CN115504751A

CN115504751A - Concrete and preparation method thereof

Info

Publication number: CN115504751A
Application number: CN202110698317.7A
Authority: CN
Inventors: 柳祚龙; 施文照; 韦景然; 金伟; 胡广君
Original assignee: CR Chemical Materials Technology Inc
Current assignee: CR Chemical Materials Technology Inc
Priority date: 2021-06-23
Filing date: 2021-06-23
Publication date: 2022-12-23
Anticipated expiration: 2041-06-23
Also published as: CN115504751B

Abstract

The invention discloses a concrete and a preparation method thereof, wherein the concrete comprises the following components: cement, polyester foaming beads, fly ash, quicklime, gravel, fine slag, a compatilizer and a slow-setting water reducer. The concrete prepared by the composition has excellent tensile strength and buffering performance, greatly reduces the cracking probability in use, can be easily cast and formed, has good stability, impermeability and heat insulation performance, and shows good temperature resistance and chemical, oil and frost attack resistance. At the same time the concrete also has a lower weight, resulting in a better strength to weight ratio, which has a positive impact on the costs of transportation and composite construction. In addition, the concrete helps to reduce the carbon footprint and improve concrete sustainability, thereby allowing the concrete to be used to build stronger, more flexible, lighter and more sustainable concrete structures, for example, from sidewalks and street fences, to precast concrete exterior wall cladding and manholes, and the like.

Description

Concrete and preparation method thereof

Technical Field

The invention relates to the field of building materials, in particular to concrete and a preparation method thereof.

Background

Concrete, referred to as "concrete" for short, is usually prepared by mixing cement as a cementitious material, sand and stone as aggregates, and water in a certain proportion, and stirring. The concrete has the characteristics of rich raw materials, low price and simple production process, has wide application range, is used in various civil engineering, and is also an important material in shipbuilding industry, mechanical industry, ocean development, geothermal engineering and the like. The concrete has the advantages of high compressive strength, easily obtained materials, easy forming and low price, can be combined with steel materials to prepare various bearing components, but has the fatal defects of low tensile strength, large brittleness and easy cracking, thereby reducing the bearing capacity of the concrete structure, shortening the service life and becoming the hidden danger of various disastrous accidents.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. To this end, an object of the present invention is to provide a concrete having excellent tensile strength and cushioning properties, greatly reducing the possibility of cracking in use, being easily cast and formed, and having good stability, impermeability and heat retention properties, exhibiting good temperature resistance and resistance to attack by chemicals, oils and frost. At the same time the concrete also has a lower weight, resulting in a better strength to weight ratio, which has a positive impact on the costs of transportation and composite construction. In addition, the concrete helps to reduce the carbon footprint and improve concrete sustainability, thereby allowing the concrete to be used to build stronger, more flexible, lighter and more sustainable concrete structures, for example, from sidewalks and street fences, to precast concrete exterior wall cladding and manholes, and the like.

In one aspect of the invention, a concrete is provided. According to an embodiment of the invention, the concrete comprises: cement, polyester foaming beads, fly ash, quicklime, gravel, fine slag, a compatilizer and a slow-setting water reducer.

According to the concrete provided by the embodiment of the invention, cement, polyester foaming beads, fly ash, quicklime, gravel, fine slag, compatilizer and slow-setting water reducer are mixed, namely the polyester foaming beads are filled in the concrete, so that the tensile strength and the buffering performance of the concrete can be obviously improved, the cracking probability of the concrete during use is greatly reduced, and the pouring and the forming are easily realized; meanwhile, the concrete has good stability, impermeability and heat insulation performance, and shows good temperature resistance and chemical, oil and frost attack resistance. Meanwhile, the weight of concrete can be greatly reduced by adding the polyester expanded beads as the filler, a better strength-weight ratio is generated, and positive influence is generated on the cost of transportation and a composite structure. In addition, the addition of polyester-based expanded beads as a filler helps to reduce the carbon footprint of the concrete, improving concrete sustainability. And the compatilizer is added, so that the problem of poor compatibility between the concrete and the polyester expanded beads can be effectively solved, and the mixing uniformity of the concrete raw material and the polyester expanded beads is greatly improved. The addition of the retarding water reducing agent enables the water reducing agent molecules to be directionally adsorbed on the surfaces of cement particles, so that the surfaces of the cement particles have the same charge (usually negative charge), an electrostatic repulsion effect is formed, the mutual dispersion of the cement particles is promoted, the flocculation structure is disintegrated, the wrapped part of water is released, and the water participates in flowing, so that the fluidity of the concrete mixture is effectively increased. In addition, the structure of the retarding and water reducing agent has hydrophilic branched chains which extend in the water solution, so that a hydrophilic three-dimensional adsorption layer with a certain thickness is formed on the surface of the adsorbed cement particles. When the cement particles are close to each other, the adsorption layers begin to overlap, namely, steric hindrance is generated among the cement particles, the more the overlap is, the larger the steric hindrance repulsive force is, the larger the obstruction to the coagulation among the cement particles is, and the slump of the concrete is kept good. Thus, the concrete of the present invention can be used to construct stronger, more flexible, lighter and more sustainable concrete structures, for example, from sidewalks and street barriers, to precast concrete exterior wall coverings and manholes, and the like.

In addition, the concrete according to the above embodiment of the present invention may have the following additional technical features:

in some embodiments of the present invention, the mass ratio of the cement, the polyester-based expanded beads, the fly ash, the quick lime, the gravel, the fine slag, the compatilizer, and the water-reducing retarder is (40-60): (20 to 30): (5-10): (5-10): (5-10): (5-10): (2-5): (1-5). Therefore, the tensile strength and the buffering performance of the concrete are obviously improved, and the cracking probability of the concrete in use is greatly reduced, so that the pouring and the forming are easily realized.

In some embodiments of the present invention, the compatibilizing agent is selected from at least one of polyether-modified polysiloxane and silicone oil, preferably polyether-modified polysiloxane. Therefore, the mixing uniformity of the concrete raw material and the polyester foaming beads can be greatly improved.

In some embodiments of the invention, the set retarding water reducer comprises at least one of sodium gluconate and sodium salt of B-tea sulfonic acid formaldehyde hyper-condensate.

In some embodiments of the present invention, the polyester-based expanded beads have a density of 100kg/m ³ ～250kg/m ³ . Thus, the weight of the concrete can be greatly reduced, resulting in a better strength to weight ratio, with a positive impact on the cost of transportation and composite structures.

In some embodiments of the present invention, the polyester-based expanded beads include polyester, a chain extender, a nucleating agent, an anti-hydrolysis agent, a stabilizer, a high temperature resistant lubricant, and a physical foaming agent. Therefore, the polyester expanded beads which are environment-friendly, high in expansion ratio, small in volume weight and high in compression resilience can be obtained, and the tensile strength, the buffering performance and other performances of the concrete can be remarkably improved by using the expanded beads as concrete fillers.

