CN102352606A - Transverse in-vitro prestress solidifying method of road hinged hollow slab bridge - Google Patents

Abstract

The invention provides a transverse in-vitro prestress solidifying method of a road hinged hollow slab bridge, belonging to the technical field of bridge construction. The method comprises the following steps of: carrying out paving treatment on a bridge surface, wherein a paving layer of the bridge surface has the thickness of 12-14cm, the concrete grade is improved, and a steel bar of the bridge surface is changed to have a diameter of 10 and a distance of 12*12cm; carrying out warping joint treatment: clearing original warping joint concrete and filling C50 micro-expanded mortar; detecting an inter-seam connecting steel slab: detecting whether an original inter-seam connecting steel slab unsolders or deforms, if so, soldering or dismounting and replacing the steel slab again; planting bars on the top of a hollow core slab: planting steel bars on the top of a midspan web of each hollow core slab and a wet joint part of a beam end part; applying transverse in-vitro prestress: arranging 5-7 transverse prestress steel tendons below each bridge midspan top slab; and longitudinally reinforcing the longitudinal midspan of the hollow core slab: sticking carbon fibers to the lower flange of a slab midspan with cracks to solidify. The invention has the beneficial effects that connecting steel bars are arranged on the top surface of a hinged slab after the original bridge surface is dismantled, so that the transverse distribution of loads is more uniform; and transverse in-vitro prestress steel bars are arranged among the surroundings of the midspans of all hinged hollow core slabs, so that the transverse connection of all the slabs is enhanced.

Description

The horizontal external prestress strengthening method of the hinged hollow slab bridge of highway

Technical field

The invention belongs to the bridge construction technical field.

Background technology

At present; Road bridge is owing to be subjected to cause influences such as design, construction, use; The bridge floor that continuous hinged hollow slab bridge technology behind the first freely-supported of a lot of employings is arranged; Exist bridge floor the crack to occur, plate span centre basal crack transfinites; So-called " veneer is stressed " phenomenon occurs, the reason that this disease takes place is mainly in the following aspects:

1, deck paving thickness is less; Be generally 8cm; The direction across bridge reinforcing bar is encrypted in the bridge deck pavement near each bridge pier fulcrum; Encrypt spacing and be generally 5cm, other location gap is generally 15cm, and the bearing that the fulcrum place is provided with has retrained the lateral deformation of hollowcore slab to a certain extent; Therefore near each hollowcore slab stressed more even fulcrum; And near the span centre each hollowcore slab since the bridge deck pavement reinforcing bar that spacing is set is bigger, not enough to each plate horizontal restrain, make each plate unbalance stress;

2, the transmission of vertical shear realizes by hinged structures between the hinged cored slab of assembled; Realize the lateral transport and the distribution of traffic load by the transmission of this shearing; When bond strength between plate is not enough to resist the vertical shear of traffic load generation; The joint sealing material concrete can ftracture under the driving load action between plate; The torsional interaction that each plate produces owing to the side vertical shear; Aggravated crack on concrete between plate; Under the driving load action; So-called " veneer is stressed " phenomenon appears; This cross direction profiles with the design cored slab is not inconsistent certainly; The appearance of " veneer is stressed " phenomenon; Make some plate stressed excessive, ftracture so that exceed the permission field of load of plate;

The existence of disease has a strong impact on durability of structures, and traffic safety is also constituted harm, rebuilds like complete removal; Not only influence traffic operation; Invest also greatlyyer, for making full use of existing bridge construction, it is very necessary that the hinged hollow slab bridge of disease is carried out horizontal external prestressing strengthening.

Summary of the invention

The objective of the invention is: provide the hinged hollow slab bridge of a kind of highway horizontal external prestress strengthening method, it can reinforce hollow slab bridge effectively, solves the stressed problem of hollow slab bridge veneer.

