阅读说明：本技术 一种污水混凝土构筑物快硬型高耐腐蚀砂浆修补材料 (Rapid-hardening high-corrosion-resistance mortar repair material for sewage concrete structure ) 是由 史若昕 陈广 樊俊江 於林锋 于 2021-08-05 设计创作，主要内容包括：本发明公开了一种污水混凝土构筑物快硬型高耐腐蚀砂浆修补材料,由以下重量百分比的组分组成：61％-70％的普通硅酸盐水泥、2％～5％硫铝酸盐水泥、8％～10％的粉煤灰、2％～5％的硅灰、2％～5％的石膏、4％～7％的膨胀剂、0.5％～1％的减水剂、2％～6％的乳胶粉以及0.1％～0.2％的乙醇胺；该快硬型高耐腐蚀砂浆修补材料的抗蚀系数达到1.2、拉伸粘结强度达到1.7MPa,28d抗压强度达到48MPa以上,并且经酸腐蚀浸泡180d试验验证,该材料具有较高的耐弱酸腐蚀作用,满足了污水混凝土构筑物高耐腐蚀性的要求,作为一种有效的防腐混凝土涂层,对污水处理设施的长期安全运营具有重要的意义。(The invention discloses a quick-hardening high-corrosion-resistance mortar repair material for a sewage concrete structure, which comprises the following components in percentage by weight: 61-70% of ordinary portland cement, 2-5% of sulphoaluminate cement, 8-10% of fly ash, 2-5% of silica fume, 2-5% of gypsum, 4-7% of expanding agent, 0.5-1% of water reducing agent, 2-6% of latex powder and 0.1-0.2% of ethanolamine; the corrosion resistance coefficient of the rapid-hardening high-corrosion-resistance mortar repair material reaches 1.2, the tensile bonding strength reaches 1.7MPa, the 28d compressive strength reaches more than 48MPa, and acid corrosion soaking 180d tests prove that the material has a high weak acid corrosion resistance effect, meets the requirement of high corrosion resistance of a sewage concrete structure, is an effective anticorrosive concrete coating, and has important significance for long-term safe operation of a sewage treatment facility.)

1. The fast-hardening high-corrosion-resistance mortar repair material for the sewage concrete structure is characterized by comprising the following components in percentage by weight:

61-70% of ordinary portland cement, 2-5% of sulphoaluminate cement, 8-10% of fly ash, 2-5% of silica fume, 2-5% of gypsum, 4-7% of expanding agent, 0.5-1% of water reducing agent, 2-6% of polymer acrylic latex powder and 0.1-0.2% of ethanolamine.

2. The rapid-hardening high-corrosion-resistance mortar repair material for a sewage concrete structure according to claim 1, wherein the rapid-hardening high-corrosion-resistance mortar repair material has a corrosion resistance coefficient of 1.2 or more, a tensile bond strength of 1.7MPa or more, and a 28d compressive strength of 48MPa or more.

3. The rapid-hardening high-corrosion-resistance mortar repair material for sewage concrete structures as claimed in claim 1, wherein the Portland cement is P.II 52.5 Portland cement.

4. The rapid hardening high corrosion resistance mortar repair material for sewage concrete structures according to claim 1, wherein the sulphoaluminate cement is 42.5 grade rapid hardening sulphoaluminate cement.

5. The fast-hardening high-corrosion-resistance mortar repair material for sewage concrete structures as claimed in claim 1, wherein the latex powder is polymer acrylic latex powder.

6. The rapid-hardening high-corrosion-resistance mortar repair material for sewage concrete structures as claimed in claim 1, wherein the silica fume has a specific surface area of not less than 18000m²/kg。

7. The rapid-hardening high-corrosion-resistant mortar repair material for sewage concrete structures as claimed in claim 1, wherein the rapid-hardening high-corrosion-resistant mortar repair material has a 28d permeation pressure of 1.8MPa or more and a 72h water absorption of less than 2.0 kg-m^-3And 28d abrasion resistance less than 0.5 g.

8. The fast-hardening high-corrosion-resistance mortar repair material for the sewage concrete structure as claimed in claim 1, which is characterized by comprising the following components in percentage by weight:

61-66% of ordinary portland cement, 2-5% of sulphoaluminate cement, 8-10% of fly ash, 2-5% of silica fume, 2-5% of gypsum, 4-7% of expanding agent, 0.5-1% of water reducing agent, 2-6% of polymer acrylic latex powder and 0.1-0.2% of ethanolamine.