In some embodiments of the present invention, the mass ratio of the polyester, the chain extender, the nucleating agent, the hydrolysis resistance agent, the stabilizer, the high temperature resistant lubricant, and the physical foaming agent is 100: (0.5-2): (0.5-2): (0.5-1): (0.5-1): (0.2-0.5): (1.5-3). Therefore, the tensile strength, the buffering performance and other performances of the concrete can be obviously improved.

In some embodiments of the invention, the polyester comprises at least one of PET, PETG, PBT, PLA, PC, TPEE and rPET.

In some embodiments of the invention, the chain extender comprises at least one of pyromellitic anhydride (PMDA), 2,2' bis (2-oxazoline), and triglycidyl isocyanurate (TGIC). Therefore, the melt strength of the polyester is effectively improved, the foaming property of the polyester is improved, the phenomenon of obvious weakening along with the processing time is avoided, and the phenomena of foam collapse, foam hole breakage and foam hole combination in the foaming process are effectively prevented.

In some embodiments of the invention, the nucleating agent comprises at least one of silica, talc, montmorillonite.

In some embodiments of the invention, the anti-hydrolysis agent is a hindered aromatic carbodiimide-based anti-hydrolysis agent. Therefore, a large number of low potential energy points are formed at the interface between the melts in the foaming process, and a large number of uniform nucleation hot points are formed, so that the subsequent obtaining of the higher-magnification polyester foaming beads is facilitated.

In some embodiments of the invention, the stabilizer comprises at least one of trimethyl phosphate (TMP) and triphenyl phosphate (TPP).

In some embodiments of the invention, the high temperature lubricant comprises at least one of polyethylene wax, EBS, and PETs, preferably PETs.

In some embodiments of the invention, the physical blowing agent comprises at least one of carbon dioxide, nitrogen, an alkane, and a fluoride.

In a further aspect of the invention, the invention provides a method of making the above concrete. According to an embodiment of the invention, the method comprises: mixing cement, fly ash, quicklime, gravel, fine slag, compatilizer, retarding and water reducing agent and polyester foaming beads to obtain the concrete.

According to the method for preparing the concrete, disclosed by the embodiment of the invention, cement, the polyester foaming beads, the fly ash, quicklime, gravel, fine slag, the compatilizer and the slow setting water reducing agent are mixed, namely the polyester foaming beads are filled in the concrete, so that the tensile strength and the buffering performance of the concrete can be obviously improved, the cracking probability of the concrete in use is greatly reduced, and the pouring and the forming are easily realized; meanwhile, the concrete has good stability, impermeability and heat insulation performance, and shows good temperature resistance and chemical, oil and frost attack resistance. Meanwhile, the weight of concrete can be greatly reduced by adding the polyester foaming beads as fillers, a better strength-weight ratio is generated, and positive influence is generated on the cost of transportation and composite structures. In addition, the addition of polyester-based expanded beads as a filler helps to reduce the carbon footprint of the concrete, improving concrete sustainability. And the compatilizer is added, so that the problem of poor compatibility between the concrete and the polyester expanded beads can be effectively solved, and the mixing uniformity of the concrete raw material and the polyester expanded beads is greatly improved. The addition of the retarding water reducing agent enables the water reducing agent molecules to be directionally adsorbed on the surfaces of cement particles, so that the surfaces of the cement particles have the same charge (usually negative charge), an electrostatic repulsion effect is formed, the mutual dispersion of the cement particles is promoted, the flocculation structure is disintegrated, the wrapped part of water is released, and the water participates in flowing, so that the fluidity of the concrete mixture is effectively increased. In addition, the structure of the retarding and water reducing agent has hydrophilic branched chains which extend in the water solution, so that a hydrophilic three-dimensional adsorption layer with a certain thickness is formed on the surface of the adsorbed cement particles. When the cement particles are close to each other, the adsorption layers begin to overlap, namely, steric hindrance is generated among the cement particles, the more the overlap is, the larger the steric hindrance repulsive force is, the larger the obstruction to the coagulation among the cement particles is, and the slump of the concrete is kept good. Thus, the concrete obtained by the method of the application can be used for building stronger, more flexible, lighter and more sustainable concrete structures, for example, from sidewalks and street guardrails, to precast concrete exterior wall cladding and manholes, and the like.

In addition, the method for preparing concrete according to the above embodiment of the present invention may further have the following additional technical features:

in some embodiments of the present invention, the polyester-based expanded beads include polyester-based expanded beads, and the polyester-based expanded beads are prepared by the following steps: (1) Mixing polyester, a chain extender, a nucleating agent, an anti-hydrolysis agent, a stabilizer and a high-temperature-resistant lubricant, and then performing melt blending extrusion for granulation so as to obtain polyester modified particles; (2) Adding the polyester modified particles into a dry high-pressure reaction kettle, injecting a physical foaming agent into the dry high-pressure reaction kettle under high pressure, and infiltrating the polyester modified particles with the physical foaming agent under the conditions that the temperature is 160-260 ℃ and the vapor pressure is 5-10 MPa to form a polyester modified particle/foaming agent homogeneous saturated system; (3) And (3) opening a discharge valve at the bottom of the dry-type high-pressure reaction kettle in the step (2) to release pressure, forming internal and external pressure drop, enabling the homogeneous system to be in a thermodynamically unstable state, driving the cells to grow up, and then cooling, cleaning and drying to obtain the polyester foaming beads. Therefore, the polyester expanded beads which are environment-friendly, high in expansion ratio, small in volume weight and high in compression resilience can be obtained, and the tensile strength, the buffering performance and other performances of the concrete can be remarkably improved by using the expanded beads as concrete fillers.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a photograph of the polyester-based expanded beads obtained in example 1;

FIG. 2 is a sectional view of concrete obtained in example 2;

FIG. 3 is a photograph of concrete of example 3 after casting.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are illustrative and intended to explain the present invention and should not be construed as limiting the present invention.

In one aspect of the invention, a concrete is provided. According to the embodiment of the invention, the concrete comprises cement, polyester foaming beads, fly ash, quicklime, sand, fine slag, a compatilizer and a slow-setting water reducer.

