Special high-pumpability concrete for high-rise buildings and preparation method of special high-pumpability concrete

Abstract

The invention discloses special high-pumpability concrete for high-rise buildings and a preparation method of the special high-pumpability concrete, and belongs to the technical field of building materials. The special high-pumpability concrete for the high-rise building is prepared from the following raw materials: cement, fly ash, river sand, broken stone, silica fume, water, an additive, a thickening and water-retaining agent, an air entraining agent and a retarder. According to the invention, by compounding the thickening water-retaining agent and the air entraining agent and scientifically proportioning the sand ratio, the mortar-to-bone ratio and other components, the concrete fluidity is large, the pumping resistance is reduced, the segregation and water seepage phenomena during high-rise concrete pumping are avoided at the same time, and the concrete pumping agent is suitable for smooth pumping of high-rise building concrete; in addition, when the concrete is in a standing state, the wrapping performance is high, aggregate distribution is uniform, it is guaranteed that the concrete has high homogeneity in the pumping process, the pump blocking risk is reduced, and meanwhile the concrete strength meets the concrete strength requirement of high-rise buildings.

Description

Technical Field

[0001] The invention belongs to the technical field of building materials, and in particular relates to a high-pumpability concrete specially used for high-rise buildings and a preparation method thereof. Background Art

[0002] With the continuous advancement of urbanization, a large number of super-high-rise buildings have emerged, which has pushed up the requirements for building quality and the difficulty of construction. At the same time, it has also put forward higher requirements on the mix design, production methods and construction technology of high-performance concrete.

[0003] With the increase in construction projects, pumped concrete has been widely used. However, with the increase in building height, the pressure and difficulty of concrete pumping also increase. For high-rise building concrete pumping, especially for super high-rise buildings over 100 meters, high pumping pressure is required, and high pressure will cause concrete bleeding problems, resulting in concrete segregation, serious collapse or pump blockage, and concrete pumping is difficult. For example, in the super high-rise pumping of high-grade concrete with a height greater than 200 meters, the concrete has high strength and high viscosity, and the pumping pressure is high, which can easily lead to leakage, concrete segregation and pipe blockage. However, most of the high-rise concrete patents currently disclosed study its mechanical properties. For example, Chinese patent CN108821699SA discloses a high-strength concrete for high-rise buildings, which mainly uses steel fibers and high-elastic polyethylene fibers to form a three-dimensional random support network, which makes up for the initial defects of concrete to a certain extent and enhances the compressive strength, bending strength and toughness of the matrix. Chinese patent CN106242429A discloses a high-toughness hybrid fiber reinforced concrete and its preparation method. The concrete is mixed with nano-silicon dioxide and hybrid fibers at the same time, and the bending toughness and fracture toughness are significantly improved. It can be used in large-span and high-rise building structural projects with high toughness requirements.

[0004] Therefore, there is an urgent need to develop a high-pumpability concrete specifically for high-rise buildings to improve the pumpability of concrete and avoid water seepage during high-rise concrete pumping. Summary of the invention

[0005] The present invention aims at the problems existing in the prior art and provides a high-pumpability concrete specially used for high-rise buildings, which can effectively improve the fluidity of concrete, reduce pumping resistance, improve the pumpability of concrete, and avoid water seepage during high-rise concrete pumping.

[0006] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

[0007] A high-pumpability concrete specially used for high-rise buildings comprises the following raw materials in parts by weight: 450-480 parts of cement, 100-130 parts of fly ash, 750-780 parts of river sand, 900-960 parts of crushed stone, 28-35 parts of silica fume, 160-170 parts of water, 9-10 parts of admixture, 10-15 parts of thickening and water-retaining agent, 1-3 parts of air-entraining agent and 5-10 parts of retarder.

[0008] Furthermore, the cement is silicate cement with a strength grade of 42.5 or above; the SiO2 content in the silica fume is above 90wt%; and the crushed stone is granite.

[0009] Furthermore, the admixture is a polycarboxylic acid water-reducing agent, and the water-reducing rate reaches 35%.

[0010] Furthermore, the thickening and water-retaining agent includes microsilica powder, sodium linoleate and cassava flour, and the mass ratio of the three is 1:2:2.

[0011] Furthermore, the air entraining agent includes sodium ricinoleate and sodium dioctyl sulfosuccinate, and the mass ratio of the two is 1:1.

