阅读说明：本技术 一种清水混凝土表面色斑清洗剂及其制法和使法 (Clear water concrete surface color spot cleaning agent and preparation method and application method thereof ) 是由 陈彦文 刘华南 彭海辉 孙强 王兆峰 朱定进 沈福斌 张昊楠 周信 惠安明 于 2021-09-13 设计创作，主要内容包括：一种清水混凝土表面色斑清洗剂及其制法和使法,属于化学建材领域。该清水混凝土表面色斑清洗剂,包括的原料及其质量份数为：草酸2～10份,柠檬酸5～30份,氨水2～12份,水180～380份。其制法为：配制质量浓度为2％～5％的草酸溶液和质量浓度为5％～15％的柠檬酸溶液；将柠檬酸溶液和氨水混合,得到柠檬酸铵-柠檬酸混合缓冲溶液；将草酸溶液和柠檬酸铵-柠檬酸混合缓冲溶液混合均匀,得到清水混凝土表面色斑清洗剂。用该清水混凝土表面色斑清洗剂清洗混凝土,既能有效清洗清水混凝土表面产生的色斑、霉斑,又可保留混凝土的原始性能和外观,混凝土的强度损失率低5％,而且生产成本低、工艺简单、重复性好,便于操作。(A clear water concrete surface color spot cleaning agent and a preparation method and a using method thereof belong to the field of chemical building materials. The clear water concrete surface color spot cleaning agent comprises the following raw materials in parts by weight: 2-10 parts of oxalic acid, 5-30 parts of citric acid, 2-12 parts of ammonia water and 180-380 parts of water. The preparation method comprises the following steps: preparing an oxalic acid solution with the mass concentration of 2-5% and a citric acid solution with the mass concentration of 5-15%; mixing the citric acid solution with ammonia water to obtain an ammonium citrate-citric acid mixed buffer solution; and uniformly mixing the oxalic acid solution and the ammonium citrate-citric acid mixed buffer solution to obtain the clear water concrete surface color spot cleaning agent. The concrete surface color spot cleaning agent is used for cleaning concrete, so that color spots and mildew spots generated on the surface of the fair-faced concrete can be effectively cleaned, the original performance and the appearance of the concrete can be kept, the strength loss rate of the concrete is low by 5%, the production cost is low, the process is simple, the repeatability is good, and the operation is convenient.)

1. The clear water concrete surface color spot cleaning agent is characterized by comprising the following raw materials in parts by weight:

2-10 parts of oxalic acid, 5-30 parts of citric acid, 2-12 parts of ammonia water and 180-380 parts of water.

2. The preparation method of the as-cast finish concrete surface color spot cleaning agent as claimed in claim 1, characterized by comprising the following steps:

(1) preparing an oxalic acid solution with the mass concentration of 2-5%; preparing a citric acid solution with the mass concentration of 5-15%;

(2) mixing the citric acid solution with ammonia water to obtain an ammonium citrate-citric acid mixed buffer solution; wherein, according to the volume ratio, ammonia water: 2-6 parts of citric acid solution: 100, respectively;

(3) according to the mass ratio, oxalic acid solution: ammonium citrate-citric acid mixed buffer solution (1-2): (1-2) uniformly mixing the oxalic acid solution and the ammonium citrate-citric acid mixed buffer solution to obtain the clear water concrete surface color spot cleaning agent.

3. The method for preparing the as-cast finish concrete surface stain cleaning agent as claimed in claim 2, wherein the ammonia water is analytically pure ammonia water, and the mass concentration of the ammonia water is 25-28%.

4. The use method of the clear water concrete surface color spot cleaning agent as claimed in claim 1, characterized by comprising the following steps:

and (3) cleaning the surface of the fair-faced concrete by adopting the fair-faced concrete surface color spot cleaning agent, and washing the cleaned surface of the fair-faced concrete by using water while cleaning until the initial color of the concrete is recovered.