The inventor finds that the tensile strength and the buffering performance of concrete can be remarkably improved by mixing cement, polyester foamed beads, fly ash, quicklime, gravel, fine slag, a compatilizer and a slow-setting water reducing agent, namely filling the polyester foamed beads in the concrete, the cracking probability of the concrete in use is greatly reduced, and thus pouring and forming are easily realized; meanwhile, the concrete has good stability, impermeability and heat insulation performance, and shows good temperature resistance and chemical, oil and frost attack resistance. Meanwhile, the weight of concrete can be greatly reduced by adding the polyester foaming beads as fillers, a better strength-weight ratio is generated, and positive influence is generated on the cost of transportation and composite structures. In addition, the addition of polyester-based expanded beads as fillers helps to reduce the carbon footprint of the concrete and improve concrete sustainability. And the compatilizer is added, so that the problem of poor compatibility between the concrete and the polyester expanded beads can be effectively solved, and the mixing uniformity of the concrete raw material and the polyester expanded beads is greatly improved. Adding the polyester modified particles into a dry high-pressure reaction kettle, injecting a physical foaming agent into the dry high-pressure reaction kettle under high pressure, and infiltrating the polyester modified particles with the physical foaming agent under the conditions that the temperature is 160-260 ℃ and the vapor pressure is 5-10 MPa to form a polyester modified particle/foaming agent homogeneous saturated system. Thus, the concrete of the present invention can be used to construct stronger, more flexible, lighter and more sustainable concrete structures, for example, from sidewalks and street barriers, to precast concrete exterior wall coverings and manholes, and the like.

Further, in the concrete composition, the mass ratio of cement, polyester foaming beads, fly ash, quicklime, gravel, fine slag, compatilizer and slow setting water reducer is (40-60): (20 to 30): (5-10): (5-10): (5-10): (5-10): (2-5): (1-5). The inventor finds that if the polyester foaming beads are added too much, the bonding force between the polyester foaming beads and concrete is poor, and the polyester foaming beads are easy to peel off; if too few polyester foaming beads are added, the weight is not obviously reduced, the carbon footprint is not obviously reduced, and the tensile strength, the buffering performance and the like of the concrete cannot be obviously improved; meanwhile, the compatilizer and the retarder are added into the concrete according to the mass ratio, the concrete and the polyester foaming beads have good compatibility and associativity, and the dispersion, lubrication, fluidity and anti-collapse performance of a concrete/polyester foaming bead system are excellent. Specifically, the above-mentioned compatibilizing agent includes, but is not limited to, at least one of polyether-modified polysiloxane and silicone oil. The inventor finds that, on one hand, a siloxane chain segment in the compatilizer has lipophilicity and good compatibility with silicate parts in concrete, and a polyether chain segment has hydrophilicity and good compatibility with polyester expanded beads, so that the problem of poor compatibility between the concrete and the polyester expanded beads is solved; on the other hand, the compatilizer has lower surface tension, heat resistance and excellent acid and alkali salt resistance, and when the compatilizer is added into a polyester foaming bead/concrete system, the friction force between the polyester foaming bead and concrete can be reduced, so that the damage of the polyester foaming bead in the stirring process is reduced, and the leveling property and the durability of the concrete are improved; on the other hand, the existence of the hydrophilic group enables the polyester foaming beads to be bonded with the concrete more tightly, the polyester foaming beads are not easy to peel off, the dispersibility of the polyester foaming beads in the concrete is improved, the stress of the concrete is better dispersed on the polyester foaming beads, and the tensile strength, the buffering performance and the heat preservation performance of the concrete are greatly improved.

Further, in the concrete composition, the retarding and water reducing agent comprises but is not limited to at least one of sodium gluconate and B-tea sulfonic acid formaldehyde high-condensation sodium salt, and the fine slag can be derived from industrial waste slag, so that the waste product is favorably recycled, and the requirement of the maximum particle size of the fine slag is not higher than 3cm.

Further, the polyester-based expanded beads include polyester-based expanded beads, and the density of the polyester-based expanded beads is 100kg/m ³ ～250kg/m ³ 5 to 20 times of foaming multiplying power and 50 to 300um of foam hole size. According to the GBT10799-2008 standard, the closed cell rate of the polyester foaming beads is more than 96 percent; according to ASTM C297, the polyester-based expanded beads had a tensile strength of greater than 1.0 MPa. According to one embodiment of the present invention, the polyester-based expanded beads include polyester, a chain extender, a nucleating agent, an anti-hydrolysis agent, a stabilizer, a high temperature resistant lubricant, and a physical foaming agent. The inventor finds that the addition of the chain extender can effectively improve the melt strength of the polyester and improve the foaming property of the polyester, does not have obvious weakening phenomenon along with the processing time, and effectively prevents the generation of foam collapse, foam breakage and foam combination phenomenon in the foaming process; the nucleating agent forms a large number of low potential energy points at the interface between melts in the foaming process to form a large number of uniform nucleating hot points, thereby being beneficial to obtaining higher-magnification polyester foaming beads subsequently; the hydrolysis resistance agent is added, so that the hydrolysis of the polyester generated in the processing process is effectively reduced, and the stability of the strength of the polyester foaming melt is ensured. The high-temperature-resistant lubricant can improve the phenomena of thermal degradation, melt fracture and surface roughness of the melt caused by excessive high temperature and shearing, improve the fluidity of the melt, enable the extruded and discharged surface to be smoother, is beneficial to the molding of the foaming material, and is also beneficial to the formation of uniform and stable foam holes with controllable size. The physical foaming agent impregnates polyester modified particles of polyester at certain temperature and vapor pressure (supercritical fluid) to form polymerizationAnd finally, opening a discharge valve at the bottom of the dry-type high-pressure reaction kettle to relieve pressure, forming internal and external pressure drop and thermodynamic instability, and finally driving the cells to grow up to obtain the polyester foaming beads with excellent characteristics of environmental friendliness, high foaming rate, small volume weight, high compression resilience and the like, so that the polyester foaming beads serving as the filler in the concrete can not only enable the stress of the concrete to be better dispersed on the polyester foaming beads, but also can obviously improve the performances of the concrete such as tensile strength, buffering and the like.

Further, in the polyester-based expanded beads, the mass ratio of the polyester to the chain extender to the nucleating agent to the hydrolysis resistant agent to the stabilizer to the high-temperature-resistant lubricant to the physical foaming agent is 100: (0.5-2): (0.5-2): (0.5-1): (0.5-1): (0.2-0.5): (1.5-3). The inventor finds that if the chain extender is added too high, the melt is in a gel state, similar to a rubber state, the color is also darkened, and the extrusion is not facilitated; if the addition of the chain extender is too low, the growth of foam cannot be supported, and the foam collapse phenomenon is caused; meanwhile, if the nucleating agent is added too much, agglomeration can be formed, which is not beneficial to the formation of a uniform cell structure; if the addition of the nucleating agent is too low, an ideal nucleating effect cannot be achieved, heterogeneous nucleating points are few, and a compact foam structure cannot be formed; if the adding amount of the stabilizer exceeds 2 parts by weight, the effects of inhibiting thermal degradation and side reactions are not increased any more, and a precipitation phenomenon exists; if the addition of the stabilizer is too low, the stability of melt processing and the generated thermal degradation cannot be effectively reduced, so that the material is discolored; in addition, the hydrolysis resistance agent added in the above amount can reduce the hydrolysis of the polyester in the processing process and ensure the stability of the strength of the polyester foaming melt; if the addition amount of the high-temperature-resistant lubricant is too low, the lubricating effect cannot be achieved, and the melt is relatively rough at a high temperature; if the addition amount of the high-temperature-resistant lubricant is too high, the melt strength of the melt is reduced, and the gas is not supported by the foam holes; meanwhile, if the addition amount of the physical foaming agent is too high, the excessive foaming agent does not participate in the cell growth process and the phenomenon of hole string exists because the solubility of the foaming agent is limited under certain temperature and pressure conditions; if the amount of the physical foaming agent added is too low, the foaming ratio is too low and the weight reduction is not significant.

