating or solid fire retardants, such as intumescent rods. Such liquid-based fire-retardant additives may be solids provided in a liquid medium. These liquid mediums include mere mobile phases, such as a base of water or alcohol, or any other medium which would suspend the fire-retardant material until introduced into or onto the foam and which is intended to dry or evaporate away from the core after introduction. Similarly, the fire-retardant materials may include metal hydroxides or other compounds known to release water or fire suppressing gases when heated. As can be appreciated, non-toxic gases are preferable as there may be persons present when the fire-retardant materials decomposes.
In an infusion technique, the fire-retardant material is injected into the elastically-compressible core 128, whether by needles in a liquid medium or by simple imposition, after the elastically-compressible core 128 has solidified.
Alternatively, infusion may be accomplished by other methods to drive the fire retardant into the elastically-compressible core 128, including by compressing the elastically-compressible core 128 and permitting expansion in the presence of the fire-retardant material, resulting in suction within the elastically-compressible core 128 as the internal voids refill, and then permitting any medium, such as a binder, to evaporate or weep out.
As known in the art, impregnation includes introducing a compressed elastically-compressible core 128 to a fire retardant in a liquid medium, permitting the elastically-compressible core 128 to expand and thereby create suction as the internal voids re-expand, then compressing the elastically-compressible core 128 to expel the liquid medium so that a desired volume, less than maximum, is retained within the elastically-compressible core 128. Alternatively, an elastically-compressible core 128 may be impregnated by impregnating a generally non-elastic core with a flexible elastomer, acrylic, or other similar flowing material to impart elasticity.
Alternatively, a solid fire retardant material may be introduced. Intumescent bodies or materials, such as graphite, may contact or be imposed within the elastically-compressible core 128. Referring to
In a further alternative, well-known in the art, a solid fire-retardant material, such as neoprene, may be introduced to the constituents of the elastically-compressible core 128 before foaming. Neoprene does not suppress fire but rather is a synthetic rubber produced by polymerization of chloroprene which protects the elastically compressible core during the initial temperature rise and resists burning due to its high burn point of about 500° C. Small pieces of neoprene can be introduced into an elastically-compressible core 128 made of polyurethane prior to the foam forming. Polyurethane results from the mixing of a polyol and diisocyanate to form a stable long-chain molecule. The neoprene, or other fire-retardant material can be introduced with these two liquids are combined, resulting in the fire-retardant material being suspended within and throughout the elastically-compressible core 128. The fire retardant materials can be uniformly dispersed or concentrated in specific areas. Neoprene can further be used to protect the elastically-compressible core 128 through the early stages of a fire and serve as part of staged design where it protects until another fire retardant starts reaches its decomposition temperature. An elastically-compressible core 128 formed in this way can be used without the need for impregnation, infusion, or coating, but may have increased fire-retardant properties should it be so treated.
Other systems may alternatively be used to introduce a fire retardant, or any functional filler. These may be printed onto the elastically-compressible core 128 by a screen method, gravure process, pressure sensitive injection rollers or by computer numerical control equipment. The fire retardant or filler may be surface coated or injected. It can then be compressed by a platen or rollers to increase the depth or concentration/density.
When the elastically-compressible core 128 is selected from a low-density material, selective impregnation/infusion may be beneficial to control the volume applied at the location of application, such as at the exposed surface, ensuring consistent fire retardancy, waterproofing and other functions and at levels equivalent to that otherwise achieved at higher densities/compression ratios known in the art.
