Inorganic cementing material for preparing concrete with high frost resistance and high strength in plateau environment

Abstract

The invention discloses an inorganic cementing material for preparing high-frost-resistance and high-strength concrete in a plateau environment, and relates to the field of concrete materials. The inorganic cementing material comprises the following components in percentage by mass: 70%-85% of PO.42.5 ordinary Portland cement, 2%-5% of nano silicon nitride tubes and 13%-25% of limestone powder. The special antifreeze agent is prepared from the following components in percentage by mass: 0.5 to 1 percent of polycarboxylate superplasticizer, 0.5 to 1 percent of glutathione and 1 to 2 percent of epoxy phosphate. The preparation method of the anti-freezing concrete comprises the following steps: mixing the components with the natural sandstone material, molding in a wrapping and curing manner, and obtaining the concrete with high anti-freezing performance and high strength after 28 days, so that the anti-freezing concrete has a great application prospect.

Description

Technical Field

[0001] The present invention discloses a preparation method of an inorganic cementitious material for preparing high frost-resistant performance and high-strength concrete in a plateau environment, belonging to the technical field of new building materials. When using this cementitious material to prepare concrete, the frost resistance and compressive strength of the concrete can be greatly improved. Background Art

[0002] In recent years, the highway construction in Tibet has been in a period of rapid development. The mileage of newly built highways in high-altitude and difficult areas has increased year by year. However, due to the unique plateau climate in high-altitude areas, the durability of plateau highway concrete is worse than that in the inland areas and the service life is short due to the repeated freeze-thaw effects. It can be known from the literature that the annual temperature difference in the plateau environment can reach 40-50°C, the daily temperature difference can reach 20-30°C, and the lowest temperature is close to minus 50 degrees Celsius, which is extremely likely to cause problems such as early frost damage and poor frost resistance durability of concrete in the later stage.

[0003] At present, the research on plateau freeze-thaw resistance technology is relatively less, and the mass loss rate of these technologies after 200 freeze-thaw cycles is about 2.02%, which cannot meet the durability requirements of areas above 5000 meters above sea level. To solve the above problems, the present invention is based on solving the problems existing in the application of highway concrete in areas above 5000 meters above sea level in Tibet, and intends to develop an inorganic cementitious material for preparing high frost-resistant performance and high-strength concrete in a plateau environment. Summary of the Invention

[0004] The main components and special admixtures of the inorganic cementitious material for preparing high frost-resistant performance and high-strength concrete in a plateau environment involved in the present invention include:

[0005] 1. The composition of the inorganic cementitious material consists of PO·42.5 ordinary Portland cement, nano silicon nitride tubes and limestone powder, and their mass ratios are respectively:

[0006] (1) The mass ratio of PO·42.5 ordinary Portland cement: 70% - 85%;

[0007] (2) The mass ratio of nano silicon nitride tubes: 2% - 5%;

[0008] (3) The mass ratio of limestone powder: 13% - 25%;

[0009] The sum of the mass ratios of the above three components is 100%.

[0010] 2. The composition of the special antifreeze agent is:

[0011] (1) The mass ratio of polycarboxylate water reducer to inorganic cementitious material: 0.5% - 1%;

[0012] (2) The mass ratio of glutathione to inorganic cementitious material: 0.5% - 1%;

[0013] (3) The mass ratio of epoxy phosphate to inorganic cementitious material: 1% - 2%;

[0014] The mass ratio of the above components polycarboxylate superplasticizer: glutathione: epoxy phosphate is 1:1:2.

[0015] 3. The particle size of the nano silicon nitride is 500 - 800 nm.

[0016] 4. The preparation method of the cementitious material is as follows:

[0017] (1) Weighing materials: Weigh each component according to the mass ratio of each component.

[0018] (2) Prepare a special antifreeze agent: Use a high-frequency vibrating mixer with a frequency of 200 Hz to uniformly stir the polycarboxylate superplasticizer, glutathione, and epoxy phosphate for 5 minutes to prepare the special antifreeze agent.