Specifically, the polyester comprises but is not limited to at least one of PET, PETG, PBT, PLA, PC, TPEE and rPET, wherein the base material of the rPET polyester foamed bead can adopt recycled PET bottle flakes, thereby realizing the recycling of waste resources and solving the problem of environmental protection. In addition, the concrete manufacturing process generates a large amount of CO ₂ The addition of the polyester foaming beads is beneficial to reducing the carbon footprint of concrete and improving the sustainability of the concrete. Chain extenders include, but are not limited to, at least one of pyromellitic anhydride (PMDA), 2,2' bis (2-oxazoline), and triglycidyl isocyanurate (TGIC); nucleating agents include, but are not limited to, at least one of silica, talc, montmorillonite; hydrolysis resistance agents include, but are not limited to, hindered aromatic carbodiimide-based hydrolysis resistance agents; stabilizers include, but are not limited to, at least one of trimethyl phosphate (TMP) and triphenyl phosphate (TPP); high temperature resistant lubricants include, but are not limited to, at least one of polyethylene wax, EBS, and PETs, preferably PETs; physical blowing agents include, but are not limited to, at least one of carbon dioxide, nitrogen, alkanes.

Further, the polyester-based expanded beads include at least one of PET expanded beads, TPEE expanded beads, PLA expanded beads, PETG expanded beads, PBT expanded beads, rPET expanded beads and PC expanded beads (including at least one of bisphenol a polycarbonate and carbon dioxide-based polycarbonate PPC), that is, the polyester-based expanded beads of the present application are a bead combination consisting of at least one of PET expanded beads, TPEE expanded beads, PLA expanded beads, PETG expanded beads, PBT expanded beads, rPET expanded beads and PC expanded beads, and the rPET expanded beads, PLA expanded beads and PPC expanded beads are preferably selected from the group consisting of rPET expanded beads, rpt expanded beads and PPC expanded beads from the carbon neutral point of view, so as to reduce the carbon footprint of the concrete and improve the sustainability of the concrete. The inventor also finds that rPET expanded beads have excellent strength, and the rPET expanded beads are combined with PETG expanded beads to be used as filler to be added into concrete, so that better strength-weight ratio can be generated, the porosity of the foamed concrete is improved, and the tensile strength, the buffering performance and the heat insulation performance are greatly improved. Meanwhile, the polyester foaming beads are filled in a water seepage channel in a concrete system, so that the water seepage resistance of the concrete can be improved; meanwhile, the PETG foaming bead with excellent toughness is added into a concrete/rPET foaming bead system, so that the problem of large brittleness of concrete can be solved, the stress of the rPET foaming bead and slurry in the stirring process is buffered, the foam wall of the polyester foaming bead is not easy to break, and the stability of the foam structure is kept.

In a further aspect of the invention, the invention provides a method of making the above concrete. According to an embodiment of the invention, the method comprises: mixing cement, fly ash, quicklime, gravel, fine slag, compatilizer, retarding and water reducing agent and polyester foaming beads to obtain the concrete. The inventor finds that the tensile strength and the buffering performance of concrete can be remarkably improved by mixing cement, polyester foamed beads, fly ash, quicklime, gravel, fine slag, a compatilizer and a slow-setting water reducing agent, namely filling the polyester foamed beads in the concrete, the cracking probability of the concrete in use is greatly reduced, and thus pouring and forming are easily realized; meanwhile, the concrete has good stability, impermeability and heat insulation performance, and shows good temperature resistance and chemical, oil and frost attack resistance. Meanwhile, the weight of concrete can be greatly reduced by adding the polyester foaming beads as fillers, a better strength-weight ratio is generated, and positive influence is generated on the cost of transportation and composite structures. In addition, the addition of polyester-based expanded beads as fillers helps to reduce the carbon footprint of the concrete and improve concrete sustainability. And the compatilizer can effectively improve the problem of poor compatibility between the concrete and the polyester expanded beads, and greatly improve the mixing uniformity of the concrete raw material and the polyester expanded beads. The addition of the water-reducing retarder not only increases the dispersion, lubrication, fluidity and slump of concrete, but also has the function of synergistically improving the compatibility of the polyester foaming beads and the concrete due to the existence of hydrophilic groups. Thus, the concrete of the present invention can be used to construct stronger, more flexible, lighter and more sustainable concrete structures, for example, from sidewalks and street barriers, to precast concrete exterior wall coverings and manholes, and the like.

Further, the mixing of the cement, the fly ash, the quicklime, the gravel, the fine slag, the compatilizer, the water reducing retarder and the polyester foaming beads can be carried out by the following steps: firstly, mixing and stirring cement, fly ash, quicklime, water and a retarding and water reducing agent uniformly to obtain a mixture A; adding the sandstone and the fine slag into the mixture A, and uniformly stirring to obtain a mixture B; and finally, adding the polyester foaming beads and the compatilizer into the mixture B, and uniformly stirring to obtain the concrete C. Therefore, the efficiency and uniformity of mixing of the components can be greatly improved. Preferably, the stirring speed in the mixing process of the cement, the fly ash, the quicklime, the water and the retarding and water reducing agent is 200-300r/min, and the stirring time is 15-20 minutes; the sand and the fine slag are added into the mixture A with the stirring speed of 100-200r/min and the stirring time of 10-15 minutes; adding the polyester foaming beads and the compatilizer into the mixture B, and stirring at the speed of 50-80r/min for 10-15 minutes.

Further, the polyester-based expanded beads include polyester-based expanded beads, and according to an embodiment of the present invention, the polyester-based expanded beads may be prepared by:

s100: polyester, chain extender, nucleating agent, hydrolysis resistant agent, stabilizer and high temperature resistant lubricant are mixed and then are subjected to melt blending extrusion for granulation

In the step, polyester, a chain extender, a nucleating agent, an anti-hydrolysis agent, a stabilizer and a high-temperature-resistant lubricant are mixed and then are subjected to melt blending extrusion for granulation, so that polyester modified particles with the particle size of 0.5-1mm are obtained. The inventor finds that the addition of the chain extender can effectively improve the melt strength of the polyester and improve the foaming property of the polyester, does not obviously weaken along with the processing time, and effectively prevents the phenomena of collapse, cell breakage and cell combination in the foaming process; the nucleating agent forms a large number of low potential energy points at the interface between melts in the foaming process to form a large number of uniform nucleating hot points, thereby being beneficial to obtaining higher-magnification polyester foaming beads subsequently; the hydrolysis resistance agent is added, so that the hydrolysis of the polyester generated in the processing process is effectively reduced, and the stability of the strength of the polyester foaming melt is ensured; the high-temperature-resistant lubricant can improve the phenomena of thermal degradation, melt fracture and surface roughness of the melt caused by high temperature and shearing, improve the fluidity of the melt, enable the extruded and discharged surface to be smoother, is beneficial to the molding of the foaming material, and is also beneficial to the formation of uniform, stable and size-controllable cells, thereby being beneficial to the subsequent obtaining of the higher-magnification polyester foaming beads.

