1. The high-strength high-heat-insulation concrete is characterized by comprising the following components in parts by weight: 250-350 parts of ordinary portland cement, 80-180 parts of fly ash, 350-500 parts of sand, 800-900 parts of ceramsite, 8-20 parts of steel fiber, 8-20 parts of polypropylene fiber, 5-15 parts of modified polystyrene particles, 5-12 parts of a water reducing agent and 100-150 parts of water;

the modified polystyrene particles are prepared by the following method: melting polystyrene particles into a flowing state, adding silica particles and an air entraining agent, and uniformly stirring and mixing to obtain a mixed material; and conveying the mixed material into a double-screw extruder for extrusion forming, setting the heating temperature of the double-screw extruder to be 150-200 ℃, and carrying out underwater granulation and drying on the extruded melt to obtain modified polystyrene particles with silica particles as inner cores and polystyrene as outer layers.

2. The concrete of claim 1, wherein the mass ratio of the polystyrene particles, the silica particles and the air entraining agent in the mixture is: 100: (50-80): (0.3-0.5).

3. The concrete with high strength and high thermal insulation as claimed in claim 2, wherein the air entraining agent is sodium alkyl sulfonate or sodium alkyl benzene sulfonate.

4. The concrete of claim 1, wherein the Portland cement has a grade strength of P.042.5.

5. The concrete of claim 1, wherein the fly ash is more than two-grade fly ash.

6. The concrete of claim 1, wherein the ceramsite has a particle size of 5-15 mm and continuous gradation.

7. A high strength high thermal insulation concrete according to claim 1, wherein the polypropylene fibers have a tensile strength greater than 360MPa, a modulus of elasticity greater than 3.5GPa, and a tensile limit greater than 15%.

8. The concrete of claim 1, wherein the water reducer is a polycarboxylic acid water reducer.

9. The high-strength high-heat-insulation concrete according to any one of claims 1 to 8, further comprising the following components in parts by weight: 10-20 parts of an expanding agent.

10. The production process of the high-strength high-heat-insulation concrete according to any one of claims 1 to 9, characterized by comprising the following steps:

(1) adding ordinary portland cement, fly ash, sand, ceramsite, steel fiber, polypropylene fiber and modified polystyrene particles into a concrete mixer, and uniformly mixing;

(2) and adding a water reducing agent and water into the concrete mixer, and continuously and uniformly mixing to obtain the high-strength high-heat-preservation concrete.

Background

With the continuous deepening of the urbanization process in China, the resource consumption in the construction process and the energy consumption in the building operation process become the bottleneck of economic sustainable development. Because the total building construction amount and the requirement of people on living comfort are continuously improved at present, the proportion of building energy consumption in the total social energy consumption of China is over one third and is also increasing. The heat preservation and heat insulation performance of the building envelope is improved to reduce the building energy consumption.

At present, the heat preservation of the building wall is mainly realized by three modes, namely inner heat preservation of an outer wall, outer heat preservation of the outer wall and self heat preservation of the wall. The heat insulation in the outer wall is realized by laying heat insulation materials such as polystyrene heat insulation boards and the like on the inner side of the wall body, so that the heat insulation effect is achieved, the construction method is simple, the construction difficulty is low, the construction cost is low, but the wall body is easy to dewing and mildew due to the heat bridge phenomenon; and the inner heat-insulating wall body is greatly influenced by the external environment, and the wall body is easy to crack due to the day and night temperature difference and the season difference. The external wall external heat preservation is that heat preservation materials are paved outside the wall body to play a role in heat preservation and heat insulation, and the heat loss is reduced. Although the external thermal insulation of the external wall can avoid the phenomenon of a thermal bridge, the thermal insulation layer is paved outside, the construction is complex, the consumption is high, the external thermal insulation layer is seriously influenced by the climate environment, the phenomena of cracking, local falling and the like are easy to occur, the durability is poor, and the fire hazard exists. The self-insulation wall has the advantages of simple construction process and good heat insulation effect, and the wall material with the self-insulation effect is directly adopted without adopting additional heat insulation measures, so that the self-insulation wall becomes the first choice for reducing energy consumption of building construction.