5. The use method of the as-cast finish concrete surface color spot cleaning agent as claimed in claim 4, wherein in the use method of the as-cast finish concrete surface color spot cleaning agent, the cleaning time of the as-cast finish concrete surface color spot cleaning agent is 1-4 h.

6. The use method of the as-cast finish concrete surface color spot cleaning agent as claimed in claim 4, wherein in the use method of the as-cast finish concrete surface color spot cleaning agent, the strength retention rate of the as-cast finish concrete after cleaning is more than 95%.

Technical Field

The invention belongs to the technical field of chemical building materials. In particular to a clear water concrete surface color spot cleaning agent and a preparation method and a using method thereof.

Background

China is a large country of basic construction, high-speed railways and highways are important projects for the infrastructure of China, and the bare concrete of bridges and piers for the construction of the high-speed railways and the highways is distributed over the whole road network. In the process of building and serving the bare concrete large member, because the water for curing the concrete contains iron ions, copper ions and manganese ions, the water is attached to the surface of the concrete in the process of curing the concrete to form color spots; meanwhile, because the metal component of the upper structure generates rust, under the scouring action of rainwater and snow water, rust and patina are deposited on the surface of the concrete along with the flowing of the rainwater and the snow water, brown and brown color spots and black mildew spots are formed on the surface of the concrete, and the surface state and the attractiveness of the concrete are influenced. According to the condition of stains formed on the surface of the bare concrete, most stains are ferric oxide, tung oxide, manganese oxide and mildew stains at present. At present, the method for cleaning the color spots on the surface of the bare concrete is usually to clean the bare concrete by using oxalic acid, but the cleaning effect is poor, and meanwhile, the strength of the cleaned concrete is reduced because the oxalic acid corrodes the concrete to a certain extent.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provides a clear water concrete surface color spot cleaning agent, a preparation method and a use method thereof, the method can effectively clean color spots and mildew spots generated on the clear water concrete surface, can keep the original performance and appearance of the concrete, has the advantages of low strength loss rate of the concrete by 5 percent, low production cost, simple process, good repeatability and convenient operation.

In order to realize the purpose, the following technical scheme is adopted:

the invention relates to a clear water concrete surface color spot cleaning agent, which comprises the following raw materials in parts by weight:

2-10 parts of oxalic acid, 5-30 parts of citric acid, 2-12 parts of ammonia water and 180-380 parts of water.

The invention discloses a preparation method of a clear water concrete surface color spot cleaning agent, which comprises the following steps:

(1) preparing an oxalic acid solution with the mass concentration of 2-5%; preparing a citric acid solution with the mass concentration of 5-15%;

(2) mixing the citric acid solution with ammonia water to obtain an ammonium citrate-citric acid mixed buffer solution; wherein, according to the volume ratio, ammonia water: 2-6 parts of citric acid solution: 100, respectively;

(3) according to the mass ratio, oxalic acid solution: ammonium citrate-citric acid mixed buffer solution (1-2): (1-2) uniformly mixing the oxalic acid solution and the ammonium citrate-citric acid mixed buffer solution to obtain the clear water concrete surface color spot cleaning agent.

The invention discloses a use method of a clear water concrete surface color spot cleaning agent, which comprises the following steps:

and (3) cleaning the surface of the fair-faced concrete by adopting the fair-faced concrete surface color spot cleaning agent, and washing the cleaned surface of the fair-faced concrete by using water while cleaning until the initial color of the concrete is recovered.

In the using method of the fair-faced concrete surface color spot cleaning agent, the cleaning time of the fair-faced concrete surface color spot cleaning agent is 1-4 h.

In the using method of the fair-faced concrete surface color spot cleaning agent, the strength retention rate of the cleaned fair-faced concrete is more than 95%.