[0019] (3) Place the PO·42.5 ordinary Portland cement, nano silicon nitride tubes, and limestone powder weighed in step (1) into a mixer and mix them evenly, then add the special antifreeze agent prepared in step (2) and mix for 10 minutes to prepare a special cementitious material for high antifreeze performance concrete.

[0020] 5. Preparation of antifreeze concrete

[0021] (1) The mass ratio of water: special cementitious material: sand: gravel is 0.35:1:2:3

[0022] Among them, the particle size of the sand is between 2.36 - 3.7 mm, and the particle size of the gravel is less than 2 cm.

[0023] (2) Weighing materials: Weigh each component according to the mass ratio of each component;

[0024] (3) Put the weighed special cementitious material, sand, and gravel materials into a mixing pot and dry mix for 3 minutes; then add water and continue to mix for 5 minutes to prepare the concrete mixture;

[0025] (4) Place the mixture in a test mold, vibrate it densely, compact it and level it, cover it with a layer of plastic wrap and cure for 1 day, then demold it, and completely seal it with a plastic film and place it in a standard concrete curing box for 28 days to prepare the antifreeze concrete.

[0026] Compared with the prior art, the present invention has the following advantages

[0027] (1) The gelling material developed in this invention is used to prepare concrete. Its main features include not only improving the flexural strength, abrasion resistance, and crack resistance of the concrete, but most importantly, it has excellent frost resistance. Even after 450 freeze-thaw cycles in a high-altitude area, no obvious large pores or cracks will occur inside the concrete, which may lead to the expansion of frozen water inside and cause the concrete to crack.

[0028] (2) Glutathione acts as an antioxidant and is not easily oxidized in water, which can effectively protect the internal structure of the concrete from being damaged by the external environment.

[0029] (3) The special antifreeze can protect the internal structure of the concrete at the microscale, improve the frost resistance of the inorganic gelling material, and thus effectively improve the frost resistance of the concrete. Detailed implementation method

[0030] To further demonstrate the efficacy brought by this invention, the following combines specific application cases to further elaborate on this invention in detail.

[0031] Example 1: A preparation method of an inorganic gelling material for preparing high-frost-resistance and high-strength concrete in a high-altitude environment disclosed in this invention includes the following steps.

[0032] 1. The inorganic gelling material consists of PO·42.5 ordinary Portland cement, nano-silicon nitride tubes, and limestone powder. The mass ratios of the three are respectively:

[0033] (1) The mass ratio of PO·42.5 ordinary Portland cement: 70%;

[0034] (2) The mass ratio of nano-silicon nitride tubes: 5%;

[0035] (3) The mass ratio of limestone powder: 25%;

[0036] 2. The composition of the special antifreeze is:

[0037] (1) The mass ratio of polycarboxylate superplasticizer to the inorganic gelling material: 0.5%;

[0038] (2) The mass ratio of glutathione to the inorganic gelling material: 0.5%;

[0039] (3) The mass ratio of epoxy phosphate to the inorganic gelling material: 1%;

[0040] Among them, the polycarboxylate water reducer used is a standard polycarboxylate water reducer, the manufacturer is Sichuan Dongrun Baisheng New Materials Co., Ltd., and the product model is DFTR-PCE (standard type); the glutathione used is reduced glutathione, the manufacturer is Shanghai Macklin Biochemical Technology Co., Ltd., and the CAS number is 70-18-8; the product model of the epoxy phosphate is F-9, and the manufacturer is Foshan Aona Polymer Co., Ltd. The following examples uniformly use this type of antifreeze component, but are not limited to this, and will not be repeated.

[0041] 3. The preparation method of the cementitious material of the high frost-resistant performance concrete prepared according to the present invention is as follows:

[0042] (1) Weighing: Weigh each component according to the mass ratio of each component.

[0043] (2) Prepare a special admixture: Uniformly stir the powder polycarboxylate water reducer, glutathione, and epoxy phosphate with a high-frequency vibration mixer at 200 Hz for 5 minutes to prepare a special antifreeze.

