A low-carbon cement concrete steam-curing enhancer and its application

Abstract

The invention discloses a kind of low carbon cement concrete steam curing strengthening agent and application thereof, the present invention screens and obtains a kind of strengthening agent for high iron phase cement clinker, and the strengthening agent can be adapted to steam curing process, and quickly improves the early strength and ultimate strength of concrete member.The strengthening agent includes 0.5-5 parts of nano-calcium carbonate, 0.02-0.2 parts of alcoholamine additives, 0-2 parts of inorganic salts, 0.01-0.2 parts of surfactants; Alcoholamine additives are selected from diethanol monoisopropanolamine, monoethanol diisopropanolamine, triethanolamine, triisopropanolamine, and inorganic salts are selected from aluminum sulfate, sodium metaaluminate, sodium chloride, sodium sulfate, calcium chloride, and the surfactant includes at least one of polydimethylsiloxane, fluorosilicone, and ethylene glycol siloxane.The present invention reverses the effect decline problem caused by the combination of alcoholamine strengthening agent and steam curing process by adjusting the temperature system and strengthening agent component before steam curing, so that strengthening agent and steam curing process produce synergistic effect.

Description

Technical Field

[0001] The present invention relates to a concrete reinforcing agent and application thereof, in particular to a low-carbon cement concrete steam-curing reinforcing agent and application thereof in concrete steam-curing preparation. Background Art

[0002] Compared to ordinary Portland cement clinker, high-iron cement clinker can reduce carbon dioxide emissions during the firing process, achieving low-carbon and energy-saving effects. However, excessive iron content in high-iron cement clinker can reduce the early strength of the clinker.

[0003] Steam curing, also known as steam curing, can improve the early strength of concrete components. Steam curing involves pre-curing poured concrete components in saturated steam at a relative humidity of 90% or higher and a temperature of 60-80°C for 5-8 hours. Steam curing typically rapidly increases the early strength of concrete.

[0004] Adding concrete strengtheners during the cement clinker forming process can effectively improve the early strength of cement clinker. However, existing strengtheners (such as some alcoholamines and inorganic salts) are not suitable for steam curing processes. After adding these strengtheners to cement clinker under steam curing conditions, the early and final strength of concrete will decrease. Therefore, how to screen and obtain a strengthener composition for preparing high-strength concrete by steam curing high-iron phase cement clinker has become a technical problem that needs to be solved urgently. Summary of the Invention

[0005] Objectives of the invention: This invention aims to provide a low-carbon cement concrete steam-curing enhancer to improve the strength of concrete during steam curing. Another objective of the invention is to propose the use of a low-carbon cement concrete steam-curing enhancer in the preparation of steam-cured concrete, thereby addressing the problem of how to prepare concrete components through steam curing.

[0006] Technical solution: The low-carbon cement concrete steam-curing enhancer described in the present invention comprises the following components in parts by weight: 0.5-5 parts of nano-calcium carbonate, 0.02-0.2 parts of an alcoholamine additive, 0-2 parts of an inorganic salt, and 0.01-0.2 parts of a surfactant; the alcoholamine additive comprises at least one of diethanol monoisopropanolamine, monoethanol diisopropanolamine, triethanolamine, and triisopropanolamine; the inorganic salt comprises at least one of aluminum sulfate, sodium metaaluminate, sodium chloride, sodium sulfate, and calcium chloride; and the surfactant comprises at least one of polydimethylsiloxane, fluorosilicone, and ethylene glycol siloxane.

[0007] In some embodiments, the concrete steam curing enhancer comprises the following components in parts by weight: 0.08-0.3 parts of aluminum sulfate, 0.02-0.06 parts of an alcoholamine additive, and 0-0.03 parts of sodium chloride; the alcoholamine additive is composed of 0.01-0.03 parts of diethanol monoisopropanolamine and 0.01-0.03 parts of monoethanol diisopropanolamine;

[0008] In some embodiments, the concrete steam curing enhancer comprises the following components in parts by weight: 0.08-0.3 parts of sodium metaaluminate, 0.02-0.06 parts of an alcoholamine additive, and 0-0.03 parts of sodium chloride; the alcoholamine additive is composed of 0.01-0.03 parts of diethanol monoisopropanolamine and 0.01-0.03 parts of monoethanol diisopropanolamine;

[0009] In some embodiments, the concrete steam curing enhancer comprises the following components in parts by weight: 0.02-0.06 parts of an alcoholamine additive and 0.03 parts of sodium chloride; the alcoholamine additive is composed of 0.01-0.03 parts of diethanol monoisopropanolamine and 0.01-0.03 parts of monoethanol diisopropanolamine;

[0010] In some embodiments, the concrete autoclaving enhancer comprises the following components in parts by weight: 0.08-0.3 parts of aluminum sulfate, 0.03 parts of triethanolamine, and 0.03 parts of sodium chloride.