Compared with the prior art, the clear water concrete surface color spot cleaning agent, the preparation method and the using method thereof have the beneficial effects that:

1) the cleaning agent takes the mixed solution of oxalic acid, citric acid and ammonia water as the cleaning agent, has poor corrosivity, can remove color spots on the surface of concrete completely, simultaneously enables the strength retention rate of the concrete to reach more than 95%, does not influence the strength and durability of the concrete, has good cleaning effect, has simple raw material composition, simple and easy preparation method and strong operability of the cleaning method, and realizes the requirement of environmental protection because the cleaning waste liquid has no pollution to the environment.

2) The invention takes the mixed solution of oxalic acid, citric acid and ammonia water as a cleaning agent to remove the rust spots on the surface of the concrete. The oxalic acid reacts with iron ions to remove rust on the surface of the concrete. Adding a proper amount of ammonia water into citric acid to prepare a buffer solution, wherein the buffer solution contains ammonium citrate generated by the ammonia water and the citric acid and surplus citric acid, the citric acid can further react with residual iron ions after oxalic acid removal to generate ferric citrate, so that the rust removal effect is improved, ammonium ions and copper ions react to generate cuprammonium complex ions, and the copper ions on the surface of concrete can be removed. The mixed solution of oxalic acid, citric acid and ammonia water is used as a cleaning agent, so that color spots on the surface of the concrete can be better cleaned.

3) The technology has the advantages of simple process, convenient operation, easy process control, low cost and no pollution to the environment.

Drawings

FIG. 1 is a diagram showing a cleaned bare concrete surface with a mottle cleaning agent for bare concrete surface according to example 1;

FIG. 2 is a view showing a state after a surface of a fair-faced concrete is cleaned with the oxalic acid solution of comparative example 1;

FIG. 3 is a diagram showing a state after a surface of fair-faced concrete is cleaned with citric acid + 4% ammonia water of comparative example 1;

FIG. 4 is a diagram showing a state after a surface of fair-faced concrete is cleaned using the oxalic acid solution of comparative example 5;

FIG. 5 is a diagram showing a state after a surface of fair-faced concrete is cleaned using a mixed solution of oxalic acid and ammonium citrate of comparative example 6;

in the above figures, black spots are holes, gray spots are rusty spots on the surface of bare concrete, and dark gray spots are concrete which is not thoroughly cleaned.

Detailed Description

The present invention will be described in further detail with reference to examples.

In the following examples, the ammonia water used was analytically pure ammonia water, and its mass concentration was 25% to 28%.

The following embodiment provides a preparation method of an as-cast finish concrete color spot cleaning agent, which comprises the following steps:

(1) adding oxalic acid 2.0-5.0 g into deionized water 98-95mL, and fully and uniformly stirring to prepare an oxalic acid solution with the mass concentration of 2.0-5.0%;

(2) adding 5.0-15 g of citric acid into 95-85mL of deionized water, and fully and uniformly stirring to prepare a citric acid solution with the concentration of 5.0-15.0%;

(3) taking 100mL of the citric acid solution prepared in the step (2), adding 2-6 mL of ammonia water, and fully stirring to obtain an ammonium citrate-citric acid mixed buffer solution;

(4) mixing the solutions prepared in the steps (1) and (3) according to the mass ratio of oxalic acid solution: ammonium citrate-citric acid mixed buffer solution (1-2): (1-2), uniformly mixing the components in proportion, and preparing the cleaning agent.

(5) Cleaning the polluted concrete surface by using the mixed solution prepared in the step (4), wherein the cleaning time is 1-4h, and the initial color of the concrete is recovered;

(6) and (5) washing the concrete surface cleaned in the step (5) by using tap water, removing color spots on the concrete surface, and recovering the initial state of the concrete, wherein the strength retention rate of the concrete is more than 95%.

Example 1

Preparing 2 parts by mass of an oxalic acid solution with the mass concentration of 2%;

mixing a citric acid solution with a mass concentration of 15% and pure ammonia water with a volume percentage concentration of 6% of the citric acid solution to obtain an ammonium citrate-citric acid mixed buffer solution; preparing 1 part by mass of ammonium citrate-citric acid mixed buffer solution;

mixing the oxalic acid solution and the ammonium citrate-citric acid mixed buffer solution to obtain the clear water concrete surface color spot cleaning agent, coating the concrete surface with C20-C50 for less than 4h, observing to remove the color spot surface of the concrete (shown in figure 1), recovering the original concrete color, and cleaning the solution on the concrete surface with clear water to obtain the concrete strength retention rate of 99.6-100%.

