KR20050033581A - Pavement method of bridge surface using ductile concrete composites - Google Patents

Abstract

A process for pavement of bridge surface is provided, which uses high ductile concrete composite to express superior strain hardening and multiple crack properties without reduction of stress caused by bridging state of fibers after initial cracking. The high ductile concrete composite used in the pavement of a bridge surface comprises water and a binder in W/B weight ratio of 25-50 wt.%; a miscible material, an additive and a CSA based rapid binder with a substitution ratio of 5-50 wt.%, 0-25 wt.% and 0-25 wt.% respectively; 0-2.0 wt.% of high performance water reducing agent and 0-15 wt.% of SBR polymer based on total weight of the binder; 0-1.5 wt.% of thickener; a concrete composite composed of 10-40 vol.% of fine aggregates and 0-25 vol.% of coarse aggregate, and each of polyethylene, polyvinyl alcohol and polypropylene fibers and/or a hybrid form in combination with two or more of them having 1.00-3.20 vol.% of VF.

Description

Bridge Method Using Ductile Concrete Composites

The present invention is a high toughness concrete that exhibits deformation hardening behavior and multiple cracking characteristics under bending and tensile load by incorporating various amounts of synthetic fibers of small diameter and length into a matrix having specially adjusted viscosity, flowability and toughness. The manufacturing technology of the composite and a method of constructing a bridge having high durability, toughness and waterproofing performance by utilizing it in the construction of new or aging bridges for the protection of steel and concrete decks.

In the existing construction method, a method of forming a waterproof layer on a bridge deck and paving asphalt on it as a bridge pavement protection for bridge deck was mainly used for economic and construction reasons.However, in the case of such asphalt bridge paving, thermal behavior and elasticity of the bridge deck Due to the difference in coefficients, various defects such as cracks, potholes, and plastic deformations are generated. As a result, various problems such as destruction of the waterproof layer, moisture penetrating into the bridge deck, and various deterioration phenomena are generated.

Recently, in order to solve the durability problem of asphalt bridge pavement, LMC (Latex Modified Concrete) bridge pavement using polymer and super hard cement has been developed and used as a bridge pavement for top plate repair. The resistance to fatigue load, ie fatigue load, which mainly acts on bridge decks, is only a problem because it only increases the bending and tensile strength of.

Meanwhile, in order to improve the toughness and crack control performance of concrete, highly reinforced cement composites (ECC) have been developed, in which steel fibers are mixed with special synthetic fibers in paste or mortar. In this case, the flexural strength and toughness are improved compared to general concrete, but the crack control performance is comparable. In the case of high toughness cement composites, the deformation performance, toughness and crack control performance under bending and tensile loads are greatly improved, but the paste or mortar matrix It has been pointed out that the elastic modulus is greatly reduced compared to the general concrete.

In the present invention, it is possible to solve the fatigue performance and crack width control performance for the wheel load, which is pointed out as a problem of LMC bridge pavement and steel fiber reinforced concrete pavement developed to solve the problem of durability degradation of asphalt bridge pavement, and moreover to solve this problem To solve the problem of lowering the elastic modulus of high toughness cement composite (ECC) developed in the United States and Japan, the reduction of life cycle cost (LCC) by reducing the long life and maintenance cost of bridges, which are social overhead capital facilities. To develop bridge paving method for bridge deck protection.

To this end, in the present invention, even after the initial crack occurs under the bending and tensile load action, the strain hardening behavior of the stress increases again with the increase of the strain without deterioration of the stress and in the process, the width of the initial crack does not progress, To develop a technique for manufacturing high toughness concrete composites with multiple cracking characteristics that generate a large number of microcracks (about 100 ㎛ or less) and to utilize them as cross-linking packaging materials, thereby improving crack dispersibility and cracking width of cross-linking packaging materials. By controlling, not only the waterproofing performance and the penetration resistance of harmful substances such as Cl ^- or CO ₂ can be significantly improved, but also the flexural toughness and deformation performance can be improved to significantly improve the fatigue performance against lubricating load of the bridge.

The high toughness concrete composite of the present invention has a water / binder ratio (W / B) of 25 to 50% by weight, and a replacement ratio of the admixture, filler, and CSA-based fastener to the binder weight is 5 to 50, respectively.

Wt%, 0-25 wt% and 0-25

The mixing ratios of the high-performance water reducing agent and the SBR polymer with respect to the weight% and the weight of the binder are 0 to 2.0 wt% and 0 to 15, respectively.

0 to 1.5% by weight of methylcellulose thickener based on the weight%, unit quantity, and the mixing ratio of fine aggregate and coarse aggregate to the total volume of concrete was 20 to 40, respectively.