[0011] The present invention further uses the low-carbon cement concrete steam curing enhancer to prepare concrete by steam curing, and the specific method includes the following steps:

[0012] (1) dissolving an alcohol amine additive, an inorganic salt, and a surfactant in water to obtain an enhancement solution;

[0013] (2) Grinding gypsum, limestone powder, and cement clinker together to obtain cement, mixing cement, nano calcium carbonate, and aggregate uniformly, and adding reinforcing liquid to mix to obtain concrete or mortar;

[0014] (3) After the concrete is formed, it is allowed to stand and undergo standard curing, followed by steam curing, and then standard curing and water curing are carried out in sequence to obtain a concrete component.

[0015] Preferably, in step (1), the enhancement solution contains diethanol monoisopropanolamine with a final concentration of 0.025-0.05wt%, monoethanol diisopropanolamine with a final concentration of 0.025-0.05wt%, aluminum sulfate with a final concentration of 0.2-0.5wt%, sodium metaaluminate with a final concentration of 0.2-0.5wt%, and fluorosilicone with a final concentration of 0.01-0.25wt%;

[0016] Or the enhancement solution contains sodium chloride with a final concentration of 0.01-0.05wt%, diethanol monoisopropanolamine with a final concentration of 0.025-0.05wt%, monoethanol diisopropanolamine with a final concentration of 0.025-0.05wt%, and fluorosilicone with a final concentration of 0.01-0.25wt%;

[0017] Or the enhancement solution contains triethanolamine with a final concentration of 0.025-0.05 wt%, aluminum sulfate with a final concentration of 0.2-0.5 wt%, sodium chloride with a final concentration of 0.01-0.05 wt%, and fluorosilicone with a final concentration of 0.01-0.25 wt%.

[0018] Preferably, in step (2), the cement clinker contains at least 60 wt% of high iron phase cement clinker.

[0019] Preferably, in step (2), the cement clinker consists of 0-30 parts by weight of Portland cement clinker and 60-90 parts by weight of high iron phase cement clinker.

[0020] Preferably, the components of the high iron phase cement clinker are:

[0021] C3A≤1.5wt%, 19.0±1.0wt%C4AF, 53.0±1.0wt%C3S, 23.0±1.0wt%C2S, KH

[0022] 0.880±0.01, SM was 2.10±0.10, and IM was 0.70±0.10.

[0023] Preferably, in step (2), the mass ratio of gypsum: limestone: cement clinker is 3-7: 3-7: 86-94; when preparing concrete or mortar, the mass ratio of reinforcing liquid: nano calcium carbonate: cement: aggregate is 100-270: 5-50: 250-500: 900-2000.

[0024] Preferably, in step (3), the standing time is 1-4 hours; and the steaming treatment condition is heating to 80-90° C. and steaming for 2-8 hours.

[0025] Preferably, the method of standard curing and water curing is standard curing for 24 hours and then water curing for 28 days.

[0026] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:

[0027] The present invention screens out a reinforcing agent for high-iron phase cement clinker, which can be adapted to the steam curing process and quickly improve the early strength and final strength of concrete components.

[0028] The present invention reverses the strength reduction problem caused by the combination of an alcoholamine enhancer and a steam curing process by adjusting the standing time and ratio before steam curing, thereby achieving a synergistic effect between the enhancer and the steam curing process. The high-iron phase cement concrete components prepared by the present invention can achieve a strength of 24.5 MPa after 3 days. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described below.

[0030] Example 1: A low-carbon cement concrete steam-cured enhancer, comprising the following components in parts by weight: 20 parts of nano-calcium carbonate, 0.08 parts of aluminum sulfate, 0.08 parts of sodium metaaluminate, 0.01 parts of diethanol monoisopropanolamine, 0.01 parts of monoethanol diisopropanolamine, and 0.01 parts of fluorosilicone;

[0031] The above-mentioned reinforcing agent is used to prepare a concrete component in the following manner:

[0032] (1) dissolving aluminum sulfate, sodium aluminate, diethanol monoisopropanolamine, monoethanol diisopropanolamine, and fluorosilicone in water to obtain an enhancement solution, ensuring that the final concentration of diethanol monoisopropanolamine in the enhancement solution is 0.025 wt %, the final concentration of monoethanol diisopropanolamine is 0.025 wt %, the final concentration of aluminum sulfate is 0.2 wt %, the final concentration of sodium aluminate is 0.2 wt %, and the final concentration of fluorosilicone is 0.025 wt %;