S200: adding the polyester modified particles and water into a dry high-pressure reaction kettle for mixing, and then injecting a physical foaming agent into the dry high-pressure reaction kettle

In the step, the polyester modified particles obtained by granulation are added into a dry high-pressure reaction kettle, then a physical foaming agent is injected into the dry high-pressure reaction kettle under high pressure, and the physical foaming agent and the polyester modified particles achieve better infiltration under the conditions that the temperature is 160-260 ℃ and the vapor pressure is 5-10 MPa, so that a polyester modified particle/foaming agent homogeneous saturated system is formed.

S300: opening the discharge valve at the bottom of the dry-type high-pressure reaction kettle in the step S200 to release pressure, and forming internal and external pressure drop

In the step, a discharge valve at the bottom of the dry-type high-pressure reaction kettle in the step S200 is opened for pressure relief, so that internal and external pressure drop is formed, a polyester modified particle/foaming agent homogeneous phase system is in a thermodynamically unstable state, cells are driven to grow up, and then the polyester modified particle/foaming agent homogeneous phase system is cooled, cleaned and dried to obtain polyester foaming beads. Preferably, the change in internal and external pressure drop is maintained between-0.1 MPa and 0.1MPa. Specifically, compare in prior art from the pressure release blowing start to the whole blowing in-process dry-type autoclave pressure that the blowing ended and reduce all the time, the pressure drop that later stage discharged polyester bead passed through is less than the pressure drop of earlier stage discharged polyester bead promptly to lead to having the inhomogeneous problem of density and cell size between the polyester foaming bead, this application maintains the inside and outside pressure drop of dry-type autoclave stable, thereby obtains the even polyester foaming bead of foam density and cell size. Specifically, the polyester foaming bead is filled in concrete, the weight is reduced by more than 30%, the surface of the concrete is not cracked, the combination of the polyester foaming bead and the concrete is good, and the tensile strength, the water seepage resistance and the heat preservation performance are improved to some extent.

It should be noted that the features and advantages described above for concrete apply equally to the method for preparing concrete, and are not described in detail here.

The following embodiments of the present invention are described in detail, and it should be noted that the following embodiments are exemplary only, and are not to be construed as limiting the present invention. In addition, all reagents used in the following examples are commercially available or can be synthesized according to methods herein or known, and are readily available to those skilled in the art for reaction conditions not listed, if not explicitly stated.

Example 1

Method for preparing expanded beads a:

(1) Uniformly mixing 100 parts by weight of rPET (from a recycled bottle flake), 0.5 part by weight of pyromellitic dianhydride (PMDA), 0.5 part by weight of 2,2' bis (2-oxazoline) (BO), 1 part by weight of talcum powder (Talc), 1 part by weight of trimethyl phosphate (TMP), 0.5 part by weight of hydrolysis resistant agent TNK-01 (hindered aromatic carbodiimide) and 0.5 part by weight of PETs (polyethylene terephthalate), and performing melt extrusion granulation at 260 ℃ by using a double-screw extruder (Koduralon STS-50MC 11) to obtain modified particles with the diameter of 1 mm;

(2) Adding the modified particles into a dry high-pressure reaction kettle, and then adding a physical foaming agent CO ₂ (the addition amount accounts for 2wt% of the final polyester foaming beads) is injected into a dry high-pressure reaction kettle, and under the conditions of vapor pressure of 10MPa and 250 ℃, the foaming agent is used for soaking rPET modified particles to form a homogeneous saturated system;

(3) Releasing pressure and discharging materials at a discharging valve at the bottom of the reaction kettle, cooling, cleaning with clear water, and drying to obtain rPET foaming beads A (the density is 200 kg/m) ³ )。

The method for preparing the concrete comprises the following steps:

(a) Mixing 11000g of cement, 1150g of fly ash, 1080g of quicklime, 5000g of water and 250g of sodium gluconate at a mixing speed of 250r/min for 15 minutes to obtain a mixture A;

(b) Then 1080g of sand and 1150g of fine slag are added into the mixture A and stirred for 12 minutes under the condition that the stirring speed is 130r/min, so as to obtain a mixture B;

(c) 4500g of the expanded beads A and 400g of the polyether-modified polysiloxane were added to the mixture B, and the mixture was stirred at a stirring speed of 70r/min for 12 minutes to obtain concrete.

Example 2

Method for preparing expanded beads C:

(1) Uniformly mixing 100 parts by weight of PETG, 0.5 part by weight of 2,2' bis (2-oxazoline) (BO), 0.5 part by weight of triglycidyl isocyanurate (TGIC), 1 part by weight of talcum powder (Talc), 0.8 part by weight of trimethyl phosphate (TMP), 0.5 part by weight of hydrolysis resistant agent TNK-01 (hindered aromatic carbodiimide) and 0.5 part by weight of PETs in proportion, and carrying out melt extrusion granulation at 220 ℃ by a double-screw extruder (Kedoulong STS-50MC 11) to obtain modified particles with the diameter of 1 mm;

(2) Adding the modified particles into a dry high-pressure reaction kettle, and respectively adding a physical foaming agent CO ₂ Injecting a foaming agent cyclopentane (the additive amount accounts for 2wt% of the final polyester foaming bead) and a foaming agent cyclopentane (the additive amount accounts for 1wt% of the final polyester foaming bead) into a dry high-pressure reaction kettle, and impregnating PETG modified particles with the foaming agent to form a homogeneous saturated system under the conditions of vapor pressure of 6MPa and 220 ℃;

(3) Releasing pressure and discharging at a discharging valve at the bottom of the reaction kettle, cooling, cleaning with clear water, and drying to obtain PETG foamed beads C (density of 150 kg/m) ³ )。

The method for preparing the concrete comprises the following steps:

(a) Stirring 10000g of cement, 1280g of fly ash, 1150g of quicklime, 5000g of water and 250g of sodium gluconate for 15 minutes at a stirring speed of 220r/min to obtain a mixture A;

(b) Then 1080g of sand and 1250g of fine slag are added into the mixture A and stirred for 12 minutes under the condition that the stirring speed is 120r/min, and a mixture B is obtained;

(c) 4500g of the expanded beads A of example 1, 500g of the expanded beads C and 520g of the polyether-modified polysiloxane were added to the mixture B and stirred at a stirring speed of 60r/min for 13 minutes to obtain concrete.

