CN111018395A - Corrosion-inhibition slow-setting synergistic cement water reducer and preparation method thereof - Google Patents

Abstract

The invention discloses a corrosion-inhibition slow-setting synergistic type cement water reducer and a preparation method thereof, and aims to solve the problems of poor adaptability, uneven dispersion, short coagulation time, corrosion to reinforcing steel bars and the like of the conventional polycarboxylic acid water reducer. The water reducing agent is prepared by compounding an ether type polycarboxylate water reducing agent, hydroxyethylidene diphosphonic acid, a polycarboxylate dispersing agent, sodium gluconate, sodium hydroxide and water. The water reducer can fully utilize the synergistic advantage of a water treatment agent, and on one hand, the water bleeding rate can be effectively reduced while the cement fluidity is increased and the using amount of the polycarboxylic acid water reducer is reduced; on the other hand, the function of the water quality stabilizer can be fully exerted, the adaptability of the cement to water quality is increased, and the corrosion of the water quality to building steel and production materials is reduced.

Description

Corrosion-inhibition slow-setting synergistic cement water reducer and preparation method thereof

Technical Field

The invention relates to the technical field of cement admixtures, in particular to a corrosion-inhibition and slow-setting synergistic cement water reducer and a preparation method thereof.

Background

China is in the outbreak period of the building industry, the rapid development of the building industry puts forward more extensive requirements on cement additives, and the polycarboxylate water reducer serving as a high-end engineering additive is widely applied to common cement engineering nowadays and is increasingly favored due to the advantages of strong dispersibility, low mixing amount, small concrete slump loss and the like. Aiming at the expansion of the application area of the polycarboxylic acid water reducing agent, the research of the additive also provides some new requirements. For example, CN201310421488.0 proposes "composite clay adsorbent for shielding high content clay in concrete from adsorbing and agglomerating carboxylic acid water reducer, its preparation method and use method", CN201310373176.7 proposes a high temperature resistant super retarder with good dispersion property and its preparation method, and CN201610481673.2 proposes an antifreezing concrete water reducer. The research of the new methods expands the application range of the polycarboxylic acid water reducing agent to a certain extent. But the problems of poor adaptability, uneven dispersion, short coagulation time, corrosion to reinforcing steel bars and the like of the water reducing agent can not be effectively solved.

The water treatment agent is used as a high-efficiency water quality stabilizer, has multiple effects of retarding coagulation, inhibiting corrosion, dispersing and the like, is used as a synergist applied to cement admixtures, and is beneficial to expanding and improving the performance of cement. For example, CN201710158736.5 reports an admixture for improving compatibility of a polycarboxylic acid water reducing agent and concrete constituent materials, and modified lignosulfonic acid and hydroxyethylidene diphosphonic acid are used as mud resistance agents to increase compatibility among the concrete materials, with significant effect. CN200510024395.X reports a concrete super-retarding water reducing agent and a preparation method thereof, and the invention uses ethylene polyamine alkyl phosphonic acid and phosphine butane tricarboxylic acid as retarding components to prepare the water reducing agent with super-normal retarding effect. CN201711289700.7 reports a preparation method of a low hydration heat super-retarding polycarboxylate water reducer, which utilizes water reducer molecules to gradually release hydroxyethylidene diphosphonic acid to achieve the effect of retarding. CN201310097839.7 discloses a method for synthesizing a polycarboxylic acid type high slump retaining water reducer, wherein a water treatment agent acrylic acid-maleic anhydride copolymer is added into tap water to replace purified water for carrying out polymerization reaction of the water reducer, the discovery shows that the conversion rate of raw materials is high, the cost is saved, and the slump retaining capability of the product is superior to that of the prior art. The above applications are only to give the water reducing agent new properties by utilizing a certain component property of the water treatment agent, and cannot be comprehensively considered from the synergistic effect of the water treatment agent. For example, organic phosphoric acid has a remarkable effect on the retardation of cement, but tends to cause an increase in bleeding amount. The polycarboxylic acid water treatment agent has good dispersion corrosion inhibition performance and cannot be fully utilized.