[0033] (2) Gypsum, limestone powder, and cement clinker are ground together in a mass ratio of 5:5:90 to obtain cement. 375 parts by weight of cement, 20 parts by weight of nano-calcium carbonate, and 1000 parts by weight of standard sand are uniformly mixed, and then 150 parts by weight of reinforcing liquid are added and mixed to obtain mortar. The cement clinker is entirely high-iron phase cement clinker, and the composition of the high-iron phase cement clinker is as follows:

[0034]

[0035] (3) After the mortar is poured into the mold and formed, it is left to stand in a standard curing box for 2 hours, and then moved to the steam curing equipment for steam curing with the mold. The steam curing conditions are to heat the temperature to 90℃ and steam curing for 4 hours. After the steam curing is completed, standard curing is performed for 24 hours, and then water curing is performed for 28 days to obtain the mortar specimens.

[0036] Example 2: A low-carbon cement concrete steam-cured enhancer, comprising the following components in parts by weight: 0.5 parts of nano-calcium carbonate, 0.3 parts of aluminum sulfate, 0.3 parts of sodium metaaluminate, 0.03 parts of diethanol monoisopropanolamine, 0.03 parts of monoethanol diisopropanolamine, and 0.01 parts of ethylene glycol siloxane;

[0037] The above-mentioned reinforcing agent is used to prepare a concrete component in the following manner:

[0038] (1) dissolving aluminum sulfate, sodium aluminate, diethanol monoisopropanolamine, and monoethanol diisopropanolamine in water to obtain a reinforcing solution, ensuring that the final concentration of diethanol monoisopropanolamine in the reinforcing solution is 0.05 wt %, the final concentration of monoethanol diisopropanolamine is 0.05 wt %, the final concentration of aluminum sulfate is 0.5 wt %, the final concentration of sodium aluminate is 0.5 wt %, and the final concentration of ethylene glycol siloxane is 0.017 wt %;

[0039] (2) Gypsum, limestone powder and cement clinker are ground together in a mass ratio of 3:3:94 to obtain cement. 25 parts by weight of cement, 0.5 parts by weight of nano-calcium carbonate and 90 parts by weight of standard sand are mixed evenly, and then 10 parts by weight of reinforcing liquid are added and mixed evenly to obtain mortar; the cement clinker is composed of 60 parts by weight of high-iron phase cement clinker and 30 parts by weight of ordinary Portland cement clinker, and the high-iron phase cement clinker is the same as in Example 1.

[0040] (3) After the concrete colloid is poured into the mold and formed, it is left to stand in a standard curing box for 4 hours, and then moved to the steam curing equipment for steam curing with the mold. The steam curing conditions are to heat the temperature to 80℃ and steam cure for 2 hours. After the steam curing is completed, standard curing is performed for 24 hours, and then water curing is performed for 28 days to obtain the concrete component.

[0041] Example 3: A low-carbon cement concrete steam-cured enhancer, comprising the following components in parts by weight: 50 parts of nano-calcium carbonate, 0.025 parts of sodium chloride, 0.0125 parts of diethanol monoisopropanolamine, 0.0125 parts of monoethanol diisopropanolamine, and 0.125 parts of polydimethylsiloxane;

[0042] The above-mentioned reinforcing agent is used to prepare a concrete component in the following manner:

[0043] (1) dissolving sodium chloride, diethanol monoisopropanolamine, and monoethanol diisopropanolamine in water to obtain an enhancement solution, ensuring that the final concentration of diethanol monoisopropanolamine in the enhancement solution is 0.025 wt %, the final concentration of monoethanol diisopropanolamine is 0.025 wt %, the final concentration of sodium chloride is 0.05 wt %, and the final concentration of polydimethylsiloxane is 0.25 wt %;

[0044] (2) Gypsum, limestone powder, and cement clinker are ground together in a mass ratio of 7:7:86 to obtain cement. 500 parts by weight of cement, 50 parts by weight of nano-calcium carbonate, and 2000 parts by weight of standard sand are evenly mixed, and then 270 parts by weight of reinforcing liquid are added and mixed to obtain mortar; the cement clinker is all high-iron phase cement clinker, and the high-iron phase cement clinker is the same as in Example 1.

