CN-122013665-A - Magnesium phosphate cement inorganic gel material steel bridge deck pavement structure and preparation method

CN122013665ACN 122013665 ACN122013665 ACN 122013665ACN-122013665-A

Abstract

The invention discloses a magnesium phosphate cement inorganic gel material steel bridge deck pavement structure and a preparation method thereof. The pavement structure comprises a steel bridge deck, a waterproof bonding layer, a magnesium phosphate cement concrete layer and a wear-resistant anti-slip layer, wherein the surface of the steel bridge deck is subjected to shot blasting rust removal treatment, the waterproof bonding layer is coated by epoxy resin to form a continuous uniform film layer, the magnesium phosphate cement concrete layer is formed by pouring magnesium phosphate cementing material generated by reacting dead burned magnesium oxide with monoammonium phosphate, fly ash, borax, a polycarboxylate water reducer, steel fibers and selected graded quartz sand, a guide seam is arranged in the magnesium phosphate cement concrete cementing material to control crack development, and the wear-resistant anti-slip layer is fixed by adopting a thin wear-resistant coating or an asphalt concrete wearing layer through the bonding layer. The preparation method comprises the steps of basal surface treatment, waterproof bonding layer construction, magnesium phosphate cement concrete pouring, maintenance and surface treatment. The invention eliminates the traditional mechanical anchoring of the stud and the like, utilizes the chemical compatibility of materials to form high-strength and durable interface connection, and improves the fatigue life.

Inventors

LI KAI
HAO ZENGHENG
HU XIAOYANG
PENG CHONG
XU JIANHUI
LIU PAN
XIAO LI
DAI YU
FAN CHAO

Assignees

招商智翔道路科技(重庆)有限公司
招商局重庆交通科研设计院有限公司

Dates

Publication Date: 20260512
Application Date: 20260210

Claims (10)