For a similar benefit, a functional membrane 1202 may be imposed between layers of the elastically-compressible core 128, as illustrated in
The membrane may be a polymer that cures or thermosets at temperatures between 65-260° C. and which is flexible until the exposure to a high temperature event. Due to the selective placement in the elastically-compressible core 128, the polymer does not provide a potential fuel source and can be placed where it will cure within the elastically-compressible core 128 in a fire event, such that it will not burn but will instead be heated to its reaction temperature, cure and provide a rigid structural support for the remainder of the elastically-compressible core 128. Elastically-compressible cores 128 with a density after compression of less than 200 kg/m3 with the internal recovery member/membrane 1202 exhibit superior performance over elastically-compressible cores 128 having densities in excess of 200 kg/m3 materials, as those higher densities in concert with high compression ratios can force the rib 124 or cover plate 120 up and/or out of the joint or cause the joint to push down due the higher density. When desired, the membrane 1202 may provide a connection to the adjacent first substrate 102 and/or the second substrate 104 and may provide noise dampening. The membrane 1202 may alternatively be positioned atop the elastically-compressible core 128, and provide a wear surface in the event the cover plate 120 is omitted or lost. The membrane 1202 can optionally be a conductive member or as a carrier for a wire or cable. The membrane 1202 can also have an internal tubing or conduit to allow for remedial waterproofing or other post installation features. The internal recovery member/membrane provides for movement greater than +/−7.5% with long term cycling capacity of greater than 7,300 equal to ten years of thermal cycling. Surprisingly, the internal recovery member/membrane further provides structural and fire resistance for EN 1366 type testing requiring joint cycling during the actual fire endurance testing which not known in the art.
The elastically-compressible core 128 may be shaped to aid in installation, such as by providing a trapezoidal shape, wherein the elastically-compressible core 128 is wider at the core surface top 130 than at the core bottom surface 132, such that the profile provides a nosing at the core surface top 130 at the first substrate 102 and noise dampening surface that supports the cover plate 120. Other shapes or profiles, including open sections or voids, that facilitate the movement and function of the expansion joint have been found to beneficial. Elastically-compressible cores with up to 50% open area or voids allow for highly desirable movement recovery such that the total density of the core volume can be doubled while retain excellent expansion joint properties. Lower density while providing the required back-pressure and recovery force is desirable such than materials for example, with a total volume density of less than 200 kg/m3, provide the same functional properties as materials with a density greater than 200 kg/m3.
When desired, the compressibility of the elastically-compressible core 128 may be altered by forming the elastically-compressible core 128 from two foams, or other elements, of differing compressibility, providing a different spring force on the two sides of the ribs 124. Unequal densities, and thus spring forces, may provide a desirable spring force in the direction of movement of the traffic above, such as a roadway or one side of a concourse, to return the ribs 124 to the original position and to avoid the potential for a compression set over time due to the unequal application of movement to the expansion joint seal system 100. This may be accomplished by the foam in the elastically-compressible core 128 on one side of the ribs 124 having a first foam body density and the foam in the elastically-compressible core 128 on opposing side of the ribs 124 having a second foam body density. In a further alternatively, the elastically-compressible core 128 may be composed of laminations of materials layer one atop another, rather than as laterally-adjacent elements. Thus, an elastically-compressible core 128 may comprise a first layer of an open-celled foam with fire retardant additives, whether by impregnation, infusion or any other methods known in the art, with a second layer of a more rigid and/or closed cell foam, such that the more rigid layer may comprise, for example, 10-25% of the total thickness. That second layer of the elastically-compressible core 128 may be selected to provide movement and compression in response to seismic cycling and be used for support or as a filler which resiliently tolerates high compression, such in a seismic event. That second layer of the elastically-compressible core 128 may have a rigidity with flexibility to maintain shape and volume under the application of force until a threshold is reached, after which the material permits compression without permanently damaged, and which returns to standard performance thereafter. The sequence of layering may be selected based on functionality—water resistance, fire resistance, and flexibility.
Alternatively, the compost on of the elastically-compressible core 128 on one side of the ribs 124 may be homogenous, while the opposing side may be a composite, such as a laminate of two foams or extruded glands, or a combination thereof.
