CN111377639B - Water-based cement hydration rate regulating material and preparation method thereof - Google Patents

Abstract

The invention provides an aqueous cement hydration rate regulating material and a preparation method thereof, wherein the aqueous cement hydration rate regulating material is a derivative obtained by reacting aldehyde groups of reducing sugars with amino groups of amino reactants; the preparation method is a simple aqueous solution reaction method, the aqueous solution obtained by the method has a better cement hydration rate regulation and control effect on the premise of not influencing the final total heat release of the cement, so that the cement hydration heat release is more stable, and meanwhile, the preparation process is simple, the drying of solid finished products and the use of organic solvents are reduced, and the preparation method accords with the theme of green chemistry.

Description

Water-based cement hydration rate regulating material and preparation method thereof

Technical Field

The invention belongs to the field of concrete admixtures, and particularly relates to an aqueous cement hydration rate regulating material and a preparation method thereof.

Background

Cement hydration can give off a large amount of heat, and when the hydration rate of cement in concrete is not controlled, a large amount of heat can be given off in a short time. If the heat can not be dissipated in time, the central temperature of the concrete can be increased rapidly, so that the concrete member has great internal and external temperature difference, and the volume change of the concrete is caused. When the concrete is under the constrained condition, the tensile stress generated by temperature deformation exceeds the tensile strength of the concrete, so that temperature cracks are generated, and great harm is caused to the durability and safety of engineering.

In order to reduce the generation of temperature cracks, the method not only improves the heat dissipation efficiency, but also regulates and controls the hydration of the cement, reduces the hydration rate of the cement, and further reduces the temperature peak, and is also an effective method.

Such materials having the function of regulating the hydration rate of cement have been widely studied.

CN104710131A is coated with insoluble polymer to modify dextrin, so as to obtain a hydration rate regulating material which can effectively reduce the hydration rate in an acceleration period and a deceleration period and hardly affect the hydration induction period of cement.

CN104628296A is prepared by reacting starch with an acid catalyst and a cross-linking agent, and then reacting with alkenyl succinic anhydride, thereby preparing a regulating material which has a spatial network structure, high acid-base resistance and high shearing capacity and can effectively reduce hydration heat release rate.

CN105060762B discloses a preparation method of a starch-based cement hydration rate regulating material, which is characterized in that starch is completely gelatinized and then is added with enzyme for hydrolysis, ethanol is added for precipitation, filtration and pulverization to prepare dextrin, and the dextrin is continuously reacted with an emulsifier to prepare the starch-based cement hydration rate regulating material with hydration regulating effect.

The products prepared by the above patents are all solid products, and are not uniformly stirred in the construction process, so that the hydration regulation effect is greatly influenced. Therefore, designing the cement hydration rate regulating material in the form of the water aqua is a feasible way.

The saccharide is a retarder widely used, can effectively prolong the setting time of concrete and improve the construction efficiency. The saccharides mainly prolong the induction period of cement hydration, but have little influence on the acceleration period or deceleration period of cement hydration, and thus have no effect on weakening the peak of hydration heat release rate. The action mechanism of the saccharide retarder is generally considered to be that hydroxyl groups on the saccharide are adsorbed on the surfaces of cement particles and hydrated products or the hydroxyl groups and water molecules form a stable solvated water film through hydrogen bonds, so that the hydration process of the cement is inhibited.

Disclosure of Invention

The purpose of the invention is as follows: in order to overcome the defects of the prior art, the invention provides an aqueous cement hydration rate regulating material and a preparation method thereof.

The applicant found that: when the aldehyde group and the amino group of the saccharide react, the density of the electron cloud of the saccharide hydroxyl group can be effectively changed, so that the hydrogen bonding effect of the saccharide hydroxyl group is reduced. On the other hand, the amino reactant has stronger oleophylic groups (such as long-chain alkyl), can effectively reduce the hydrophilicity of sugar, provides larger steric hindrance, and reduces the adsorption of hydroxyl on the sugar on the surface of cement particles and the surface of hydration products, thereby achieving the effect of slowing down the hydration of cement.

The invention provides an aqueous cement hydration rate regulating material, which is an aqueous solution of a derivative obtained by reacting reducing sugar with amino.

The reducing sugar is one or more of glucose, fructose, galactose, lactose and maltose.