[0012] Furthermore, the retarder is sodium citrate.

[0013] Furthermore, the river sand has a particle size of 5 mm, the crushed stone has a particle size of 5-10 mm and 10-20 mm, and the mass ratio of the two crushed stones with different particle sizes is 2:1.

[0014] A method for preparing high-pumpability concrete specially used for high-rise buildings comprises the following steps:

[0015] Mix cement, fly ash and water evenly and stir at low speed. Then add admixture, retarder, thickener and water-retaining agent and air-entraining agent in sequence and stir at low speed. Finally, add silica fume, river sand and gravel in sequence and stir at high speed to obtain the final product, high-pumpability concrete for high-rise buildings.

[0016] Furthermore, the rotation speed of the low-speed stirring is 150 r / min, and the time is 5 minutes; the rotation speed of the high-speed stirring is 400 r / min, and the time is 3 minutes.

[0017] The sand ratio and mortar-brick ratio used in the concrete of the present invention make the concrete workability and lubricating layer performance better.

[0018] The thickening and water-retaining agent added is composed of silicon micropowder, sodium linoleate and tapioca flour. Sodium linoleate can improve the dispersibility of cement and sand, and greatly improve the plasticity and water retention of mortar; silicon micropowder also has the function of retaining water, preventing segregation and water seepage; and the starch particles in tapioca flour will absorb water and swell in water to form a gel-like substance, thereby increasing the viscosity of concrete, improving its fluidity and smoothness, and on the other hand, tapioca flour can absorb and retain water. The blend of the three in a specific ratio can significantly improve the workability of concrete, reduce the water seepage of concrete, and improve the water retention of concrete.

[0019] Air-entraining agents composed of sodium ricinoleate and sodium dioctyl sulfosuccinate in a specific ratio can effectively improve the workability of concrete mixtures. When air-entraining agents are added to concrete, they generate a large number of tiny closed bubbles. These bubbles act like balls, reducing the friction resistance between aggregate particles, thereby improving the fluidity of concrete. In addition, since water is evenly distributed on the surface of the bubbles to form a bubble film, the amount of water that moves freely is reduced, resulting in a decrease in the amount of water bleeding in the concrete. This mechanism not only enhances the fluidity of concrete, but also improves its water retention and cohesion.

[0020] Beneficial Effects

[0021] The concrete of the present invention has high concrete fluidity and greatly reduces pumping resistance by adjusting the sand ratio, mortar-brick ratio, thickening water-retaining agent and air-entraining agent, and avoids water seepage during high-rise concrete pumping. The concrete is suitable for smooth pumping of high-rise building concrete within 100 meters. The concrete has high wrapping when it is in a static state, and the aggregate can be evenly distributed, reducing the risk of pump blockage, while ensuring high homogeneity during concrete pouring. In addition, the concrete strength meets the concrete strength requirements for high-rise buildings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a state diagram of the concrete pump inlet and pump outlet in Example 1 of the present invention. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is further described below in conjunction with specific embodiments, but is not limited thereto.

[0024] Example 1

[0025] A high-pumpability concrete specially used for high-rise buildings comprises the following raw materials in parts by weight: 450 parts of cement, 100 parts of fly ash, 750 parts of river sand, 900 parts of crushed stone, 28 parts of silica fume, 160 parts of water, 9 parts of admixture, 10 parts of thickening and water-retaining agent, 1 part of air-entraining agent and 5 parts of retarder.

[0026] The admixture is polycarboxylic acid water reducer, and the water reduction rate reaches 35%.

[0027] The thickening and water-retaining agent includes 2 parts of microsilica powder, 4 parts of sodium linoleate, and 4 parts of tapioca flour, and the mass ratio of the three is 1:2:2.

[0028] The air entraining agent includes 0.5 parts of sodium ricinoleate and 0.5 parts of dioctyl sodium sulfosuccinate, and the mass ratio of the two is 1:1.

[0029] The retarder is sodium citrate.

[0030] The crushed stones are 600 parts of 5-10 mm particle size and 300 parts of 10-20 mm particle size, and the mass ratio of the two types of crushed stones is 2:1.