In one embodiment, the elastically-compressible core 128 provides support to each of the ribs 124 from below. While each of the ribs 124 pierces, or is formed in situ with a void in the elastically-compressible core 128, the elastically-compressible core 128 at the core top surface 130, in this embodiment, the rib bottom surface 140 does not extend to the core bottom surface 132. As a result, the elastically-compressible core 128 is not pierced through by the ribs 124, though the rib 124 may extend partially or nearly to the core bottom surface 132. Additionally, the elastically-compressible core 128 provides lateral forces against each side of each of the ribs 124, maintaining each rib 124 in position relative to the two substrates 102, 104. Beneficially, where the ribs 124 do not pierce the elastically-compressible core 128, the elastically-compressible core 128 remains integral such that a portion of the elastically-compressible core 128 provides a seal against outside contaminates in the expansion joint, to seal and support the bottom of the rib 124, the rib bottom surface 140. The ribs 124 may be cast, laminated or bonded to the elastically-compressible core 128 or, where present, to membrane 1202, such as a rigid layer thereof, to provide structural, transfer or reduces transfer forces within the elastically-compressible core 128 or from its top to bottom.
The present disclosure thus provides a seal against contaminants following a rib 124 through the seal, and allows for extra wide joint systems without the added expense depth requirements of systems without a bottom support.
Alternatively, the ribs 124 may extend through the core bottom surface 132. The rib 124 may therefore include or be connected to a flared base as illustrated in
Some or all of the ribs 124 may be electrically conductive or be composed, or contain, hydrophilic, hydrophobic or fire-retardant compositions. In the event of a failure of the elastically-compressible core 128 to retard water or to inhibit water penetration, the hydrophilic or hydrophobic composition in a rib 124 may react to inhibit further inflow of water. Some or all of the ribs 124 may further include a radio frequency identification device to transmit internal data when needed or may include cathodic protections. Some or all of the ribs 124 may conductively connected and/or have data collection sensors such as pressure, force, strain and water or a combination of data collection sensors. Functional sensors or indicators, whether mechanical or electro-mechanical, may be used to provide data or permit visual information related to the expansion joint system 100, substrate 102, 104, or connected materials and assemblies. Upon failure of the elastically-compressible core 128 to retard water or to inhibit water penetration, a hydrophilic or hydrophobic composition on the rib 124 may react to inhibit further inflow of water. Additionally, each rib 124 may contain or bear an intumescing agent, so that upon exposure to high heat, the rib 124 may react, and provide protection to the expansion joint.
Where the elastically-compressible core 128 is an extruded gland, the rib 124 or ribs 124 may be part of the extrusion or be adhesively or heat bonded to the rib 124. As the extruded gland core can be solid or have an open matrix or structurally distinct sections, the elastically-compressible core 128 may further include a radio frequency identification device to transmit internal data when needed or may include cathodic protections, such as explained previously in connection with the ribs 124.
As provided in
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Moreover, the expansion joint seal system 100 may be initially installed such that the ribs 124 are angled against the intended flow of traffic when the elastically-compressible core 128 is composed of three or more foam members, such that a foam at the top of the elastically-compressible core 128 which is to be in compression due to traffic is of a higher density and that the opposing side, lower edge is likewise of a higher density. Because the relative force of elastically-compressible core 128 determines the position of the ribs 124, equal densities maintain the elastically-compressible core 128 in an intermediate position, one which limits operation to a maximum of 50% of the joint width for compression. Varied densities in the elastically-compressible core 128 on the two sides of the ribs 124, provides an additional 10-20% more compressive resistance to traffic impact. This improvement may be particularly beneficial in situations such as the down ramp in a parking garage where traffic attempts to decelerate while traveling over the joint cover 120, as this repeated circumstance will wear out a joint based on materials which are evenly compressed and providing evenly offsetting forces.