Technical Field

The invention relates to the field of building materials, in particular to a quick-hardening high-corrosion-resistance mortar repairing material for a sewage concrete structure.

Background

The urban sewage treatment plant plays a key leading role in water environment protection, a concrete structure in a sewage treatment system can be corroded by various corrosive media such as microorganisms in long-term operation, so that the phenomena of fouling, loosening, falling, exposure of aggregate steel bars and the like on the surface of concrete can be caused, concrete cracking and steel bar corrosion can be generated in severe cases, due to the lack of sufficient knowledge and effective prevention and treatment measures, the existing sewage treatment concrete structure is mostly not subjected to anticorrosion treatment, a large amount of existing sewage treatment facilities which are put into operation in early stage are seriously corroded and damaged, the service function of the structure is influenced, the structure cannot reach the design service life, and obvious corrosion phenomena can be generated in short term in some newly-put-into-operation sewage treatment projects. The corrosion problem of concrete structures in the urban sewage treatment system needs to be solved urgently, and effective protective measures are taken, for example, a high-corrosion-resistance material is prepared, so that the method has important significance on the long-term safe operation of sewage treatment facilities.

Besides improving the durability of the concrete, the adoption of the anti-corrosion coating material on the surface of the concrete can isolate the concrete from surrounding corrosive media or prevent the invasion of harmful media, and the anti-corrosion coating material is also an effective anti-corrosion measure. The measure is to coat a layer of high corrosion resistant material on the surface of the concrete to form an isolating layer to prevent the medium such as water, oxygen, chloride ions and the like from permeating into the concrete to cause corrosion. How to prepare a quick-hardening high-corrosion-resistance mortar repair material according to the rapid repair construction requirement and the high durability requirement of a sewage concrete structure, the quick-hardening high-corrosion-resistance mortar repair material is used as a corrosion-resistance mortar coating on the surface of concrete, and the quick-hardening high-corrosion-resistance mortar repair material has important significance for the long-term safe operation of a sewage treatment facility.

Disclosure of Invention

The invention aims to solve the technical problem of providing a quick-hardening high-corrosion-resistance mortar repair material which is used as an anti-corrosion mortar coating on the surface of concrete and aims at meeting the long-term safe operation requirement on a sewage treatment facility aiming at the requirements of quick repair construction and high durability of a sewage concrete structure.

The technical problem to be solved can be implemented by the following technical scheme.

The fast-hardening high-corrosion-resistance mortar repair material for the sewage concrete structure is characterized by comprising the following components in percentage by weight:

61-70% of ordinary portland cement, 2-5% of sulphoaluminate cement, 8-10% of fly ash, 2-5% of silica fume, 2-5% of gypsum, 4-7% of expanding agent, 0.5-1% of water reducing agent, 2-6% of emulsion powder and 0.1-0.2% of ethanolamine.

The Portland cement is preferably P.II 52.5 ordinary Portland cement.

The sulphoaluminate cement is preferably 42.5 grade quick hardening sulphoaluminate cement.

The latex powder is preferably polymer acrylate latex powder.

The specific surface area of the silica fume is not less than 18000m²/kg。

As a further improvement of the technical proposal, the mortar repair material has the corrosion resistance coefficient of more than 1.2, the tensile bonding strength of more than 1.7MPa and the 28d compressive strength of more than 48 MPa.

Also as a further improvement of the technical proposal, the 28d seepage pressure resistance of the mortar repair material reaches more than 1.8MPa, and the water absorption capacity of 72h is less than 2.0 kg.m^-3And 28d abrasion resistance less than 0.5 g.

Furthermore, after the mortar repairing material is subjected to an acid corrosion soaking 180d test, the compressive strength is only slightly reduced, and the electric flux is obviously increased.

As a preferred embodiment of the invention, the mortar repair material consists of the following components in percentage by weight:

61-66% of ordinary portland cement, 2-5% of sulphoaluminate cement, 8-10% of fly ash, 2-5% of silica fume, 2-5% of gypsum, 4-7% of expanding agent, 0.5-1% of water reducing agent, 2-6% of polymer acrylic latex powder and 0.1-0.2% of ethanolamine.