[0031] A method for preparing high-pumpability concrete specially used for high-rise buildings, characterized in that it comprises the following steps:

[0032] Stir cement, fly ash and water at 150r / min for 5 minutes until evenly mixed, then add admixtures, retarders, thickeners and water-retaining agents in sequence and stir at 150r / min for 5 minutes. Finally, put silica fume, river sand and gravel into the mixer in sequence and stir at 400r / min for 3 minutes to obtain the final product, high-pumpability concrete for high-rise buildings.

[0033] In this embodiment, the concrete discharge at the pump outlet at a height of 100m is uniform. Figure 1 As shown, the fluidity and wrapping properties are good, and the casting is dense.

[0034] Example 2

[0035] A high-pumpability concrete specially used for high-rise buildings comprises the following raw materials in parts by weight: 460 parts of cement, 120 parts of fly ash, 760 parts of river sand, 930 parts of crushed stone, 31 parts of silica fume, 165 parts of water, 9.5 parts of admixture, 10 parts of thickening and water-retaining agent, 2 parts of air-entraining agent, and 8 parts of retarder.

[0036] The admixture is polycarboxylic acid water reducer, and the water reduction rate reaches 35%.

[0037] The thickening and water-retaining agent includes 2 parts of microsilica powder, 4 parts of sodium linoleate, and 4 parts of tapioca flour, and the mass ratio of the three is 1:2:2.

[0038] The air entraining agent includes 1 part of sodium ricinoleate and 1 part of dioctyl sodium sulfosuccinate, and the mass ratio of the two is 1:1.

[0039] The retarder is sodium citrate.

[0040] The crushed stones are 620 parts of 5-10 mm particle size and 310 parts of 10-20 mm particle size, and the mass ratio of the two types of crushed stones is 2:1.

[0041] A method for preparing high-pumpability concrete specially used for high-rise buildings, characterized in that it comprises the following steps:

[0042] Stir cement, fly ash and water at 150r / min for 5 minutes until evenly mixed, then add admixtures, retarders, thickeners and water-retaining agents in sequence and stir at 150r / min for 5 minutes. Finally, put silica fume, river sand and gravel into the mixer in sequence and stir at 400r / min for 3 minutes to obtain the final product, high-pumpability concrete for high-rise buildings.

[0043] Example 3

[0044] A high-pumpability concrete specially used for high-rise buildings comprises the following raw materials in parts by weight: 480 parts of cement, 130 parts of fly ash, 780 parts of river sand, 960 parts of crushed stone, 35 parts of silica fume, 170 parts of water, 10 parts of admixture, 15 parts of thickening and water-retaining agent, 3 parts of air-entraining agent, and 10 parts of retarder.

[0045] The admixture is polycarboxylic acid water reducer, and the water reduction rate reaches 35%.

[0046] The thickening and water-retaining agent includes 3 parts of microsilica powder, 6 parts of sodium linoleate, and 6 parts of tapioca flour, and the mass ratio of the three is 1:2:2.

[0047] The air entraining agent includes 1.5 parts of sodium ricinoleate and 1.5 parts of dioctyl sodium sulfosuccinate, and the mass ratio of the two is 1:1.

[0048] The retarder is sodium citrate.

[0049] The crushed stones are 640 parts of 5-10 mm particle size and 320 parts of 10-20 mm particle size, and the mass ratio of the two types of crushed stones is 2:1.

[0050] A method for preparing high-pumpability concrete specially used for high-rise buildings, characterized in that it comprises the following steps:

[0051] Stir cement, fly ash and water at 150r / min for 5 minutes until evenly mixed, then add admixtures, retarders, thickeners and water-retaining agents in sequence and stir at 150r / min for 5 minutes. Finally, put silica fume, river sand and gravel into the mixer in sequence and stir at 400r / min for 3 minutes to obtain the final product, high-pumpability concrete for high-rise buildings.

[0052] Comparative Example 1

[0053] A high-pumpability concrete specially used for high-rise buildings comprises the following raw materials in parts by weight: 480 parts of cement, 130 parts of fly ash, 780 parts of river sand, 960 parts of crushed stone, 35 parts of silica fume, 170 parts of water, 10 parts of admixture, 15 parts of thickening and water-retaining agent, 3 parts of air-entraining agent, and 10 parts of retarder.

[0054] The admixture is polycarboxylic acid water reducer, and the water reduction rate reaches 35%.

[0055] The thickening and water-retaining agent includes 5 parts of microsilica powder, 5 parts of sodium linoleate, and 5 parts of tapioca flour, and the mass ratio of the three is 1:1:1.

