Floor slab laying sealing material

Abstract

To provide a sealing material for preventing leakage of grout filled between a girder and a floor slab, which can be fitted between the girder and the floor slab formed in advance.SOLUTION: In a floor slab laying sealing material 11 consisting of a rod-like elastic material used as a form material between a girder and a floor slab to form a filling space filled with grout, a rod-like body part 12 is constituted of a sponge of high compressive stress. A girder corresponding surface corresponding to an upper surface of the girder and a floor slab facing surface corresponding to a lower surface of the floor slab are formed in the body part 12 by being fitted into a gap previously formed by the upper surface of the girder and the lower surface of the floor slab, and the girder corresponding surface and the floor slab corresponding surface are coated with a water-expanding nonwoven fabric 13 which absorbs moisture and expands. Then, the overall height including the water-expandable nonwoven fabric 13 is about 2 mm to 5 mm higher than a height of the filling space.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a deck slab laying sealant used when laying a deck slab on a girder in the construction or repair of a bridge, viaduct, or the like. [Background technology]

[0002] The deck slab is placed on top of the girder via a rod-shaped elastic sealant, and then the space surrounded by the girder, deck slab, and sealant is filled with grout to secure it to the girder. To achieve a strong fixation, the sealant must be installed so that the low-viscosity grout does not leak.

[0003] However, the deck rests on a sealant placed on the top surface of the girder. The heavy deck is lifted and placed by a crane, placed on the elastic sealant, and then shifted on the sealant to correct its position. During this process, the deck and the sealant rub against each other strongly, which can damage the sealant. If the sealant breaks and the grout leaks, a gap can form between the deck and the girder, reducing the deck's supporting strength.

[0004] To avoid such inconveniences, the sealing material (leak-proofing material for deck support) in Patent Document 1 below employs a structure in which a sliding tape with a surface having a low coefficient of friction is attached to the entire upper surface of a rubber packing material.

[0005] Figure 10 is a copy of Figures 4 to 6 of Patent Document 1, and as can be seen in (b) and (c) of Figure 10, the sealing material 101 has a sliding tape 103 over the entire upper surface of a packing material 102 having a rectangular vertical cross section. (a) of Figure 10 is a plan view of the deck support structure, and corresponds to Figure 4 of Patent Document 1. Similarly, (b) of Figure 10 is a cross-sectional view of the main parts, and corresponds to Figure 5 of Patent Document 1, and (c) of Figure 10 is a side view of the main parts, and corresponds to Figure 6 of Patent Document 1.

[0006] In FIG. 10, 104 denotes a girder, and sealing material 101 is arranged parallel to the longitudinal direction of girder 104. Positioning pins (stud dowels) 105 are arranged in pairs at predetermined intervals along the longitudinal direction on the top surface of girder 104, and deck slabs 106 are aligned along the longitudinal direction of girder 104 using these positioning pins 105. A through-hole 107 is provided in haunch portion 106a of deck slab 106, through which the positioning pins 105 are inserted and which serves as a grout filling port. A support bolt 108 is threadedly inserted near through-hole 107, and its tip protrudes downward from haunch portion 106a. The protruding length of support bolt 108 determines the height of the filling space. In (c), 106b denotes a joint piece that protrudes from the lower end of deck slab 106 toward the joint side, and 109 denotes a folded-back portion of the reinforcing bar used for joining.

[0007] During construction, when the deck slab 106 is suspended and the haunch portion 106a is placed on the sealing material 101, the sealing material 101 is compressed to a predetermined degree by the deck slab 106, creating a filling gap of a predetermined height, as shown in Figure 10(c). The compression rate is generally about 40% to 60%. At this time, a gap remains between the deck slab 106 and the set deck slab 106, and the deck slab 106 must be moved to close the gap with the set deck slab 106. The presence of the sliding tape 103 on the top surface of the sealing material 101 reduces the frictional resistance acting when the deck slab 106 is moved, reducing the force required for movement and making the sealing material 101 less likely to deform. For this reason, it is believed that filling the filling space with grout through the through-holes 107 in the deck slab 106 can be done without leaks.

[0008] Although the presence of the sliding tape 103 reduces the workload and the burden on the sealing material when moving the deck slab 106, the alignment of the deck slab 106 is performed by sliding it on the sealing material 101, which has been compressed and deformed by the load of the deck slab 106. For this reason, a considerable amount of stress is generated when moving, so accurate alignment is not necessarily easy.