The amino reactant is one or more of ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, ethylenediamine, propylenediamine, butylenediamine, pentylenediamine, hexyldiamine, heptylenediamine, octylenediamine, nonylenediamine, decylamine, diethylenetriamine, triethylenetetramine, triethylenediamine, tetraethylenepentamine and polyethylenepolyamine.

Preferably: one or more of nonanamine, decylamine, nonanediamine, decanediamine, polyethylene polyamine.

The preparation method of the water aqua cement hydration rate regulating material comprises the following steps:

(1) dissolving reducing sugar and amino compound in water to obtain solution with solute concentration of 10-50 wt%;

(2) adding a catalyst, heating to 40-70 ℃, and keeping the temperature for 2-5h to obtain the water aqua cement hydration rate regulating material.

The catalyst is one of acetic acid, phosphoric acid, citric acid and lactic acid.

Has the advantages that: the water-based cement hydration rate regulating material provided by the invention is prepared by reacting reducing sugar and amino compound, and has the advantages of simple preparation process and low cost. Compared with a solid product, the process reduces the link of drying and the production cost; the production process takes water as a medium, and the process is green and environment-friendly. Meanwhile, the water aqua cement hydration rate regulating material provided by the invention has good stability, is convenient to transport, carry and construct and use, and avoids the defect of unobvious hydration regulating effect caused by uneven stirring. In addition, the water aqua cement hydration rate regulating material provided by the invention has little influence on hydration setting time (induction period), but can effectively reduce the hydration rate in an acceleration period and a deceleration period, thereby reducing the temperature peak of concrete and reducing the probability of temperature crack generation.

Detailed Description

In order to better understand the invention, the following examples are given for further illustration of the invention, but the invention is not limited to the scope of the examples.

In the examples of the present invention, no particular description is given, and all the cements used are 52.5 cement for small open-field. The cement hydration heat release rate is measured by using a TAM AIR isothermal calorimeter of the company TA of America, the test temperature is 20 ℃, the test piece is pure slurry, the water-gel ratio is 0.4, and the addition percentage of the cement hydration regulation material is relative to the mass of the gel material. The maximum heat release rate peak value reduction amplitude is used as a judgment standard of the performance of the hydration regulation material, and the larger the heat release rate peak value reduction amplitude under the same condition is, the better the performance of the cement hydration regulation material is. The test method is described in GB/T2022-1980.

In the embodiment of the invention, the concrete mixing proportion adopted in the test is as follows: 320kg/m cement³80kg/m of fly ash³753kg/m river sand³1084kg/m coarse aggregate³160kg/m of water³The fly ash is first-grade fly ash, the sand is medium sand with fineness modulus of 2.6, and the stones are continuous graded broken stones with particle size of 5-20 mm.

The concrete adiabatic temperature rise is measured BY using a BY-ATC/JR adiabatic temperature rise instrument of Bo Yuan science and technology development Limited company in Zhoushan, and the initial temperature of the adiabatic temperature rise test is 15 ℃.

TABLE 1 concrete base mix ratio (kg/m)³)

The concrete compressive strength and the setting time are executed according to GB/T50081-2002 Standard for testing the mechanical properties of common concrete.

Example 1

The preparation of the water aqua cement hydration rate regulating material comprises the following steps: adding 100g of glucose (0.56mol) and 200g of ethylenediamine (3.3mol) into 600ml of water to prepare a 33 wt% solution, adding phosphoric acid, heating to 50 ℃, and keeping the temperature for 2h to obtain the water-based cement hydration rate regulating material product.

Example 2

The preparation of the water aqua cement hydration rate regulating material comprises the following steps: adding 100g of fructose (0.56mol) and 100g of decylamine (0.63mol) into 600ml of water to prepare a 25 wt% solution, adding lactic acid, heating to 40 ℃, and keeping the temperature for 4 hours to obtain the water agent cement hydration rate regulating material product.

Example 3

The preparation of the water aqua cement hydration rate regulating material comprises the following steps: 100g of galactose (0.56mol) and 300g of decamethylene diamine (1.74mol) are added into 400ml of water to prepare a 50wt% solution, citric acid is added, the temperature is raised to 60 ℃, and the temperature is kept for 3h, so that the water-based cement hydration rate regulating material product can be obtained.

Example 4

The preparation of the water aqua cement hydration rate regulating material comprises the following steps: 100g of lactose (0.29mol) and 400g of nonanamine (2.79mol) are added into 600ml of water to prepare a 46 wt% solution, acetic acid is added, the temperature is raised to 70 ℃, and the temperature is kept for 5 hours, so that the water aqua cement hydration rate regulating material product can be obtained.

