JPH0313604A - Seamless expansion joint structure between bridge slabs - Google Patents

Abstract

PURPOSE:To prevent the occurrence of cracking and breakage of elastic material and floating and cracking of an asphalt concrete paving portion by separating a slab surface from the lower surface of an elastic material layer having wear resistance, which is disposed above the slab surface in such a manner as to slide by a separation sheet. CONSTITUTION:A Slide plate 5 is placed on a resin impregnated portion 4 in such a manner as to freely slide extending over a seam gap 3 between concrete slabs 2, 2 of a bridge, and two, upper and lower layers of elastic resin mortars 71, 72 are placed on the slabs 2, 2, the impregnated-portions 4, 4 and the plate, 5 through a separation sheet 6. At this time, the mortar 7 is fixed to be integral with the slabs 2, 2 by wedge-shaped anchoring elements 8, 8 outside the impregnated portion 4. Thus, the occurrence of cracking and breakage of elastic material 7 of a local portion right above a seam gap l is eliminated, and the expansion stress is cut off in view of stress from an asphalt concrete paving portion 9 to prevent floating and cracking of the portion.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a seamless expansion joint structure constructed at a joint between slabs in a bridge such as a general road or an expressway.

(Prior art) lil! has been used on expressways, etc. Between the beam slugs 91, there are comb-like expansion joints that protrude and engage with each other in order to absorb the expansion and contraction of the bridge slab caused by temperature changes.
Finger joints) and expansion joints made of rubber-like elastic bodies are used.

(Problem to be solved by the invention) Although the conventional bridge expansion joint described above has many advantages, due to its structure, the attachment part is easily destroyed, and the slab around the attachment part is secondarily affected by the damage. and unpleasant vibrations that occur when a vehicle passes over the joint.
Further, there are other problems such as stones and other foreign objects falling down from the road through the gaps between the joints, and dust, rainwater, etc. easily entering.

Furthermore, if the joint is damaged, it takes time and effort to repair it, and there is a problem in that traffic must be shut off for a long period of time.

Furthermore, conventional rubber-like elastic bodies have a problem of low durability against the load of passing vehicles and a short joint life.

(Means and effects for solving the problems) The present invention aims to solve the above-mentioned problems, namely: In a joint structure between bridge slabs, (a) a joint gap extending from both bridges; Slabs on both sides facing each other across (b
) A central slide plate mounted on the slab surface on both sides across the joint gap so as to be slidable; (d) an isolation sheet coated on the surface of the exposed slide plate and the exposed slab;
e) a wear-resistant stretchable material layer cast on the isolation sheet, both ends of which are adhered to at least the front surface of the anchorage body, and whose surface is flush with the paved concrete surface; (f) a paving concrete section cast flush with the outside of the abrasion-resistant elastic material layer; and a seamless expansion joint structure between bridge slabs. be.

Note that in the above, the slab means a concrete slab, a steel plate slab, etc., which are usually employed as an I-beam road slab.

Furthermore, the term "paving concrete" refers to a road surface paving material layer such as asphalt concrete (ASCON) or road surface concrete.

In the above, the wear-resistant stretchable material used may be any material with greater stretchability than the lower slab material, but stretchable resin mortar is preferably used; Preferably, it is composed of a plurality of upper and lower layers, with the upper layer having wear resistance similar to that of paving concrete, and the lower layer having softer rubber elasticity than the upper layer.

In addition, the anchor body is a wedge-shaped body with the front part shaved off by light weight.
It is preferable to increase the contact (adhesion) surface area with the material layer having abrasion resistance.

-m road Pt beam, as shown in Fig. 1,
Due to seasonal and skin temperature changes, the bridge slab 2.
As a result of expansion and contraction of 2, the length r of the joint gap between these slabs changes in proportion to the expansion f of one slab material and the temperature difference, and changes by the total amount, but usually the amount of change is several cm. This results in a considerable length change.

If a stretchable material is directly cast and bonded to the upper surface of the slabs at the joint, the stretchable material at the slab joint will change due to the change in the gap length e between the slabs due to temperature changes. Δl) is the short gap length! As a result, the stretchable material is directly applied as stretching stress to the upper stretchable material part, and the stretchable material has to contract #J in the short part of the distance Ml, resulting in cracks in the covered part.
Or amputation occurs.

In the present invention, the slab surface and the lower surface of the stretchable material layer above it are slidably isolated by an isolation sheet, so that the ends of the slabs on both sides, which are caused by expansion and contraction of the slabs 2 and 2 due to temperature changes, are removed. Length l at seam gap
The change amount Δl (#! of the expansion coefficient and temperature difference of one slab material is dispersed and absorbed in the length L portion of the entire stretchable material.