Example 3

Method for preparing expanded beads B:

(1) 100 parts by weight of rPET (from recycled bottle chips), 0.5 part by weight of pyromellitic anhydride (PMDA), 0.5 part by weight of 2,2' bis (2-oxazoline) (BO) and 1 part by weight of Silica (SiO) ₂ ) 0.5 weight part of trimethyl phosphate (TMP), 0.5 weight part of anti-hydrolysis agent TNK-01 (steric hindrance aromatic carbodiimide) and 0.5 weight part of PETs are uniformly mixed in proportion, and are subjected to melt extrusion granulation at 260 ℃ by a double-screw extruder (Cordouron STS-50MC 11) to obtain modified particles with the diameter of 1 mm;

(2) Adding the modified particles into a dry high-pressure reaction kettle, and then adding a physical foaming agent CO ₂ (the addition amount accounts for 2wt% of the final polyester expanded beads) is injected into a dry high-pressure reaction kettle, and under the conditions of vapor pressure of 10MPa and 260 ℃, the foaming agent is used for impregnating rPET modified particles to form a homogeneous saturated system;

(3) Releasing pressure and discharging materials at a discharging valve at the bottom of the reaction kettle, cooling, cleaning with clear water and drying to obtain rPET expanded beads B (the density is 150 kg/m) ³ )。

The method for preparing the concrete comprises the following steps:

(a) 11000g of cement, 1150g of fly ash, 1080g of quicklime, 5000g of water and 250g of sodium gluconate are stirred for 15 minutes at a stirring speed of 250r/min to obtain a mixture A;

(c) 4500g of the expanded beads B and 400g of silicone oil were added to the mixture B, and the mixture was stirred at a stirring speed of 70r/min for 12 minutes to obtain concrete.

Example 4

The method for preparing the concrete comprises the following steps:

(c) 4500g of the expanded beads B of example 3, 500g of the expanded beads C of example 2, and 520g of the polyether-modified polysiloxane were added to the mixture B, and the mixture was stirred at a stirring speed of 60r/min for 13 minutes to obtain concrete.

Example 5

Method for preparing expanded beads D:

(1) Uniformly mixing 100 parts by weight of PLA, 0.5 part by weight of pyromellitic dianhydride (PMDA), 1 part by weight of talcum powder (Talc), 0.5 part by weight of triphenyl phosphate (TPP), 0.5 part by weight of anti-hydrolysis agent TNK-01 (steric-hindrance aromatic carbodiimide) and 0.3 part by weight of PETs in proportion, and carrying out melt extrusion granulation at 190 ℃ by using a double-screw extruder (Kedoulong STS-50MC 11) to obtain modified particles with the diameter of 1 mm;

(2) Adding the modified particles into a dry high-pressure reaction kettle, and then adding a physical foaming agent N ₂ (the addition amount is 3wt% of the final polyester foaming beads) is injected into a dry high-pressure reaction kettle, and the foaming agent is soaked in the PLA modified particles to form a homogeneous saturated system under the conditions of vapor pressure of 5MPa and 190 ℃;

(3) Releasing pressure and discharging materials at a discharging valve at the bottom of the reaction kettle, cooling, cleaning with clear water and drying to obtain PLA foaming beads D (the density is 180 kg/m) ³ )。

The method for preparing the concrete comprises the following steps:

(a) Stirring 11200g of cement, 1100g of fly ash, 1180g of quicklime, 5000g of water and 250g of sodium gluconate for 15 minutes at the stirring speed of 250r/min to obtain a mixture A;

(b) Then adding 500g of sand and 200g of fine slag into the mixture A, and stirring for 12 minutes at the stirring speed of 130r/min to obtain a mixture B;

(c) 4000g of the expanded beads D and 480g of the polyether-modified polysiloxane were added to the mixture B, and the mixture was stirred at a stirring speed of 70r/min for 12 minutes to obtain concrete.

Example 6

Method for preparing expanded beads E:

(1) Uniformly mixing 100 parts by weight of rPBT, 0.5 part by weight of 2,2' bis (2-oxazoline) (BO), 1 part by weight of talcum powder (Talc), 0.5 part by weight of triphenyl phosphate (TPP), 0.5 part by weight of anti-hydrolysis agent TNK-01 (hindered aromatic carbodiimide) and 0.3 part by weight of PETs in proportion, and carrying out melt extrusion granulation at 220 ℃ by a double-screw extruder (Kedoulong STS-50MC 11) to obtain modified particles with the diameter of 1 mm;

(2) Adding the modified particles into a dry high-pressure reaction kettle, and then adding a physical foaming agent CO ₂ (the addition amount is 1.5wt% of the final polyester expanded beads) is injected into a dry high-pressure reaction kettle, and the blowing agent is soaked in the PBT modified particles to form a homogeneous saturated system under the conditions of vapor pressure of 7MPa and 220 ℃;

(3) Releasing pressure and discharging materials at a discharging valve at the bottom of the reaction kettle, cooling, cleaning with clear water and drying to obtain PBT (Polybutylece terephthalate) foamed beads E (the density is 180 kg/m) ³ )。

The method for preparing the concrete comprises the following steps:

(a) Stirring 10500g of cement, 1350g of fly ash, 1280g of quicklime, 5000g of water and 250g of sodium salt of a high condensation compound of B-tea sulfonic acid formaldehyde for 15 minutes at the stirring speed of 250r/min to obtain a mixture A;

(b) Then 1250g of sand and 1280g of fine slag are added into the mixture A and stirred for 12 minutes under the condition that the stirring speed is 120r/min, so as to obtain a mixture B;

(c) 4200g of the expanded beads E and 480g of the polyether-modified polysiloxane were added to the mixture B and stirred at a stirring speed of 70r/min for 12 minutes to obtain concrete.

Example 7

Method for preparing expanded beads F:

(1) 100 parts by weight of TPEE, 1 part by weight of triglycidyl isocyanurate (TGIC), 1 part by weight of Silica (SiO) ₂ ) 0.5 part by weight of triphenyl phosphate (TPP), 0.5 part by weight of anti-hydrolysis agent TNK-01 (steric hindrance aromatic carbodiimide), and 0.2 part by weight of polyethylene wax are uniformly mixed in proportion, and are subjected to melt extrusion granulation at 220 ℃ by a double-screw extruder (Kyoklung STS-50MC 11) to obtain modified particles with the diameter of 1 mm;

(2) Adding the modified particles into a dry high-pressure reaction kettle, and then adding a physical foaming agent CO ₂ (addition ofThe amount of the foaming agent accounts for 2wt percent of the final polyester foaming bead) and then the foaming agent is injected into a dry high-pressure reaction kettle, so that the foaming agent is impregnated into TPEE modified particles to form a homogeneous saturated system under the conditions of 6MPa of vapor pressure and 220 ℃;

(3) Releasing pressure and discharging materials at a discharging valve at the bottom of the reaction kettle, cooling, cleaning with clear water and drying to obtain TPEE foamed beads F (the density is 160 kg/m) ³ )。

The method for preparing the concrete comprises the following steps:

(a) Stirring 10200g of cement, 1280g of fly ash, 1280g of quicklime, 5000g of water and 250g of sodium salt of a high condensation compound of B-tea sulfonic acid formaldehyde for 15 minutes at the stirring speed of 250r/min to obtain a mixture A;

(b) Then 1250g of sand and 1250g of fine slag are added into the mixture A and stirred for 12 minutes under the condition that the stirring speed is 130r/min, and a mixture B is obtained;

(c) 4600g of the expanded beads F and 480g of the polyether-modified polysiloxane were added to the mixture B, and the mixture was stirred at a stirring speed of 70r/min for 12 minutes to obtain concrete.