1. The magnesium phosphate cement inorganic gel material steel bridge deck pavement structure is characterized by comprising a steel bridge deck, a waterproof bonding layer, a magnesium phosphate cement concrete layer and a wear-resistant and anti-slip layer which are sequentially arranged from bottom to top; the steel bridge deck is used as a base layer of a paving structure, the waterproof bonding layer is made of high polymer materials and is coated on the surface of the steel bridge deck, the magnesium phosphate cement concrete layer is poured above the waterproof bonding layer, and the wear-resistant anti-skid layer is covered above the magnesium phosphate cement concrete layer; The pavement structure does not adopt mechanical anchoring, and directly utilizes the chemical compatibility of the magnesium phosphate cement concrete layer and the materials in the waterproof bonding layer to form an interlayer bonding interface with high strength and good durability.
2. The pavement structure of claim 1, wherein the wear-resistant and skid-resistant layer is a thin wear-resistant coating or asphalt concrete wearing layer and is fixed on the magnesium phosphate cement concrete layer through an adhesive layer.
3. The paving structure of claim 1, wherein the waterproof adhesive layer is made of an epoxy resin material with a coating weight of 0.8-1.2kg/m 2 and a thickness of 0.5-1.0mm, and the epoxy resin material has a bonding strength with a steel plate panel of not less than 5MPa at 25 ℃ and a bonding strength with a magnesium phosphate cement concrete layer of not less than 2.5MPa and an elongation of more than 30% to adapt to deformation of the steel bridge panel.
4. The pavement structure of claim 1, wherein the steel bridge deck surface is subjected to shot blasting to a cleaning degree of Sa2.5, and the surface roughness after the rust removal is controlled within a range of 50-100 μm to increase the mechanical biting force with the waterproof adhesive layer.
5. The paving structure according to claim 1, wherein the thickness of the magnesium phosphate cement concrete layer is 40-60mm, the thickness is adjusted according to the bridge design requirement, the guide slits are arranged in the magnesium phosphate cement concrete layer, the distance between the guide slits is 1/4-1/6 of the length of the plate, the depth is 1/3-1/2 of the thickness of the paving layer, and the crack resistance is improved by doping steel fiber reinforcement.
6. The paving structure according to claim 1, wherein the magnesium phosphate cement concrete layer is formed by casting magnesium phosphate cement, and the magnesium phosphate cement is prepared by mixing, by mass, 45% -75% of cementing materials, 18% -28% of mineral admixtures, 2% -7% of retarders, 1% -5% of dispersing agents, 1% -6% of viscosity reducers, 3% -9% of toughening materials and a proper amount of aggregates; The cementing material is prepared by carrying out acid-base neutralization reaction on the reburning magnesium oxide and ammonium dihydrogen phosphate in the molar ratio of 3:1 in the presence of water.
7. The paving structure according to claim 6, wherein the burned magnesia and ammonium dihydrogen phosphate are respectively ground to have a specific surface area of 500-700m 2 /kg, the mass percentage of magnesia in the burned magnesia is greater than 90%, and the mass percentage of active ingredient in the ammonium dihydrogen phosphate is greater than 98%.
8. The paving structure of claim 6, wherein the mineral admixture is fly ash, the mass percentage content of active SiO 2 in the fly ash is 40% -50%, the mass percentage content of active Al 2 O 3 is 30% -40%, the fluidity of slurry is improved, and the hydration heat is reduced; the retarder is borax, borax decahydrate with purity of more than 95% is adopted, the dispersing agent is a polycarboxylic acid high-efficiency water reducing agent, the toughening material is steel fiber or carbon fiber, and the aggregate is selected graded quartz sand with maximum particle size of not more than 2.36 mm.
9. A method for preparing a magnesium phosphate cement inorganic gel material steel bridge deck pavement structure according to any one of claims 1-8, comprising the following steps: s1, basal surface treatment, namely performing shot blasting rust removal treatment on the top surface of the steel bridge deck to achieve Sa 2.5-level cleanliness, thoroughly removing oxide scales and pollutants, cleaning the surface by high-pressure air to ensure that the surface is free from impurities affecting adhesion, preheating the steel bridge deck before coating a waterproof bonding layer, and controlling the temperature to be 40-60 ℃; S2, constructing a waterproof bonding layer, namely accurately preparing and uniformly stirring epoxy resin materials according to a proportion, uniformly coating the epoxy resin on the surface of a steel bridge deck by adopting a blade coating or spraying device, controlling the coating weight to be 0.8-1.2kg/m 2 and the thickness to be 0.5-1.0mm, and forming a continuous and uniform film layer to ensure no leakage coating and no accumulation; S3, constructing a magnesium phosphate cement concrete layer, namely, controlling pouring of the subsequent magnesium phosphate cement concrete before initial setting of epoxy resin after coating, setting a construction section according to a bridge structure in a sectional pouring mode, uniformly paving a magnesium phosphate cement concrete mixture above a waterproof bonding layer with a paving thickness of 40-60mm, slightly vibrating by using a vibrating Liang Huoping plate vibrator to ensure that the concrete is compact and avoid damaging the waterproof bonding layer, leveling the surface by using a scraping bar, controlling the height and flatness of the paving layer, and setting induction joints in the paving layer according to the requirement, wherein the interval of the induction joints is 1/4-1/6 of the plate length, and the depth is 1/3-1/2 of the paving layer thickness; S4, curing, namely covering the surface of the magnesium phosphate cement concrete layer by using a plastic film after pouring is finished by using the self-curing characteristic of the magnesium phosphate cement without wet curing or thermal curing measures, so as to prevent moisture from evaporating too fast; s5, surface treatment, namely carrying out surface roughening treatment before initial setting of the magnesium phosphate cement concrete to increase the binding force with the wear-resistant anti-slip layer, wherein the wear-resistant anti-slip layer adopts a thin wear-resistant coating or an asphalt concrete wearing layer, and before the wear-resistant anti-slip layer is paved, an adhesive layer is paved on the magnesium phosphate cement concrete layer, and the wear-resistant anti-slip layer is fixed on the magnesium phosphate cement concrete layer through the adhesive layer.
10. The method according to claim 9, wherein the preparation process of the magnesium phosphate cement concrete comprises: a) 45% -75% of cementing material, 18% -28% of mineral admixture, 2% -7% of retarder, 1% -5% of dispersing agent, 1% -6% of viscosity reducer and 3% -9% of toughening material according to the mass percentage are placed in a mixer for dry mixing for 5-10 minutes, so that uniform mixing is ensured; b) Gradually adding 90% of the designed water amount into the dry blend, stirring for 3-5 minutes, then adding the residual water amount, and continuously stirring for 2-3 minutes to form uniform slurry; c) Adding the selected graded quartz sand aggregate into the slurry, and stirring for 2-3 minutes to form a uniform concrete mixture; The mixing amount of the retarder is adjusted according to the on-site environment temperature so as to control the coagulation time and ensure the construction operability.