In addition, the polycarboxylate superplasticizer serving as a high-efficiency water reducing agent has single component and high price, and also limits the application range of the water reducing agent.

Disclosure of Invention

In view of the above, the invention aims to provide a corrosion-inhibition slow-setting synergistic type cement water reducer and a preparation method thereof. The water reducer can make full use of the synergistic advantage of a water treatment agent, and on one hand, the water bleeding rate can be effectively reduced while the cement fluidity is increased and the using amount of the polycarboxylic acid water reducer is reduced. On the other hand, the function of the water quality stabilizer can be fully exerted, the adaptability of the cement to water quality is increased, and the corrosion of the water quality to building steel and production materials is reduced.

In order to achieve the purpose, the invention provides the following technical scheme: a corrosion inhibition slow setting synergistic type cement water reducer is characterized by comprising the following components in parts by weight (calculated by dry weight, except water): 10-30 parts of an ether type polycarboxylate water reducer, 0.1-1 part of hydroxyethylidene diphosphonic acid, 2-6 parts of a polycarboxylate dispersant, 3-10 parts of sodium gluconate, and adjusting the pH value to 6-7 by sodium hydroxide, and adding water to adjust the concentration of the water reducer (preferably adding water to make up 100 parts).

Preferably, the weight parts of the components are as follows: 15-20 parts of ether type polycarboxylic acid water reducing agent, 0.4-0.5 part of hydroxyethylidene diphosphonic acid, 4-6 parts of polycarboxylic acid dispersing agent, 7-9 parts of sodium gluconate, and 100 parts of water for supplementing, wherein the pH value of the sodium hydroxide is adjusted to 6-7.

The ether polycarboxylate superplasticizer is prepared from 30-50% of a commercially available ether polycarboxylate superplasticizer mother liquor or a commercially available solid ether polycarboxylate superplasticizer by adding water to 30-50% of the ether polycarboxylate superplasticizer mother liquor. Wherein the ether type polycarboxylate superplasticizer is a copolymer taking Allyl Polyoxyethylene Ether (APEG) or methyl allyl polyoxyethylene ether (TPEG) and acrylic acid or acrylic acid derivatives as monomers.

The polycarboxylic acid dispersant comprises one or more of sodium Polyacrylate (PAA) (S), hydrolyzed polymaleic anhydride (HPMA), maleic acid-acrylic acid copolymer (MA/AA), polyepoxysuccinic acid (sodium) (PESA), polyaspartic acid (sodium) (PASP), more preferably polyepoxysuccinic acid (sodium) (PESA) and polyaspartic acid sodium. Is a common article for commercial industrial water treatment agents.

The preparation method of the corrosion-inhibition slow-setting synergistic type cement water reducer is characterized by comprising the following steps of:

1) weighing the raw materials according to the parts by weight, and respectively adding water to dissolve sodium gluconate and sodium hydroxide to prepare solutions with proper concentrations;

2) sequentially adding an ether polycarboxylic acid water reducing agent, hydroxyethylidene diphosphonic acid, a polycarboxylic acid dispersing agent and a sodium gluconate solution into a stirring tank under stirring, and uniformly stirring to obtain a mixed solution;

3) slowly adding a sodium hydroxide solution into the mixed solution obtained in the step 2), and adjusting the pH value to 6-7;

4) and (3) adding water (to make up 100 parts) into the mixed solution in the step 3), and uniformly stirring to obtain the cement water reducer.