Method of the present invention is:

1, deck paving is handled

For increasing deck paving rigidity, improve the effect that the hollowcore slab lateral force is transmitted, make each plate stressed more even, remove original deck paving, under the situation of breaking off a friendship, pour into a mould the deck paving concrete again;

The deck paving layer thickness is 12-14cm, and improves concrete grade to the C40 waterproof concrete, and the bridge floor reinforcing bar changes Φ 10 into, and spacing changes 12 * 12cm into;

Bituminous concrete thickness is kept the concrete standard of former 7cm water proofing asphalt;

2, the hinge seam is handled

After cleaning out original deck paving, clear up original hinge seam concrete, will cut with scissors seam with clear water and rinse well, perfusion C50 microdilatancy mortar; Mortar requires that suitable degree of mobilization is arranged, early strong characteristics, and its expansion characteristics should be tested before construction;

3, connect steel plate between the seam

After waiting to remove original deck paving, check immediately between former seam to connect steel plate whether sealing-off, distortion, as have above situation, should weld or change steel plate and firm welding again;

4, hollowcore slab top bar planting

To strengthen the hollow boards and effect links between pavement in each hollow webs across the top of the wet end of the girder seams with

12 bars for anchorage, one end of which made inverted" L "type, in order to strengthen the bridge panels and hollow plate coupling effect;

5, laterally external prestressing applies

5-7 bundle transverse prestress steel bundle is set below the top board in every width of cloth spanning, every a branch of 7 Φ of steel Shu Caiyong 5 un-bonded prestressed steel strands, every steel bundle tension stress is 65% of a proof stress, steel bundle ground tackle adopts interchangeable, so that maintenance from now on;

After treating that steel Shu Zhangla finishes, the seal cap in steel bundle end, interior notes butter is anticorrosion;

6, the vertical span centre of hollowcore slab is vertically strengthened

After removing deck paving, carbon fiber reinforcement is pasted in the plate span centre bottom flange that the crack occurs, the one, strengthen its supporting capacity, the 2nd, primary fracture is sealed, in case steel strand stress corrosion.

The invention has the beneficial effects as follows: on the articulated slab end face after removing original bridge floor connecting reinforcement is set, has increased being connected of bridge deck and hollowcore slab, make the load cross direction profiles more even;

Utilize existing construction tool, prestressed reinforcement outside the weft element is set between near each hinged hollowcore slab span centre, strengthened each plate and laterally connected.

Take measure of comprehensive, can solve hinged hollow slab bridge " veneer is stressed " disease at all.

Description of drawings

Fig. 1 is that the present invention reinforces FB(flow block);

Fig. 2 is a bridge floor bar planting layout plan of the present invention;

Fig. 3 is a span centre bar planting facade arrangement diagram of the present invention;

Fig. 4 is a bridge pier end bar planting facade arrangement diagram of the present invention;

Fig. 5 is that transverse prestressed reinforcing steel bar of the present invention is arranged elevation;

Fig. 6 is the vertical arrangement diagram of single span transverse prestressed reinforcing steel bar of the present invention.

The specific embodiment

Embodiment 1

Whether successful how to strengthen with striding transverse integral stress performance between each hollowcore slab is to reinforce key; The present invention starts with from increasing with the method for striding transverse splicing between each hollowcore slab; Through increasing the deck paving layer thickness; Strengthen the bridge deck pavement reinforcing bar; Strengthen the connection of bridge deck pavement and each plate; To hinge seam concrete handle make between each plate more closely connected; Applying outside the weft element prestressed reinforcement through near top, cross section span centre strengthens measure such as each plate transverse splicing and realizes; Strengthening between each plate in the transverse splicing; Carbon fiber reinforcement is carried out in existing crack; Reinforcement; To seal existing crack; Improve the supporting capacity of span centre stress area; Prevent the stress corrosion of prestressed reinforcement.

This type bridge reinforcement means should be main with transversely strengthening mainly, and considers the sealing in existing crack and the reinforcement of tensile zone.