[0009] Therefore, there is a demand for post-fitting of the sealant to a portion of the area where the deck is laid. In other words, it is conceivable to fit the sealant between the girder and the deck after the deck is partially placed in the correct position on the girder. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Patent No. 3066432 Summary of the Invention [Problem to be solved by the invention]

[0011] The primary object of this invention is to provide a seal that can be retrofitted. [Means for solving the problem]

[0012] To solve this problem, the sealing material of this invention has the following configuration. Specifically, it is a deck slab installation sealing material made of a rod-shaped elastic material that is used as a formwork material between a girder and a deck slab to form a filling space to be filled with grout. The rod-shaped main body is made of a sponge with high compressive stress. The main body has a girder-corresponding surface that fits into the gap pre-formed between the upper surface of the girder and the lower surface of the deck slab and corresponds to the upper surface of the girder, and a deck-facing surface that fits into the lower surface of the deck slab. These girder-corresponding surface and deck-facing surface are covered with a water-expandable nonwoven fabric that expands upon absorbing moisture. The overall height, including the water-expandable nonwoven fabric, is higher than the height of the filling space. The difference between the overall height and the height of the filling space is commensurate with the compressive stress of the main body; in other words, it is the height at which the main body can be compressed vertically and fitted, and at which a resilient force is exerted when fitted. For example, it can be less than 10 mm.

[0013] In this configuration, the slab laying sealant is compressed and fitted between the girder and the slab. The water-swelling nonwoven fabric helps distinguish the upside-down orientation of the slab laying sealant and makes the grippy surfaces of the main body smooth by sliding between the girder and the slab, facilitating the fitting process. The main body, made of a sponge with high compressive stress, maintains its rod-like shape and cross-sectional shape due to its hardness, facilitating the fitting process and minimizing deformation. The fitted slab laying sealant is stretched vertically by the high compressive stress of the sponge constituting the main body, pressing the water-swelling nonwoven fabric against the girder and the slab, maintaining the fitting position and forming a filling space. When grout is filled into the filling space and the water in the grout reaches the water-swelling nonwoven fabric, the water-swelling portion of the water-swelling nonwoven fabric expands, preventing grout leakage and increasing its thickness. When the water-swellable nonwoven fabric expands, the body is compressed, causing the body to exert a higher stress and creating a seal between the girder and the deck. [Effects of the Invention]

[0014] This invention provides a slab installation sealant that is easy to install, resistant to misalignment, and prevents grout leakage, thanks to the cooperation of the high-compression-stress sponge that constitutes the main body and the water-swelling nonwoven fabric that absorbs water. Unlike conventional sealants that achieve watertightness by placing a slab on the sealant and compressing it heavily, the slab installation sealant of this invention can be installed under a pre-installed slab, and the high compressive stress of the main body allows for positioning at the time of installation. When grout is then injected, the water-swelling nonwoven fabric on the girder- and slab-contacting surfaces expands, further increasing stress and achieving watertightness between the upper surface of the girder and the lower surface of the slab. This ensures reliable grout leakage prevention and construction that achieves the desired support strength. Furthermore, because it is installed after installation, the slab can be accurately placed on the girder, thereby improving construction accuracy. [Brief explanation of the drawings]

[0015] [Figure 1] A perspective view of a deck laying sealing material. [Figure 2] Cross-sectional view of the deck laying sealant. [Figure 3] Photo of the deck slab installation sealant. [Figure 4] Schematic diagram showing thermal compression of a water-swellable nonwoven fabric. [Figure 5] FIG. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] An explanatory diagram showing a deck slab laying sealing material that is used in a shorter length. [Figure 10] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] An embodiment of the present invention will be described below with reference to the drawings.

[0017] The sealing material used in laying deck slabs is used as a formwork material between the girder and the deck slab to form a filling space that is filled with grout, and is made of a rod-shaped elastic material. Among these sealing materials, the deck slab laying sealing material 11 (hereinafter referred to as "sealing material") of this invention shown in the perspective view of Figure 1 is used by placing the deck slab on the girder and then fitting it into the gap that forms between the girder and the deck slab. In other words, it is used by being retrofitted or fitted into a pre-formed gap.