Description

Magnesium phosphate cement inorganic gel material steel bridge deck pavement structure and preparation method Technical Field The invention belongs to the technical field of bridge deck pavement and structural reinforcement, and particularly relates to a magnesium phosphate cement inorganic gel material steel bridge deck pavement structure and a preparation method thereof. Background The steel bridge deck pavement technology is a key link in bridge engineering, and the quality of the steel bridge deck pavement technology directly influences the service performance, safety and durability of the bridge. At present, the common steel bridge deck pavement technology mainly comprises two main types, namely epoxy asphalt mixture pavement and ultra-high performance concrete (UHPC) pavement. Epoxy asphalt mixture paving technology, such as Min-pu bridge engineering, mainly relies on epoxy asphalt as a bonding material to form a multilayer paving structure. The structure utilizes the excellent high-temperature stability and fatigue resistance of the epoxy asphalt, and the pavement layer can adapt to the deformation requirement of the steel bridge deck through the special mixture design. However, the paving mode has obvious defects that the epoxy asphalt has extremely high requirements on the construction process, the temperature and time parameters are required to be accurately controlled, the toughness of the material is relatively insufficient, cracking is easy to occur under heavy traffic and extreme temperature conditions, the repairing is difficult, the local maintenance is difficult once the damage is carried out, and the integral renovation is often required. Ultra-high performance concrete (UHPC) paving is a new paving technology developed in recent years. Common steel-UHPC composite structures typically employ densely-packed shear keys (e.g., studs) to achieve interlayer connection, such as welding a large number of studs to a steel bridge deck, and then disposing a dense, stressed rebar grid in the UHPC layer. The structure can raise the local rigidity of bridge deck system and prolong the fatigue life of pavement and steel bridge deck. However, the traditional connection mode has the remarkable problems that the densely arranged shear keys not only cause inconvenience to the construction of the ultra-high performance concrete pavement layer, but also greatly increase the maintenance difficulty in the subsequent use period. Meanwhile, the plasticity of the ultra-high performance concrete is generally lower than that of common concrete, and the densely distributed reinforcing steel bar net greatly increases the construction difficulty, so that the casting is possibly not compact, and the forming quality of the ultra-high performance concrete layer, particularly the thin ultra-high performance concrete layer, is seriously influenced. In the prior art, some improved UHPC paving structures try to optimize construction by arranging deformation joints, reducing the consumption of reinforcing steel bars and the like, such as an ultra-high performance concrete steel bridge deck paving structure proposed by Chinese patent with publication number of CN 108589518A. According to the structure, the deformation joint extending along the width direction of the steel bridge deck is arranged in the ultra-high performance concrete layer, the paving layer is divided into a plurality of sections, and the number of shear keys is reduced. However, the improvement is not completely free from mechanical connection modes such as bolts and the like, and the construction process is still relatively complex. In another example, chinese patent with publication No. CN115142053a discloses a surface treatment method for steel bridge surface or steel structural member, which adopts phosphate interface agent to treat steel structure, uses the phosphating and electrochemical principles of dilute phosphoric acid and zinc oxide and zinc powder, combines the acid-base reaction characteristics of phosphate interface agent, makes the steel plate produce phosphate layer before coating phosphate interface agent, and improves the interface bonding strength between the steel plate and magnesium phosphate cement concrete through phosphate interface agent, thereby remarkably improving the interface bonding strength between magnesium phosphate cement concrete and steel plate, realizing rapid construction of steel bridge surface pavement and steel plate protection, and providing new technical approach and technical guarantee for effectively utilizing magnesium phosphate cement concrete in the fields of steel bridge surface construction and steel structure protection. Although the phosphate interfacial agent is resistant to high temperature, the phosphate interfacial agent is a rigid inorganic material, has insufficient flexibility, is easier to generate microcracks and expand at a brittle interface under long-term fatigue load, and has poor water-tightne