[0045] (3) After the concrete colloid is poured into the mold and formed, it is left to stand in a standard curing box for 1 hour, and then moved to the steam curing equipment for steam curing with the mold. The steam curing conditions are to heat the temperature to 85℃ and steam cure for 3 hours. After the steam curing is completed, standard curing is performed for 24 hours, and then water curing is performed for 28 days to obtain the concrete component.

[0046] Example 4: The rest are the same as Example 1, except that:

[0047] The enhancement solution contains triethanolamine at a final concentration of 0.05 wt %, aluminum sulfate at a final concentration of 0.2 wt %, sodium chloride at a final concentration of 0.01 wt %, and fluorosilicone at a final concentration of 0.05 wt %. The amount of the enhancement solution used is 200 parts by weight.

[0048] The cement clinker consists of 80 parts by weight of high iron phase cement clinker and 10 parts by weight of ordinary Portland cement clinker.

[0049] Example 5: The rest is the same as Example 1, except that:

[0050] Taking the standing time in step (3) as a variable, four time gradients of 0, 1, 2, and 4 h were set to prepare different concrete components.

[0051] Comparative Example 1: The rest is the same as Example 1, except that:

[0052] After the mortar was poured into the mold and formed, it was not allowed to stand or steam for treatment. It was directly subjected to standard curing at 20°C for 24 hours, and then water-cured for 28 days to obtain the mortar specimens.

[0053] Comparative Example 2: The rest is the same as Example 5, except that:

[0054] Replace high iron phase cement clinker with ordinary Portland cement clinker.

[0055] Comparative Example 3: The rest is the same as Example 1, except that:

[0056] Replace high iron phase cement clinker with ordinary Portland cement clinker.

[0057] After the mortar was poured into the mold and formed, it was not allowed to stand or steam for treatment. It was directly subjected to standard curing at 20°C for 24 hours, and then water-cured for 28 days to obtain the mortar specimens.

[0058] Comparative Example 4: The rest is the same as Example 5, except that:

[0059] The high iron phase cement clinker is replaced by a mixed clinker of 60 parts by weight of high iron phase cement clinker and 30 parts by weight of ordinary Portland cement clinker.

[0060] Comparative Example 5: The rest is the same as Example 1, except that:

[0061] The high iron phase cement clinker is replaced by a mixed clinker of 60 parts by weight of high iron phase cement clinker and 30 parts by weight of ordinary Portland cement clinker.

[0062] After the mortar was poured into the mold and formed, it was not allowed to stand or steam for treatment. It was directly subjected to standard curing at 20°C for 24 hours, and then water-cured for 28 days to obtain the mortar specimens.

[0063] Comparative Example 6: All other aspects are the same as Example 1, except that no reinforcing agent is added.

[0064] Comparative Example 7: All other aspects are the same as Example 1, except that the reinforcing agent does not contain an alcoholamine reinforcing agent, but contains the following components by weight: 5 parts of nano-calcium carbonate, 0.08 parts of aluminum sulfate, and 0.01 parts of fluorosilicone. The final concentration of fluorosilicone is 0.2 wt%.

[0065] Comparative Example 8: All other aspects are the same as Example 1, except that the low-carbon cement concrete steam curing enhancer does not contain nano-calcium carbonate, inorganic salts, and surfactants, and comprises the following components in parts by weight: 0.01 parts of diethanol monoisopropanolamine and 0.01 parts of monoethanol diisopropanolamine. The final concentration of diethanol monoisopropanolamine in the enhancing solution is 0.025wt%, and the final concentration of monoethanol diisopropanolamine is 0.025wt%.

[0066] Comparative Example 9: The rest are the same as Example 1, except that:

[0067] 0.01 parts of diethanol monoisopropanolamine and 0.01 parts of monoethanol diisopropanolamine were replaced with 0.02 parts of triisopropanolamine.

[0068] The flexural strength and compressive strength of the mortars prepared in Examples 1-5 and Comparative Examples 1-5 were measured on the 3rd and 28th days of curing, respectively. Each component was tested three times and the average value was taken. The results are as follows:

[0069] Table 1 Strength test results of different concrete components on the 3rd and 28th days of curing

[0070]

[0071]

[0072] The results in Table 1 show that, when Comparative Example 1 is compared with the group in Example 5 left standing for 0 h, when Comparative Example 3 is compared with the group in Example 2 left standing for 0 h, and when Comparative Example 5 is compared with the group in Example 4 left standing for 0 h, for different cement clinkers, if steam curing is performed directly after adding the reinforcing agent, the early and final strengths will decrease. The combination of the reinforcing agent and the steam curing process not only fails to improve the strength of the concrete, but significantly reduces the strength of the concrete.

