CN108069632B - Erosion-resistant phosphoaluminate cement-based gel material suitable for marine engineering - Google Patents

Abstract

The invention discloses an erosion-resistant phosphoaluminate cement-based gel material suitable for marine engineering, which consists of 60-75% of iron-rich phosphoaluminate cement clinker, 5-15% of fly ash, 3-8% of silicon carbide powder, 2-6% of rubber powder, 3-6% of alkali-resistant glass fiber and 0.5-2% of aluminum-zirconium coupling agent. The gel material utilizes the properties of high-iron phosphoaluminate cement such as early strength, high strength, corrosion resistance, permeability resistance and frost resistance, and is blended with materials such as fly ash, silicon carbide, rubber powder, aluminum-zirconium coupling agent, alkali-resistant glass fiber and the like, so that the gel material has good scouring resistance and abrasion resistance, fully exerts the properties of high polymers, and improves the chloride ion permeation resistance and the abrasion resistance of the structure.

Description

A kind of erosion-resistant aluminophosphate cement-based gel material suitable for marine engineering

technical field

The invention relates to an erosion-resistant aluminophosphate cement-based cementitious material suitable for marine engineering, and belongs to the technical field of building materials.

Background technique

The marine environment is a complex corrosive environment, and seawater is a natural electrolyte with strong corrosiveness in nature. It contains a large number of corrosive ions. At the same time, under the action of additional loads such as wind, rain, waves and mechanical shocks of ocean currents, the seawater carries With the movement of suspended sediment or bedding sediment, hard sand particles with a certain kinetic energy and other suspended matter repeatedly impact and cut the overflow wall of the discharge building, causing wear and fracture of the overflow wall, mainly manifested in Due to the fish-scale pits on the surface of the material and the expansion of a large number of cracks, the durability of marine engineering structures under the action of this erosive environment continues to deteriorate, resulting in a decrease in bearing capacity and structural damage. Therefore, in addition to the strong anti-corrosion ability of cement for marine engineering, it also puts forward higher requirements for the anti-abrasion ability of concrete. The characteristics of structural materials are the key factors affecting the impact and wear of structures.

At present, the structural materials used in marine engineering are mainly cement concrete structures. In terms of use effects, cement concrete materials are a better structural material. Anti-abrasion materials mainly include organic cementitious and inorganic cementitious materials according to cementing materials. Organic cementing materials mainly include polymer cemented concrete, furan concrete, epoxy resin concrete, etc.; inorganic cementing materials mainly include silica fume concrete. , Modified silica fume concrete, fiber concrete, fly ash concrete, etc. Regarding the impact resistance and crack resistance of concrete, the existing research results show that the impact resistance of concrete mixed with silica fume is higher, but the plastic cracking of silica fume concrete is easy to occur; the impact resistance and toughness of conventional fiber concrete It has been improved, but its alkalinity is high, which is not conducive to the long-term durability of fibers; the introduction of fly ash can improve the crack resistance of concrete, but its interfacial adhesion is weak; polymers can improve the flexibility and crack resistance of cement. However, its dispersion has not been effectively solved, and its advantages cannot be fully exploited. At the same time, the existing anti-abrasion concrete has poor resistance to ion erosion, and the service time in the marine environment is short, which is far from meeting the service time requirements for marine engineering.

SUMMARY OF THE INVENTION

In view of the problems existing in the prior art, the present invention provides an erosion-resistant aluminophosphate cement-based cementitious material for marine engineering. The gel material utilizes the properties of high iron aluminophosphate cement, such as early strength and high strength, corrosion resistance, impermeability and frost resistance, and is mixed with fly ash, silicon carbide, rubber powder, aluminum-zirconium coupling agent, alkali-resistant glass fiber and other materials. , so that it has good anti-erosion and abrasion resistance, gives full play to the properties of the polymer, and improves the resistance to chloride ion penetration and abrasion resistance of the structure.

The present invention adopts following technical scheme:

An erosion-resistant aluminophosphate cement-based gel material suitable for marine engineering is made from the following raw materials by weight: 60-75% of iron-rich aluminophosphate cement clinker, 5-5% of fly ash 15%, silicon carbide powder 3-8%, rubber powder 2-6%, alkali-resistant glass fiber 3-6%, aluminum-zirconium coupling agent 0.5-2%.

Preferably, the iron-rich aluminophosphate cement clinker has a bulk density of 2.98 g/cm ³ , a specific surface area of 319 m ² /kg, a cement fineness of 200 mesh, a sieve residue of 3.1%, and a setting time of 220 min of initial setting, The final setting is 260min, and the iron phase content is 11%.