The corrosion-inhibition slow-setting synergistic cement water reducer takes an ether type polycarboxylate water reducer, hydroxyethylidene diphosphonic acid, sodium gluconate and a polycarboxylate dispersant as basic raw materials; the ether type polycarboxylate superplasticizer is a main superplasticizer component, on one hand, the hydroxyethylidene diphosphonic acid and the sodium gluconate can effectively increase the fluidity of cement, and has the effects that 1+1 is larger than 2, and the retarding effect is obvious; the molecular weight range of the polycarboxylic acid dispersant is 4000-8000, the polycarboxylic acid dispersant has excellent dispersing performance, the stability of cement particles in water can be effectively improved, the sedimentation is reduced, and the bleeding rate is effectively reduced; in addition, the polycarboxylic acid dispersant and the polycarboxylic acid water reducing agent are compatible for use, the two molecular structures are similar, the adaptability with other admixtures is good, and a good synergistic effect is achieved. The hydroxyethylidene diphosphonic acid, the polycarboxylic acid dispersant and the sodium gluconate are combined, the stability of the water quality under the alkaline condition of cement is good, the hydroxyethylidene diphosphonic acid has a plurality of functional groups and is a good complexing agent, the polycarboxylic acid dispersant and the hydroxyethylidene diphosphonic acid are used cooperatively, the limit effect of a water treatment agent can be exerted, and the effect of ultra-equivalent metering is achieved by the amount of PPM.

In actual use, the early strength and the later strength of the cement are improved by 3-5 MPa, and the fluidity of the cement paste is not lost for 2 hours; and the paint does not contain any chloride ion and sulfate ion components, is nontoxic, green and environment-friendly, has no corrosivity, and does not damage human bodies, buildings and the like. The cement water reducing agent is subjected to retarding by compounding hydroxyethylidene diphosphonic acid, sodium gluconate and a polycarboxylic acid dispersing agent, and compared with common retarders such as sodium gluconate, white sugar and sodium tripolyphosphate, the cement water reducing agent has the advantages of obviously improved retarding efficiency, good chemical stability and temperature resistance, and good retarding effect at 250 ℃; and the calcium ion complex can form a complex with calcium ions in cement slurry, can well control the concentration of the calcium ions in a liquid phase at the initial stage of hydration, is well adsorbed on crystal embryos of a new phase of a hydration product, changes the generation speed of the crystal embryos of the hydration product in a saturated solution, and has a good retarding effect. The polycarboxylic acid dispersant can also reduce the surface energy of particles, improve the affinity with a dispersion medium, effectively inhibit agglomeration among the particles, release interstitial water among the particles, further reduce the water consumption of the standard consistency of cement, improve the performance of the cement, improve the fluidity of the particles and improve the surface property of cement paste, thereby increasing the dispersion performance of the cement paste, increasing the thickness of a hydrated layer on the surface of the particles and ensuring that the paste is soft and has better fluidity. When the sodium gluconate is used in a compounding way, an ideal synergistic effect is shown, so that the bleeding performance of the cement paste is obviously reduced.

Detailed Description

The synergistic water reducing agent for cement and the preparation method thereof provided by the present invention will be described in detail with reference to the following examples, which should not be construed as limiting the scope of the present invention. The commercially available polyether type polycarboxylate superplasticizer is a TPEG polycarboxylate superplasticizer mother liquor (40%) catabol Bailai building materials Co.

Example 1

45 parts of ether type polycarboxylate superplasticizer mother liquor (40%), 0.8 part of hydroxyethylidene diphosphonic acid (60%), 16.4 parts of polyacrylic acid (PAA) dispersing agent (30%) and 8.3 parts of solid sodium gluconate are respectively weighed. Wherein the sodium gluconate is dissolved by adding equal amount of water. Adding the ether type polycarboxylate superplasticizer mother liquor into a stirring tank, stirring, sequentially adding a polyacrylic acid (PAA) dispersing agent (30%), hydroxyethylidene diphosphonic acid (60%) and a sodium gluconate solution, and stirring to obtain a mixed solution. And slowly adding 7.0 parts of 30% sodium hydroxide solution into the mixed solution, and controlling the pH to be 6-7. And adding 14.2 parts of water into the mixed solution, and uniformly stirring to obtain the cement water reducing agent.