[0018] The sealing material 11 has a rod-shaped main body 12 and a water-swelling nonwoven fabric 13 that covers a part of the main body.

[0019] The main body 12 is made of a sponge with high compressive stress and has a rectangular column shape. Specifically, as shown in FIG. 2, the cross-sectional shape is rectangular or square. As described above, the sealing material 11 is fitted into the gap S formed in advance between the upper surface 51a of the girder 51 and the lower surface 61a of the deck slab 61, so that the lower surface of the main body 12 becomes the girder-corresponding surface corresponding to the upper surface 51a of the girder 51, and the upper surface of the main body 12 becomes the deck-facing surface corresponding to the lower surface 61a of the deck slab 61. Because the cross-sectional shape of the main body 12 is rectangular or square, there is essentially no distinction between the upper surface (the deck-facing surface) and the lower surface (the girder-corresponding surface).

[0020] The sponge constituting the main body 12 is preferably one that is highly resilient and hard. Here, "hard" means that the force required to impart a specified deformation under certain conditions (JIS K 6400-2) is large. A sponge with high compressive stress is preferably used. Compressive stress is expressed as a value measured according to the test standard [JIS K 6767], and to have a high compressive stress sufficient to constitute the sealing material 11, the 25% compressive stress value must be 30 kPa or more. Specifically, it is preferable to use one with a 25% compressive stress of approximately 30 kPa to 90 kPa, and more preferably one with a 25% compressive stress of approximately 40 kPa, which combines appropriate resilience and hardness.

[0021] When considering the physical properties of sponge, a low apparent density is preferable from the viewpoint of ease of handling. 3 The lower the value, the lighter and softer the foam. The preferred apparent density is 50 kg / m 3 ~100kg / m 3 Figure 3 shows photographs of the sealing material 11. In Figure 3, (a) is a perspective view, (b) is a front view, (c) is a left side view, and (d) is a plan view. (e) is an enlarged photograph showing the main body of the sealing material shown in the front view, and (f) is an enlarged photograph of the water-expandable nonwoven fabric shown in the plan view. The one shown in (e) has an apparent density of 60 kg / m 3 The main body 12 is made of a sponge.

[0022] The main body 12, which has a rectangular or square cross-section, is required to block the grout filled in the filling space, so the size of its cross-sectional shape is set according to the height h1 of the gap S. In other words, the sealing material 11 is custom-made to fit the height h1 of the gap S for which it is to be used. Since the height h1 of the gap S is generally 30 mm, 40 mm, 50 mm, etc., the horizontal dimension a of the cross-sectional shape of the main body 12 is set, for example, in the range of approximately 25 mm to 100 mm so as to ensure a sufficient contact area with the portion to be sealed. The vertical dimension b corresponds to the predetermined height h1 of the gap S (see Figure 2). Specifically, the height is set within a range from a few mm lower to a few mm higher than the height h1 of the gap S, based on the height h1 of the gap S.

[0023] The length of the main body 12 can also be determined and manufactured as desired, but it may also be manufactured to a predetermined length, such as 1 m or 1.8 m.

[0024] The water-swellable nonwoven fabric 13 swells upon absorbing water, and is made by mixing highly absorbent fibers made from highly absorbent polymers with synthetic resin fibers such as polyester. Since the non-shrink mortar used as grout is strongly alkaline and the highly absorbent fibers do not expand easily, it is preferable that the water-swellable nonwoven fabric 13 has a large water absorption capacity and a high volume expansion ratio. In terms of the content of highly absorbent fibers in the water-swellable nonwoven fabric 13, the higher the content, the better, for example, about 50% to 80%. Since the water-swellable nonwoven fabric 13 also needs to be strong, it is preferable that the fabric has a basis weight of 200 g / m 2 ~700g / m 2 The thickness of the water-swellable nonwoven fabric 13 is set, for example, in the range of 1 mm to 6 mm. The water-swellable nonwoven fabric shown in FIG. 3(f) has a water-swellable fiber content of 70% and a basis weight of 500 g / m 2 is.

