CN115259893A - Light environment-friendly building material - Google Patents

Abstract

The invention discloses a light environment-friendly building material which mainly comprises the following raw materials in parts by weight: 5 to 45 portions of cement, 20 to 30 portions of water, 50 to 70 portions of ceramsite, 10 to 25 portions of slag, 10 to 15 portions of fly ash, 5 to 10 portions of hollow glass microsphere, 5 to 8 portions of superfine silicon powder, 1 to 3 portions of polyether modified polycarboxylic acid water reducing agent, 0.5 to 1.0 portion of foaming agent and 0.2 to 1.0 portion of air entraining agent. The modified polycarboxylate water reducer prepared by the invention basically does not generate extra air entrainment, can uniformly disperse cement particles, is beneficial to forming a pore structure with smaller and more uniform size in concrete, greatly improves the compression resistance and frost resistance of the material, and has very important significance for improving the durability of lightweight concrete.

Description

Light environment-friendly building material

Technical Field

The invention relates to the technical field of building materials, in particular to a light environment-friendly building material.

Background

The building material is a material foundation of building production activities, has certain cultural characteristics and historical characteristics, and along with the continuous improvement of economic development and people's demand, the variety and function of novel building materials are continuously improved and perfected. The novel building material is different from the traditional building material, has the performance which is not reached by the traditional building material in terms of function and material, has more varieties, and has excellent characteristics of light weight, high strength, heat preservation, energy conservation, soil conservation, decoration and the like. The novel building material not only greatly improves the basic requirements of people on house functions, promotes the modernization of building construction technology, but also enables the current buildings to have more modern interest, and meets the continuously improved aesthetic requirements and taste of people to a certain extent, so the novel building material can be continuously applied and popularized.

The lightweight concrete is a porous concrete material which is prepared by uniformly mixing cement, water, optional component aggregate, infiltration material and an additive according to a certain mixing ratio to prepare slurry, then fully and uniformly mixing the slurry with fine foam prepared by a foaming agent aqueous solution in a physical foaming mode, carrying out covering molding on a construction site or a factory, carrying out maintenance under a certain condition, and hardening to obtain a large amount of micro-bubbles. The lightweight concrete is greatly different from common concrete in raw material composition and production process, a large amount of foam is introduced through foaming of a foaming agent in the production process, and no coarse aggregate is used, so that the unique production process endows the lightweight concrete with a plurality of excellent properties: (1) light weight: during the production process of the lightweight concrete, a large amount of air foam is introduced into cement slurry, and after the air foam is solidified and hardened, a large amount of independent closed air holes are formed in the cement slurry, so that the lightweight concrete has the characteristics of low density and light weight. The range of +/-density of light concrete commonly used in engineering is generally less than 1000kg/m ³ It can be seen that the density is much lower than that of the conventional civil engineering material, if the material is used for replacing the conventional filling materialThe material is subjected to replacement and filling treatment, so that the additional stress of the foundation can be obviously reduced; (2) density and intensity adjustability: the dosage of foam, cement, water and other materials in the lightweight concrete can be properly adjusted within a certain density range according to different actual engineering requirements, and a product meeting the requirements is obtained. The density and the compressive strength of the lightweight concrete have a certain corresponding relationship, and the wet density can be controlled to indirectly ensure that the compressive strength meets the requirement in the construction process; (3) self-supporting property after curing: the lightweight concrete takes cement as a cementing material, and has self-supporting property after being set and hardened, so that the lightweight concrete can be vertically filled, the construction working surface is small, and the removal amount can be avoided or reduced. In addition, when the light soil is used for back filling of a supporting and retaining structure, the supporting and retaining structure is almost free from lateral pressure due to the self-supporting characteristic, the safety of the structure is ensured, and particularly in the back filling of a bridge abutment, the light soil is used, so that the lateral pressure is low, and the problem of slope releasing of a conical slope of conventional filling can be effectively avoided; (4) good workability: the lightweight concrete is mainly composed of fine particles and does not contain coarse aggregate, and the cement content in construction is large and generally is over 0.5, so that the freshly mixed slurry has good fluidity, can realize the characteristics of self-leveling and self-filling compaction, has a vertical conveying height of 120m without segregation, and has a horizontal conveying distance of 800m. Lightweight concrete generally adopts concentrated mix at the scene, then constructs through the mode that the hose was sent cumulatively, need not construct the access road and transport, and the shared place of construction is little, only need place machine and raw and other materials can. In addition, the lightweight concrete takes cement as a cementing material, has very high strength after setting and hardening, and does not need compaction operation like the conventional filling plus or minus, so the lightweight concrete has the characteristics of convenient and efficient construction; (5) good shock resistance: the light concrete contains a large number of closed air holes, and seismic waves are blocked by the air holes when being transmitted inside the light concrete, so that a great deal of seismic energy is consumed under the continuous reflection and transmission effects. In addition, compared with the traditional building material, the lightweight concrete has the characteristic of small density and low elastic modulus, can generate larger deformation under the action of earthquake load, thereby consuming most energy and having good earthquake resistance; (6) good sound insulation and fire resistance: light concreteA large amount of foam is introduced in the production process, and a large amount of closed holes are formed by feeding the foam after the foam is condensed and hardened, so that external noise can be effectively isolated. In addition, the raw materials used for producing the lightweight concrete, such as cement, fly ash and the like, are non-combustible inorganic materials and have good flame retardance in terms of material components. The characteristic enables the lightweight concrete to have great advantages in the field of building heat preservation and heat insulation, and the lightweight concrete not only can insulate sound and heat, but also has good fire resistance; (7) environmental protection and economy: the foaming agent used for the lightweight concrete mainly contains ions and animal and vegetable proteins, does not contain any toxic substance, and in addition, in the production process of the lightweight concrete, a large amount of industrial waste materials such as fly ash and silica powder discharged by power plants and steel plants, and slag, steel slag, coal ore and other waste materials remained in factories can be added, so that the waste materials are changed into valuable materials, the pollution to the environment is reduced, the production cost is reduced, and the environment-friendly economic effect is good.