The ribs 124 need not be uniformly positioned. The ribs 124 may be positioned in staggered relationship such that no more than one half of the elastically-compressible core 128 can be subject to compression. The balance of the elastically-compressible core 128 resists the compression outside direct force of the ribs 124. The portion of the elastically-compressible core 128 in compression may be further altered by angling the ribs 124 so as to subject less than half of an elastically-compressible core 128 to direct compression. This allows the balance of the elastically-compressible core 128 to be in a state of less compression and for the portion of the elastically-compressible core 128 have a less compression to run longitudinally along the joint, such that at any one point in the length of the joint the elastically-compressible core 128 is in lower compression contact with the ribs 124, reducing compression set and creating a mechanical locking relationship between the elastically-compressible core 128 and the ribs 124. These ribs 124 may be attached to the force transfer plate 226. Moreover, by directing the various ribs 124 at differing angles within the 124, the ribs 124 may entangle the elastically-compressible core 128 so as to make it integral with the ribs 124 and, by extension, to the cover plate.
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Alternatively, the elastically-compressible core 128 may be extruded or shaped in a bellows or wave configuration to facilitate compression so that the coating 124 may comprise an elastomer or high modulus or stiff sealant, capable of elongation of less than 500%. Higher modulus elastomers installed in this manner, in addition to water/UV/other properties, provide additional expansion force against the substrate that reduces the compression set in traditional density and compression ratios. Beneficially, this also increases the expansion recovery and adds structural support for an elastically-compressible core 128 of lower density, such as those that have a density, after installation of less than 200 kg/m3, i.e. having an operable density of less than 200 kg/m3. Further, this permits a compression of up to 80% and an extension of 100% from the installed mean gap/joint opening. The coating 128 may also be semi-rigid, permitting some compression while providing some restorative force. The coating 128 may be continuous or intermittently placed, or may be a combination of layers of a high modulus elastomer and a low modulus elastomer, depending on the desired function. Alternatively, the elastically-compressible core 128 may be selected from a material or composite having a higher density or configured with a higher compression ratio, such that the elastically-compressible core 128 has an operable density of at greater than 750 kg/m3. Where the elastically-compressible core 128 has an overall high density, or a density which causes substantial difficulty in compressing to the designed joint width, the elastically-compressible core 128 may be provided with a shaped to remove material near the core bottom surface 132 such that the volume density is lower than the equal solid core density.
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The selection of components providing resiliency, compressibility, water-resistance and fire resistance, the system 100 may be constructed to provide sufficient characteristics to obtain fire certification under any of the many standards available. In the United States, these include ASTM International's E 814 and its parallel Underwriter Laboratories UL 1479 “Fire Tests of Through-penetration Firestops,” ASTM International's E1966 and its parallel Underwriter Laboratories UL 2079 “Tests for Fire-Resistance Joint Systems,” ASTM International's E 2307 “Standard Test Method for Determining Fire Resistance of Perimeter Fire Barrier Systems Using Intermediate-Scale, Multi-story Test Apparatus, the tests known as ASTM E 84, UL 723 and NFPA 225 “Surface Burning Characteristics of Building Materials,” ASTM E 90 “Standard Practice for Use of Sealants in Acoustical Applications,” E 119 and its parallel UL 263 “Fire Tests of Building Construction and Materials, ” ASTM E 136 “Behavior of Materials in a Vertical Tube Furnace at 750° C.” (Combustibility), ASTM E 1399 “Tests for Cyclic Movement of Joints,” ASTM E 595 “Tests for Outgassing in a Vacuum Environment,” ASTM G 21 “Determining Resistance of Synthetic Polymeric Materials to Fungi.” Some of these test standards are used in particular applications where firestop is to be installed.
Most of these use the Cellulosic time/temperature curve, described by the known equation T=20+345*LOG(8*t÷1) where t is time, in minutes, and T is temperature in degrees Celsius including E 814/UL 1479 and E 1966/UL 2079.