Preferably, the mineral phase composition percentage content of the iron-rich aluminate phosphate cement clinker is 20-60% calcium aluminate phosphate, 10-30% calcium phosphate, 15-25% calcium aluminate, tetracalcium ferric aluminate 10-25%, vitreous mesophase 2-10%.

Preferably, the sieve balance of the fly ash 45 μm sieve is 11.7%.

Preferably, the SiC content of the silicon carbide powder is greater than 96.5%.

Preferably, the tensile strength of the alkali-resistant glass fiber is greater than 350 MPa.

Concrete mixed with silica fume can improve the abrasion resistance, and the incorporation of silica fume here reflects its physical filling effect. In this paper, silicon carbide powder is added, and the chemical formula is SiC. It has been proved by experiments that the addition of SiC can improve the anti-abrasion performance of cement hardened paste. The cement mortar modified by rubber powder is composed of rigid and ductile materials. When the polymer is added in a certain proportion, cement hydration products and polymers will be formed in the polymer-modified cement mortar. It is equivalent to the space network structure of "microfibers" crossing each other, thereby strengthening the cement stone matrix and improving the ability of the matrix to resist wear and spalling; the addition of aluminum-zirconium coupling agent inhibits the "phase" separation of the cement system, and makes the minerals blend. The material is organic and can be well dispersed evenly, which improves the comprehensive performance of the structure; high iron phosphoaluminate cement is a kind of low alkalinity cement, which can exert the reinforcing effect of alkali-resistant glass fiber for a long time without worrying about the glass fiber in the cement. The corrosion damage effect in the glass fiber destroys the glass fiber, and the uniform distribution of the chaotic direction makes the structure more compact and improves the impact resistance and erosion resistance of the structure. In addition, the particle size of fly ash is small and belongs to small spherical particles, which can fill the gap between cement and silicon carbide powder. Division of labor and cooperation, together to achieve the effect of corrosion resistance, high wear resistance and high strength.

The beneficial effects of the present invention are as follows: the present invention increases the content of its iron phase (tetracalcium ferric aluminate) on the basis of aluminophosphate cement, which can improve the impact and abrasion resistance of the structure; and then blends fly ash and silicon carbide. , rubber powder, aluminum-zirconium coupling agent, alkali-resistant glass fiber and other materials, fly ash, silicon carbide powder and alkali-resistant glass fiber contain free Si ²⁺ , calcium aluminophosphate and aluminum in iron-rich aluminophosphate cement The calcium acid hydration product can react with Si ²⁺ to form hydrated calcium aluminate feldspar, so as to avoid the decrease of strength caused by the large generation of hydration product C ₃ AH ₆ in the later stage. In addition, the "bridging" effect of glass fiber can limit the plastic cracking after the addition of silicon carbide powder, and improve the interface friction and interface adhesion. The PH of ordinary Portland cement is about 13, and the iron-rich aluminophosphate The PH of the cement is around 11. This low-alkali environment can better play the "bridging" effect of the alkali-resistant glass fibers. Therefore, the synergistic effect of each component makes the obtained gel material have good erosion resistance and abrasion resistance, and give full play to the The properties of the polymer improve the resistance to chloride ion penetration and abrasion resistance of the structure.

Detailed ways

The present invention will be further described in detail below in conjunction with specific embodiments.

Example 1

An erosion-resistant aluminophosphate cement-based gel material suitable for marine engineering is carried out according to the following weight percentages:

Iron-rich aluminophosphate cement clinker 75%

Fly Ash 10%

Silicon carbide powder 8%

Rubber powder 3%

Alkali-resistant glass fiber 3%

Aluminum zirconium coupling agent 1%

The iron-rich aluminophosphate cement clinker has a bulk density of 2.98 g/cm ³ , a specific surface area of 319 m ² /kg, a cement fineness of 200 mesh, a sieve residue of 3.1%, and a setting time of 220 minutes for initial setting and 260 minutes for final setting. , the iron phase content is 11%.

Example 2

An erosion-resistant aluminophosphate cement-based gel material suitable for marine engineering is carried out according to the following weight percentages:

Iron-rich aluminophosphate cement clinker 67%

Fly Ash 15%

Silicon carbide powder 4.5%

Rubber powder 6%

Alkali-resistant glass fiber 6%

Aluminum zirconium coupling agent 1.5%

The iron-rich aluminophosphate cement clinker has a bulk density of 2.98 g/cm ³ , a specific surface area of 319 m ² /kg, a cement fineness of 200 mesh, a sieve residue of 3.1%, and a setting time of 220 minutes for initial setting and 260 minutes for final setting. , the iron phase content is 11%.