The currently common self-insulation material is polyphenyl granule concrete, for example, chinese patent CN202010629141.5 discloses a high-strength light-weight heat-insulation concrete and a preparation method thereof, and the product is prepared from the following raw materials in parts by weight: 25-40 parts of cement; 15-20 parts of fly ash; 30-40 parts of aggregate; 0.5-1 part of polystyrene particles; 1-2 parts of a foaming agent; 0.5-1.5 parts of a water reducing agent; 8-12 parts of water; 1-1.5 parts of steel fiber and 1-1.5 parts of polypropylene fiber, and has the advantages of good heat preservation effect, light wall body and high strength; the preparation method is that the aggregate and the steel fiber are mixed and stirred evenly; adding cement and fly ash into the material c, and then adding water into the material c to obtain a material d; adding polystyrene particles and polypropylene fibers into the material d to obtain a material e; preparing a water reducing agent and a foaming agent into a mixed aqueous solution, uniformly stirring, spraying into the material e in an atomization mode, and uniformly stirring to prepare the high-strength light-weight heat-insulating concrete; the concrete prepared by the method has the advantages of good heat preservation effect, light wall and high strength. However, the density and strength of the polystyrene particles are very low, and the polystyrene particles are easy to float upwards in the concrete preparation and stirring process, so that the polystyrene particles cannot be uniformly mixed in the concrete, the strength and the heat preservation performance of different positions in a prepared and molded concrete block are inconsistent, and the overall strength index and the heat preservation performance of the finished concrete are affected.

Disclosure of Invention

The invention aims to provide high-strength high-heat-insulation concrete and a production process thereof aiming at the defects of the prior art.

In order to solve the technical problems, the invention adopts the following technical scheme:

the high-strength high-heat-insulation concrete comprises the following components in parts by weight: 250-350 parts of ordinary portland cement, 80-180 parts of fly ash, 350-500 parts of sand, 800-900 parts of ceramsite, 8-20 parts of steel fiber, 8-20 parts of polypropylene fiber, 5-15 parts of modified polystyrene particles, 5-12 parts of a water reducing agent and 100-150 parts of water;

the modified polystyrene particles are prepared by the following method: melting polystyrene particles into a flowing state, adding silica particles and an air entraining agent, and uniformly stirring and mixing to obtain a mixed material; and conveying the mixed material into a double-screw extruder for extrusion forming, setting the heating temperature of the double-screw extruder to be 150-200 ℃, and carrying out underwater granulation and drying on the extruded melt to obtain modified polystyrene particles with silica particles as inner cores and polystyrene as outer layers.

Preferably, the mass ratio of the polystyrene particles, the silica particles and the air entraining agent in the mixed material is as follows: 100: (50-80): (0.3-0.5).

Preferably, the air entraining agent is sodium alkyl sulfonate or sodium alkyl benzene sulfonate.

Preferably, the portland cement has a grade strength of p.042.5.

Preferably, the fly ash is more than two-grade fly ash.

Preferably, the particle size of the ceramsite is 5-15 mm, and the grading is continuous.

Preferably, the tensile strength of the polypropylene fiber is more than 360MPa, the elastic modulus is more than 3.5GPa, and the tensile limit is more than 15%.

Preferably, the water reducing agent is a polycarboxylic acid water reducing agent.

Preferably, the food also comprises the following components in parts by weight: 10-20 parts of an expanding agent.

The invention also provides a production process of the high-strength high-heat-insulation concrete, which comprises the following steps:

(1) adding ordinary portland cement, fly ash, sand, ceramsite, steel fiber, polypropylene fiber and modified polystyrene particles into a concrete mixer, and uniformly mixing;

(2) and adding a water reducing agent and water into the concrete mixer, and continuously and uniformly mixing to obtain the high-strength high-heat-preservation concrete.