E 814/UL 1479 tests a fire-retardant system for fire exposure, temperature change, and resilience and structural integrity after fire exposure (the latter is generally identified as “the Hose Stream test”). Fire exposure, resulting in an F [Time] rating, identifies the time duration—rounded down to the last completed hour, along the Cellulosic curve before flame penetrates through the body of the system, provided the system also passes the hose stream test. Common ratings include 1, 2, 3 and 4 hours Temperature change, resulting in a T [Time] rating, identifies the time for the temperature of the unexposed surface of the system, or any penetrating object, to rise 181° C. above its initial temperature, as measured at the beginning of the test. The rating is intended to represent how long it will take before a combustible item on the non-fireside will catch on fire from heat transfer. In order for a system to obtain a UL 1479 listing, it must pass both the fire endurance (F rating) and the Hose Stream test. The temperature data is only relevant where building codes require the T to equal the F-rating.
When required, the Hose Steam test is performed after the fire exposure test is completed. In some tests, such UL 2079, the Hose Stream test is required with wall-to-wall and head-of-wall joints, but not others. This test assesses structural stability following fire exposure as fire exposure may affect air pressure and debris striking the fire-resistant system. The Hose Stream uses a stream of water. The stream is to be delivered through a 64 mm hose and discharged through a National Standard playpipe of corresponding size equipped with a 29 mm discharge tip of the standard-taper, smooth-bore pattern without a shoulder at the orifice consistent with a fixed set of requirements:
The nozzle orifice is to be 6.1 m from the center of the exposed surface of the joint system if the nozzle is so located that, when directed at the center, its axis is normal to the surface of the joint system. If the nozzle is unable to be so located, it shall be on a line deviating not more than 3020 from the line normal to the center of the joint system. When so located its distance from the center of the joint system is to be less than 6.1 m by an amount equal to 30.5 for each 10° of deviation from the normal. Some test systems, including UL 1479 and UL 2079 also provide for air leakage and water leakage tests, where the rating is made in conjunction with a L and W standard. These further ratings, while optional, are intended to better identify the performance of the system under fire conditions.
When desired, the Air Leakage Test, which produces an L rating and which represents the measure of air leakage through a system prior to fire testing, may be conducted. The L rating is not pass/fail, but rather merely system property. For Leakage Rating test, air movement through the system at ambient temperature is measured. A second measurement is made after the air temperature in the chamber is increased so that it reaches 177° C. within 15 minutes and 204° C. within 30 minutes. When stabilized at the prescribed air temperature of 204±5° C. the air flow through the air flow metering system and the test pressure difference are to be measured and recorded. The barometric pressure, temperature and relative humidity of the supply air are also measured and recorded. The air supply flow values are corrected to standard temperature and pressure (STP) conditions for calculation and reporting purposes. The air leakage through the joint system at each temperature exposure is then expressed as the difference between the total metered air flow and the extraneous dumber leakage. The air leakage rate through the joint system is the quotient of the air leakage divided by the overall length at the joint system in the test assembly and is less than 0.005 L/s·m2 at 75 Pa or equivalent air flow extraneous, ambient and elevated temperature leakage tests.
When desired, the Water Leakage Test produces a W pass-fail rating and which represents an assessment of the watertightness of the system, can be conducted. The test chamber for or the test consists of a well-sealed vessel sufficient to maintain pressure with one open side against which the system is sealed and wherein water can be placed in the container. Since the system will be placed in the test container, its width must be equal to or greater than the exposed length of the system. For the test, the test fixture is within a range of 10 to 32° C. and chamber is sealed to the test sample. Non-hardening mastic compounds, pressure-sensitive tape or rubber gaskets with clamping devices may be used to seal the water leakage test chamber to the test assembly. Thereafter, water, with a permanent dye, is placed in the water leakage test chamber sufficient to cover the systems to a minimum depth of 152 mm. The top of the joint system is sealed by whatever means necessary when the top of the joint system is immersed under water and to prevent passage of water into the joint system. The minimum pressure within the water leakage test chamber shall be 1.3 psi applied for a minimum of 72 hours. The pressure head is measured at the horizontal plane at the top of the water seal. When the test method requires a pressure head greater than that provided by the water inside the water leakage test chamber, the water leakage test chamber is pressurized using pneumatic or hydrostatic pressure. Below the system, a white indicating medium is placed immediately below the system. The leakage of water through the system is denoted by the presence of water or dye on the indicating media or on the underside of the test sample. The system passes if the dyed water does not contact the white medium or the underside of the system during the 72 hour assessment.