[0056] The air entraining agent includes 1.5 parts of sodium ricinoleate and 1.5 parts of dioctyl sodium sulfosuccinate, and the mass ratio of the two is 1:1.

[0057] The retarder is sodium citrate.

[0058] The crushed stones are 640 parts of 5-10 mm particle size and 320 parts of 10-20 mm particle size, and the mass ratio of the two types of crushed stones is 2:1.

[0059] A method for preparing high-pumpability concrete specially used for high-rise buildings, characterized in that it comprises the following steps:

[0060] Stir cement, fly ash and water at 150r / min for 5 minutes until evenly mixed, then add admixtures, retarders, thickeners and water-retaining agents in sequence and stir at 150r / min for 5 minutes. Finally, put silica fume, river sand and gravel into the mixer in sequence and stir at 400r / min for 3 minutes to obtain the final product, high-pumpability concrete for high-rise buildings.

[0061] Compared with Example 3, this comparative example has the same raw materials and steps as Example 3 except that the mass ratio of the three components of the thickening and water-retaining agent is changed to 1:1:1.

[0062] Comparative Example 2

[0063] A high-pumpability concrete specially used for high-rise buildings comprises the following raw materials in parts by weight: 480 parts of cement, 130 parts of fly ash, 780 parts of river sand, 960 parts of crushed stone, 35 parts of silica fume, 170 parts of water, 10 parts of admixture, 15 parts of thickening and water-retaining agent, 3 parts of air-entraining agent, and 10 parts of retarder.

[0064] The admixture is polycarboxylic acid water reducer, and the water reduction rate reaches 35%.

[0065] The thickening and water-retaining agent includes 6 parts of microsilica powder, 3 parts of sodium linoleate, and 6 parts of tapioca flour, and the mass ratio of the three is 2:1:2.

[0066] The air entraining agent includes 1.5 parts of sodium ricinoleate and 1.5 parts of dioctyl sodium sulfosuccinate, and the mass ratio of the two is 1:1.

[0067] The retarder is sodium citrate.

[0068] The crushed stones are 640 parts of 5-10 mm particle size and 320 parts of 10-20 mm particle size, and the mass ratio of the two types of crushed stones is 2:1.

[0069] A method for preparing high-pumpability concrete specially used for high-rise buildings, characterized in that it comprises the following steps:

[0070] Stir cement, fly ash and water at 150r / min for 5 minutes until evenly mixed, then add admixtures, retarders, thickeners and water-retaining agents in sequence and stir at 150r / min for 5 minutes. Finally, put silica fume, river sand and gravel into the mixer in sequence and stir at 400r / min for 3 minutes to obtain the final product, high-pumpability concrete for high-rise buildings.

[0071] Compared with Example 3, this comparative example has the same raw materials and steps as Example 3 except that the ratio of the three components of the thickening and water-retaining agent is changed to 2:1:2.

[0072] Comparative Example 3

[0073] A high-pumpability concrete specially used for high-rise buildings comprises the following raw materials in parts by weight: 480 parts of cement, 130 parts of fly ash, 780 parts of river sand, 960 parts of crushed stone, 35 parts of silica fume, 170 parts of water, 10 parts of admixture, 15 parts of thickening and water-retaining agent, 3 parts of air-entraining agent, and 10 parts of retarder.

[0074] The admixture is polycarboxylic acid water reducer, and the water reduction rate reaches 35%.

[0075] The thickening and water-retaining agent includes 6 parts of microsilica powder, 6 parts of sodium linoleate, and 3 parts of cassava flour, and the mass ratio of the three is 2:2:1.

[0076] The air entraining agent includes 1.5 parts of sodium ricinoleate and 1.5 parts of dioctyl sodium sulfosuccinate, and the mass ratio of the two is 1:1.

[0077] The retarder is sodium citrate.

[0078] The crushed stones are 640 parts of 5-10 mm particle size and 320 parts of 10-20 mm particle size, and the mass ratio of the two types of crushed stones is 2:1.

[0079] A method for preparing high-pumpability concrete specially used for high-rise buildings, characterized in that it comprises the following steps:

[0080] Stir cement, fly ash and water at 150r / min for 5 minutes until evenly mixed, then add admixtures, retarders, thickeners and water-retaining agents in sequence and stir at 150r / min for 5 minutes. Finally, put silica fume, river sand and gravel into the mixer in sequence and stir at 400r / min for 3 minutes to obtain the final product, high-pumpability concrete for high-rise buildings.