Compared with the prior art, the invention has the beneficial effects that:

according to the high-strength high-heat-preservation concrete, the modified polystyrene particles are added, so that the prepared concrete has self-heat-preservation performance, and meanwhile, compared with the traditional polystyrene particle concrete, the density of the modified polystyrene particles is improved, so that the modified polystyrene particles are not easy to float upwards in the stirring process, and further, the modified polystyrene particles can be distributed more uniformly at each point in the concrete, and the overall heat-preservation performance and structural strength of the finished concrete are improved; on the other hand, the silica particles coated in the modified polystyrene particles can not only improve the density of the modified polystyrene particles, but also enhance the strength of the modified polystyrene particles, so that the overall strength of the finished concrete is further improved.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims thereof.

It will be appreciated by those skilled in the art that the objects and advantages that can be achieved with the present invention are not limited to the specific details set forth above, and that these and other objects that can be achieved with the present invention will be more clearly understood from the detailed description that follows.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.

It is to be understood that the processing equipment or apparatus not specifically identified in the following examples is conventional in the art.

Furthermore, it is to be understood that one or more method steps mentioned in the present invention does not exclude that other method steps may also be present before or after the combined steps or that other method steps may also be inserted between these explicitly mentioned steps, unless otherwise indicated; moreover, unless otherwise indicated, the numbering of the various method steps is merely a convenient tool for identifying the various method steps, and is not intended to limit the order in which the method steps are arranged or the scope of the invention in which the invention may be practiced, and changes or modifications in the relative relationship may be made without substantially changing the technical content.

The embodiment of the invention provides high-strength high-heat-insulation concrete which comprises the following components in parts by weight: 250-350 parts of ordinary portland cement, 80-180 parts of fly ash, 350-500 parts of sand, 800-900 parts of ceramsite, 8-20 parts of steel fiber, 8-20 parts of polypropylene fiber, 5-15 parts of modified polystyrene particles, 5-12 parts of water reducing agent and 100-150 parts of water. The grade strength of the ordinary portland cement can be selected to be P.042.5, so that the prepared concrete block has good compressive strength. The fly ash can be selected from two-stage or one-stage fly ash, and the fly ash with more than two stages has the advantages of good workability, strong pumpability, high impact resistance and strong frost resistance. The grain size of the ceramsite can be selected to be 5-15 mm, and the grading is continuous. The water reducing agent can be selected from polycarboxylic acid water reducing agents. In addition, a proper amount of thickener can be added into the concrete raw material formula to improve the viscosity of the concrete. The concrete raw materials of the embodiment of the invention are all commercially available except that the modified polystyrene particles are self-made.

The modified polystyrene particles are prepared by the following method: melting polystyrene particles into a flowing state, adding silica particles and an air entraining agent, and uniformly stirring and mixing to obtain a mixed material; and (3) conveying the mixed material into a double-screw extruder for extrusion forming, setting the heating temperature of the double-screw extruder to be 150-200 ℃, and carrying out underwater granulation and drying on the extruded melt to obtain modified polystyrene particles with silica particles as inner cores and polystyrene as outer layers.

The specific gravity of the conventional polystyrene particles is only about 1.0, so that in the process of preparing the polystyrene particle concrete by using the conventional polystyrene particles, the polystyrene particles are greatly different from other raw materials of the concrete, such as sand, so that the polystyrene particles are easy to float on the upper part of the concrete slurry in the stirring process, the heat insulation performance and the strength index of each point in the finally prepared finished concrete are inconsistent, the concrete is characterized in that the heat conductivity coefficient of the upper part of the finished concrete block is lower than that of the lower part of the finished concrete block, and the compressive strength of the upper part of the finished concrete block is lower than that of the lower part of the finished concrete block, so that the uniformity of the heat insulation performance and the compressive strength of the whole concrete block is not facilitated. On the other hand, the polystyrene particles are prepared from organic material styrene through crosslinking and polymerization reaction, and compared with inorganic components in concrete raw materials, the compressive strength of the polystyrene particles is obviously reduced, so that the strength of the polystyrene particle concrete is gradually reduced along with the increase of the content of the polystyrene particles in the polystyrene particle concrete, the increase of the overall strength of the polystyrene particle concrete is not facilitated, and the application of the polystyrene particle concrete in certain projects with high requirements on the pressure-bearing strength is limited.

