Corrosion-resistant salt field UHPC pavement and construction method thereof

Abstract

The invention belongs to the technical field of concrete products, and particularly relates to a corrosion-resistant salt field UHPC pavement and a construction method thereof.The pavement is divided into a corrosion-resistant and wear-resistant layer located on the upper layer, a waterproof isolation layer located on the middle layer and a base impervious layer located on the lower layer, the corrosion-resistant and wear-resistant layer is a UHPC layer with the thickness of 4-6 cm, and 1-3 wt% of copper-plated steel fibers are doped; 0.5 to 1 weight percent of silane water repellent and 1 to 3 weight percent of nano silicon dioxide filler are added; the waterproof isolation layer is a polymer waterproof mortar layer with the thickness of 2-4 cm, and glass fiber gridding cloth is embedded in the waterproof isolation layer; the base impervious layer is a UHPC layer with the thickness of 18-22 cm and is doped with 4-6 wt% of silica fume, 4-6 wt% of fly ash and 1-3 wt% of a corrosion inhibitor. The salt field UHPC pavement is good in corrosion resistance, and salt permeation is effectively blocked; infiltration moisture can be rapidly removed, and the anti-permeability grade is high.

Description

Technical Field

[0001] The invention belongs to the technical field of concrete products, and in particular relates to a corrosion-resistant salt field UHPC pavement and a construction method thereof. Background Art

[0002] Ultra-High Performance Concrete (UHPC) pavement has many significant advantages over traditional concrete pavement, which makes it more and more used in high-performance road construction, bridge repair and special engineering fields. The following are the main advantages of UHPC pavement: 1) Extremely high strength and durability: UHPC has compressive and tensile strength far exceeding that of ordinary concrete, can withstand greater loads, reduce pavement damage and wear, and significantly extend service life. Its excellent durability means better resistance to adverse weather conditions (such as extreme temperatures, salt spray corrosion, etc.). 2) Good crack control ability: Through fine mix design and low water-binder ratio, UHPC can effectively reduce internal pores and improve the density of the material, thereby significantly reducing the risk of cracks and maintaining the integrity and flatness of the pavement. 3) Lightweight design potential: Although UHPC itself has a high density, its high strength allows for thinner cross-section design, which not only reduces the weight of the structure, but also reduces the amount of material used, which is beneficial to environmental protection and cost control. 4) Excellent wear resistance and skid resistance: The surface of UHPC pavement has been specially treated to provide good skid resistance, ensuring driving safety even in wet conditions. At the same time, its high wear resistance reduces pavement loss caused by vehicle tire wear. 5) Low maintenance cost: Due to its excellent durability and crack resistance, the maintenance frequency and maintenance cost of UHPC pavement in long-term use are much lower than those of traditional pavement materials, improving road service efficiency.

[0003] The existing UHPC pavement has some shortcomings when applied to salt fields. First, its corrosion resistance is poor and it cannot effectively block salt penetration. Second, it cannot quickly remove infiltrated water. Third, its impermeability is poor and chloride ion diffusion is prone to occur. Therefore, optimization and improvement are needed. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned problems existing in the conventional technology and to provide a corrosion-resistant salt field UHPC pavement and a construction method thereof.

[0005] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions: The present invention provides a corrosion-resistant salt field UHPC pavement, which is divided into the following from top to bottom: The anti-corrosion and wear-resistant layer is a 4-6 cm thick UHPC layer. The anti-corrosion and wear-resistant layer is mixed with 1-3 wt% copper-plated steel fiber, 0.5-1 wt% silane water repellent and 1-3 wt% nano-silica filler based on the total mass of the UHPC layer. A waterproof isolation layer, wherein the waterproof isolation layer is a 2-4 cm thick polymer waterproof mortar layer with glass fiber mesh cloth embedded therein; The base anti-seepage layer is a UHPC layer with a thickness of 18 to 22 cm. The base anti-seepage layer is mixed with 4 to 6 wt% of silica fume, 4 to 6 wt% of fly ash and 1 to 3 wt% of rust inhibitor based on the total mass of the UHPC layer.

[0006] Furthermore, in the above-mentioned salt field UHPC pavement, the length of the copper-plated steel fibers in the anti-corrosion and wear-resistant layer is 12 to 15 mm.