Example 2

45 parts of ether type polycarboxylate superplasticizer mother liquor (40%), 0.8 part of hydroxyethylidene diphosphonic acid (60%), 18.3 parts of sodium Polyacrylate (PAAS) dispersant (30%) and 8.3 parts of solid sodium gluconate are respectively weighed. Wherein the sodium gluconate is dissolved by adding equal amount of water. Adding mother liquor of the ether polycarboxylic acid water reducing agent into a stirring tank, stirring, sequentially adding a sodium Polyacrylate (PAAS) dispersing agent (30%), hydroxyethylidene diphosphonic acid (60%) and a sodium gluconate solution, and stirring to obtain a mixed solution. And slowly adding 3.1 parts of 30% sodium hydroxide solution into the mixed solution, and controlling the pH to be 6-7. And adding 16.2 parts of water into the mixed solution, and uniformly stirring to obtain the cement water reducing agent.

Example 3

45 parts of ether type polycarboxylate superplasticizer mother liquor (40%), 0.8 part of hydroxyethylidene diphosphonic acid (60%), 16.4 parts of hydrolytic polymaleic anhydride (HPMA) dispersing agent (30%) and 8.3 parts of solid sodium gluconate are respectively weighed. Wherein the sodium gluconate is dissolved by adding equal amount of water. Adding the ether polycarboxylic acid water reducing agent mother liquor into a stirring tank, stirring, sequentially adding a hydrolyzed polymaleic anhydride (HPMA) dispersing agent (30%), hydroxyethylidene diphosphonic acid (60%) and a sodium gluconate solution, and stirring to obtain a mixed solution. And slowly adding 6.1 parts of 30% sodium hydroxide solution into the mixed solution, and controlling the pH to be 6-7. And adding 15.1 parts of water into the mixed solution, and uniformly stirring to obtain the cement water reducing agent.

Example 4

45 parts of ether type polycarboxylate superplasticizer mother liquor (40%), 0.8 part of hydroxyethylidene diphosphonic acid (60%), 18.3 parts of maleic acid-acrylic acid copolymer (MA/AA) dispersing agent (30%) and 8.3 parts of solid sodium gluconate are respectively weighed. Wherein the sodium gluconate is dissolved by adding equal amount of water. Adding mother liquor of the ether polycarboxylic acid water reducing agent into a stirring tank, stirring, sequentially adding a maleic acid-acrylic acid copolymer (MA/AA) dispersing agent (30%), hydroxyethylidene diphosphonic acid (60%) and a sodium gluconate solution, and stirring to obtain a mixed solution. And slowly adding 3.1 parts of 30% sodium hydroxide solution into the mixed solution, and controlling the pH to be 6-7. And adding 16.2 parts of water into the mixed solution, and uniformly stirring to obtain the cement water reducing agent.

Example 5

45 parts of ether type polycarboxylate superplasticizer mother liquor (40%), 0.8 part of hydroxyethylidene diphosphonic acid (60%), 16.4 parts of polyepoxysuccinic acid (PESA) dispersant (30%) and 8.3 parts of solid sodium gluconate are respectively weighed. Wherein the sodium gluconate is dissolved by adding equal amount of water. Adding the ether polycarboxylic acid water reducing agent mother liquor into a stirring tank, stirring, sequentially adding polyepoxysuccinic acid (PESA) dispersant (30%), hydroxyethylidene diphosphonic acid (60%) and sodium gluconate solution, and stirring to obtain a mixed solution. And slowly adding 7.0 parts of 30% sodium hydroxide solution into the mixed solution, and controlling the pH to be 6-7. And adding 14.2 parts of water into the mixed solution, and uniformly stirring to obtain the cement water reducing agent.

Example 6

45 parts of ether type polycarboxylate superplasticizer mother liquor (40%), 0.8 part of hydroxyethylidene diphosphonic acid (60%), 18.3 parts of polyepoxy sodium succinate (PESAS) dispersant (30%) and 8.3 parts of solid sodium gluconate are respectively weighed. Wherein the sodium gluconate is dissolved by adding equal amount of water. Adding the mother liquor of the ether polycarboxylic acid water reducing agent into a stirring tank, stirring, sequentially adding a polyepoxy sodium succinate (PESAS) dispersing agent (30%), hydroxyethylidene diphosphonic acid (60%) and a sodium gluconate solution, and stirring to obtain a mixed solution. And slowly adding 3.1 parts of 30% sodium hydroxide solution into the mixed solution, and controlling the pH to be 6-7. And adding 16.2 parts of water into the mixed solution, and uniformly stirring to obtain the cement water reducing agent.