Aiming at the defects of polystyrene particle concrete prepared from conventional polystyrene particles, the embodiment of the invention improves the conventional polystyrene particles, melts the polystyrene particles into a viscous flowing state at the melting temperature of polystyrene, namely within the range of 150-200 ℃, then adds silica particles and an air entraining agent into the polystyrene particles, and continuously stirs the mixture to ensure that the silica particles are uniformly distributed in the polystyrene; meanwhile, the addition of the air entraining agent can promote the silica particles to be distributed more uniformly in the polystyrene melt and can also form a plurality of fine bubbles in the polystyrene melt, so that the inner core of the modified polystyrene particles prepared by extruding and cooling and forming the uniformly stirred mixed material underwater is the silica particles, and the outer layer is porous polystyrene. The introduction of the inner core silica particles can obviously improve the specific gravity of the modified polystyrene particles, so that the modified polystyrene particles are not easy to float in the preparation process of the concrete and can be distributed in the concrete raw material more uniformly; the outer porous polystyrene still retains the good heat preservation and heat insulation performance of the conventional polystyrene. On the other hand, the introduction of the inorganic silica particles can also improve the strength performance of the polystyrene particles, so that the strength of the prepared finished concrete block is further improved. In addition, the introduction of the inorganic silica particles can also improve the fire resistance of the prepared concrete. Preferably, the air entraining agent can be sodium alkyl sulfonate or sodium alkyl benzene sulfonate.

Preferably, the mass ratio of the polystyrene particles, the silica particles and the air entraining agent in the mixed material is as follows: 100: (50-80): (0.3-0.5). The addition amount of the silica particles needs to be strictly controlled, and if the addition amount of the silica particles is too low, the inner core of the finally prepared modified polystyrene particle will contain a small amount of silica, and the effect of improving the density cannot be achieved; however, since the addition amount of the silica particles is too high, the coating thickness of the polystyrene particles as a coating layer is limited, and the heat insulating property and heat insulating property of the modified polystyrene particles are lowered, the silica particles in the embodiment of the present invention are preferably added in an amount of 50 to 80% by mass of the polystyrene particles. Because the polystyrene particles can destroy the internal porosity characteristic of the original polystyrene particles after melting, cooling and re-forming, a small amount of air entraining agent is added into the melt of the polystyrene, so that the outer layer of the re-formed modified polystyrene particles still has the porosity characteristic, the heat preservation and heat insulation performance of the modified polystyrene particles is improved, and the addition amount of the air entraining agent is preferably 0.3-0.5% of the mass of the polystyrene particles.

Preferably, the polypropylene fibers have a tensile strength greater than 360MPa, an elastic modulus greater than 3.5GPa, and a tensile limit greater than 15%. The tensile strength and the crack resistance of concrete can be improved by adding the polypropylene fibers, the larger the length of the polypropylene fibers is, the larger the frictional drawing resistance between the polypropylene fibers and a concrete matrix is, the better the damage degree of the concrete to the external force is, but the blending performance between the overlong polypropylene fibers and the concrete raw materials in the stirring process is poorer, so that the length of the polypropylene fibers selected in the embodiment of the invention is 8-12 mm.

In order to improve the crack resistance of the finished concrete block, preferably, the high-strength high-heat-preservation concrete of the embodiment of the invention further comprises the following components in parts by weight: 10-20 parts of an expanding agent. The addition of the expanding agent can improve the cracking problem of concrete caused by rapid temperature rise or rapid temperature drop.

The embodiment of the invention also provides a production process of the high-strength high-heat-insulation concrete, which comprises the following steps:

(1) adding the ordinary portland cement, the fly ash, the sand, the ceramsite, the steel fiber, the polypropylene fiber and the modified polystyrene particles in the proportion into a concrete mixer, and uniformly mixing;

(2) and adding a water reducing agent and water into the concrete mixer, and continuously and uniformly mixing to obtain the high-strength high-heat-preservation concrete. During this stirring, a swelling agent may also be added in the amount prescribed.

The following is a further description with reference to specific examples.

Example 1

The embodiment 1 of the invention provides high-strength high-heat-insulation concrete and a production process thereof. The high-strength high-heat-insulation concrete comprises the following components in parts by weight: 250 parts of ordinary portland cement, 100 parts of fly ash, 350 parts of sand, 800 parts of ceramsite, 8 parts of steel fiber, 10 parts of polypropylene fiber, 8 parts of modified polystyrene particles, 5 parts of a water reducing agent and 100 parts of water.

