阅读说明：本技术 一种钢-混凝土组合梁的混凝土层修补材料及其制备方法 (Concrete layer repairing material for steel-concrete composite beam and preparation method thereof ) 是由 周骏宇 于 2019-09-16 设计创作，主要内容包括：本发明公开了一种钢-混凝土组合梁的混凝土层修补材料及其制备方法,属于混凝土修补材料领域。本发明的钢-混凝土组合梁的混凝土层修补材料,由MgO、水玻璃、砂、石、矿渣、PTB乳液和水组成,各组分质量百分数为：MgO 0.5％～4.5％、水玻璃0.5％～6.0％、砂20％～50％、石0％～55％、矿渣14.0％～31.5％、PTB乳液0.5％～1.5％、水6.5％～10.0％,各组分质量百分数和为100％。本发明的钢-混凝土组合梁的混凝土层修补材料具有环保性和工作性好、凝结时间短且凝结时间可控、早期强度高、防水性好、粘结性(与混凝土或钢质材料基底粘结)和耐久性优异等优点,具有较好的市场应用前景。(The invention discloses a concrete layer repairing material of a steel-concrete composite beam and a preparation method thereof, belonging to the field of concrete repairing materials. The concrete layer repairing material of the steel-concrete composite beam comprises MgO, water glass, sand, stone, slag, PTB emulsion and water, and comprises the following components in percentage by mass: 0.5 to 4.5 percent of MgO, 0.5 to 6.0 percent of water glass, 20 to 50 percent of sand, 0 to 55 percent of stone, 14.0 to 31.5 percent of slag, 0.5 to 1.5 percent of PTB emulsion and 6.5 to 10.0 percent of water, wherein the sum of the mass percentages of the components is 100 percent. The concrete layer repairing material of the steel-concrete composite beam has the advantages of environmental protection, good workability, short setting time, controllable setting time, high early strength, good waterproofness, excellent cohesiveness (the concrete or steel material substrate is bonded), excellent durability and the like, and has better market application prospect.)

1. The concrete layer repairing material of the steel-concrete composite beam is characterized in that: the raw material components by mass percent are as follows: 0.5 to 4.5 percent of MgO, 0.5 to 6.0 percent of water glass, 20 to 50 percent of sand, 0 to 55 percent of broken stone, 14.0 to 31.5 percent of slag, 0.5 to 1.5 percent of PTB emulsion and 6.5 to 10.0 percent of water, wherein the sum of the mass percentages of the components is 100 percent.

2. The concrete layer repairing material for a steel-concrete composite beam according to claim 1, wherein: the MgO is calcined for 1-2h at 900 ℃, and the average grain diameter is 20-50 μm.

3. The concrete layer repairing material for a steel-concrete composite beam according to claim 1, wherein: the water glass has a water glass modulus of 1.0-1.5, the water glass temperature is controlled within the range of 10-60 ℃, and the water glass is Na in percentage by mass₂And (4) an O equivalent meter.

4. The concrete layer repairing material for a steel-concrete composite beam according to claim 1, wherein: the slag is S95 level granulated blast furnace slag powder.

5. The concrete layer repairing material for a steel-concrete composite beam according to claim 1, wherein: the grain diameter of the sand is 0.15 mm-4.75 mm.

6. The concrete layer repairing material for a steel-concrete composite beam according to claim 1, wherein: the particle size of the broken stone is 4.75-15 mm.

7. The concrete layer repairing material for a steel-concrete composite beam according to claim 1, wherein: the PTB emulsion is an ethylene-vinyl chloride-vinyl ester product, is in a white emulsion state, and has the physical property indexes of viscosity: 80-120 mPa.s, solid content: 52. + -. 1 wt%, specific gravity: 1.1, pH value: 7 to 9.

8. The concrete layer repairing material for a steel-concrete composite beam according to claim 1, wherein: the water is the mass sum of water in the water glass and externally added water.

9. The method for preparing a concrete layer repairing material for a steel-concrete composite beam according to any one of claims 1 to 8, wherein: the preparation method comprises the following steps:

(1) metering: respectively metering each component material according to the mass percentage of the raw material components;

(2) mixing dry materials: pouring slag and MgO into a stirrer, and stirring the slag and the MgO until the slag and the MgO are uniformly mixed, then pouring sand and broken stone, and stirring the mixture uniformly to obtain a mixed dry material;

(3) preparing a repairing material: controlling the temperature of water glass to be 10-60 ℃, then dissolving the water glass and PTB emulsion in added water, and stirring for 2-3 minutes to prepare an additive solution; and then pouring the additive solution into the mixed dry material and stirring for 2-3 minutes to obtain the concrete layer repairing material of the steel-concrete composite beam.