[0081] Compared with Example 3, this comparative example has the same raw materials and steps as Example 3 except that the ratio of the three components of the thickening and water-retaining agent is changed to 2:2:1.

[0082] Comparative Example 4

[0083] A high-pumpability concrete specially used for high-rise buildings comprises the following raw materials in parts by weight: 480 parts of cement, 130 parts of fly ash, 780 parts of river sand, 960 parts of crushed stone, 35 parts of silica fume, 170 parts of water, 10 parts of admixture, 15 parts of thickening and water-retaining agent, 3 parts of air-entraining agent, and 10 parts of retarder.

[0084] The admixture is polycarboxylic acid water reducer, and the water reduction rate reaches 35%.

[0085] The thickening and water-retaining agent includes 5 parts of microsilica powder and 10 parts of sodium linoleate, and the mass ratio of the two is 1:2.

[0086] The air entraining agent includes 1.5 parts of sodium ricinoleate and 1.5 parts of dioctyl sodium sulfosuccinate, and the mass ratio of the two is 1:1.

[0087] The retarder is sodium citrate.

[0088] The crushed stones are 640 parts of 5-10 mm particle size and 320 parts of 10-20 mm particle size, and the mass ratio of the two types of crushed stones is 2:1.

[0089] A method for preparing high-pumpability concrete specially used for high-rise buildings, characterized in that it comprises the following steps:

[0090] Stir cement, fly ash and water at 150r / min for 5 minutes until evenly mixed, then add admixtures, retarders, thickeners and water-retaining agents in sequence and stir at 150r / min for 5 minutes. Finally, put silica fume, river sand and gravel into the mixer in sequence and stir at 400r / min for 3 minutes to obtain the final product, high-pumpability concrete for high-rise buildings.

[0091] Compared with Example 3, this comparative example is the same as Example 3 except that the thickening and water-retaining agent only uses microsilica powder and sodium linoleate, and the other raw materials and steps are the same as Example 3.

[0092] Comparative Example 5

[0093] A high-pumpability concrete specially used for high-rise buildings comprises the following raw materials in parts by weight: 480 parts of cement, 130 parts of fly ash, 780 parts of river sand, 960 parts of crushed stone, 35 parts of silica fume, 170 parts of water, 10 parts of admixture, 15 parts of thickening and water-retaining agent, 3 parts of air-entraining agent, and 10 parts of retarder.

[0094] The admixture is polycarboxylic acid water reducer, and the water reduction rate reaches 35%.

[0095] The thickening and water-retaining agent includes 5 parts of microsilica powder and 10 parts of cassava flour, and the mass ratio of the two is 1:2.

[0096] The air entraining agent includes 1.5 parts of sodium ricinoleate and 1.5 parts of dioctyl sodium sulfosuccinate, and the mass ratio of the two is 1:1.

[0097] The retarder is sodium citrate.

[0098] The crushed stones are 640 parts of 5-10 mm particle size and 320 parts of 10-20 mm particle size, and the mass ratio of the two types of crushed stones is 2:1.

[0099] A method for preparing high-pumpability concrete specially used for high-rise buildings, characterized in that it comprises the following steps:

[0100] Stir cement, fly ash and water at 150r / min for 5 minutes until evenly mixed, then add admixtures, retarders, thickeners and water-retaining agents in sequence and stir at 150r / min for 5 minutes. Finally, put silica fume, river sand and gravel into the mixer in sequence and stir at 400r / min for 3 minutes to obtain the final product, high-pumpability concrete for high-rise buildings.

[0101] Compared with Example 3, this comparative example is the same as Example 3 except that only microsilica powder and cassava flour are used as thickening and water-retaining agents. The other raw materials and steps are the same as those of Example 3.

[0102] Comparative Example 6

[0103] A high-pumpability concrete specially used for high-rise buildings comprises the following raw materials in parts by weight: 480 parts of cement, 130 parts of fly ash, 780 parts of river sand, 960 parts of crushed stone, 35 parts of silica fume, 170 parts of water, 10 parts of admixture, 15 parts of thickening and water-retaining agent, 3 parts of air-entraining agent, and 10 parts of retarder.

[0104] The admixture is polycarboxylic acid water reducer, and the water reduction rate reaches 35%.