The modified polystyrene particles are prepared by the following method: melting polystyrene particles into a flowing state at 180 ℃, adding silicon dioxide particles and an alkyl sodium sulfonate air entraining agent, stirring and mixing uniformly to obtain a mixed material, wherein the mass ratio of the polystyrene particles to the silicon dioxide particles to the air entraining agent in the mixed material is as follows: 100: 50: 0.3; and (3) conveying the mixed material into a double-screw extruder for extrusion forming, setting the heating temperature of the double-screw extruder to be 180-200 ℃, and carrying out underwater granulation and drying on the extruded melt to obtain modified polystyrene particles with silica particles as inner cores and polystyrene as outer layers.

The production process of the high-strength high-heat-preservation concrete comprises the following steps: (1) adding the ordinary portland cement, the fly ash, the sand, the ceramsite, the steel fiber, the polypropylene fiber and the modified polystyrene particles in the proportion into a concrete mixer, and uniformly mixing;

(2) and adding the water reducing agent and the water in the ratio into a concrete mixer, and continuously and uniformly mixing to obtain the high-strength high-heat-preservation concrete.

Example 2

The embodiment 2 of the invention provides high-strength high-heat-preservation concrete and a production process thereof. The high-strength high-heat-insulation concrete comprises the following components in parts by weight: 300 parts of ordinary portland cement, 150 parts of fly ash, 400 parts of sand, 800 parts of ceramsite, 12 parts of steel fiber, 15 parts of polypropylene fiber, 10 parts of modified polystyrene particles, 8 parts of water reducing agent and 120 parts of water.

The modified polystyrene particles are prepared by the following method: melting polystyrene particles into a flowing state at 180 ℃, adding silicon dioxide particles and sodium alkyl benzene sulfonate air entraining agent, stirring and mixing uniformly to obtain a mixed material, wherein the mass ratio of the polystyrene particles to the silicon dioxide particles to the air entraining agent in the mixed material is as follows: 100: 60: 0.4; and (3) conveying the mixed material into a double-screw extruder for extrusion forming, setting the heating temperature of the double-screw extruder to be 150-180 ℃, and carrying out underwater granulation and drying on the extruded melt to obtain modified polystyrene particles with silica particles as inner cores and polystyrene as outer layers.

The production process of the high-strength high-heat-preservation concrete is the same as that of the example 1.

Example 3

The embodiment 3 of the invention provides high-strength high-heat-insulation concrete and a production process thereof. The high-strength high-heat-insulation concrete comprises the following components in parts by weight: 350 parts of ordinary portland cement, 180 parts of fly ash, 500 parts of sand, 900 parts of ceramsite, 18 parts of steel fiber, 20 parts of polypropylene fiber, 15 parts of modified polystyrene particles, 12 parts of a water reducing agent and 150 parts of water.

The modified polystyrene particles are prepared by the following method: melting polystyrene particles into a flowing state at 180 ℃, adding silicon dioxide particles and sodium alkyl benzene sulfonate air entraining agent, stirring and mixing uniformly to obtain a mixed material, wherein the mass ratio of the polystyrene particles to the silicon dioxide particles to the air entraining agent in the mixed material is as follows: 100: 80: 0.5; and (3) conveying the mixed material into a double-screw extruder for extrusion forming, setting the heating temperature of the double-screw extruder to be 180-200 ℃, and carrying out underwater granulation and drying on the extruded melt to obtain modified polystyrene particles with silica particles as inner cores and polystyrene as outer layers.

The production process of the high-strength high-heat-preservation concrete is the same as that of the example 1.

Example 4

The embodiment 4 of the invention provides high-strength high-heat-preservation concrete and a production process thereof. The high-strength high-heat-insulation concrete comprises the following components in parts by weight: 300 parts of ordinary portland cement, 150 parts of fly ash, 450 parts of sand, 850 parts of ceramsite, 15 parts of steel fiber, 18 parts of polypropylene fiber, 10 parts of modified polystyrene particles, 8 parts of water reducing agent, 15 parts of expanding agent and 130 parts of water.