[0025] For this water-expandable nonwoven fabric 13, it is preferable to use one that has been post-processed by thermal compression to reduce its thickness t1 from that at the time of manufacture, in order to prevent it from expanding when in contact with mortar and to improve smoothness. That is, as shown in Fig. 4, water-expandable nonwoven fabric 13, which is approximately 6 mm to 8 mm at the time of manufacture, is passed between heated rolls 71 and 72 and compressed to reduce its thickness t2. If the thickness t1 before thermal compression is 6 mm to 8 mm, it is preferable that thickness t2 be approximately 1 mm to 3 mm.

[0026] Such water-swelling nonwoven fabric 13 covers the girder-facing surface and deck-facing surface of the main body 12, as well as the entire longitudinal end faces of the main body 12. The water-swelling nonwoven fabric 13 is covered using double-sided adhesive tape (not shown).

[0027] The height h2 of the entire sealing material 11, including the thickness t of the water-swelling nonwoven fabric 13 that covers the girder-corresponding surface and the deck-corresponding surface of the main body 12, is higher than the height h1 of the gap S that becomes the filled space. The difference between the overall height h2 and the height h1 of the gap S is set to a range of less than 10 mm depending on the compressive stress of the main body 12 and the thickness of the water-swelling nonwoven fabric 13. Specifically, when the 25% compressive stress of the main body 12 is 30 to 90 kPa, the difference between the overall height h2, including the water-swelling nonwoven fabric 13, and the height h1 of the gap S should be in the range of 2 mm to 5 mm.

[0028] The sealing material 11 configured as described above is fitted into the gap S between the pre-formed girder 51 and the deck slab 61 to form a filled space, as shown in FIG. 5. When the deck slab 61 has a joint piece 62 at its lower end that protrudes in the joining direction, as shown in FIG. 6, the sealing material 11 is fitted by being pushed in from the side of the girder 51 in the cross-sectional direction of the sealing material 11. When the end face of the deck slab 61 in the joining direction is vertical and does not have a joint piece, as shown in FIG. 7, multiple sealing materials 11 are fitted from two directions to form a square frame below the haunch portion 63 on the underside of the deck slab 61. In other words, there are sealing materials 11a that extend in the width direction of the girder 51 and move in the longitudinal direction of the girder 51 to be fitted, and sealing materials 11b that extend in the longitudinal direction of the sealing material 11 and move in the width direction of the girder 51 to be fitted. As shown in FIG. 8, these seals 11a and 11b are preferably fitted so that both ends of the seal 11a extending in the width direction of the beam 51 are pressed by the ends of the seal 11b extending in the length direction of the beam 51.

[0029] 5 to 7, the stud dowels, the bolts for adjusting the height of the deck slab 61, and the grout filling holes into which the stud dowels fit are not shown. Also, in FIGS. 6 and 7, 15 denotes the sealing material 15 that has been previously installed and compressed by the deck slab 61.

[0030] To fit the sealing material 11, the upper and lower surfaces bearing the water-swelling nonwoven fabric 13 are oriented vertically, and the material is pressed between the girder 51 and the deck slab 61 while being slightly compressed vertically. The water-swelling nonwoven fabric 13, which has a different appearance and feel from the sponge-made main body 12, determines the vertical orientation, allowing the material to be fitted in the desired correct position. Furthermore, the water-swelling nonwoven fabric 13 is smoother than the porous main body 12, which has high contact resistance and grip, reducing resistance during fitting and making it easier to fit. The water-swelling nonwoven fabric 13 covers the entire upper and lower surfaces of the main body 12, making fitting exceptionally easy.

[0031] Moreover, although the main body 12 made of sponge with high compressive stress bends, it strongly maintains its rod-like form and cross-sectional shape. In other words, whether pressed in the longitudinal direction or cross-sectional direction of the hard sealant 11, the high resilience minimizes deformation and maintains its shape, making it easy to fit into gaps that are lower in height than the sealant 11.

[0032] When sealing material 11 is fitted, water-swellable nonwoven fabric 13 at the longitudinal end of sealing material 11 abuts against the opposing sealing material. Because sealing material 11 has water-swellable nonwoven fabric 13 on both longitudinal end surfaces, as shown in Figure 9, even if sealing material 11 is cut to reduce its length, connection via water-swellable nonwoven fabric 13 is possible as long as water-swellable nonwoven fabric 13 is present on the end surface of sealing material 11 that is butted together for connection.