[0044] (3) Place the PO·42.5 ordinary Portland cement, nano silicon nitride tube, and limestone powder weighed in step (1) into a mixer and mix them evenly, then add the special antifreeze prepared in step (2), and mix and stir for 10 minutes to prepare a special cementitious material for high frost-resistant performance concrete.

[0045] 4. Preparation of frost-resistant concrete

[0046] (1) The mass ratio of water: special cementitious material: sand: gravel is 0.35:1:2:3

[0047] Among them, the particle size of the sand is between 2.36 and 3.7 mm, and the particle size of the gravel is below 2 cm.

[0048] (2) Weighing: Weigh each component according to the mass ratio of each component;

[0049] (3) Put the weighed special cementitious material, sand, and gravel materials into a mixing pot and dry mix for 3 minutes; then add water and continue to stir for 5 minutes to prepare a concrete mixture;

[0050] (4) Place the mixture in a test mold, vibrate it densely, compact it and level it, cover it with a layer of plastic wrap and cure for 1 day, then demold it, and completely seal it with a plastic film and place it in a concrete standard curing box for 28 days to prepare frost-resistant concrete.

[0051] 5. Test the frost-resistant strength of the frost-resistant concrete after 450 freeze-thaw cycles according to the "Concrete Quality Control Standard" GB50164-2011.

[0052] Example 2: A preparation method of an inorganic cementitious material for preparing high frost-resistant performance and high-strength concrete in a plateau environment, comprising the following steps,

[0053] 1. The inorganic cementitious material consists of PO·42.5 ordinary Portland cement, nano-silicon nitride tubes and limestone powder, and the mass ratios of the three are respectively:

[0054] (1) The mass ratio of PO·42.5 ordinary Portland cement: 75%;

[0055] (2) The mass ratio of nano-silicon nitride tubes: 4%;

[0056] (3) The mass ratio of limestone powder: 21%;

[0057] 2. The composition components of the special antifreeze agent are:

[0058] (1) The mass ratio of polycarboxylate superplasticizer to inorganic cementitious material: 0.67%;

[0059] (2) The mass ratio of glutathione to inorganic cementitious material: 0.67%;

[0060] (3) The mass ratio of epoxy phosphate to inorganic cementitious material: 1.35%;

[0061] 3. The preparation method of the cementitious material of the high frost-resistant performance concrete prepared according to the present invention is as follows:

[0062] (1) Weighing: Weigh each component according to the mass ratio of each component.

[0063] (2) Prepare the special antifreeze agent: Uniformly stir the powder polycarboxylate superplasticizer, glutathione and epoxy phosphate with a high-frequency vibrating mixer at 200 Hz for 5 minutes to prepare the special antifreeze agent.

[0064] (3) Place the PO·42.5 ordinary Portland cement, nano-silicon nitride tubes and stone powder weighed in step (1) in a mixer and mix and stir evenly, then add the special antifreeze agent prepared in step (2) and mix and stir for 10 minutes to prepare the special cementitious material for high frost-resistant performance concrete.

[0065] 4. Preparation of frost-resistant concrete

[0066] (1) Water: special cementitious material: sand: stone mass ratio is 0.35:1:2:3;

[0067] Among them, the particle size of the sand is between 2.36 and 3.7 mm, and the particle size of the stone is below 2 cm.

[0068] (2) Weighing: Weigh each component according to the mass ratio of each component;

[0069] (3) Put the weighed special cementitious material, sand, and stone materials into the mixing pot and dry mix for 3 minutes; then add water and continue to mix for 5 minutes to prepare the concrete mixture.

[0070] (4) Place the mixture in the test mold, vibrate it densely and compact it and level it, cover it with a layer of plastic wrap and cure for 1 day, then demold it, and then completely seal it with plastic film and place it in the concrete standard curing box for 28 days to prepare the frost-resistant concrete.

[0071] 5. Test the frost-resistant strength of the frost-resistant concrete obtained according to the "Concrete Quality Control Standard" GB50164-2011 after 450 freeze-thaw cycles.