Technical Field

The invention belongs to the field of concrete repairing materials, and particularly relates to a concrete layer repairing material for a steel-concrete composite beam and a preparation method thereof.

Background

The steel-concrete composite structure is one of the common structural forms of a large-span bridge, and the main structure of the steel-concrete composite structure is formed by embedding shear connectors (shear keys, shear nails and the like) on a steel box girder and then pouring a concrete layer. However, after the cracks and the pit defects are repaired by adopting the traditional concrete repairing material, secondary damage is easy to occur at a repairing interface, and mainly the repairing material and the bonding interface of the steel bridge deck or the original concrete contact surface are broken and failed, so that the repairing material loses boundary support, the concrete layer in the steel-concrete composite structure is repaired and failed, and further the pavement layer of the steel bridge deck is damaged again. The traditional concrete layer repairing material for the steel-concrete composite beam has the defects of complex preparation mode, high cost, long time for meeting the strength requirement of open traffic, low bonding force with a steel bridge deck, easy falling off under the action of fatigue load and the like, and seriously restricts the popularization and application of the concrete layer repairing material for the steel-concrete composite beam.

At present, a plurality of patents related to concrete repairing materials are applied in China, but no report related to concrete layer repairing materials of steel-concrete composite beams is found. For example, the CN108328977A patent discloses a concrete repair material; the CN108911632A patent discloses a concrete repair material and a preparation method thereof; the patent CN108546071A discloses a concrete patching material and a preparation method thereof. Patent CN109574611A discloses an environment-friendly cement-based material for rapid pavement patching and a preparation and use method thereof, wherein the patching materials of the patents can be effectively bonded on a concrete base surface, but can not be applied to patching of concrete on a steel base surface, and the materials have the advantages of more components, high cost, uncontrollable setting time and inconvenience for large-scale production and construction. The invention adopts environment-friendly cement-based materials (gelled materials generated by slag excited by alkaline excitants such as water glass) for repairing, and can ensure that the materials are reliably bonded with steel base surfaces or concrete base surfaces through specific raw material proportion. The condensation time can be controlled by regulating the temperature of the water glass, the operation is convenient, and the industrialization prospect is wide.

Disclosure of Invention

Aiming at the defects and problems in the prior art, the invention provides a concrete layer repairing material of a steel-concrete composite beam and a preparation method thereof.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention firstly provides a concrete layer repairing material of a steel-concrete composite beam. The concrete layer repairing material of the steel-concrete composite beam consists of MgO, water glass, sand, stone, slag, PTB emulsion and water, and comprises the following components in percentage by mass: 0.5 to 4.5 percent of MgO, 0.5 to 6.0 percent of water glass, 20 to 50 percent of sand, 0 to 55 percent of stone, 14.0 to 31.5 percent of slag, 0.5 to 1.5 percent of PTB emulsion and 6.5 to 10.0 percent of water, wherein the sum of the mass percentages of the components is 100 percent.

Furthermore, the MgO is calcined for 1.5h at 900 ℃ and has the average grain diameter of 33.292 mu m.

Furthermore, the modulus of the water glass is 1.0-1.5, the temperature of the water glass is 10-60 ℃, and the mass of the water glass is Na₂And (4) an O equivalent meter.

Furthermore, the grain diameter of the sand is 0.15 mm-4.75 mm.

Furthermore, the particle size of the stones is 4.75 mm-15 mm.

Further, the slag is S95-grade granulated blast furnace slag powder.

Further, the PTB emulsion is an ethylene-vinyl chloride-vinyl ester product, in the form of a white emulsion. The physical property indexes are viscosity: 80-120 mPa.s, solid content: 52. + -. 1 wt%, specific gravity: 1.1, pH value: 7 to 9.

Further, the water is the mass sum of water in the water glass and externally added water.

The invention also provides a preparation method of the concrete layer repairing material of the steel-concrete composite beam, which comprises the following steps:

(1) metering: respectively metering the materials according to the proportion;

(2) mixing dry materials: pouring slag and MgO into a stirrer, dry-stirring for 2-3 minutes, and then pouring sand and stone, and stirring for 2-3 minutes;

(3) preparing a repairing material: controlling the temperature of the water glass to be the required temperature (by heating or cooling and other measures), then dissolving the water glass and the PTB emulsion in water, and stirring for 2-3 minutes to prepare an additive solution; and then pouring the additive solution into the mixed dry material and stirring for 2-3 minutes to obtain the concrete layer repairing material of the steel-concrete composite beam.