[0033] When the sealing material 11 is fitted into place with its longitudinal end faces butted against each other without any gaps, the high compressive stress of the sponge that makes up the main body 12 tensions the sealing material 11 in the vertical direction. The water-expanding nonwoven fabrics 13 on both the top and bottom surfaces press against the upper surface 51a of the girder 51 and the lower surface 61a of the deck slab 61, respectively, preventing it from shifting from its fitted position. Similarly, the longitudinal connection parts also have a high repulsive force that tries to maintain their position.

[0034] When grout is filled into the filling space formed by fitting the sealing material 11 in this way, the moisture in the grout is absorbed by the water-swellable fibers of the water-swellable nonwoven fabric 13. The water-swellable fibers that have absorbed the moisture swell to prevent water from passing through and close the gaps between the fibers, causing the water-swellable nonwoven fabric 13 to expand. The expanded water-swellable nonwoven fabric 13 becomes thicker and compresses the main body 12. This generates even higher stress in the main body 12, and the repulsive force of the main body 12 and the expansion pressure of the water-swellable nonwoven fabric 13 seal the space between the girder 51 and the deck slab 61.

[0035] In this way, even if the sealant 11 is added later, the main body 12, which is made of a sponge with high compressive stress, and the water-swelling nonwoven fabric 13, which expands when it absorbs water, work together to prevent grout leakage. Moreover, the hardness of the main body 12 makes it easy to fit, and its high resilience prevents it from shifting position after fitting, so the sealant 11 will not come off when the grout is injected. Therefore, even if this sealant 11 is used in place of part or all of the conventional sealant that achieves watertightness by being heavily compressed when the deck slab is placed, it is possible to lay a deck slab 61 with the desired support strength.

[0036] Moreover, the sealing material 11 is attached later, and the deck slab 61 can be placed in the correct position before the sealing material 11 is fitted, and the deck slab 61 is not displaced even when the sealing material 11 is fitted under the deck slab 61, thereby improving the accuracy of construction.

[0037] The water-swellable nonwoven fabric 13 is post-processed by thermal compression to reduce its thickness compared to when it was manufactured, so that it can expand sufficiently even when filled with a strongly alkaline grout. Furthermore, the surface of the water-swellable nonwoven fabric 13 can be made smoother rather than fluffy, making it easier to fit.

[0038] Since the water-swelling nonwoven fabric 13 is also provided on both longitudinal end surfaces of the main body, even if the length is adjusted by cutting on site, the desired construction with the water-swelling nonwoven fabric 13 on the butting surfaces is possible.

[0039] The above configuration is one embodiment for carrying out the present invention, and the present invention is not limited to the above configuration, and other configurations can also be adopted.

[0040] For example, the cross-sectional shape of the sealing material 11 is not limited to a rectangle or a square, and the upper or lower surface may have a shape other than a flat surface. The left and right side surfaces of the sealing material 11 from which the main body 12 is exposed may also have other shapes, such as an inclined surface, instead of being parallel to each other as described above. [Explanation of symbols]

[0041] 11...Sealing material for deck installation 12...Main body 13...Water-swelling nonwoven fabric 51...digit 51a...Top surface of girder 61…Floor slab 61a...Underside of deck S...gap

Claims

1. A deck laying sealant made of a rod-shaped elastic material that is used as a formwork material between a girder and a deck to form a filling space to be filled with grout, The rod-shaped main body is made of a sponge with high compressive stress, and is fitted into a gap formed in advance between the upper surface of the girder and the lower surface of the deck slab, and has a girder-corresponding surface corresponding to the upper surface of the girder and a deck-facing surface corresponding to the lower surface of the deck slab, The girder and deck surfaces are covered with a water-expanding nonwoven fabric that absorbs water and expands. The total height, including the water-swelling nonwoven fabric, is higher than the height of the filling space. Deck laying sealing material.

2. The water-expandable nonwoven fabric is post-processed by heat compression to reduce its thickness compared to when it was manufactured. The deck laying sealant according to claim 1.

3. Both longitudinal end surfaces of the main body are also covered with a water-swelling nonwoven fabric that absorbs water and expands. The deck slab laying sealant according to claim 1 or 2.

4. The 25% compressive stress of the main body is set to 30 to 90 kPa, and the difference between the height of the entire body including the water-expandable nonwoven fabric and the height of the filling space is set to 2 mm to 5 mm. The deck slab laying sealant according to claim 1 or 2.

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