Example 8

Method for preparing expanded beads G:

(1) Uniformly mixing 100 parts by weight of PET, 0.5 part by weight of pyromellitic dianhydride (PMDA), 0.5 part by weight of 2,2' bis (2-oxazoline) (BO), 2 parts by weight of montmorillonite (MMT), 1 part by weight of trimethyl phosphate (TMP), 0.5 part by weight of hydrolysis resistant agent TNK-01 (hindered aromatic carbodiimide), and 0.5 part by weight of EBS according to a proportion, and performing melt extrusion granulation at 260 ℃ by using a double-screw extruder (Kedoulong STS-50MC 11) to obtain modified particles with the diameter of 1 mm;

(2) Adding the modified particles into a dry high-pressure reaction kettle, and then adding a physical foaming agent CO ₂ (the addition amount accounts for 2wt% of the final polyester foaming beads) is injected into a dry high-pressure reaction kettle, and the foaming agent is used for impregnating the PET modified particles to form a homogeneous saturated system under the conditions of vapor pressure of 10MPa and 260 ℃;

(3) Releasing pressure and discharging materials at a discharging valve at the bottom of the reaction kettle, cooling, cleaning with clear water and drying to obtain PET foaming beads G (the density is 150 kg/m) ³ )。

The method for preparing the concrete comprises the following steps:

(a) Stirring 10800g of cement, 1180g of fly ash, 1120g of quicklime, 5000g of water and 250g of sodium gluconate for 15 minutes at a stirring speed of 250r/min to obtain a mixture A;

(b) Then 1080g of sand and 1150g of fine slag are added into the mixture A and stirred for 15 minutes under the condition that the stirring speed is 120r/min, so as to obtain a mixture B;

(c) 4500G of the expanded beads G and 450G of the polyether-modified polysiloxane were added to the mixture B, and the mixture was stirred at a stirring speed of 70r/min for 12 minutes to obtain concrete.

Example 9

Method for preparing expanded beads H:

(1) Uniformly mixing 100 parts by weight of PPC, 1 part by weight of 2,2' bis (2-oxazoline) (BO), 2 parts by weight of montmorillonite (MMT), 1 part by weight of trimethyl phosphate (TMP), 0.5 part by weight of anti-hydrolysis agent TNK-01 (hindered aromatic carbodiimide) and 0.5 part by weight of EBS in proportion, and carrying out melt extrusion granulation at 160 ℃ by using a double-screw extruder (Kedoulong STS-50MC 11) to obtain modified particles with the diameter of 1 mm;

(2) Adding the modified particles into a dry high-pressure reaction kettle, and then adding a physical foaming agent CO ₂ (the addition amount accounts for 2wt% of the final polyester foaming beads) is injected into a dry high-pressure reaction kettle, and under the conditions of vapor pressure of 10MPa and 160 ℃, the foaming agent is used for soaking PPC modified particles to form a homogeneous saturated system;

(3) Releasing pressure and discharging at a discharging valve at the bottom of the reaction kettle, cooling, cleaning with clear water, and drying to obtain PPC foamed beads H (density of 150 kg/m) ³ )。

The method for preparing the concrete comprises the following steps:

(b) Then 1080g of sandstone and 1150g of fine slag are added into the mixture A and stirred for 15 minutes under the condition that the stirring speed is 120r/min, so as to obtain a mixture B;

(c) 4500g of the expanded beads H and 450g of the polyether-modified polysiloxane were added to the mixture B, and the mixture was stirred at a stirring speed of 70r/min for 12 minutes to obtain concrete.

Example 10

The method for preparing the concrete comprises the following steps:

(a) Mixing 10400g of cement, 1000g of fly ash, 1280g of quicklime, 5000g of water and 250g of sodium gluconate at a mixing speed of 250r/min for 15 minutes to obtain a mixture A;

(b) Then 1250g of sand and 1380g of fine slag are added into the mixture A and stirred for 15 minutes under the condition that the stirring speed is 130r/min to obtain a mixture B;

(c) 3500G of the expanded beads G, 1000G of the expanded beads F and 520G of the polyether-modified polysiloxane were added to the mixture B, and the mixture was stirred at a stirring speed of 70r/min for 12 minutes to obtain concrete.

Example 11

The method for preparing the concrete comprises the following steps:

(a) 10100g of cement, 1240g of fly ash, 1200g of quicklime, 5000g of water and 250g of sodium gluconate are stirred for 15 minutes at the stirring speed of 250r/min to obtain a mixture A;

(b) Then 1250g of sand and 1280g of fine slag are added into the mixture A and stirred for 15 minutes under the condition that the stirring speed is 130r/min, so as to obtain a mixture B;

(c) The mixture B was stirred at a stirring speed of 70r/min for 12 minutes by adding 900g of the expanded beads C, 3800g of the expanded beads D and 520g of the polyether-modified polysiloxane to obtain concrete.

Example 12

The method for preparing the concrete comprises the following steps:

(a) Stirring 10500g of cement, 1100g of fly ash, 1180g of quicklime, 5000g of water and 250g of sodium gluconate for 15 minutes at a stirring speed of 250r/min to obtain a mixture A;

(b) Then 1150g of sand and 1150g of fine slag are added into the mixture A and stirred for 15 minutes under the condition that the stirring speed is 130r/min, so as to obtain a mixture B;

(c) 4100g of the expanded beads A, 600g of the expanded beads F, and 520g of the polyether-modified polysiloxane were added to the mixture B, and the mixture was stirred at a stirring speed of 70r/min for 12 minutes to obtain concrete.

Example 13

The method for preparing the concrete comprises the following steps:

(a) 10600g of cement, 1280g of fly ash, 1120g of quicklime, 5000g of water and 250g of sodium gluconate are stirred for 15 minutes at the stirring speed of 250r/min to obtain a mixture A;

(c) 1000g of the expanded beads E, 3500g of the expanded beads F and 520g of the polyether-modified polysiloxane were added to the mixture B, and the mixture was stirred at a stirring speed of 70r/min for 12 minutes to obtain concrete.