Another frequently encountered classification is ASTM E-84 (also found as UL 723 and NFPA 255), Surface Burning Characteristics of Burning Materials. A surface burn test identifies the flame spread and smoke development within the classification system. The lower a rating classification, the better fire protection afforded by the system. These classifications are determined as follows:
UL 2079, Tests for Fire Resistant of Building Joint Systems, comprises a series of tests for assessment for fire resistive building joint system that do not contain other unprotected openings, such as windows and incorporates four different cycling test standards, a fire endurance test for the system, the Hose Stream test for certain systems and the optional air leakage and water leakage tests. This standard is used to evaluate floor-to-floor, floor-to-wall, wall-to-wall and top-of-wall (head-of-wall) joints for fire-rated construction. As with ASTM E-814, UL 2079 and E-1966 provide, in connection with the fire endurance tests, use of the Cellulosic Curve. UL 2079/E-1966 provides for a rating to the assembly, rather than the convention F and T ratings. Before being subject to the Fire Endurance Test, the same as provided above, the system is subjected to its intended range of movement, which may be none. These classifications are:
ASTM E2307, Standard Test Method for Determining Fire Resistance of Perimeter Fire Barrier Systems Using Intermediate-Scale, Multi-story Test Apparatus, is intended to test for a systems ability to impede vertical spread of fire from a floor of origin to that above through the perimeter joint, the joint installed between the exterior wall assembly and the floor assembly. A two-story test structure is used wherein the perimeter joint and wall assembly arc exposed to an interior compartment fire and a flame plume from an exterior burner. Test results are generated in F-rating and T-rating. Cycling of the joint may be tested prior to the fire endurance test and an Air Leakage test may also be incorporated.
While the first body of compressible foam 120 has a first body fire rating, and the second body of compressible foam 128 has a second body fire rating, the first body fire rating need not be the same as the second body fire rating. Moreover, while this first body of compressible foam 120 provides a primary sealant layer, it can be altered as a result of any water which permeates into it, as this changes its properties, thus fire-rating properties may differ in ease of water penetration, a circumstance which must be accounted for in any testing regime. Fortunately, because the second body of compressible foam 128 is protected from water penetration by the barrier 134, the functional properties, such as the fire-rating properties, of the second body of compressible foam 128 are not compromised. Similarly, the second body of compressible foam 128 may be protected from deleterious materials, such as flowing chemicals, by the barrier 134. The current art does not provide for water and fire-resistant joints can obtain listings or certifications to applicable fire tests such as UL 2079 or EN 366 when the fire-resistant layer or material suffers from water penetration. A body's fire rating may include the temperature at which the body burns, or flame spreads, or, in conjunction with or as an alternative thereto, the time-duration at which a body passes any one of several test standards known in the art. In one embodiment, the first body fire rating is unequal to the second body fire rating. Selection of the fire rating for the various layers of the joint seal 100 may be made to address operational issues, such as a high fire rating for the first layer or body 120, which will be directly exposed to fire, but which may provide limited waterproofing, coupled with a second body of compressible foam 128 which may have a lower fire rating, but a higher waterproofing rating, to address the potential loss of the first body of compressible foam 120 in a fire. The first body of compressible foam 120 may be fire resistant but may ablate in response to exposure, shedding size or volume when exposed to high temperature or fire with the membrane separating it from other layers, which may retain their structural integrity or otherwise continue to provide some sealing function and providing functional properties during exposure. The selection of foam, fire retardant impregnation, thickness and compression after imposition may provide sufficient resilience to repeated compression to pass at least one of the cycling regimes for various fire rating and may likewise provide sufficient fire retardancy to rate at least a one-hour rating is desirable, through a 2, 3, or 4 hour rating may be preferable.