Example 2

Preparing 1 part by mass of an oxalic acid solution with the mass concentration of 2%;

mixing a citric acid solution with a mass concentration of 15% and pure ammonia water with a volume percentage concentration of 6% of the citric acid solution to obtain an ammonium citrate-citric acid mixed buffer solution; preparing 1 part by mass of ammonium citrate-citric acid mixed buffer solution;

mixing the oxalic acid solution and the ammonium citrate-citric acid mixed buffer solution to obtain the clear water concrete surface color spot cleaning agent, coating the concrete surface with C20-C50 for less than 4h, observing that the concrete color spot surface is cleaned and the original concrete color is recovered, and measuring that the concrete strength retention rate is 98.5-100% by cleaning the solution on the concrete surface with clear water.

Example 3

Preparing 1 part by mass of an oxalic acid solution with the mass concentration of 2%;

mixing a citric acid solution with a mass concentration of 15% and a pure ammonia water solution with a volume percentage concentration of 6% of the citric acid solution to obtain an ammonium citrate-citric acid mixed buffer solution; preparing 2 parts by mass of ammonium citrate-citric acid mixed buffer solution;

mixing the oxalic acid solution and the ammonium citrate-citric acid mixed buffer solution to obtain the clear water concrete surface color spot cleaning agent, coating the concrete surface with C20-C50 for less than 4h, observing that the concrete color spot surface is cleaned, recovering the original concrete color, and cleaning the solution on the concrete surface with clear water to obtain the concrete strength retention rate of 95.8-100%.

Example 4

Preparing 2 parts by mass of an oxalic acid solution with the mass concentration of 5%;

mixing a citric acid solution with the mass concentration of 5% and a pure ammonia water solution with the volume percentage concentration of 4% of the citric acid solution to obtain an ammonium citrate-citric acid mixed buffer solution; preparing 1 part by mass of ammonium citrate-citric acid mixed buffer solution;

mixing the oxalic acid solution and the ammonium citrate-citric acid mixed buffer solution to obtain the clear water concrete surface color spot cleaning agent, coating the concrete surface with C20-C50 for less than 3h, observing that the concrete color spot surface is cleaned, recovering the original concrete color, and cleaning the solution on the concrete surface with clear water to obtain the concrete strength retention rate of 96.4-100%.

Example 5

Preparing 1 part by mass of an oxalic acid solution with the mass concentration of 5%;

mixing a citric acid solution with the concentration of 5% and pure ammonia water with the volume percentage concentration of 4% of the citric acid solution to obtain an ammonium citrate-citric acid mixed buffer solution; preparing 1 part by mass of ammonium citrate-citric acid mixed buffer solution;

mixing the oxalic acid solution and the ammonium citrate-citric acid mixed buffer solution to obtain the clear water concrete surface color spot cleaning agent, coating the concrete surface with C20-C50 for less than 3h, observing that the concrete color spot surface is cleaned, recovering the original concrete color, and cleaning the solution on the concrete surface with clear water to obtain the concrete strength retention rate of 98.6-99.8%.

Example 6

Preparing 1 part by mass of an oxalic acid solution with the mass concentration of 5%;

mixing a citric acid solution with the mass concentration of 5% and pure ammonia water with the volume percentage concentration of 4% of the citric acid solution to obtain an ammonium citrate-citric acid mixed buffer solution; preparing 2 parts by mass of ammonium citrate-citric acid mixed buffer solution;

mixing the oxalic acid solution and the ammonium citrate-citric acid mixed buffer solution to obtain the clear water concrete surface color spot cleaning agent, coating the concrete surface with C20-C50 for less than 3h, observing that the concrete color spot surface is cleaned, recovering the original concrete color, and cleaning the solution on the concrete surface with clear water to obtain the concrete strength retention rate of 99.6-99.2%.