[0073] Example 5, Comparative Example 2, and Comparative Example 4 show that the strength reduction problem caused by the combined use of a reinforcing agent and steam curing can be reversed by extending the standing time, and the reinforcing agent and steam curing treatment can synergistically improve the early strength and final strength of concrete, and the effect is better for high-iron phase cement clinker or mixed clinker containing high-iron phase cement clinker.

[0074] Furthermore, Comparative Example 6 shows that without the addition of a reinforcing agent, the early and late strengths of high-iron-phase low-carbon cement under rapid steam curing conditions decreased significantly, affecting the cement's performance. Comparative Examples 7 and 8 show that adding an alcoholamine and other components separately can slightly improve the early and late strengths of steam-cured specimens, but the effect is significantly lower than when they are added together.

[0075] In addition, Comparative Example 9 shows that the type of alcoholamine additives has a key influence on the effect of the reinforcing agent. The wrong choice of alcoholamine substances will affect the strength of concrete under steam curing conditions.

Claims

1. A low carbon cement concrete steam curing enhancer, characterized in that: The invention comprises the following components in parts by weight: 0.5-5 parts of nano-calcium carbonate, 0.02-0.2 parts of an alcoholamine additive, and 0-2 parts of an inorganic salt, wherein the weight of the inorganic salt is not 0 and 0.01-0.2 parts of a surfactant; the alcoholamine additive comprises at least one of diethanol monoisopropanolamine, monoethanol diisopropanolamine, triethanolamine, and triisopropanolamine; the inorganic salt comprises at least one of aluminum sulfate, sodium metaaluminate, sodium chloride, sodium sulfate, and calcium chloride; and the surfactant comprises at least one of polydimethylsiloxane, fluorosilicone, and ethylene glycol siloxane; The cement clinker used in the low-carbon cement concrete contains at least 60 wt% of high-iron cement clinker; The components of the high-iron phase cement clinker are: C3A≤1.5wt%, 19.0±1.0 wt% C4AF, 53.0±1.0wt% C3S, 23.0±1.0wt% C2S, KH is 0.880±0.01, SM is 2.10±0.10, and IM is 0.70±0.

10.

2. Use of the low-carbon cement concrete steam curing enhancer according to claim 1 in the preparation of concrete steam curing.

3. The use according to claim 2, characterized in that The steps include: (1) dissolving an alcohol amine additive, an inorganic salt, and a surfactant in water to obtain an enhancement solution; (2) Grind gypsum, limestone powder and cement clinker together to obtain cement, mix cement, nano calcium carbonate and aggregate evenly, add reinforcing liquid and mix to obtain concrete or mortar; (3) After the concrete is formed, it is left to stand and standard-cured, then steam-cured, and then standard-cured and water-cured in sequence to obtain concrete components.

4. The use according to claim 3, characterized in that In step (1), the enhancement solution contains diethanol monoisopropanolamine with a final concentration of 0.025-0.05wt%, monoethanol diisopropanolamine with a final concentration of 0.025-0.05wt%, aluminum sulfate with a final concentration of 0.2-0.5wt%, sodium metaaluminate with a final concentration of 0.2-0.5wt%, and fluorosilicone with a final concentration of 0.01-0.25wt%; Or the enhancement solution contains sodium chloride with a final concentration of 0.01-0.05wt%, diethanol monoisopropanolamine with a final concentration of 0.025-0.05wt%, monoethanol diisopropanolamine with a final concentration of 0.025-0.05wt%, and fluorosilicone with a final concentration of 0.01-0.25wt%; Or the enhancement solution contains triethanolamine with a final concentration of 0.025-0.05 wt%, aluminum sulfate with a final concentration of 0.2-0.5 wt%, sodium chloride with a final concentration of 0.01-0.05 wt%, and fluorosilicone with a final concentration of 0.01-0.25 wt%.

5. The use according to claim 3, characterized in that In step (2), the cement clinker is composed of 0-30 parts by weight of Portland cement clinker and 60-90 parts by weight of high iron phase cement clinker.

6. The use according to claim 3, characterized in that In step (2), the mass ratio of gypsum: limestone: cement clinker is 3-7: 3-7: 86-94; when preparing concrete or mortar, the mass ratio of reinforcing liquid: nano calcium carbonate: cement: aggregate is 100-270: 5-50: 250-500: 900-2000.

7. The use according to claim 3, characterized in that In step (3), the standing time is 1-4 hours; the steam curing treatment condition is to heat the mixture to 80-90°C and steam for 2-8 hours.

8. The use according to claim 3, characterized in that The method of standard curing and water curing is standard curing for 24 hours and then water curing for 28 days.

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