Example 5

The preparation of the water aqua cement hydration rate regulating material comprises the following steps: adding 100g of maltose (0.28mol) and 150g of polyethylene polyamine into 600ml of water to prepare a 29.4 wt% solution, adding lactic acid, heating to 65 ℃, and keeping the temperature for 4.5 hours to obtain the water agent cement hydration rate regulating material product.

Example 6

The preparation of the water aqua cement hydration rate regulating material comprises the following steps: adding 50g of glucose (0.28mol),50g of fructose (0.28mol) and 100g of nonane diamine (0.63mol) into 1800ml of water to prepare a 10 wt% solution, adding acetic acid, heating to 45 ℃, and keeping the temperature for 2.5 hours to obtain the water-based cement hydration rate regulating material product.

Example 7

The preparation of the water aqua cement hydration rate regulating material comprises the following steps: adding 60g of lactose (0.18mol), 30g of galactose (0.18mol), 10g of fructose (0.056mol), 50g of nonanamine (0.34mol) and 50g of decylamine (0.32mol) into 300ml of water to prepare a 40 wt% solution, adding phosphoric acid, heating to 66 ℃, and preserving the temperature for 3.5 hours to obtain the water-based cement hydration rate regulating material product.

Example 8

The preparation of the water aqua cement hydration rate regulating material comprises the following steps: adding 50g of fructose (0.28mol),50g of galactose (0.28mol),50g of diethylenetriamine (0.58mol), 50g of triethylene tetramine (0.34mol) and 50g of tetraethylenepentamine (0.32mol) into 750ml of water to prepare a 25 wt% solution, adding citric acid, heating to 55 ℃, and preserving the temperature for 4.8 hours to obtain the water agent cement hydration rate regulating material product.

Comparative example 1

Datum

Comparative example 2

40 wt% glucose and ethylenediamine mixed solution (glucose and ethylenediamine mass ratio 1:1)

TABLE 2

The cement hydration regulation and control effect of the product is the standard of judgment by taking the reduction amplitude of the maximum hydration rate peak value as a standard, and generally, the larger the reduction amplitude is, the better the hydration regulation and control effect is. The examples all show excellent hydration regulation effects.

It can be seen from table 2 that various aqueous hydration rate regulating materials with hydration regulating effects are prepared by performing amination modification on reducing sugar.

Claims (3)

1. The application of the aminated and modified reducing sugar is characterized in that the aminated and modified reducing sugar is used as a hydration rate regulating material of water-based cement; the cement hydration rate regulating material is a derivative aqueous solution obtained by reacting reducing sugar and amino reactants under the action of a catalyst, and is obtained by reacting at 40-70 ℃ after the catalyst is added;

the reducing sugar is one or more of glucose, fructose, galactose, lactose and maltose;

the amino reactant is one or more of ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, ethylenediamine, propylenediamine, butylenediamine, pentylenediamine, hexyldiamine, heptylenediamine, octylenediamine, nonylenediamine, decylamine, diethylenetriamine, triethylenetetramine, triethylenediamine, tetraethylenepentamine and polyethylenepolyamine;

the catalyst is one of acetic acid, phosphoric acid, citric acid and lactic acid.

2. The use of claim 1, wherein the amino reactant is one or more of nonanamine, decylamine, nonanediamine, decanediamine, polyethylenepolyamines.

3. A preparation method of an aqueous cement hydration rate regulating material is characterized by comprising the following steps:

(1) dissolving reducing sugar and amino reactant in water to obtain solution with solute concentration of 10-50 wt%;

(2) adding a catalyst, reacting at 40-70 ℃, and keeping the temperature for 2-5h to obtain the water-based cement hydration rate regulating material;

the cement hydration rate regulating material is a derivative aqueous solution obtained by reacting reducing sugar and amino reactants under the action of a catalyst;

the reducing sugar is one or more of glucose, fructose, galactose, lactose and maltose;

the amino reactant is one or more of ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, ethylenediamine, propylenediamine, butylenediamine, pentylenediamine, hexyldiamine, heptylenediamine, octylenediamine, nonylenediamine, decylamine, diethylenetriamine, triethylenetetramine, triethylenediamine, tetraethylenepentamine and polyethylenepolyamine;

the catalyst is one of acetic acid, phosphoric acid, citric acid and lactic acid.