Example 7

Preparing 2 parts by mass of an oxalic acid solution with the mass concentration of 3.5%;

mixing a citric acid solution with the concentration of 10% with a pure ammonia water solution with the volume percentage concentration of 6% of the citric acid solution to obtain an ammonium citrate-citric acid mixed buffer solution; preparing 1 part by mass of ammonium citrate-citric acid mixed buffer solution;

mixing the oxalic acid solution and the ammonium citrate-citric acid mixed buffer solution to obtain the clear water concrete surface color spot cleaning agent, coating the concrete surface with C20-C50 for less than 2h, observing that the concrete color spot surface is cleaned, recovering the original concrete color, and cleaning the solution on the concrete surface with clear water to obtain the concrete strength retention rate of 97.6-100%.

Example 8

Preparing 1 part by mass of an oxalic acid solution with the mass concentration of 3.5%;

mixing a citric acid solution with the concentration of 10% with pure ammonia water with the volume percentage concentration of 6% of the citric acid solution to obtain an ammonium citrate-citric acid mixed buffer solution; preparing 1 part by mass of ammonium citrate-citric acid mixed buffer solution;

mixing the oxalic acid solution and the ammonium citrate-citric acid mixed buffer solution to obtain the clear water concrete surface color spot cleaning agent, coating the concrete surface with C20-C50 for less than 2h, observing that the concrete color spot surface is cleaned, recovering the original concrete color, and cleaning the solution on the concrete surface with clear water to obtain the concrete strength retention rate of 96.4-99.6%.

Example 9

Preparing 1 part by mass of an oxalic acid solution with the mass concentration of 3.5%;

mixing a citric acid solution with the mass concentration of 10% and pure ammonia water with the volume percentage concentration of 6% of the citric acid solution to obtain an ammonium citrate-citric acid mixed buffer solution; preparing 2 parts by mass of ammonium citrate-citric acid mixed buffer solution;

mixing the oxalic acid solution and the ammonium citrate-citric acid mixed buffer solution to obtain the clear water concrete surface color spot cleaning agent, coating the concrete surface with C20-C50 for less than 2h, observing that the concrete color spot surface is cleaned, recovering the original concrete color, and cleaning the solution on the concrete surface with clear water to obtain the concrete strength retention rate of 98.7-99.9%.

Example 10

Preparing 1 part by mass of an oxalic acid solution with a mass concentration of 4%;

mixing a citric acid solution with a mass concentration of 15% and pure ammonia water with a volume percentage concentration of 2% of the citric acid solution to obtain an ammonium citrate-citric acid mixed buffer solution; preparing 1 part by mass of ammonium citrate-citric acid mixed buffer solution;

mixing the oxalic acid solution and the ammonium citrate-citric acid mixed buffer solution to obtain the clear water concrete surface color spot cleaning agent, coating the concrete surface with C20-C50 for less than 2 hours, observing that the concrete color spot surface is cleaned, recovering the original concrete color, and cleaning the solution on the concrete surface with clear water to obtain the concrete strength retention rate of 96.5%.

Comparative example 1

The method comprises the following steps of brushing the surfaces of the concrete with C20-C50 by using an oxalic acid solution with the mass concentration of 5%, wherein the brushing time is less than 4h, observing that the surfaces of the concrete color spots cannot be cleaned, some brown and yellow color spots remain, and the original color of the concrete cannot be recovered, and comparing the cleaned surfaces of the fair-faced concrete with the reference chart shown in figure 2 with that shown in figure 1, wherein the oxalic acid is independently used as a cleaning agent, the color spots remain on the concrete surface, and the residual color spots are in the middle of a mark frame in figure 2. The concrete strength retention rate is measured to be 97.2% -100% by using clear water to clean the solution on the surface of the concrete.