[0007] Furthermore, in the above-mentioned salt field UHPC pavement, the surface layer of the anti-corrosion and wear-resistant layer is coated with an epoxy resin coating.

[0008] Furthermore, in the above-mentioned salt field UHPC pavement, the specification of the glass fiber mesh cloth in the waterproof isolation layer is 160g / m 2 .

[0009] Furthermore, in the above-mentioned UHPC pavement of the salt field, the elastic modulus of the waterproof isolation layer is ≥15GPa, and the bonding strength with the upper and lower layers is ≥2.5MPa‌6; a two-way drainage slope is set in the waterproof isolation layer, and PVC water pipes are pre-buried in the waterproof isolation layer. The spacing between the PVC water pipes is 2m×2m, so as to quickly remove the infiltrated water‌.

[0010] Furthermore, in the above-mentioned salt field UHPC pavement, the rust inhibitor in the base anti-seepage layer is calcium nitrite-based.

[0011] Furthermore, in the above-mentioned salt field UHPC pavement, the UHPC layer in the anti-corrosion and wear-resistant layer and the UHPC layer in the base anti-seepage layer are both made of corrosion-resistant UHPC, and the corrosion-resistant UHPC contains the following raw materials in parts by weight: 100 parts of PPII525 cement, 35 parts of 92 fully-densified silica fume, 87 parts of heavy calcium carbonate, 68 parts of 140 mesh quartz sand, 71 parts of 70 mesh quartz sand, 4.5 parts of admixture, 29 parts of water, and 28 parts of steel fiber; wherein the admixture is composed of 34% water reducer, 34% slump retaining agent and defoaming agent in a volume ratio of 6-10:6-10:1.

[0012] The present invention also provides a construction method for the above-mentioned salt field UHPC pavement, comprising the following steps: 1) Pretreatment of salt field foundation The salt field foundation needs to be paved with 30cm graded gravel with a particle size of 5 to 20mm, and then geogrids with a tensile strength of ≥80kN / m and a compaction degree of ≥95%; ‌2) Construction of base anti-seepage layer‌ The corrosion-resistant UHPC mixed with silica fume, fly ash and rust inhibitor was poured in two layers, compacted by an inserted vibrator, and the surface was roughened before initial setting; it was covered with a permeable geotextile and cured for 7 days, and the humidity was maintained at ≥90%; ‌3) Construction of waterproof isolation layer‌ The polymer waterproof mortar is sprayed mechanically in two passes; the first pass is 1.5 cm thick, and the second pass is sprayed after final setting; the water pipe installation must be consistent with the road slope, and the outlet is connected to the drainage ditch; ‌4) Construction of anti-corrosion and wear-resistant layer‌ The corrosion-resistant UHPC mixed with copper-plated steel fiber, silane hydrophobic agent and nano-silica filler was poured in two layers. During the pouring, a high-frequency vibration table with a frequency of 50 Hz was used to eliminate bubbles, and a laser leveling machine was used to control the flatness. After 48 hours of constant temperature steam curing at 80°C, the epoxy resin coating was sprayed.

[0013] The beneficial effects of the present invention are: The present invention provides a corrosion-resistant salt field UHPC pavement, which is mainly composed of an anti-corrosion and wear-resistant layer located on the upper layer, a waterproof isolation layer located in the middle layer, and a base anti-seepage layer located in the lower layer. The anti-corrosion and wear-resistant layer has a high surface finish and a porosity of less than 0.2%, which can effectively block salt penetration; the compressive strength is ≥150MPa, and the chloride ion permeability is ≤500C (ASTMC1202 standard); the surface is sprayed with an epoxy resin coating to enhance chemical corrosion resistance. The elastic modulus of the waterproof isolation layer is ≥15GPa, and the bonding strength with the upper and lower layers is ≥2.5MPa; a two-way drainage slope (1.5%) is set, and PVC water pipes are pre-buried (spacing 2m×2m) to quickly remove infiltrated water. The anti-seepage grade of the base anti-seepage layer is ≥P12, and the chloride ion diffusion coefficient is ≤3×10 -12 m 2 / s‌.