[0105] The thickening and water-retaining agent includes 7.5 parts of sodium linoleate and 7.5 parts of tapioca flour, and the mass ratio of the two is 1:1.

[0106] The air entraining agent includes 1.5 parts of sodium ricinoleate and 1.5 parts of dioctyl sodium sulfosuccinate, and the mass ratio of the two is 1:1.

[0107] The retarder is sodium citrate.

[0108] The crushed stones are 640 parts of 5-10 mm particle size and 320 parts of 10-20 mm particle size, and the mass ratio of the two types of crushed stones is 2:1.

[0109] A method for preparing high-pumpability concrete specially used for high-rise buildings, characterized in that it comprises the following steps:

[0110] Stir cement, fly ash and water at 150r / min for 5 minutes until evenly mixed, then add admixtures, retarders, thickeners and water-retaining agents in sequence and stir at 150r / min for 5 minutes. Finally, put silica fume, river sand and gravel into the mixer in sequence and stir at 400r / min for 3 minutes to obtain the final product, high-pumpability concrete for high-rise buildings.

[0111] Compared with Example 3, this comparative example is the same as Example 3 except that the thickening and water-retaining agent only uses sodium linoleate and cassava flour, and the other raw materials and steps are the same as Example 3.

[0112] Comparative Example 7

[0113] A high-pumpability concrete specially used for high-rise buildings comprises the following raw materials in parts by weight: 480 parts of cement, 130 parts of fly ash, 780 parts of river sand, 960 parts of crushed stone, 35 parts of silica fume, 170 parts of water, 10 parts of admixture, 15 parts of thickening and water-retaining agent, 3 parts of air-entraining agent, and 10 parts of retarder.

[0114] The admixture is polycarboxylic acid water reducer, and the water reduction rate reaches 35%.

[0115] The thickening and water-retaining agent includes 3 parts of microsilica powder, 6 parts of sodium linoleate, and 6 parts of tapioca flour, and the mass ratio of the three is 1:2:2.

[0116] The air entraining agent is 3 parts of sodium ricinoleate.

[0117] The retarder is sodium citrate.

[0118] The crushed stones are 640 parts of 5-10 mm particle size and 320 parts of 10-20 mm particle size, and the mass ratio of the two types of crushed stones is 2:1.

[0119] A method for preparing high-pumpability concrete specially used for high-rise buildings, characterized in that it comprises the following steps:

[0120] Stir cement, fly ash and water at 150r / min for 5 minutes until evenly mixed, then add admixtures, retarders, thickeners and water-retaining agents in sequence and stir at 150r / min for 5 minutes. Finally, put silica fume, river sand and gravel into the mixer in sequence and stir at 400r / min for 3 minutes to obtain the final product, high-pumpability concrete for high-rise buildings.

[0121] Compared with Example 3, this comparative example is the same as Example 3 except that only sodium ricinoleate is used as the air entraining agent. Other raw materials and steps are the same as those of Example 3.

[0122] Comparative Example 8

[0123] A high-pumpability concrete specially used for high-rise buildings comprises the following raw materials in parts by weight: 480 parts of cement, 130 parts of fly ash, 780 parts of river sand, 960 parts of crushed stone, 35 parts of silica fume, 170 parts of water, 10 parts of admixture, 15 parts of thickening and water-retaining agent, 3 parts of air-entraining agent, and 10 parts of retarder.

[0124] The admixture is polycarboxylic acid water reducer, and the water reduction rate reaches 35%.

[0125] The thickening and water-retaining agent includes 3 parts of microsilica powder, 6 parts of sodium linoleate, and 6 parts of tapioca flour, and the mass ratio of the three is 1:2:2.

[0126] The air entraining agent is 3 parts of dioctyl sodium sulfosuccinate.

[0127] The retarder is sodium citrate.

[0128] The crushed stones are 640 parts of 5-10 mm particle size and 320 parts of 10-20 mm particle size, and the mass ratio of the two types of crushed stones is 2:1.

[0129] A method for preparing high-pumpability concrete specially used for high-rise buildings, characterized in that it comprises the following steps:

[0130] Stir cement, fly ash and water at 150r / min for 5 minutes until evenly mixed, then add admixtures, retarders, thickeners and water-retaining agents in sequence and stir at 150r / min for 5 minutes. Finally, put silica fume, river sand and gravel into the mixer in sequence and stir at 400r / min for 3 minutes to obtain the final product, high-pumpability concrete for high-rise buildings.