Comparative example 2

The concrete surface of C20-C50 is coated with a mixture of citric acid with the mass concentration of 5% and ammonia water with the mass concentration of 4%, the coating time is less than 3h, through observation, the dark brown color spots on the surface of the concrete color spots become light, but the concrete color spots can not be completely cleaned, and residual spots still exist, the comparison chart of the cleaned fair-faced concrete surface is shown in figure 3, the upper part of the horizontal line in figure 3 is the concrete cleaned in comparative example 2, the lower part of the horizontal line is the concrete cleaned in example 6, and through comparison, the concrete can not be cleaned only by using citric acid-citric acid buffer solution, and black in the figure is the holes of the concrete. The concrete strength retention rate is measured to be 99.3% -99.8% by using clear water to clean the solution on the surface of the concrete.

Comparative example 3

Mixing the citric acid with the mass concentration of 10% and the ammonia water solution with the mass concentration of 6%, painting the surface of the concrete with the concentration of C20-C50 for less than 2 hours, observing that black brown spots remain on the surface of concrete stains and the original color of the original concrete cannot be recovered, and cleaning the solution on the surface of the concrete with clear water to obtain the concrete strength retention rate of 99.4-100%.

Comparative example 4

Mixing the mixture with citric acid with the concentration of 15% and ammonia water solution with the concentration of 4%, painting the surface of the concrete with the concentration of C20-C50 for less than 3h, observing that black brown color spots are reserved on the surface of the concrete, and the color of the concrete can not be restored to the original color of the concrete, and washing the solution on the surface of the concrete with clear water to obtain the concrete strength retention rate of 99.1-100%.

Comparative example 5

The method is characterized in that the oxalic acid solution with the mass concentration of 10% is adopted to clean the water concrete, the color spots on the surface of the concrete are cleaned, the cleaned figure is shown in figure 4, due to the fact that the oxalic acid concentration is high, water hydration products in the concrete are corroded, the concrete pores are increased, the pore diameter is enlarged, the concrete compactness is reduced, the performance is reduced, the strength retention rate of the cleaned concrete is lower than 85%, the strength loss of the concrete is large, and the safety of a building is reduced.

Comparative example 6

The oxalic acid and the ammonium citrate solution are added, so that the ammonium citrate solution is added, no redundant citric acid is added, the buffering effect cannot be achieved, the oxalic acid and the ammonium citrate manganate are mixed to generate ammonium oxalate, the rust removal effect of the oxalic acid is inhibited, the copper ammonium complex generated by the reaction with copper ions is reduced, the copper rust removal capacity is reduced, the color spot cleaning effect is weakened, the cleaning effect is shown in figure 5, and compared with figure 1, the concrete color spot cleaning effect is shown in figure 1, and the situation that in a place with serious concrete color spots, the concrete surface is cleaned by directly preparing the cleaning solution by adding the oxalic acid and the ammonium citrate, the color spot marks still remain on the concrete surface, and the color spot is not thoroughly cleaned. In the embodiment 1 of the invention, the ammonium citrate-citric acid buffer solution is adopted, so that even places with serious color spot pollution can be cleaned, and the natural color of the concrete can be recovered.

Comparative example 7

Directly adding oxalic acid and citric acid into water, and then adding ammonia water, wherein after the ammonia water is added into the mixed solution of oxalic acid and citric acid, the ammonia water and the oxalic acid firstly react to generate ammonium oxalate, so that calcium ions in concrete are corroded, the iron rust removing capability of the oxalic acid is reduced, the reaction capability of the ammonium citrate solution and copper ions is reduced, and the spot removing capability of the cleaning agent is reduced; and after the ammonia water is added into the mixed solution of oxalic acid and citric acid, the ammonia water and the oxalic acid firstly react to generate ammonium oxalate, calcium ions in concrete are corroded, the iron rust removing capability of the oxalic acid is reduced, the reaction capability of the ammonium citrate solution and copper ions is reduced, and the spot removing capability of the cleaning agent is weakened.