[0014] Of course, any product implementing the present invention does not necessarily need to achieve all of the above advantages at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0016] Figure 1It is a schematic diagram of the composition of the corrosion-resistant salt field UHPC pavement of the present invention; In the figure, the relevant structures are labeled as follows: 1- Anti-corrosion and wear-resistant layer; 2- Waterproof isolation layer; 3- Base anti-seepage layer. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] like Figure 1 As shown, this embodiment provides a corrosion-resistant salt field UHPC pavement, which is divided into an anti-corrosion and wear-resistant layer 1 located at the upper layer, a waterproof isolation layer 2 located at the middle layer, and a base anti-seepage layer 3 located at the lower layer.

[0019] In this embodiment, the anti-corrosion and wear-resistant layer is a 4-6 cm thick UHPC layer. The anti-corrosion and wear-resistant layer is mixed with 1-3 wt% copper-plated steel fiber based on the total mass of the UHPC layer, and 0.5-1 wt% silane hydrophobic agent and 1-3 wt% nano-silica filler are added.

[0020] In this embodiment, the length of the copper-plated steel fibers in the anti-corrosion and wear-resistant layer is 12 to 15 mm.

[0021] In this embodiment, the surface of the anti-corrosion and wear-resistant layer is coated with an epoxy resin coating.

[0022] In this embodiment, the waterproof isolation layer is a 2-4 cm thick polymer waterproof mortar layer, embedded with a glass fiber mesh cloth, and the specification of the glass fiber mesh cloth is 160g / m 2 .

[0023] In this embodiment, the elastic modulus of the waterproof isolation layer is ≥15GPa, and the bonding strength with the upper and lower layers is ≥2.5MPa‌6; a two-way drainage slope is set in the waterproof isolation layer, and PVC water pipes are pre-buried in the waterproof isolation layer. The spacing between the PVC water pipes is 2m×2m to quickly drain the infiltrated water‌.

[0024] In this embodiment, the base anti-seepage layer is a UHPC layer with a thickness of 18 to 22 cm. The base anti-seepage layer is mixed with 4 to 6 wt% silica fume, 4 to 6 wt% fly ash and 1 to 3 wt% rust inhibitor based on the total mass of the UHPC layer.

[0025] In this embodiment, the rust inhibitor in the base anti-seepage layer is calcium nitrite-based.

[0026] In this embodiment, the UHPC layer in the anti-corrosion and wear-resistant layer and the UHPC layer in the base anti-seepage layer are both made of corrosion-resistant UHPC, and the corrosion-resistant UHPC contains the following raw materials in parts by weight: 100 parts of PPII525 cement, 35 parts of 92 fully-densified silica fume, 87 parts of heavy calcium carbonate, 68 parts of 140 mesh quartz sand, 71 parts of 70 mesh quartz sand, 4.5 parts of admixture, 29 parts of water, and 28 parts of steel fiber; wherein the admixture is composed of 34% water reducer, 34% slump retaining agent and defoaming agent in a volume ratio of 6-10:6-10:1.

[0027] This embodiment also provides a construction method for the above-mentioned salt field UHPC pavement, including the following steps: 1) Pretreatment of salt field foundation The salt field foundation needs to be paved with 30cm graded gravel with a particle size of 5 to 20mm, and then geogrids with a tensile strength of ≥80kN / m and a compaction degree of ≥95%; ‌2) Construction of base anti-seepage layer‌ The corrosion-resistant UHPC mixed with silica fume, fly ash and rust inhibitor was poured in two layers, compacted by an inserted vibrator, and the surface was roughened before initial setting; it was covered with a permeable geotextile and cured for 7 days, and the humidity was maintained at ≥90%; ‌3) Construction of waterproof isolation layer‌ The polymer waterproof mortar is sprayed mechanically in two passes; the first pass is 1.5 cm thick, and the second pass is sprayed after final setting; the water pipe installation must be consistent with the road slope, and the outlet is connected to the drainage ditch; ‌4) Construction of anti-corrosion and wear-resistant layer‌ The corrosion-resistant UHPC mixed with copper-plated steel fiber, silane hydrophobic agent and nano-silica filler was poured in two layers. During the pouring, a high-frequency vibration table with a frequency of 50 Hz was used to eliminate bubbles, and a laser leveling machine was used to control the flatness. After 48 hours of constant temperature steam curing at 80°C, the epoxy resin coating was sprayed.