The modified polystyrene particles are prepared by the following method: melting polystyrene particles into a flowing state at 180 ℃, adding silicon dioxide particles and an alkyl sodium sulfonate air entraining agent, stirring and mixing uniformly to obtain a mixed material, wherein the mass ratio of the polystyrene particles to the silicon dioxide particles to the air entraining agent in the mixed material is as follows: 100: 60: 0.4; and (3) conveying the mixed material into a double-screw extruder for extrusion forming, setting the heating temperature of the double-screw extruder to be 180-200 ℃, and carrying out underwater granulation and drying on the extruded melt to obtain modified polystyrene particles with silica particles as inner cores and polystyrene as outer layers.

The production process of the high-strength high-heat-preservation concrete comprises the following steps: (1) adding the ordinary portland cement, the fly ash, the sand, the ceramsite, the steel fiber, the polypropylene fiber and the modified polystyrene particles in the proportion into a concrete mixer, and uniformly mixing;

(2) and adding the water reducing agent, the expanding agent and the water in the ratio into a concrete mixer, and continuously and uniformly mixing to obtain the high-strength high-heat-preservation concrete.

Comparative example 1

It is different from example 3 in that conventional polystyrene particles are used in the concrete raw material, and other raw materials, raw material contents, and concrete production processes are the same.

The concrete prepared in examples 1 to 4 and comparative example 1 was poured into a mold, and after 24 hours of storage at room temperature, test pieces were poured out, the test pieces were 150mm × 150mm × 150mm in size, and each molded test piece was stored in a curing chamber at a temperature of 25 ℃ and a humidity of 95% or more for 28 days, and then the thermal conductivity and compressive strength of each test piece were measured, and the measurement results are shown in table 1. The heat conductivity coefficient was measured according to GB/T10294-2019, and the compressive strength was measured according to GB/T50081-2019.

TABLE 1

As seen from Table 1, compared with comparative example 1, the concrete test piece prepared by using the modified polystyrene particles has smaller heat conductivity coefficient and obviously improved compressive strength, which shows that compared with the conventional polystyrene particle concrete, the concrete prepared by the embodiment of the invention has better heat insulation performance and compressive strength.

Further, in order to investigate the difference between the heat insulating property and the compressive property of the concrete foundation blocks in different height directions within the concrete specimen, the specimen prepared in example 3 was equally divided into three pieces along the height direction thereof, each piece having a height of 50mm, the uppermost layer was designated as 3-1, the intermediate layer was designated as 3-2, and the lowermost layer was designated as 3-3, wherein the uppermost layer represents a layer located on the upper surface when the concrete specimen was cast, the lowermost layer represents a layer located on the lower surface when the concrete specimen was cast, and the intermediate layer is located between the upper and lower surface layers. The concrete specimen prepared in comparative example 1 was equally divided into three pieces in the height direction thereof in the same manner, each piece having a height of 50mm, the uppermost layer was designated as pair 1-1, the intermediate layer was designated as pair 1-2, and the lowermost layer was designated as pair 1-3, and the thermal conductivity and compressive strength of the different layers of each specimen were measured in the same manner, and the measurement results are shown in table 2.

TABLE 2

As seen from table 2, compared with comparative example 1, the concrete blocks in different height directions in the concrete sample prepared in example 3 of the present invention have higher data concentration degree and smaller variance, which indicates that the thermal insulation performance and the compressive strength of each point in the concrete sample prepared in example 3 of the present invention are more uniform. The concrete sample prepared in comparative example 1 had an upper layer having a thermal conductivity significantly lower than that of the lower layer, and a compressive strength significantly lower than that of the lower layer, because conventional polystyrene particles have a low specific gravity and cannot be uniformly distributed in the concrete slurry. Therefore, compared with the conventional polystyrene particle concrete, the concrete prepared by the modified polystyrene particles has more excellent heat insulation performance and compressive strength.

The protective scope of the present invention is not limited to the above-described embodiments, and it is apparent that various modifications and variations can be made to the present invention by those skilled in the art without departing from the scope and spirit of the present invention. It is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.