Example 7

45 parts of ether type polycarboxylate superplasticizer mother liquor (40%), 0.8 part of hydroxyethylidene diphosphonic acid (60%), 18.3 parts of polyaspartic acid sodium salt (PASPS) dispersant (30%) and 8.3 parts of solid sodium gluconate are respectively weighed. Wherein the sodium gluconate is dissolved by adding equal amount of water. Adding the ether polycarboxylic acid water reducing agent mother liquor into a stirring tank, stirring, sequentially adding a polyaspartic acid sodium (PASPS) dispersing agent (30%), hydroxyethylidene diphosphonic acid (60%) and a sodium gluconate solution, and stirring to obtain a mixed solution. And slowly adding 3.1 parts of 30% sodium hydroxide solution into the mixed solution, and controlling the pH to be 6-7. And adding 16.2 parts of water into the mixed solution, and uniformly stirring to obtain the cement water reducing agent.

Blank control

The same batch of ether type polycarboxylate superplasticizer mother liquor (40%) sold in the market is used as a blank control.

Comparative example 1

45 parts of ether type polycarboxylate superplasticizer mother liquor (40%), 0.8 part of hydroxyethylidene diphosphonic acid (60%) and 8.3 parts of solid sodium gluconate are respectively weighed. Wherein the sodium gluconate is dissolved by adding equal amount of water. Adding the ether polycarboxylic acid water reducing agent mother liquor into a stirring tank, stirring, sequentially adding 60 percent hydroxyethylidene diphosphonic acid and sodium gluconate solution, and stirring to obtain a mixed solution. And slowly adding a 30% sodium hydroxide solution into the mixed solution, and controlling the pH to be 6-7. And adding the balance of water (complementing 100 parts) into the mixed solution, and uniformly stirring to obtain the cement water reducer.

Comparative example 2

45 parts of ether type polycarboxylate superplasticizer mother liquor (40%) and 8.3 parts of solid sodium gluconate are respectively weighed. Wherein the sodium gluconate is dissolved by adding equal amount of water. Adding the mother liquor of the ether polycarboxylic acid water reducing agent into a stirring tank, stirring, adding the sodium gluconate solution, and stirring to obtain a mixed solution. And adding the balance of water (complementing 100 parts) into the mixed solution, and uniformly stirring to obtain the cement water reducer.

Comparative example 3

45 parts of ether type polycarboxylate superplasticizer mother liquor (40%), 16.4 parts of polyacrylic acid dispersant (30%) and 8.3 parts of solid sodium gluconate are respectively weighed. Wherein the sodium gluconate is dissolved by adding equal amount of water. Adding the mother liquor of the ether polycarboxylic acid water reducing agent into a stirring tank, stirring, sequentially adding the polyacrylic acid dispersing agent (30%) and the sodium gluconate solution, and stirring to obtain a mixed solution. And slowly adding a 30% sodium hydroxide solution into the mixed solution to control the pH value to be 6-7. And adding 14.2 parts of water into the mixed solution, and uniformly stirring to obtain the cement water reducing agent.

Comparative example 4

45 parts of ether type polycarboxylate superplasticizer mother liquor (40%), 0.8 part of hydroxyethylidene diphosphonic acid (60%) and 18.3 parts of sodium polyacrylate dispersant (30%) are respectively weighed. Adding the mother liquor of the ether polycarboxylic acid water reducing agent into a stirring tank, stirring, sequentially adding the sodium polyacrylate dispersant (30%) and the hydroxyethylidene diphosphonic acid (60%), and stirring to obtain a mixed solution. And slowly adding a 30% sodium hydroxide solution into the mixed solution to control the pH value to be 6-7. And adding the balance of water (complementing 100 parts) into the mixed solution, and uniformly stirring to obtain the cement water reducer.