The fast-hardening high-corrosion-resistance mortar repair material for the sewage concrete structure, which adopts the technical scheme, has the following beneficial effects:

the fast-hardening high-corrosion-resistance mortar repair material for the sewage concrete structure has a high weak acid corrosion resistance effect, meets the requirement of high corrosion resistance of the sewage concrete structure, is an effective anticorrosive concrete coating, and has an important significance for long-term safe operation of sewage treatment facilities.

Detailed Description

The following describes the present invention in further detail with reference to specific examples.

Example 1 (comparative):

a quick-hardening high-corrosion-resistance mortar repair material for a sewage concrete structure is composed of the following raw materials in percentage by weight: 67.5% of ordinary portland cement, 5% of sulphoaluminate cement, 10% of fly ash, 5% of silica fume, 5% of gypsum, 6.8% of expanding agent, 0.5% of water reducing agent and 0.2% of ethanolamine.

Example 2:

a quick-hardening high-corrosion-resistance mortar repair material for a sewage concrete structure is composed of the following raw materials in percentage by weight: 65.5 percent of ordinary portland cement, 5 percent of sulphoaluminate cement, 10 percent of fly ash, 5 percent of silica fume, 5 percent of gypsum, 6.8 percent of expanding agent, 0.5 percent of water reducing agent, 2 percent of latex powder and 0.2 percent of ethanolamine.

Example 3:

a quick-hardening high-corrosion-resistance mortar repair material for a sewage concrete structure is composed of the following raw materials in percentage by weight: 63.5 percent of ordinary portland cement, 5 percent of sulphoaluminate cement, 10 percent of fly ash, 5 percent of silica fume, 5 percent of gypsum, 6.8 percent of expanding agent, 0.5 percent of water reducing agent, 4 percent of latex powder and 0.2 percent of ethanolamine.

Example 4:

a quick-hardening high-corrosion-resistance mortar repair material for a sewage concrete structure is composed of the following raw materials in percentage by weight: 61.5 percent of ordinary portland cement, 5 percent of sulphoaluminate cement, 10 percent of fly ash, 5 percent of silica fume, 5 percent of gypsum, 6.8 percent of expanding agent, 0.5 percent of water reducing agent, 6 percent of latex powder and 0.2 percent of ethanolamine.

The fast-hardening high-corrosion-resistance mortar repair material for the sewage concrete structures of the four examples is subjected to a mixture performance test, mechanical tests of rupture strength, compressive strength, bonding strength and elastic modulus of 12h, 3d and 28d, and a chlorine ion permeability resistance durability test, and the results are respectively shown in table 1, table 2 and table 3.

Table 1: performance test result of quick-hardening high-corrosion-resistance mortar repair material mixture for sewage concrete structure

Table 2: mechanical property test result of fast-hardening high-corrosion-resistance mortar repair material for sewage concrete structure

Table 3: durability test result of fast-hardening high-corrosion-resistance mortar repair material for sewage concrete structure

From the test results: from the embodiment 1 to the embodiment 4, the mixing amount of the latex powder is increased continuously, the water consumption for the repair mortar to reach the same fluidity is increased, and the setting time is prolonged. The increase in water usage results in some reduction in mortar strength and, while the extension of setting time is detrimental to rapid repair, increases the operational time. And the 28d bonding strength of example 4 with 6% latex powder is 2.4MPa, because the tensile strength of the polymer resin film formed by the polymer acrylate latex powder is usually more than an order of magnitude higher than that of the hydraulic material, so that the self strength and bonding strength of the mortar are enhanced, and the bonding strength of the mortar is gradually improved along with the increase of the mixing amount of the latex powder.