1, deck paving is handled

Original deck paving Thickness Design is generally 8cm, might can not reach by this thickness during construction;

For increasing deck paving rigidity, improve the effect that the hollowcore slab lateral force is transmitted, make each plate stressed more even, remove original deck paving, under the situation of breaking off a friendship, pour into a mould the deck paving concrete again;

The deck paving layer thickness is 13cm, and improves concrete grade to the C40 waterproof concrete, and the bridge floor reinforcing bar changes Φ 10 into, and spacing changes 12 * 12cm into;

Bituminous concrete thickness is kept the concrete standard of former 7cm water proofing asphalt;

2, the hinge seam is handled

After cleaning out original deck paving, clear up original hinge seam concrete, will cut with scissors seam with clear water and rinse well, perfusion C50 microdilatancy mortar; Mortar requires that suitable degree of mobilization is arranged, early strong characteristics, and its expansion characteristics should be tested before construction;

3, connect steel plate between the seam

After waiting to remove original deck paving, check immediately between former seam to connect steel plate whether sealing-off, distortion, as have above situation, should weld or change steel plate and firm welding again;

4, hollowcore slab top bar planting

To strengthen the hollow boards and effect links between pavement in each hollow webs across the top of the wet end of the girder seams with

12 bars for anchorage, one end of which made inverted" L "type, in order to strengthen the bridge panels and hollow plate coupling effect;

In the bar planting process, should avoid original hogging moment steel bundle in the beam, can damage anything but;

5, laterally external prestressing applies

7 bundle transverse prestress steel bundles are set below the top board in every width of cloth spanning, every a branch of 7 Φ of steel Shu Caiyong 5 un-bonded prestressed steel strands, every steel bundle tension stress is 65% of a proof stress, steel bundle ground tackle adopts interchangeable, so that maintenance from now on;

After treating that steel Shu Zhangla finishes, the seal cap in steel bundle end, interior notes butter is anticorrosion;

6, the vertical span centre of hollowcore slab is vertically strengthened

After removing deck paving, carbon fiber reinforcement is pasted in the plate span centre bottom flange that the crack occurs, the one, strengthen its supporting capacity, the 2nd, primary fracture is sealed, in case steel strand stress corrosion.

Claims (1)

1. horizontal external prestress strengthening method of the hinged hollow slab bridge of highway, its method is:

A, deck paving are handled

The deck paving layer thickness is 12-14cm, and improves concrete grade to the C40 waterproof concrete, and the bridge floor reinforcing bar changes Φ 10 into, and spacing changes 12 * 12cm into;

Bituminous concrete thickness is kept the concrete standard of former 7cm water proofing asphalt;

B, hinge seam are handled

After cleaning out original deck paving, clear up original hinge seam concrete, will cut with scissors seam with clear water and rinse well, perfusion C50 microdilatancy mortar;

Connect steel plate between c, seam

After waiting to remove original deck paving, check immediately between former seam to connect steel plate whether sealing-off, distortion, as have above situation, should weld or change steel plate and firm welding again;

D, the bar planting of hollowcore slab top

In the mid-span of each hollow webs top end of the girder seams with wet

12 bars for anchorage, one end of which made inverted L-shaped;

E, horizontal external prestressing apply

5-7 bundle transverse prestress steel bundle is set below the top board in every width of cloth spanning, every a branch of 7 Φ of steel Shu Caiyong 5 un-bonded prestressed steel strands, every steel bundle tension stress is 65% of a proof stress, steel bundle ground tackle adopts interchangeable, so that maintenance from now on;

After treating that steel Shu Zhangla finishes, the seal cap in steel bundle end, interior notes butter is anticorrosion;

F, the vertical span centre of hollowcore slab are vertically strengthened

After removing deck paving, carbon fiber reinforcement is pasted in the plate span centre bottom flange that the crack occurs, the one, strengthen its supporting capacity, the 2nd, primary fracture is sealed, in case steel strand stress corrosion.

Images