Example 14

The method for preparing the concrete comprises the following steps:

(a) 10400g of cement, 1170g of fly ash, 1240g of quicklime, 500g of water and 250g of sodium gluconate are stirred for 15 minutes at a stirring speed of 250r/min to obtain a mixture A;

(b) Then 1250g of sand and 1150g of fine slag are added into the mixture A and stirred for 15 minutes under the condition that the stirring speed is 120r/min, so as to obtain a mixture B;

(c) 1000G of the expanded beads E, 3600G of the expanded beads G and 520G of the polyether-modified polysiloxane were added to the mixture B, and the mixture was stirred at a stirring speed of 70r/min for 12 minutes to obtain concrete.

Example 15

The method for preparing the concrete comprises the following steps:

(a) 11000g of cement, 1020g of fly ash, 1080g of quicklime, 5000g of water and 250g of sodium gluconate are stirred for 15 minutes at the stirring speed of 250r/min to obtain a mixture A;

(b) 1050g of sandstone and 1150g of fine slag are added into the mixture A and stirred for 15 minutes under the condition that the stirring speed is 120r/min, so as to obtain a mixture B;

(c) 3500g of the expanded beads B, 1000g of the expanded beads F and 520g of the polyether-modified polysiloxane were added to the mixture B, and the mixture was stirred at a stirring speed of 70r/min for 12 minutes to obtain concrete.

Example 16

The method for preparing the concrete comprises the following steps:

(c) 3500g of the expanded beads A, 1000g of the expanded beads H, and 520g of the polyether-modified polysiloxane were added to the mixture B, and the mixture was stirred at a stirring speed of 70r/min for 12 minutes to obtain concrete.

Comparative example

The method for preparing the concrete comprises the following steps:

(a) Stirring 15000g of cement, 1200g of fly ash, 1080g of quicklime, 5000g of water and 250g of sodium gluconate for 15 minutes at the stirring speed of 250r/min to obtain a mixture A;

(b) Then, 1280g of sand and 1350g of fine slag are added into the mixture A and stirred for 12 minutes under the condition that the stirring speed is 130r/min, so as to obtain a mixture B;

(c) 400g of polyether modified polysiloxane was added to the mixture B and stirred at a stirring speed of 70r/min for 12 minutes to obtain concrete.

Evaluation:

1. the expanded beads a to H obtained in the above examples were evaluated for foam density, expansion ratio, cell size, difference between maximum and minimum sizes of cells, flexural strength, and dimensional thermal stability;

2. evaluation method of expanded bead Performance:

foam density: according to GB/T6343-86

Expansion ratio: ratio of density of material after foaming to density before foaming

Cell size: scanning Electron Microscope (SEM) dimension calibration

Difference between maximum and minimum size of cells: scanning Electron Microscope (SEM) dimension calibration

Compressive strength: according to ISO 844

The results of the tests on the expanded beads A to H obtained in the above examples are shown in Table 1.

TABLE 1 Performance data of the polyester-based expanded beads A to H

3. The concrete obtained in examples 1 to 16 and the comparative example were evaluated for volume weight, 3d flexural strength, thermal conductivity, surface cracking, and water absorption;

4. a method for evaluating concrete;

volume weight: GB/T1966-1996

Coefficient of thermal conductivity: GB/T10294

Surface cracking condition: JC/T984

Water absorption: GB/T5486

3d flexural strength: GB/T17671

The results of the characterization of the properties of the concretes obtained in examples 1 to 16 are shown in Table 2.

Table 2 concrete performance test data

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A concrete, comprising: cement, polyester foaming beads, fly ash, quicklime, gravel, fine slag, a compatilizer and a slow-setting water reducer.

2. The concrete according to claim 1, wherein the mass ratio of the cement, the polyester-based expanded beads, the fly ash, the quick lime, the gravel, the fine slag, the compatilizer, and the water-reducing retarder is (40-60): (20 to 30): (5-10): (5-10): (5-10): (5-10): (2-10): (1-5).

3. The concrete according to claim 1 or 2, wherein the compatibilizing agent is selected from at least one of polyether-modified polysiloxane and silicone oil;

optionally, the retarding and water reducing agent comprises at least one of sodium gluconate and B-tea sulfonic acid formaldehyde high condensation compound sodium salt.

4. The concrete according to claim 1 or 2, wherein the polyester-based expanded beads have a density of 100kg/m ³ ～250kg/m ³ 。

5. The method according to claim 1 or 2, wherein the polyester-based expanded beads comprise polyester, a chain extender, a nucleating agent, an anti-hydrolysis agent, a stabilizer, a high temperature resistant lubricant, and a physical foaming agent.

6. The concrete according to claim 5, wherein the mass ratio of the polyester, the chain extender, the nucleating agent, the hydrolysis resistance agent, the stabilizer, the high temperature resistant lubricant and the physical foaming agent is 100: (0.5-2): (0.5-2): (0.5-1): (0.5-1): (0.2-0.5): (1.5-3).

7. The concrete according to claim 5, wherein the polyesters comprise at least one of PET, PETG, PBT, PLA, PC, TPEE, and rPET;

optionally, the chain extender comprises at least one of pyromellitic anhydride, 2,2' bis (2-oxazoline), and triglycidyl isocyanurate;

optionally, the nucleating agent comprises at least one of silica, talc and montmorillonite;

optionally, the anti-hydrolysis agent is a hindered aromatic carbodiimide anti-hydrolysis agent.

8. The method of claim 5, wherein the stabilizer comprises at least one of trimethyl phosphate and triphenyl phosphate;

optionally, the high temperature resistant lubricant comprises at least one of polyethylene wax, EBS, and PETs, preferably PETs;

optionally, the physical blowing agent comprises at least one of carbon dioxide, nitrogen, an alkane, and a fluoride.

9. A method of making the concrete of any one of claims 1-8, comprising: mixing cement, fly ash, quicklime, gravel, fine slag, compatilizer, retarding and water reducing agent and polyester foaming beads to obtain the concrete.

10. The method as claimed in claim 9, wherein the polyester-based expanded beads are prepared by the steps of:

(1) Mixing polyester, a chain extender, a nucleating agent, an anti-hydrolysis agent, a stabilizer and a high-temperature-resistant lubricant, and then performing melt blending extrusion for granulation so as to obtain polyester modified particles;

(2) Adding the polyester modified particles into a dry high-pressure reaction kettle, injecting a physical foaming agent into the dry high-pressure reaction kettle under high pressure, and infiltrating the polyester modified particles with the physical foaming agent under the conditions that the temperature is 160-260 ℃ and the vapor pressure is 5-10 MPa to form a polyester modified particle/foaming agent homogeneous saturated system;

(3) And (3) opening a discharge valve at the bottom of the dry-type high-pressure reaction kettle in the step (2) for pressure relief, forming internal and external pressure drop, enabling the polyester modified particle/foaming agent homogeneous system to be in a thermodynamically unstable state, driving cells to grow up, and then cooling, cleaning and drying to obtain polyester foaming beads.