[0072] Example 3: An inorganic cementitious material preparation method for preparing high frost-resistant performance and high-strength concrete in a plateau environment disclosed by the present invention includes the following steps.

[0073] 1. The inorganic cementitious material is composed of PO·42.5 ordinary Portland cement, nano-silicon nitride tubes, and limestone powder, and the mass ratios of the three are respectively:

[0074] (1) The mass ratio of PO·42.5 ordinary Portland cement: 80%;

[0075] (2) The mass ratio of nano-silicon nitride tubes: 3%;

[0076] (3) The mass ratio of limestone powder: 17%;

[0077] 2. The composition of the special frost-resistant agent is:

[0078] (1) The mass ratio of polycarboxylate superplasticizer to inorganic cementitious material: 0.84%;

[0079] (2) The mass ratio of glutathione to inorganic cementitious material: 0.84%;

[0080] (3) The mass ratio of epoxy phosphate to inorganic cementitious material: 1.7%;

[0081] 3. The preparation method of the cementitious material of the high frost-resistant performance concrete prepared according to the present invention is as follows:

[0082] (1) Weighing: Weigh each component according to the mass ratio of each component.

[0083] (2) Prepare the special admixture: Use a high-frequency vibrating mixer with a frequency of 200 Hz to uniformly mix the powder polycarboxylate superplasticizer, glutathione, and epoxy phosphate for 5 minutes to prepare the special frost-resistant agent.

[0084] (3) Place the PO·42.5 ordinary Portland cement, nano silicon nitride tubes, and stone powder weighed in step (1) into a blender, mix and stir evenly, then add the special antifreeze agent prepared in step (2), and mix and stir for 10 minutes to prepare a special cementitious material for high frost-resistant performance concrete.

[0085] 4. Preparation of frost-resistant concrete

[0086] (1) The mass ratio of water: special cementitious material: sand: gravel is 0.35:1:2:3;

[0087] Among them, the particle size of the sand is between 2.36 and 3.7 mm, and the particle size of the gravel is less than 2 cm.

[0088] (2) Weighing: Weigh each component according to the mass ratio of each component;

[0089] (3) Put the weighed special cementitious material, sand, and gravel materials into the mixing pot and dry mix for 3 minutes; then add water and continue to stir for 5 minutes to prepare a concrete mixture;

[0090] (4) Place the mixture in a test mold, vibrate it densely, compact it and level it, cover it with a layer of plastic wrap and cure for 1 day, then demold it, and then completely seal it with a plastic film and place it in a standard concrete curing box for 28 days to prepare frost-resistant concrete.

[0091] 5. Test the frost-resistant strength of the frost-resistant concrete after 450 freeze-thaw cycles according to the "Concrete Quality Control Standard" GB50164-2011.

[0092] Example 4: A preparation method of an inorganic cementitious material for preparing high frost-resistant performance and high-strength concrete in a plateau environment disclosed by the present invention includes the following steps:

[0093] 1. The inorganic cementitious material is composed of PO·42.5 ordinary Portland cement, nano silicon nitride tubes, and limestone powder, and the mass ratios of the three are respectively:

[0094] (1) The mass ratio of PO·42.5 ordinary Portland cement: 85%;

[0095] (2) The mass ratio of nano silicon nitride tubes: 2%;

[0096] (3) The mass ratio of limestone powder: 13%;

[0097] 2. The composition of the special antifreeze admixture is:

[0098] (1) The mass ratio of polycarboxylate water reducer to inorganic cementitious material: 1%;

[0099] (2) The mass ratio of glutathione to inorganic cementitious material: 1%;

[0100] (3) Mass ratio of epoxy phosphate to inorganic cementitious material: 2%;

[0101] 3. The cementitious material of the high frost-resistant performance concrete prepared according to the present invention is prepared as follows:

[0102] (1) Weighing: Weigh each component according to the mass ratio of each component.