Comparative example 5

45 parts of ether type polycarboxylate superplasticizer mother liquor (40%), 8.3 parts of sodium gluconate and 18.3 parts of sodium polyacrylate dispersant (30%) are respectively weighed. Wherein the sodium gluconate is dissolved by adding equal amount of water. Adding the mother liquor of the ether polycarboxylic acid water reducing agent into a stirring tank, stirring, sequentially adding the sodium polyacrylate dispersant (30%) and the sodium gluconate solution, and stirring to obtain a mixed solution. And slowly adding a 30% sodium hydroxide solution into the mixed solution to control the pH value to be 6-7. And adding the balance of water (complementing 100 parts) into the mixed solution, and uniformly stirring to obtain the cement water reducer.

Comparative example 6

45 parts of ether type polycarboxylate superplasticizer mother liquor (40%), 0.8 part of hydroxyethylidene diphosphonic acid (60%) and 16.4 parts of hydrolytic polymaleic acid (HPMA) dispersing agent (30%) are respectively weighed. Adding the ether polycarboxylic acid water reducing agent mother liquor into a stirring tank, stirring, sequentially adding a hydrolyzed polymaleic acid (HPMA) dispersing agent (30%) and hydroxyethylidene diphosphonic acid (60%), and stirring to obtain a mixed liquor. And slowly adding a 30% sodium hydroxide solution into the mixed solution to control the pH value to be 6-7. And adding the balance of water (complementing 100 parts) into the mixed solution, and uniformly stirring to obtain the cement water reducer.

Comparative example 7

45 parts of ether type polycarboxylate superplasticizer mother liquor (40%), 8.3 parts of sodium gluconate and 16.4 parts of hydrolytic polymaleic acid (HPMA) dispersing agent (30%) are weighed respectively. Wherein the sodium gluconate is dissolved by adding equal amount of water. Adding the ether polycarboxylic acid water reducing agent mother liquor into a stirring tank, stirring, sequentially adding hydrolyzed polymaleic acid (HPMA) dispersing agent (30%) and sodium gluconate solution, and stirring to obtain a mixed solution. And slowly adding a 30% sodium hydroxide solution into the mixed solution, and controlling the pH to be 6-7. And adding the balance of water (complementing 100 parts) into the mixed solution, and uniformly stirring to obtain the cement water reducer.

Comparative example 8

45 parts of ether type polycarboxylate superplasticizer mother liquor (40%), 0.8 part of hydroxyethylidene diphosphonic acid (60%) and 18.3 parts of maleic acid-acrylic acid copolymer (MA/AA) dispersing agent (30%) are respectively weighed. Adding mother liquor of the ether polycarboxylic acid water reducing agent into a stirring tank, stirring, sequentially adding a maleic acid-acrylic acid copolymer (MA/AA) dispersing agent (30%) and hydroxyethylidene diphosphonic acid (60%), and stirring to obtain a mixed solution. And slowly adding a 30% sodium hydroxide solution into the mixed solution to control the pH value to be 6-7. And adding the balance of water (complementing 100 parts) into the mixed solution, and uniformly stirring to obtain the cement water reducer.

Comparative example 9

45 parts of ether type polycarboxylate superplasticizer mother liquor (40%), 8.3 parts of sodium gluconate and 18.3 parts of maleic acid-acrylic acid copolymer (MA/AA) dispersing agent (30%) are weighed respectively. Wherein the sodium gluconate is dissolved by adding equal amount of water. Adding the ether polycarboxylic acid water reducer mother liquor into a stirring tank, stirring, sequentially adding a maleic acid-acrylic acid copolymer (MA/AA) dispersing agent (30%) and a sodium gluconate solution, and stirring to obtain a mixed solution. And slowly adding a 30% sodium hydroxide solution into the mixed solution, and controlling the pH to be 6-7. And adding the balance of water (complementing 100 parts) into the mixed solution, and uniformly stirring to obtain the cement water reducer.