[0028] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A corrosion-resistant salt field UHPC pavement, characterized in that: The road is divided from top to bottom into: The anti-corrosion and wear-resistant layer is a 4-6 cm thick UHPC layer. The anti-corrosion and wear-resistant layer is mixed with 1-3 wt% copper-plated steel fiber, 0.5-1 wt% silane water repellent and 1-3 wt% nano-silica filler based on the total mass of the UHPC layer. A waterproof isolation layer, wherein the waterproof isolation layer is a 2-4 cm thick polymer waterproof mortar layer with glass fiber mesh cloth embedded therein; The base anti-seepage layer is a UHPC layer with a thickness of 18 to 22 cm. The base anti-seepage layer is mixed with 4 to 6 wt% of silica fume, 4 to 6 wt% of fly ash and 1 to 3 wt% of rust inhibitor based on the total mass of the UHPC layer.

2. The salt field UHPC pavement according to claim 1, characterized in that: The length of the copper-plated steel fibers in the anti-corrosion and wear-resistant layer is 12 to 15 mm.

3. The salt field UHPC pavement according to claim 1, characterized in that: The surface of the anti-corrosion and wear-resistant layer is coated with an epoxy resin coating.

4. The salt field UHPC pavement according to claim 1, characterized in that: The specification of the glass fiber mesh cloth in the waterproof isolation layer is 160g / m 2 .

5. The salt field UHPC pavement according to claim 1, characterized in that: The elastic modulus of the waterproof isolation layer is ≥15GPa, and the bonding strength with the upper and lower layers is ≥2.5MPa‌6; a two-way drainage slope is set in the waterproof isolation layer, and a PVC water pipe is pre-buried in the waterproof isolation layer‌.

6. The salt field UHPC pavement according to claim 5, characterized in that: The rust inhibitor in the base anti-seepage layer is calcium nitrite-based.

7. The salt field UHPC pavement according to claim 6, characterized in that: The UHPC layer in the anti-corrosion and wear-resistant layer and the UHPC layer in the base anti-seepage layer are both made of corrosion-resistant UHPC, and the corrosion-resistant UHPC contains the following raw materials in parts by weight: 100 parts of PPII525 cement, 35 parts of 92 fully-densified silica fume, 87 parts of heavy calcium carbonate, 68 parts of 140-mesh quartz sand, 71 parts of 70-mesh quartz sand, 4.5 parts of admixture, 29 parts of water, and 28 parts of steel fiber; wherein the admixture is composed of 34% water reducer, 34% slump retaining agent and defoaming agent in a volume ratio of 6-10:6-10:

1.

8. The method for constructing a salt field UHPC pavement according to claim 7, characterized in that: The steps include: 1) Pretreatment of salt field foundation The salt field foundation needs to be paved with 30cm graded gravel with a particle size of 5 to 20mm, and then geogrids with a tensile strength of ≥80kN / m and a compaction degree of ≥95%; ‌2) Construction of base anti-seepage layer‌ The corrosion-resistant UHPC mixed with silica fume, fly ash and rust inhibitor was poured in two layers, compacted by an inserted vibrator, and the surface was roughened before initial setting; it was covered with a permeable geotextile and cured for 7 days, and the humidity was maintained at ≥90%; ‌3) Construction of waterproof isolation layer‌ The polymer waterproof mortar is sprayed mechanically in two passes; the first pass is 1.5 cm thick, and the second pass is sprayed after final setting; the water pipe installation must be consistent with the road slope, and the outlet is connected to the drainage ditch; ‌4) Construction of anti-corrosion and wear-resistant layer‌ The corrosion-resistant UHPC mixed with copper-plated steel fiber, silane hydrophobic agent and nano-silica filler was poured in two layers. During the pouring, a high-frequency vibration table with a frequency of 50 Hz was used to eliminate bubbles, and a laser leveling machine was used to control the flatness. After 48 hours of constant temperature steam curing at 80°C, the epoxy resin coating was sprayed.

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