Preparation method of delayed coagulation type water reducing agent

Abstract

The invention discloses a preparation method of a delayed coagulation type water reducing agent, and mainly relates to the field of concrete admixtures. The preparation method comprises the followingsteps: adding metered water, a formula amount of sulfanilic acid or sodium sulfanilate, salicylic acid or sodium salicylate and glucose into a four-neck flask, adjusting to be alkaline by using sodiumhydroxide, heating to 90 DEG C, starting to dropwise add a formaldehyde solution, and reacting at a constant temperature until the end. The method has the beneficial effects that materials with different functional groups are used for condensation reaction, and the delayed coagulation type water reducing agent has the characteristics of high water reduction, controllable retarding time, good adaptability to sandstone materials and the like.

Description

technical field

[0001] The invention relates to the field of concrete admixtures, in particular to a method for preparing a retarding water reducer. Background technique

[0002] At present, the water reducing agents widely used at home and abroad mainly include polycarboxylic acid, naphthalene sulfonate, melamine, sulfamic acid, and aliphatic water reducing agent. Polycarboxylic acid water reducing agent is a free radical polymerization reaction carried out by unsaturated monomers. The other four water reducers are polymer formaldehyde condensation polymers of sulfonic acids. In order to meet the actual engineering needs, various water reducing agents are usually compounded with retarders when they are used. Commonly used retarders include sugars, hydroxycarboxylic acids, etc., all of which have hydroxyl groups or functional groups with both hydroxyl and carboxyl groups. Although the compound retarder can solve the problem of short concrete setting time in most cases, it ...

Examples

Embodiment 1

[0030] Embodiment 1: A kind of preparation method of retarding type superplasticizer

[0031] Add 471 grams of water, 163 grams of p-aminobenzenesulfonic acid, 150 grams of salicylic acid, and 20 grams of glucose in a four-necked flask equipped with a reflux condenser, agitator, and a thermometer, and neutralize to a pH of 10 with sodium hydroxide. The temperature was raised to 90°C, and 180 grams of formaldehyde solution was added dropwise for 4 hours, followed by a constant temperature reaction for 5 hours.

Embodiment 2

[0032] Embodiment 2: A kind of preparation method of retarding type superplasticizer

[0033] Add 575 grams of water, 220 grams of sodium sulfanilate, 171 grams of sodium salicylate, and 30 grams of glucose into a four-necked flask equipped with a reflux condenser, agitator, and a thermometer, and neutralize with sodium hydroxide until the pH is 10. Raise the temperature to 90°C, add 180 grams of formaldehyde solution dropwise for 4 hours, and react at constant temperature for 5 hours.

Embodiment 3

[0034] Embodiment 3: performance test

[0035] 1. Determination of the fluidity of cement paste and the setting time of cement paste: the samples synthesized in the above examples are tested according to GB / T8077-2012 "Concrete Admixture Homogeneity Test Method" and "Cement Standard Consistency Water Consumption, Setting Time , Stability Test Method" to test, the dosage of the retarded water reducer prepared by the present invention is 1.8%, the results are shown in Table 1.

[0036] Table 1

[0037]

[0038] Note: "--" in the table means no pulp fluidity.

[0039] It can be seen from the above test data that the retarded water reducer synthesized by the present invention has a good retarding effect.

[0040] 2. Concrete performance test: Test with reference to GB8076-2008 "Concrete Admixtures", the results are shown in Table 2.

[0041] Table 2

[0042]

[0043] It can be seen from the above test data that the retarded water reducer synthesized by the present invent...

technical field

[0001] The invention relates to the field of concrete admixtures, in particular to a method for preparing a retarding water reducer. Background technique

[0002] At present, the water reducing agents widely used at home and abroad mainly include polycarboxylic acid, naphthalene sulfonate, melamine, sulfamic acid, and aliphatic water reducing agent. Polycarboxylic acid water reducing agent is a free radical polymerization reaction carried out by unsaturated monomers. The other four water reducers are polymer formaldehyde condensation polymers of sulfonic acids. In order to meet the actual engineering needs, various water reducing agents are usually compounded with retarders when they are used. Commonly used retarders include sugars, hydroxycarboxylic acids, etc., all of which have hydroxyl groups or functional groups with both hydroxyl and carboxyl groups. Although the compound retarder can solve the problem of short concrete setting time in most cases, it ...

Examples

Embodiment 1

[0030] Embodiment 1: A kind of preparation method of retarding type superplasticizer

[0031] Add 471 grams of water, 163 grams of p-aminobenzenesulfonic acid, 150 grams of salicylic acid, and 20 grams of glucose in a four-necked flask equipped with a reflux condenser, agitator, and a thermometer, and neutralize to a pH of 10 with sodium hydroxide. The temperature was raised to 90°C, and 180 grams of formaldehyde solution was added dropwise for 4 hours, followed by a constant temperature reaction for 5 hours.

Embodiment 2

[0032] Embodiment 2: A kind of preparation method of retarding type superplasticizer

[0033] Add 575 grams of water, 220 grams of sodium sulfanilate, 171 grams of sodium salicylate, and 30 grams of glucose into a four-necked flask equipped with a reflux condenser, agitator, and a thermometer, and neutralize with sodium hydroxide until the pH is 10. Raise the temperature to 90°C, add 180 grams of formaldehyde solution dropwise for 4 hours, and react at constant temperature for 5 hours.

Embodiment 3

[0034] Embodiment 3: performance test

[0035] 1. Determination of the fluidity of cement paste and the setting time of cement paste: the samples synthesized in the above examples are tested according to GB / T8077-2012 "Concrete Admixture Homogeneity Test Method" and "Cement Standard Consistency Water Consumption, Setting Time , Stability Test Method" to test, the dosage of the retarded water reducer prepared by the present invention is 1.8%, the results are shown in Table 1.

[0036] Table 1

[0037]

[0038] Note: "--" in the table means no pulp fluidity.

[0039] It can be seen from the above test data that the retarded water reducer synthesized by the present invention has a good retarding effect.

[0040] 2. Concrete performance test: Test with reference to GB8076-2008 "Concrete Admixtures", the results are shown in Table 2.

[0041] Table 2

[0042]

[0043] It can be seen from the above test data that the retarded water reducer synthesized by the present invent...

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