Comparative example 10

45 parts of ether type polycarboxylate superplasticizer mother liquor (40%), 0.8 part of hydroxyethylidene diphosphonic acid (60%) and 18.3 parts of polyepoxy sodium succinate (PESAS) dispersing agent (30%) are respectively weighed. Adding the ether polycarboxylic acid water reducing agent mother liquor into a stirring tank, stirring, sequentially adding a polyepoxy sodium succinate (PESAS) dispersing agent and hydroxyethylidene diphosphonic acid (60%), and stirring to obtain a mixed solution. And slowly adding a 30% sodium hydroxide solution into the mixed solution to control the pH value to be 6-7. And adding the balance of water (complementing 100 parts) into the mixed solution, and uniformly stirring to obtain the cement water reducer.

Comparative example 11

45 parts of ether type polycarboxylate superplasticizer mother liquor (40%), 8.3 parts of sodium gluconate and 18.3 parts of polyepoxy sodium succinate (PESAS) dispersing agent (30%) are weighed respectively. Wherein the sodium gluconate is dissolved by adding equal amount of water. Adding the ether polycarboxylic acid water reducing agent mother liquor into a stirring tank, stirring, sequentially adding a polyepoxy sodium succinate (PESAS) dispersant (30%) and a sodium gluconate solution, and stirring to obtain a mixed solution. And slowly adding a 30% sodium hydroxide solution into the mixed solution, and controlling the pH to be 6-7. And adding the balance of water (complementing 100 parts) into the mixed solution, and uniformly stirring to obtain the cement water reducer.

Comparative example 12

45 parts of ether type polycarboxylate superplasticizer mother liquor (40%), 0.8 part of hydroxyethylidene diphosphonic acid (60%) and 18.3 parts of polyaspartic acid sodium (PASPS) dispersing agent (30%) are respectively weighed. Adding the ether polycarboxylic acid water reducing agent mother liquor into a stirring tank, stirring, sequentially adding a polyaspartic acid sodium (PASPS) dispersing agent and hydroxyethylidene diphosphonic acid (60%), and stirring to obtain a mixed solution. And slowly adding a 30% sodium hydroxide solution into the mixed solution, and controlling the pH to be 6-7. And adding the balance of water (complementing 100 parts) into the mixed solution, and uniformly stirring to obtain the cement water reducer.

Comparative example 13

45 parts of ether type polycarboxylate superplasticizer mother liquor (40%), 8.3 parts of sodium gluconate and 18.3 parts of polyaspartic acid sodium salt (PASPS) dispersing agent (30%) are respectively weighed. Wherein the sodium gluconate is dissolved by adding equal amount of water. Adding the ether polycarboxylic acid water reducing agent mother liquor into a stirring tank, stirring, sequentially adding a polyaspartic acid sodium salt (PASPS) dispersing agent and a sodium gluconate solution, and stirring to obtain a mixed solution. And slowly adding a 30% sodium hydroxide solution into the mixed solution, and controlling the pH to be 6-7. And adding the balance of water (complementing 100 parts) into the mixed solution, and uniformly stirring to obtain the cement water reducer.

The detection method comprises the following steps:

the performance of the water reducing agents prepared in the examples and the comparative examples in concrete is detected, and a coupon test is adopted in a corrosion test, and the tests are carried out under the same conditions. Wherein: the cementing material adopts P.O42.5 reference cement, the cement is the reference cement P.O42.5, the sand is ISO standard sand, and the water is distilled water. The water reducing agent product accounting for 1.5 percent (folded solid amount) of the total weight of the cementing material is added into concrete, performance indexes such as initial and 1-hour cement neat paste fluidity, water reducing rate, setting time, compressive strength, corrosion rate and the like are measured according to the method specified in GB/T8077-2012 test method for concrete admixture homogeneity, GB/T17671-1999 test method for cement mortar strength (ISO method), GB/T18175-2000 test method for water treatment corrosion inhibition performance by rotating hanging sheet method, and the detection results are shown in the following table.