[0131] Compared with Example 3, this comparative example is the same as Example 3 except that only sodium dioctyl sulfosuccinate is used as the air entraining agent. Other raw materials and steps are the same as those of Example 3.

[0132] Performance Testing

[0133] The slump and expansion of the concrete prepared in the embodiment of the present invention and the comparative example are tested according to the method specified in GB50080-2016 "Standard for Test Methods for Performance of Ordinary Concrete Mixtures"; the viscosity is reflected by the T500 time, which is tested according to the method specified in CECS203-2006 "Technical Specifications for Application of Self-Compacting Concrete", and the longer the time, the greater the viscosity of the concrete; the pumping resistance is obtained by the tribometer test result, which is characterized by the pumping pressure loss per unit distance; the compressive strength is tested according to the method in the Standard for Test Methods for Mechanical Properties of Ordinary Concrete (GB / T50081-2002); in addition, the compressive water bleeding rate of each group of concrete is determined; the measured data are shown in Table 1.

[0134] Table 1 Performance test data table

[0135]

[0136] As can be seen from the data in Table 1, through the slump expansion, expansion time and pumping resistance test results of the concrete, it can be seen that the concrete with high pumpability for high-rise buildings using Examples 1-3 has greater fluidity, an expansion of more than 700 mm, and a smaller pumping resistance; in addition, it can be seen from the compressive water seepage rate results measured by the compressive water seepage test method that the high pumpability concrete for high-rise buildings of the present invention has a small compressive water seepage rate and has good resistance to segregation water seepage, which fully meets the requirements of high-rise concrete for resistance to segregation water seepage. In addition, the high pumpability concrete for high-rise buildings of the present invention has excellent compressive strength and meets the requirements of high-rise concrete for mechanical strength. Therefore, the concrete synthesized by the present invention can meet the requirements of high-rise building construction for resistance to segregation water seepage and high pumping.

[0137] It should be noted that the above embodiments are only partial embodiments of the preferred methods of implementing the present invention, rather than all embodiments. Obviously, based on the above embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

Claims

1. A high-pumpability concrete specially used for high-rise buildings, characterized in that: The invention comprises the following raw materials in parts by weight: 450-480 parts of cement, 100-130 parts of fly ash, 750-780 parts of river sand, 900-960 parts of crushed stone, 28-35 parts of silica fume, 160-170 parts of water, 9-10 parts of admixture, 10-15 parts of thickening and water-retaining agent, 1-3 parts of air-entraining agent and 5-10 parts of retarder.

2. The high-pumpability concrete for high-rise buildings according to claim 1 is characterized in that: The admixture is a polycarboxylate water reducer.

3. The high-pumpability concrete for high-rise buildings according to claim 1 is characterized in that: The thickening and water-retaining agent includes microsilica powder, sodium linoleate and cassava flour, and the mass ratio of the three is 1:2:

2.

4. The high-pumpability concrete for high-rise buildings according to claim 1 is characterized in that: The air entraining agent includes sodium ricinoleate and sodium dioctyl sulfosuccinate, and the mass ratio of the two is 1:

1.

5. The high-pumpability concrete for high-rise buildings according to claim 1 is characterized in that: The retarder is sodium citrate.

6. The high-pumpability concrete for high-rise buildings according to claim 1 is characterized in that: The river sand has a particle size of 5 mm, the crushed stones are granite crushed stones with particle sizes of 5-10 mm and 10-20 mm, and the mass ratio of the two crushed stones with different particle sizes is 2:

1.

7. A method for preparing high-pumpability concrete for high-rise buildings according to any one of claims 1 to 6, characterized in that: The following steps are involved: Mix cement, fly ash and water evenly and stir at low speed. Then add admixture, retarder, thickener and water-retaining agent and air-entraining agent in sequence and stir at low speed. Finally, add silica fume, river sand and gravel in sequence and stir at high speed to obtain the final product, high-pumpability concrete for high-rise buildings.

8. The method for preparing high-pumpability concrete for high-rise buildings according to claim 7, characterized in that: The rotation speed of the low-speed stirring is 150 r / min, and the time is 5 minutes; the rotation speed of the high-speed stirring is 400 r / min, and the time is 3 minutes.

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