As a result, there is no longer a problem in which a large elastic stress is applied to the stretchable material in the local area directly above the joint gap l, and there is no risk of cracking or cutting the stretchable material in the local area.

In addition, the expansion and contraction stress generated in the stretchable resin material due to the expansion and contraction of the joint part is transmitted to the slabs on both sides via the anchoring bodies adhered to the slab surface, and the stress is Because of the disconnection, elastic stresses caused by temperature changes in the elastic material, etc., do not result in the paving concrete lifting or cracking.

(Example) Examples of the present invention will be described below.

FIG. 1 is a partially cross-sectional explanatory diagram showing the structure of a seamless expansion joint between bridge slabs according to an embodiment of the present invention.

In the figure, ■ is a seamless expansion joint between Pi beam soot 91, 2 is a concrete slab (floor slab) of a bridge such as an expressway, 3 is a joint gap 1-4 is a resin impregnated part, 5 is a slide plate, 6
is an isolation sheet, 7 is an elastic resin mortar (7, is an upper resin mortar, 72 is a lower resin mortar), 8 is an anchored body,
9 is Karasuro at Ascon Pavement Department.

In FIG. 1, the slabs 2.2 on both sides extend from the bridges on both sides and face each other at the same height across a seam gap 3(p). The resin-impregnated part 4.4 is a concrete slab reinforcement layer formed by impregnating and curing a resin monomer (methyl methacrylate (MMA) monomer), but it does not necessarily have to be an impregnated layer and can be applied to metals, plastics, ceramics (slip surface It may also be made by laminating and fixing plates such as

Furthermore, a slide plate 5 is slidably slidable on the resin-impregnated portion 4.4 across the joint gap 3! ! 1 will be erected. Upper and lower layers of elastic resin mortar 7, . 72 is poured.

The resin mortar is preferably composed of an MMA resin as a main material, a binder and an inorganic filler, and the upper layer preferably contains a large amount of inorganic filler to impart wear resistance similar to that of Ascon paving material. It is preferable that the lower layer has rubber elasticity as a binder, and the amount of inorganic binder is reduced to make it viscoelastic.

The protruding portion of the resin-impregnated portion 4.4R and the upper surface of the slide plate 5 are covered with an isolation sheet 6, which has a slippery surface (to prevent adhesion) such as a polyethylene sheet or a Teflon sheet. layer) is preferred.

This allows the upper and lower two layers of resin mortar 772 to easily slide over the resin-impregnated portion 4.4 and the slide plate 5 when expanding and contracting due to temperature changes. Furthermore, even if water intrudes from above, the lower slide plate 5 and concrete slab 2 are protected from ingress 6, and furthermore, the work of placing the elastic resin mortar is facilitated.

The slide plate 5 is a plate made of metal, plastic, ceramic, etc. that is smooth on both sides, and the lower resin mortar 7
This prevents □ from falling into the joint gap 3 and helps strengthen the reinforced joint gap.

Further, the upper and lower two layers of resin mortar 71.7□ are integrally fixed to the slabs 2.2 on both sides by anchoring bodies 8.8 on the outside of the resin-impregnated portion 4.4.

Two layers of resin mortar, top and bottom? +, 72 is transmitted to the slabs 2.2 on both sides via the anchoring bodies 8.8.

Anchor body 8.8 is made of resin mortar, resin concrete, metal,
A cast-in-place or pre-formed product made of plastic, ceramic, concrete, etc. that has practically the same strength and rigidity as slab concrete, but cannot be bonded to slab concrete or steel slabs, or bonded with bolts, anchors, explosive welding, etc. Fixed.

The shape of the anchoring bodies 8, 8 is preferably wedge-shaped as shown in the figure, and its large surface area effectively absorbs the shrinkage and compressive stress applied to the resin mortar 7.72, and also provides strong adhesive strength with the resin mortar. obtain.

If the anchoring body 8.8 is made of resin mortar, it is firmly adhesively bonded to the slab 2.2 via the same type of permeable resin brimer and the permeable resin impregnated layer of the slab 2.2. Note that embedded bolts, anchors, etc. may also be used for connection.

As mentioned above, the anchoring body 8.8 is fixed to the resin mortar 7 with a sufficient surface area (in a wedge shape with a shaved front surface), so there is a practical problem with the amount of distortion of the resin mortar 7. There is no.

The upper resin mortar 71 has a higher modulus of elasticity than the lower resin mortar 72, but the anchoring body 8.8 with the slab 2.2
are joined with a slope (wedge shape), and the length of the upper elastic section is made wider than the length of the lower elastic section, so that the amount of elongation 1a in the joint gap 3 can be easily absorbed.