TABLE 1 Experimental results of neat paste fluidity, bleeding rate and water reducing rate of cement water reducer

TABLE 2 Experimental results of setting time, compressive strength and corrosion rate of cement water reducer

From the results in table 1, it is known that: the net slurry fluidity and the compressive strength of the cement samples of examples 1-7 are obviously increased compared with those of the blank cement samples and comparative examples 1-13, which shows that the water reducing agent prepared in examples 1-7 has obvious synergistic effect and obviously improves the early strength and the later strength of the cement; compared with a blank test, a single-component test and a two-component test, the initial fluidity is obviously increased, the loss is basically avoided within 1h, the water reducing effect of the original polycarboxylic acid water reducing agent is basically enhanced, a good synergistic effect is also shown, and the adaptability of the water reducing agent is good. From the results in table 2, it is known that: the initial setting time and the final setting time of the cement samples in the examples 1 to 7 are greatly increased, which shows that the water reducing agent prepared in the examples 1 to 7 has good retarding effect and is more beneficial to long-distance transportation and long-distance pumping of commercial rammed concrete; the corrosion test also fully shows that the multi-component water treatment agent has obvious corrosion inhibition effect when being matched with the water reducing agent.

In a word, the cement water reducer provided by the invention has good net slurry fluidity effect, and obviously improves the strength of cement; the cement water reducing rate performance is excellent. And the water reducing agent has wide adaptability to water quality and obvious corrosion inhibition on building steel.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims (6)

1. A corrosion inhibition slow setting synergistic type cement water reducer is characterized by comprising the following components in parts by weight: 10-30 parts of an ether type polycarboxylate water reducer, 0.1-1 part of hydroxyethylidene diphosphonic acid, 2-6 parts of a polycarboxylate dispersant, 3-10 parts of sodium gluconate, and adjusting the pH value to 6-7 by sodium hydroxide, and adding water to adjust the concentration of the water reducer; wherein the weight parts of the ether polycarboxylic acid water reducing agent, the hydroxyethylidene diphosphonic acid, the polycarboxylic acid dispersing agent and the sodium gluconate are calculated by dry weight.

2. The corrosion-inhibiting slow-setting synergistic cement water reducer as claimed in claim 1, which is characterized by comprising the following components in parts by weight: 15-20 parts of ether type polycarboxylic acid water reducing agent, 0.4-0.5 part of hydroxyethylidene diphosphonic acid, 4-6 parts of polycarboxylic acid dispersing agent, 7-9 parts of sodium gluconate, and 100 parts of water for supplementing, wherein the pH value of the sodium hydroxide is adjusted to 6-7.

3. The corrosion-inhibition slow-setting synergistic type cement water reducer of claim 1, which is characterized in that the ether type polycarboxylate water reducer is ether type polycarboxylate water reducer mother liquor with the concentration of 30-50% or is prepared by adding water into a solid ether type polycarboxylate water reducer to prepare the ether type polycarboxylate water reducer mother liquor with the concentration of 30-50%.

4. The corrosion-inhibiting slow-setting synergistic water reducer for cement of claim 3, wherein the ether type polycarboxylate water reducer is a copolymer of methyl propenyl polyoxyethylene ether or isoamylene alcohol polyoxyethylene ether and acrylic acid or acrylic acid derivatives as monomers.

5. The water reducer of cement of any one of claims 1 to 4, wherein the polycarboxylic acid dispersant comprises one or more of polyacrylic acid, sodium polyacrylate, hydrolyzed polymaleic anhydride, maleic acid-acrylic acid copolymer, polyepoxysuccinic acid sodium, polyaspartic acid and polyaspartic acid sodium.

6. The preparation method of the corrosion-inhibition slow-setting synergistic type cement water reducer as claimed in claim 5, is characterized by comprising the following steps:

1) weighing the raw materials according to the parts by weight, and respectively adding water to dissolve sodium gluconate and sodium hydroxide to prepare solutions with proper concentrations;

2) sequentially adding an ether polycarboxylic acid water reducing agent, hydroxyethylidene diphosphonic acid, a polycarboxylic acid dispersing agent and a sodium gluconate solution into a stirring tank under stirring, and uniformly stirring to obtain a mixed solution;

3) slowly adding a sodium hydroxide solution into the mixed solution obtained in the step 2), and adjusting the pH value to 6-7;

4) and (3) adding water into the mixed solution obtained in the step 3), and uniformly stirring to obtain the cement water reducer.