Fiber comprising a matrix composed of% by volume and 0 to 25% by volume, polyethylene (PE) fiber, polyvinyl alcohol (PVA) fiber and polypropylene (PP) fiber alone or hybrid of the same or different types of fiber The volumetric mixing ratio (V _f ) of 1.00 to 3.20 is based on the total volume of the matrix.

It is composed of volume%, and it is manufactured in the field mixer and ready-mixed concrete plant and poured directly in the field to complete the high durability bridge packaging.

As described above, according to the present invention, a combination of parameters related to fiber, matrix, and fiber / matrix interfacial properties is appropriately deformed to increase the stress with the increase of the strain without deterioration of the stress, such as metal, even after the initial cracking under bending and tensile load. In this process, it is possible to manufacture high-tough concrete composites that can produce multiple cracks, which are multiple microcracks with constant crack width control. Not only is this improved but also the crack width is controlled after the occurrence of cracking to block the ingress of deterioration factors, and the elastic modulus is equivalent to that of ordinary concrete, thereby enabling the same structural behavior. A detailed description of the materials, formulations, and manufacturing characteristics of the high toughness concrete composite for cross-section paving with these functions is given below.

That is, cement as a binder used in the high toughness concrete composite of the present invention is usually used portland cement, crude steel portland cement, ultra-tight steel portland cement and cemented carbide cement, when used as a paving material for bridge repair, super speed for open traffic The use of light cement is preferred. In addition, fly ash and blast furnace slag powder, which are industrial by-products as admixtures, were added in an amount of 0 to 35% by weight and 0 to 50%, respectively, in order to improve flowability and economic efficiency of the high toughness concrete composite.

Wt%, preferably 15-30 wt% and 35-45

It is used by weight%, and the limestone fine powder is 0-25% by weight based on the amount of binder, preferably 10-15

Wt% is used, CSA-based fastener is 0-25 wt%, preferably 15-25 wt.

% By weight is used.

Unit quantity is 25-50 with respect to 100 weight% of binders

Weight percent is used, preferably 30 to 45 weight percent. On the other hand, W / B is 25-40

In the case of weight%, 0-2.0 weight% of high performance water reducing agent with respect to a binder to ensure fluidity, Preferably it is 0.5-1.0

If the weight% is added, and the W / B ratio is 40-50%, in order to ensure the dispersibility and viscosity of the fiber, the methylcellulose thickener is 0-1.5% by weight, preferably 0.5-1.0 per unit amount.

% By weight is added. Furthermore, in order to improve the bending performance of the high toughness concrete composite, the SBR-based polymer is 0 to 15% by weight, preferably 5 to 10%, based on the binder.

% By weight is used.

As fine aggregate, silica sand, sea sand, steel sand or PS ball (quench slag) are used, and it is 10 to 40% by volume with respect to the total concrete volume, preferably 20 to 30%.

Volume% is used and it is preferable to use 2.5 mm or less. In addition, coarse aggregates are used in the maximum size 13mm, 10mm and 8mm crushed and strong grind, or PS ball of 7mm or less, 0-25 to the total concrete volume

Volume% is used, preferably 10 to 20 volume% is preferably used.

Fibers include polyethylene (PE) fibers (diameter 10-30 μm, length 6-15 mm), polyvinyl alcohol (PVA) fibers

(30 ~ 100㎛ in diameter, 6 ~ 15mm in length), polypropylene (PP) fiber (30 ~ 60㎛ in diameter, 6 ~ 15mm in length) are used alone or mixed with same or different types of fibers The volumetric mixing ratio (V _f ) of the fibers with respect to 1.00-3.20

Volume%, preferably 1.50 to 2.20% by volume is used, and the proper volume mixing ratio for each fiber type is shown in the following table.

division Type of fiber Sum Remarks Polyethylene (PE) Polyvinyl Alcohol (PVA) Polypropylene (PP) Proper volume incorporation rate (% by volume) 1.00-1.50 - - 1.00-1.50 Stand alone - 1.50-2.20 - 1.50-2.20 Stand alone - - 1.80 to 2.50 1.80 to 2.50 Stand alone 0.70 to 1.00 1.00-1.50 - 1.70 to 2.50 Mixed use 0.70 to 1.00 - 1.00 to 2.00 1.70-3.00 Mixed use - 1.25-1.80 1.00-1.50 2.25-3.20 Mixed use ※ The numerical values shown in this table are the volumetric mixing ratio (Vf) of the fiber to the concrete total volume.