Further, it is preferable that the upper resin mortar 71 has sufficient strength to withstand the load of the wheels and abrasion resistance close to that of Ascon pavement 9.9, and the lower resin mortar 72 has the same strength as the upper resin mortar 7. In comparison, the anchorage is 8.8.
are approaching, and the length of the lower elastic section is shortened, but the elastic modulus is lowered so that it is soft enough to expand and contract sufficiently to correspond to the amount of expansion and contraction of the seam gap 3.

Note that the lower mortar 7 is strong enough to prevent excessive deformation or destruction due to the load of the wheels.

Two layers of resin mortar as described above? ,,7. It is viscoelastic and strong, and is a multi-layer rubber elastic body whose lower part is softer than the upper part, and is characterized by a structure that differentiates the amount of expansion and contraction between the upper and lower parts.

Next, examples of materials and compositions suitable for the above-mentioned constituent parts are listed below.

The resin in the resin-impregnated portion 4 is preferably an IL-type low-viscosity resin that hardens at room temperature as described above, such as MMAI fat monomer. It plays a role in enhancing sexuality.

The isolation sheet 6 has a thickness of 0.1 mm to 3.0 mm. OI grade polyethylene sheet, Teflon sheet, or MM
A viscoelastic sheet etc. whose main components are A resin and a plastic resin are preferable, for example, a resin (R) whose main components are an MMA resin and a plastic resin (R) 20 to 80% and a calcium carbonate powder fine powder (F) 80 to 20% as a filler. Examples include those made from a mixture consisting of %.

As the anchoring body 8, resin concrete is preferable, and viscoelastic resin concrete is particularly preferable, such as a cold polymerization type resin (R) mixed with a resin mainly composed of MMA and a plastic resin, silica stone, limestone, ore slag. Examples include room-temperature heavy-duty resin concrete in which a filler (F) with a particle size of 20 s/m or less and having a particle size of 20 s/m or less and (C) chips of a viscoelastic resin solid material (particle size of 5 to 50 um) (C) are mixed.

Preferably, the stretchable resin mortar is made of MMAwA resin as a main material and also contains a binder and an inorganic filler. It is preferable that the upper layer contains a large amount of inorganic filler to impart the same R resistance as that of the Ascon paving material. For the lower layer, it is preferable to use a binder having elasticity and to reduce the amount of inorganic binder to make it viscoelastic.

For example, a room temperature polymerizable resin (R) which is a mixture of a resin whose main component is MMA and a plastic resin, a filler (F) whose main component is silica, limestone, slag, etc. and whose particle size is 20*/m or less.
, and room-temperature polymerization type resin concrete mixed with chips (C) of viscoelastic resin solids (unvulcanized synthetic rubber, natural rubber, etc.) having a particle size of 5 to 50 um, R of 40 to 8%, F
60 to 92% and C 50% or less.

In the stretchable resin mortar, if R is more than the above range-E limit, the flow resistance will be low and it will become too soft, and if it is less than the lower limit of the above range, the viscosity will be low and there will be no followability. .

(2) If the amount of F is greater than the above upper limit range, it will become hard and brittle, resulting in low viscosity and loss of followability.

Furthermore, if the amount of F is less than the upper limit, the flow resistance will be reduced and the material will be easily deformed.

■If the amount of C is more than the upper limit, it will become brittle.

The ascon pavement section 9.9 has two upper and lower layers of resin mortar 7, . It is poured so that it is flush with the outside of 72. If the ascon pavement portion 9.9 is thick, a combination of three or more layers of elastic resin mortar may be used.

From the above, the upper and lower two layers of resin mortar 7, . 7. The stress generated in the slab 2.2 is transmitted to the slab 2.2 on both sides via the anchorage 8.8, and is disconnected from the slab 2.2 placed on the outer side of the slab 2.2.

In the above examples, an example in which stretchable resin mortar was mainly cast as the wear-resistant material was explained. In particular, it is very advantageous to apply the present invention to the fabrication of seamless expansion joints between bridge slabs. That is, a precast board with a shape and size that allows the fitting device to be placed in the recess on the isolation sheet between both sides of the anchor body is brought to the site, adhesive is applied to the front surface of the anchor body, and the plate is fitted in the place. By inserting the precast board, the work is completed by simply gluing both end faces of the precast board to the front surface of the anchor body. Therefore, in this case, the manufacturing time can be significantly shortened, and whereas it takes 1 to 2 hours for one place using resin mortar, the work can be completed in less than half the time.