[0103] (2) Prepare a special antifreeze agent: Uniformly stir the powder polycarboxylate superplasticizer, glutathione, and epoxy phosphate with a high-frequency vibrating mixer at 200 Hz for 5 minutes to prepare a special antifreeze agent.

[0104] (3) Place the PO·42.5 ordinary Portland cement, nano silicon nitride tube, and limestone powder weighed in step (1) into a mixer and mix them evenly, then add the special antifreeze agent prepared in step (2), and mix and stir for 10 minutes to prepare a special cementitious material for high frost-resistant performance concrete.

[0105] 4. Preparation of frost-resistant concrete

[0106] (1) The mass ratio of water: special cementitious material: sand: gravel is 0.35:1:2:3;

[0107] Among them, the particle size of the sand is between 2.36 and 3.7 mm, and the particle size of the gravel is less than 2 cm.

[0108] (2) Weighing: Weigh each component according to the mass ratio of each component;

[0109] (3) Put the weighed special cementitious material, sand, and gravel materials into a mixing pot and dry mix for 3 minutes; then add water first and continue to stir for 5 minutes to prepare a concrete mixture;

[0110] (4) Place the mixture in a test mold, vibrate it densely and compact it and level it, cover it with a layer of plastic wrap and cure for 1 day and then demold it, and then completely seal it with a plastic film and place it in a concrete standard curing box for 28 days to prepare frost-resistant concrete.

[0111] 5. Test the frost-resistant strength of the frost-resistant concrete after 450 freeze-thaw cycles according to the "Concrete Quality Control Standard" GB50164-2011.

[0112] Test results

[0113] Examples 1 to 4 respectively set up a control group. The water-binder ratio, forming, curing, and test methods of the control group are the same as those of the examples. The cementitious material of the control group is PO·42.5 ordinary Portland cement, and no special antifreeze agent is added. The test results of the control group and the example group after 450 freeze-thaw cycles are shown in the following table.

[0114]

[0115] It can be seen from the data in the above table that after the inorganic cementitious material of the present invention is incorporated into concrete, the strength loss rate is reduced by nearly about 30%, the compressive strength is increased by nearly about 35%, the freeze-thaw cycle resistance is greatly improved, the constructible period of concrete in the harsh plateau environment is extended, it is simple and practical, environmentally friendly and harmless, and has important practical significance and engineering application value.

Claims

1. An inorganic cementitious material for preparing high anti-freezing performance and high-strength concrete in plateau environment, characterized in that: It is composed of PO·42.5 ordinary portland cement, nano silicon nitride tubes and limestone powder, and their mass ratios are as follows: (1) The mass ratio of PO·42.5 ordinary portland cement: 70% - 85%; (2) The mass ratio of nano silicon nitride tubes: 2% - 5%; (3) The mass ratio of limestone powder: 13% - 25%; The sum of the mass ratios of the above three components is 100%.

2. The inorganic cementitious material according to claim 1, characterized in that, The particle size of the nano silicon nitride described is 500 - 800 nm.

3. A special antifreeze agent, characterized in that, The components are: (1) The mass ratio of polycarboxylate superplasticizer to inorganic binder: 0.5% - 1%; (2) The mass ratio of glutathione to inorganic binder: 0.5% - 1%; (3) The mass ratio of epoxy phosphate to inorganic binder: 1% - 2%; And the mass ratio of polycarboxylate superplasticizer: glutathione: epoxy phosphate is 1:1:

2.

4. A preparation method of a gelling material, characterized in that As follows: (1) Weighing materials: Weigh each component according to the mass ratio of each component; (2) Prepare the special antifreeze agent described in claim 3: Use a high-frequency vibrating mixer with a frequency of 200 Hz to uniformly stir polycarboxylate superplasticizer, glutathione, and epoxy phosphate for 5 minutes to prepare the special antifreeze agent; (3) Place the PO·42.5 ordinary portland cement, nano silicon nitride tubes, and limestone powder weighed in step (1) into a mixer and mix and stir evenly, then add the special antifreeze agent prepared in step (2) and mix and stir for 10 minutes to prepare the binder.

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