The manufacture of high toughness concrete composites constructed as described above is available for both field mixers and ready-mixed concrete plants, and the mixers used can be used as long as they are currently used as concrete mixers, and preferably, a pan type mixer or omni ( Omni) mixers are preferred. In addition, the order of input of materials during the bibim is prepared by mixing them in batches according to the site conditions, or by finally adding the fibers. The bibim time should be performed until each material is uniformly dispersed.

In addition, the construction of the high toughness concrete composite is generally carried out in the order shown in Fig. 3, the minimum laying thickness is 40 mm or more, and the laying height is 3 to 10 above the planned height.

Install it about mm high and finish the surface by compacting with concrete vibration finisher. On the other hand, in areas where the charging is weak, such as the corner portion and side wall portion is compacted with a separate concrete vibrator, and the finishing surface to maintain the required flatness, longitudinal and transverse height and durable surface.

When the finishing of the package is finished and the formability is maintained on the surface, the machine is finished by a tinning machine immediately. At this time, the groove depth is 3mm or more and the groove spacing is 2-3.

It should be cm to ensure a sufficient coefficient of friction. In addition, when the finish is finished, the curing agent is applied immediately to prevent the evaporation of moisture on the surface.

The high toughness concrete composite of the present invention is manufactured by properly combining the parameters of the interfacial adhesion properties of the fiber, the matrix and the fiber / matrix so that the deformation hardening behavior and the multiple cracking characteristics can be stably exhibited under the bending and tensile loads. Compared to steel fiber reinforced concrete, LMC pavement concrete, or high toughness cement composite, high bending and tensile strength can be expressed, and crack control performance, fatigue performance, deformation performance, energy absorption and durability can be greatly improved.

By utilizing the high toughness concrete composite with such performance in the bridge pavement of new or aging bridges, it improves the crack dispersibility of the bridge pavement and controls the crack width, greatly improving the waterproofing performance and the penetration resistance of harmful substances such as Cl ^- or CO ₂ . In addition to improving the flexural toughness and deformation performance, the fatigue performance of the bridge's lubrication load can be greatly improved, enabling high durability and long life of new and existing bridges, and finally reducing maintenance costs.

(Life Cycle Cost) can be reduced.

1 is an example of the measurement of the stress-strain curve by the bending test of high toughness concrete composite

Figure 2 is an example of multiple cracks generated on the bottom surface of the high toughness concrete composite during the bending test

Figure 3 is an example of the construction procedure of the bridge pavement using a high toughness concrete composite

Claims (5)

Water / Binder Ratio (W / B) 25-50% by weight, replacement ratios of admixtures, fillers, and CSA-based fasteners with respect to binder amounts are 5-50 Wt%, 0-25 wt% and 0-25 The mixing ratios of the high-performance water reducing agent and the SBR polymer with respect to the weight%, the binder content are 0 to 2.0% by weight and 0 to 15, respectively. 0 to 1.5% by weight of methylcellulose thickener based on the weight%, unit quantity, and the mixing ratio of fine aggregate and coarse aggregate to the total volume of concrete was 20 to 40, respectively. Volumetric mixing ratio of concrete composed of% by volume and 0 to 25% by volume of a mixture of polyethylene (PE) fibers, polyvinyl alcohol (PVA) fibers, and polypropylene (PP) fibers alone or a mixture of homogeneous or heterogeneous fibers (V _f ) 1.00 to 2.50 for the total concrete volume High toughness concrete composite, characterized in that the volume% The fly ash and blast furnace slag powder of industrial by-products as admixtures according to claim 1 are 0 to 35% by weight and 0 to 50%, respectively, based on the amount of the binder. Weight%, high toughness concrete composite, characterized in that 0-25% by weight of limestone fine powder is used as the filler According to claim 1, the fine aggregate is one of silica sand, sea sand, steel sand or PS ball 10 to 40% by volume with respect to the total volume of concrete, coarse aggregates of the maximum size 13mm, 10mm and 8mm crushed gravel, steel gravel, or less than 7mm One of the PS balls is 0 to 25 for the total concrete volume High toughness concrete composite, characterized in that volume% is used The fiber of claim 1, wherein the fiber is polyethylene (PE) fiber (diameter 10-30 μm, length 6-15 mm), polyvinyl alcohol (PVA) fiber (30 ~ 100㎛ in diameter, 6 ~ 15mm in length), polypropylene (PP) fiber (30 ~ 60㎛ in diameter, 6 ~ 15mm in length) are used alone or mixed with same or different types of fibers The volumetric mixing ratio of the fiber with respect to 1.00-3.20 High toughness concrete composite, characterized in that volume% Bridge construction method according to claim 1 to 4, characterized in that a high toughness concrete composite having strain hardening behavior and multiple cracking properties is utilized for the bridge paving of new or existing bridges.