The system 100 may be supplied in individual components or may be supplied in a constructed state so that it may installed in an economical one step operation yet perform like more complicated multipart systems. The cover plate can be solid continuous or be smaller segments to support the elastic-compressible core. The use of smaller cover plates or bars to provide dimensional and/or compression support is beneficial in wide and shallow depth applications where products in the art will not work. During installation, a depth setting or other support mechanism may be used, whether above or below the expansion joint. A support mechanism below the surface may left in place to provide structural support when required.
The entire system 100 may be constructed such that a gap is present between the cover plate 120 and the elastically-compressible core 128 and a retaining band positioned about the elastically-compressible core 128 to maintain compression during shipping and before installation without additional spacers that would limit test fitting of the system 100 prior to releasing the elastically-compressible core 128 from factory compression. Packaging materials, that increase the bulk and weight of the product for shipping and handling to and at the point of installation are therefore also eliminated.
The health of the system 100 may be assessed without alteration of the system 100, often accomplished by removal of the cover plate by the inclusion in the system 100 of sensors, such as radio frequency identification devices (RFIDs), which are known in the art, and which may provide identification of circumstances such as structural damage or moisture, penetration and accumulation. The inclusion of a sensor in the system 100 may be particularly advantageous in circumstances where the system 100 is concealed after installation, particularly as moisture sources and penetration may not be visually detected. Thus, by including a low cost, moisture-activated or sensitive sensor at the core bottom surface 132, the user can scan the system 100 for any points of weakness due to water penetration. A heat sensitive sensor may also be positioned within the system 100, particularly on or in the elastically-compressible core 128 thus permitting identification of actual internal temperature, or identification of temperature conditions requiring attention, such as increased temperature due to the presence of fire, external to the joint or even behind it, such as within a wall. Such data may be particularly beneficial in roof and below grade installations where water penetration is to be detected as soon as possible.
Inclusion of sensors may provide substantial benefit for information feedback and potentially activating alarms or other functions within the joint sealant or external systems. Fires that start in curtain walls are catastrophic. High and low pressure changes have deleterious effects on the long-term structure and the connecting features. Providing real time feedback from sensors, particularly given the inexpensive cost of such sensors, in those areas and particularly where the wind, rain and pressure will have their greatest impact would provide benefit. While the pressure on the wall is difficult to measure, for example, the deflection in a pre-compressed sealant is quite rapid and linear. Additionally, joint seals are used in interior structures including but not limited to bio-safety and cleanrooms. The rib 124 may be selected of a heat-conducting material and positioned in communication with the sensor. Additionally, a sensor could be selected which would provide details pertinent to the state of the Leadership in Energy and Environmental Design (LEED) efficiency of the building. Additionally, such a sensor, such as an RFID, which could identify and transmit air pressure differential data, could be used in connection with masonry wall designs that have cavity walls or in the curtain wall application, where the air pressure differential inside the cavity wall or behind the cavity wall is critical to maintaining the function of the system and can warn of impending failure. Sensors may be positioned in other locations within the joint seal 100 to provide beneficial data. A sensor may be positioned within the elastically-compressible core 128 at or near the core top surface 130 to provide prompt notice of detection of heat outside typical operating parameters, so as to indicate potential fire or safety issues. Such a positioning would be advantageous in horizontal of confined areas. A sensor positioned so positioned might alternatively be selected to provide moisture penetration data, beneficial in cases of failure or conditions beyond design parameters. The sensor may provide data on moisture content, heat or temperature, moisture penetration, and manufacturing details. A sensor may provide notice of exposure from the surface of the joint seal 100 most distant from the base of the joint. Sensors may further provide real time data. Using moisture sensitive sensors, such as RFIDs, in the system 100 and at critical junctions/connections would allow for active