Example 3

An erosion-resistant aluminophosphate cement-based gel material suitable for marine engineering is carried out according to the following weight percentages:

Iron-rich aluminophosphate cement clinker 71%

Fly Ash 11%

Silicon carbide powder 7%

Rubber powder 4.5%

Alkali-resistant glass fiber 5%

Aluminum zirconium coupling agent 1.5%

The iron-rich aluminophosphate cement clinker has a bulk density of 2.98 g/cm ³ , a specific surface area of 319 m ² /kg, a cement fineness of 200 mesh, a sieve residue of 3.1%, and a setting time of 220 minutes for initial setting and 260 minutes for final setting. , the iron phase content is 11%.

Comparative Example 1

A gel material, the composition percentage of which is: 100% of iron-rich aluminophosphate cement clinker. The iron-rich aluminophosphate cement clinker has a bulk density of 2.98 g/cm ³ , a specific surface area of 319 m ² /kg, a cement fineness of 200 mesh, a sieve residue of 3.1%, and a setting time of 220 minutes for initial setting and 260 minutes for final setting. , the iron phase content is 11%.

Comparative Example 2

A gel material, its composition percentage content is:

Ordinary Portland Cement Clinker 75%

Fly Ash 10%

Silicon carbide powder 8%

Rubber powder 3%

Alkali-resistant glass fiber 3%

Aluminum zirconium coupling agent 1%

Comparative Example 3

A gel material, its composition percentage content is:

Sulfoaluminate cement clinker 75%

Fly Ash 10%

Silicon carbide powder 8%

Rubber powder 3%

Alkali-resistant glass fiber 3%

Aluminum zirconium coupling agent 1%

The properties of the gel materials prepared in the above Examples 1-3 and Comparative Examples 1-3 were tested, and the specific test results are shown in Table 1.

Table 1 Performance test results

It can be seen from the above table 1 that the 28-day compressive and flexural strengths of the erosion-resistant aluminophosphate cement-based gel materials prepared in Examples 1-3 of the present invention are strong; the 28-day chloride ion diffusion The average value of the coefficient is 1.29, which is significantly lower than the coefficient in Comparative Examples 1-3; the average value of the 28-day sulfate corrosion resistance coefficient is 1.30, which is significantly higher than that in Comparative Examples 1-3; The rubber material has excellent resistance to chloride ion and sulfate corrosion, which is due to the synergistic effect of high-iron phosphoaluminate cement, fly ash, silicon carbide, rubber powder, aluminum-zirconium coupling agent, alkali-resistant glass fiber and other materials contained in the present invention. , so that the obtained gel material has good anti-scour and abrasion resistance, gives full play to the properties of the polymer, and improves the resistance to chloride ion penetration and erosion resistance of the structure. In addition, the wear resistance and impact resistance of the present invention are also superior.

Claims (5)

1. An erosion-resistant phosphoaluminate cement-based gel material suitable for marine engineering is characterized by being prepared from the following raw materials in percentage by weight: 60-75% of iron-rich phosphoaluminate cement clinker, 5-15% of fly ash, 3-8% of silicon carbide powder, 2-6% of rubber powder, 3-6% of alkali-resistant glass fiber and 0.5-2% of aluminum-zirconium coupling agent;

the iron-rich phosphoaluminate cement clinker has mineral phase composition comprising calcium phosphoaluminate 20-60 wt%, calcium phosphate 10-30 wt%, calcium aluminate 15-25 wt%, tetracalcium aluminoferrite 10-25 wt% and vitreous body interphase 2-10 wt%.

2. The erosion resistant phosphoaluminate cement-based gel material suitable for use in marine engineering according to claim 1, wherein the iron-rich phosphoaluminate cement clinker bulk density is 2.98g/cm³A specific surface area of 319m²The cement has the fineness of 200 meshes, the screen residue is 3.1 percent, the setting time is initial setting of 220min and final setting of 260min, and the iron phase content is 11 percent.

3. The erosion resistant phosphoaluminate cement-based gel material suitable for use in marine engineering of claim 1, wherein the fly ash 45 μ ι η sieve residue is 11.7%.

4. The erosion resistant phosphoaluminate cement-based gel material suitable for use in marine engineering according to claim 1, wherein the silicon carbide powder SiC content is > 96.5%.

5. The erosion resistant phosphoaluminate cement-based gel material suitable for use in marine engineering according to claim 1, wherein the alkali resistant glass fiber tensile strength is > 350 MPa.