In addition, as the mixing amount of the latex powder is increased in examples 1 to 4, the compressive strength and the flexural strength of the repair mortar at different ages tend to be gradually reduced. The early compressive strength of example 1 is higher, while the early compressive strengths of examples 2 to 4 are lower, but the later compressive strength is greatly increased relative to the early compressive strength because the rubber powder has a retarding effect, and the retarding effect is more obvious when the mixing amount is larger. Along with the extension of the age and the proceeding of hydration, the rubber powder particles are further coagulated to form a film with higher strength and binding power, and the spatial network structure of the rubber powder connects cement hydration products together, so that the structural form of the cement stone is improved, and the 28d compressive strength of the repair mortar is greatly increased relative to the early strength. However, since the rubber powder has a lower elastic modulus than that of the set cement and does not provide a rigid support when the composite is compressed, the compressive strength of examples 2 to 4 is still lower than that of example 1. The flexural strength of examples 2 to 4 at different ages was lower than that of example 1, but the flexural strength of 28d was greatly improved, and was close to that of example 1. The flexural strength is gradually improved along with the increase of the mixing amount of the rubber powder, because the spatial net structure is gradually formed at the age of 28d, the bonding between the aggregate and the cement stone structure is effectively enhanced, and the flexural strength is greatly improved; on the other hand, the air-entraining function of the rubber powder causes excessive bubbles, the pore structure is changed, and the flexural strength is adversely affected to a certain extent, so that the flexural strength of the mortar is in a descending trend along with the increase of the mixing amount of the rubber powder.

For example 1 without adding rubber powder, the electric flux and the chloride ion diffusion coefficient are the largest, after the rubber powder is added, the electric flux and the chloride ion diffusion coefficient of examples 2-4 are obviously reduced, along with the increase of the rubber powder adding amount, the electric flux and the chloride ion diffusion coefficient are also reduced, and the electric flux and the chloride ion diffusion coefficient can respectively reach 636C and 4.82 x 10 at the lowest^-13m²/s、1.17×10^-12m²And s. The rubber powder can obviously reduce the chloride ion diffusion capacity of the cement mortar and improve the chloride ion corrosion resistance of the cement mortar. Therefore, the proportion of the rubber powder in the quick-hardening high-corrosion-resistance mortar repair material for the sewage concrete structure is regulated to be 2-4%, and is not suitable to exceed 4%.

The results of testing the repair mortar 28d in terms of permeation resistance pressure, 72h in water absorption capacity, corrosion resistance coefficient, 28d in terms of abrasion resistance, 28d in terms of compressive strength and 28d in terms of tensile bond strength in 28d by referring to the procedure described in "repair mortar" (JC/T2381-2016) in example 3 as an object of study are shown in Table 4. In addition, the acidic corrosion environment of a sewage structure is simulated, strong acidic simulated corrosion liquid and weak acidic simulated corrosion liquid with pH values of 0.3 and 5.5 are respectively prepared, C40 common concrete is formed, the surface of the repair mortar is coated with the high corrosion-resistant polymer prepared in the embodiment 3 of the invention with the thickness of 3mm, the repair mortar is maintained for a specified age, the repair mortar is soaked in the two simulated corrosion liquids in a dry-wet cycle or for a long time, the soaking age is 180 days, after the repair mortar is soaked for a target age, the corrosion condition of the repair mortar is tested and observed, the protection effect on the internal concrete is tested, and the electric flux and the residual compressive strength of the internal concrete are tested. The test results are shown in table 5.

Table 4: performance verification test of fast-hardening high-corrosion-resistance mortar repair material for sewage concrete structure

Technical index	Standard requirements	Test value of proof test
			28d permeation pressure/MPa	≥1.5	1.8
72h water absorption capacity/kg m-3	≤2.0	1.0
			Coefficient of corrosion resistance	≥0.85	1.2
28d abrasion resistance/g	≤0.5	0.4
			28d compressive strength/MPa	≥30	48.5
28d tensile bond Strength/MPa	/	1.7

Table 5: concrete strength and strength after soaking in acidic corrosive solution

From the results in tables 4 and 5, it can be seen that the repair mortar of example 3 satisfies the standard requirements for each performance index and has outstanding corrosion resistance. After the repair mortar of example 3 is soaked in the weak acid solution for 180 days, the surface of the mortar is complete, and no chalking and peeling phenomenon after corrosion occurs, which indicates that the repair mortar has better weak acid corrosion resistance. However, the corrosion is severe in strong acid solution, obvious pulverization and peeling appear, and practically any inorganic cement mortar is corroded in the acid corrosive liquid with low pH value. In addition, whether the corrosion-resistant repair mortar on the surface of the concrete test block is corroded or not, the concrete test block inside is well protected. Compared with the standard test block in the same age period, the compressive strength of the concrete is only reduced by 6-7%, and the electric flux is obviously increased. According to the test result, the fast-hardening high-corrosion-resistance mortar repair material for the sewage concrete structure can play a good protection role on the sewage concrete structure, and has important significance on the long-term safe operation of a sewage treatment facility.