The main mechanism of the invention is as follows:

(1) the setting time of the concrete is controlled by the change of the temperature of the water glass, and the setting time of the concrete is obviously reduced along with the increase of the temperature of the water glass, so that the setting time is controllable. In addition, water glass in the system can provide a strong alkaline environment, so that Si-O and Al-O tetrahedrons in the slag can be rapidly subjected to depolymerization and polycondensation reactions to form a compact spatial network structure.

(2) The water glass activated alkali slag concrete and PTB emulsion have excellent cohesiveness. When the PTB emulsion is doped into a concrete layer repairing material of the steel-concrete composite beam, the PTB emulsion forms a polymer net-shaped space structure inside the concrete layer repairing material of the steel-concrete composite beam, so that the development of micro cracks inside the concrete layer repairing material of the steel-concrete composite beam is inhibited, the cement-based material has better flexibility, mechanical properties (bonding strength, compressive strength and the like) and durability, and the bonding effect of bonding the steel-concrete composite beam to a steel material (a steel box beam and the like) is excellent.

(3) The repairing material has the advantages of fast setting time, high early strength and the like, but also has the defect that cracks are easy to generate due to shrinkage. MgO incorporation into repair materials, Mg (OH) formed₂And the hydrotalcite-like compound has certain expansibility, the shrinkage and cracking problems are obviously inhibited, the defect of later strength shrinkage is avoided, and the engineering quality is ensured.

Compared with the prior art of concrete repair materials, the invention has the following advantages:

1) the coagulation time is controllable. The condensation time of the repairing material can be controlled by adjusting the temperature of the water glass, and the requirements of construction and traffic are met. The invention is used for repairing the concrete layer of the steel-concrete composite beam, and requires quick traffic and good bonding with a steel bridge deck.

2) PTB emulsion has water-reducing effect, and has excellent water resistance, adhesion and extraordinary flexibility, and is an organic binder that develops strength upon loss of water; the environment-friendly cement (composed of slag and water glass) is an inorganic binder, and water is consumed when strength is generated. The inorganic and organic binders are combined to make up for the deficiencies of the inorganic and organic binders, so that the cement-based material added with the PTB emulsion has good workability, toughness, strength and durability. And the alkali slag concrete excited by the water glass has good cohesiveness and is mixed with PTB for use, so that the alkali slag concrete has high bonding strength with old concrete and steel materials (such as steel box girders and the like) and is not easy to fall off under various load effects.

3) MgO is an expanding agent, and is added into alkali-activated concrete to increase the volume stability of the concrete and avoid the problem of shrinkage cracking. In addition, the invention consumes a large amount of solid waste slag, not only has obvious environmental protection benefit, but also can greatly reduce the cost of the concrete layer repairing material of the steel-concrete composite beam.

Detailed Description

The invention provides a concrete layer repairing material of a steel-concrete composite beam and a preparation method thereof. The concrete layer repairing material of the steel-concrete composite beam consists of MgO, water glass, sand, stone, slag, PTB emulsion and water, and comprises the following components in percentage by mass: 0.5 to 4.5 percent of MgO, 0.5 to 6.0 percent of water glass, 20 to 50 percent of sand, 0 to 55 percent of stone, 14.0 to 31.5 percent of slag, 0.5 to 1.5 percent of PTB emulsion and 6.5 to 10.0 percent of water, wherein the sum of the mass percentages of the components is 100 percent.

The invention relates to a concrete layer repairing material of a steel-concrete composite beam, which comprises the following preparation processes:

(1) metering: respectively metering the materials according to the proportion;

(2) mixing dry materials: pouring slag and MgO into a stirrer, dry-stirring for 2-3 minutes, and then pouring sand and stone, and stirring for 2-3 minutes;

(3) preparing a repairing material: controlling the temperature of the water glass to be the required temperature, then dissolving the water glass and the PTB emulsion in water together, and stirring for 2-3 minutes to prepare an additive solution; and then pouring the additive solution into the mixed dry material and stirring for 2-3 minutes to obtain the concrete layer repairing material of the steel-concrete composite beam.