<Effects of the Invention> As explained above, according to the present invention, the slab surface and the lower surface of the abrasion-resistant stretchable material layer above it are slidably isolated by the isolation sheet, so The change Δl in the length l in the joint gap between the ends of both slabs, which occurs when the slab expands and contracts, is
As a result of being dispersed and absorbed in the length L portion of the entire stretchable material layer,
There is no longer a problem that stretching stress is applied to the stretchable material #] portion directly above the joint gap molecule, and therefore there is no risk of cracking or cutting of the stretchable material layer in this local region.

In addition, the expansion and contraction stress generated in the elastic material layer due to the expansion and contraction of the joint part is transmitted to the slabs on both sides via the anchoring bodies adhered to the slab surface, and the stress is transmitted to the poured pavement concrete on the outside. Because of this disconnection, the expansion and contraction stresses caused by temperature changes in the elastic mortar will not cause the paving concrete to lift or crack.

Furthermore, at the joint between the 11 beam slabs, slide plates are slidably mounted on the front surfaces of the slabs on both sides facing each other across the joint gap, and isolation sheets are placed on the top surfaces of the slabs. Since a stretchable bamboo material that is resistant to mechanical damage is placed on top of this, it is possible to prevent unpleasant vibrations from occurring when the 17 cars pass through the joints, and to prevent local external forces from concentrating on the joints. Since no additional damage is added, the slab portion is not likely to be damaged as in the conventional example.

In addition, even if the bridge is damaged due to wear or the like, it can be easily and quickly repaired, so even on bridges with heavy traffic, the time required for work is short and long-term traffic control is not required.

Since it is possible to prevent dust, rainwater, etc. from entering the slab portion, the reinforcing bars and the like of the slab portion are not damaged, contributing to extending the life of the bridge.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional explanatory drawing showing the structure of a seamless expansion joint between bridge slabs according to an embodiment of the present invention. In the figure, 1: Seamless expansion joint between bridge slabs according to the embodiment of the present invention,
2: Slabs of bridges such as expressways, 3: Joint gaps, 4: M
A fat-impregnated part, 5 Ni-Ride plate, 6: Isolation sheet,
7: Resin mortar (7, double-part resin mortar, 7□:
(lower resin mortar), 8: anchoring body, 9: ascon pavement section,

Claims (10)

[Claims] (1) In the joint structure between bridge slabs, (a) the slabs on both sides extend from the bridge on both sides and face each other across the joint gap; (b) the slabs extend across the joint gap and can slide freely on the slab surfaces on both sides; (c) anchoring bodies provided on both sides of the slide plate, the lower surface of which is bonded to the slab surface and the back surface of which is bonded to the paving concrete section; d) an isolation sheet that covers the surfaces of the slide plate and the exposed portion of the slab; (e) an isolation sheet that is cast on the isolation sheet and has both ends adhered to at least the front surface of the anchor body, and whose surface is a paved concrete surface; and (f) a paving concrete part cast flush with the outer side of the wear-resistant stretchable material layer. A seamless expansion joint structure between bridge slabs, characterized by comprising: (2) The seamless expansion joint structure between bridge slabs according to claim 1, wherein the wear-resistant stretchable material layer is a wear-resistant stretchable resin mortar cured material layer. (3) The seamless expansion joint structure between bridge slabs according to claim 1, wherein the wear-resistant stretchable material layer is a wear-resistant precast resin mortar plate. (4) The elastic resin mortar cured material layer is composed of multiple upper and lower layers, with the upper layer having wear resistance similar to that of paving concrete, and the lower layer having softer rubber elasticity than the upper layer resin mortar. The seamless expansion joint structure between bridge slabs according to claim 2. (5) A precast resin mortar board with wear resistance is composed of upper and lower layers, with the upper layer having wear resistance similar to that of paving concrete material, and the lower layer having softer rubber elasticity than the upper resin mortar. 4. The seamless expansion joint structure between bridge slabs according to claim 3. (6) The seamless expansion joint structure between bridge slabs according to any one of claims 1 to 5, wherein the anchoring body is a wedge-shaped body whose front part is tapered. (7) All the expansion and contraction stress generated in the elastic resin mortar due to expansion and contraction of the joint part is transmitted to the slabs on both sides via the anchoring bodies, and is disconnected from the outside part of the poured pavement slab. The seamless expansion joint structure between bridge slabs according to any one of claims 1 to 6. (8) The seamless expansion joint structure between bridge slabs according to any one of claims 1 to 7, wherein the slabs are concrete slabs. (9) The seamless expansion joint structure between bridge slabs according to claim 8, wherein each front surface layer of the slabs on both sides is a resin-impregnated concrete slab layer. (10) The seamless expansion joint structure between bridge slabs according to any one of claims 1 to 7, wherein the slab is a steel deck plate.