feedback on the waterproofing performance of the system 100. It can also allow for routine verification of the watertightness with a hand-held sensor reader, particularly an RFID reader, to find leaks before the reach occupied space and to find the source of an existing leak. Often water appears in a location much different than it originates making it difficult to isolate the area causing the leak. A positive reading from the sensor alerts the property owner to the exact location(s) that have water penetration without or before destructive means of finding the source. The use of a sensor in the system 100 is not limited to identifying water intrusion but also fire, heat loss, air loss, break in joint continuity and other functions that cannot be checked by non-destructive means. Use of a sensor within the elastically-compressible core 128 may provide a benefit over the prior art. Impregnated foam materials, which may be fused for the elastically-compressible core 128, are known to cure fastest at exposed surfaces, encapsulating moisture remaining inside the body, and creating difficulties in permitting the removal of moisture from within the body. While heating is a known method to addressing these differences in the natural rate of cooling, it unfortunately may cause degradation of the foam in response. Similarly, while forcing air through the foam bodies may be used to address the curing issues, the potential random cell size and structure impedes airflow and impedes predictable results. Addressing the variation in curing is desirable as variations affect quality and performance properties. The use of a sensor within the body may permit use of the heating method while minimizing negative effects. The data from the sensors, such as real-time feedback from the heat, moisture and air pressure sensor, aids in production of a consistent product. Moisture, heat, and pressure sensitive sensors aid in determining and/or maintaining optimal impregnation densities, airflow properties of the foam during the coring cycle of the foam impregnation. Placement of the sensors into foam at the pre-determined different levels allows for optimum curing allowing for real time changes to temperature, speed and airflow resulting in increased production rates, product quality and traceability of the input variables to that are used to accommodate environmental and raw material changes for each product lots. Sensors, such as RFIDs or NFCs (near field communication devices), may be installed in the elastically-compressible core 128 to record actual manufacturing lot data, product, manufacturer and performance data such as a three hour UL 2079 listing or a movement rating. The data can be stored on the NFC during production directly from RFID or other sensor data to provide for accurate lot tracking, quality assurance and process improvement. The NFC can be read or updated before, during and after installation. Post installation uses may include recording other sensor data, storing warranty and service history as well as the ability to validate the correct material or rated material was installed. For example, an RFID installed in a building's structure may provide data for product improvement and for building status, which may be accumulated over time for further analysis and use, such as by constructors, designers, and/or property owners.
The present system 100 may be provided in transitions as provided previously, as unions, and in other configurations. The ribs 124 associated with a first flexible member 134 and a cover plate 120 may pierce into or be formed in a second elastically-compressible core 128 to overlap the attachment between adjacent expansion joint seal system 100, particularly when the first and second expansion joint seal systems 100 are overlapping, such as a transition or union.
The foregoing disclosure and description is illustrative and explanatory thereof. Various changes in the details of the illustrated construction may be made within the scope of the appended claims without departing from the spirit of the invention. The present invention should only be limited by the following claims and their legal equivalents.
This application is a continuation of U.S. patent application Ser. No. 15/677,811, for “Durable joint seal system with detachable cover plate end rotatable ribs,” filed Aug. 15, 2017, which is a continuation-in-part of U.S. patent application Ser. No. 15/649,927 for “Expansion Joint Seal for Surface Contact Applications,” filed Jul. 14, 2017 which is incorporated herein by reference, which issued at U.S. Pat. No. 9,840,814 on Dec. 12, 2017 which is a confirmation of U.S. patent application Ser. No. 15/062,354 for “Expansion Joint Seal for Surface Contact Applications,” filed Mar. 7, 2016, which is it herein by reference, which issued as U.S. Pat. No. 9,765,486 on Sep. 19, 2017.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15677811 | Aug 2017 | US |
| Child | 15854187 | US | |
| Parent | 15062354 | Mar 2016 | US |
| Child | 15649927 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15649927 | Jul 2017 | US |
| Child | 15677811 | US |