Patent CN 112010599A discloses a modified polyphenyl particle lightweight concrete and a preparation method thereof, and the modified polyphenyl particle lightweight concrete has good physical and chemical properties. The lightweight concrete comprises the following components in parts by weight: 450-500 parts of cement, 450-500 parts of coal slag, 300-350 parts of fly ash, 5-8 parts of redispersible latex powder, 2-5 parts of polypropylene fiber, 3-5 parts of hydroxypropyl methyl cellulose, 2-4 parts of FND high efficiency water reducing agent, 2-4 parts of defoaming agent, 20-30 parts of polyphenyl granules and 380-430 parts of water. The preparation method comprises the following steps: (10) Firstly, adding water, redispersible latex powder, hydroxypropyl methyl cellulose, FND high efficiency water reducing agent and defoaming agent, and uniformly stirring to obtain a mixture A; (20) Adding cement and fly ash into the A, and stirring for 5-8min to obtain a mixture B; (30) And adding the modified polyphenyl particles, the polypropylene fibers and the coal cinder into the B, and stirring to obtain the modified polyphenyl particle lightweight concrete.

The lightweight expansive type ultra-high performance concrete provided by patent CN 113387646B comprises the following raw materials in parts by mass: 700-1300 parts of cementing material, 20-150 parts of additive, 500-1400 parts of aggregate, 50-250 parts of fiber and 150-250 parts of water; wherein the cementing material comprises the following components in parts by mass: 500-1000 parts of ordinary portland cement, 50-300 parts of silica fume and 100-200 parts of fly ash floating beads; the admixture comprises: 5-50 parts of water reducing agent, 10-100 parts of expanding agent and 5-20 parts of defoaming agent, wherein the aggregate comprises: 0 to 1300 parts of quartz sand and 10 to 600 parts of pre-wet light aggregate. The ultra-high performance concrete prepared by the application has good working performance, mechanical property and durability, and realizes light weight and expansion.

The water reducing agent is one of main components that act on concrete, and its action on lightweight concrete is mainly expressed as an influence on concrete dispersibility, slump retention, and air permeability. Fluidity is the most basic, central property of concrete. The water reducing agent is added into the concrete, so that the dispersibility of the slurry can be obviously improved, and the workability and the homogeneity of the fresh concrete slurry in the engineering application process are improved. These effects greatly affect the internal structure of the concrete and directly affect whether the concrete is good or not in freezing resistance. The high-performance water reducing agent can obviously improve the dispersion performance of concrete at a low mixing amount, and can improve the mechanical property and durability of the hardened concrete slurry. The polycarboxylate superplasticizer is used as a third-generation superplasticizer, has higher water reducing rate, low mixing amount, good dispersibility and strong slump retention, however, the polycarboxylate superplasticizer can be inevitably entrained into slurry during mixing, which causes the air content in the prepared concrete to be increased, so that the defoamer is usually added to prevent excessive bubbles from being generated, however, the defoamer has poor compatibility with the polycarboxylate superplasticizer, and needs a large addition amount, which further causes the poor dispersibility of the defoamer in the slurry. In addition, excessive addition of the defoaming agent can also seriously hinder the effect of the air entraining agent, thereby seriously influencing the frost resistance of the concrete. Therefore, the high-efficiency polycarboxylate superplasticizer which does not cause air entrainment is developed and has a high application prospect when being applied to preparation of light building materials.

Disclosure of Invention

In view of the above-mentioned defects in the prior art, the present invention provides a lightweight and environment-friendly building material with good freezing resistance and strong compressive resistance, and a preparation method thereof.

The durability of the lightweight concrete refers to the capability of the lightweight concrete to maintain the requirements of safety, normal use and appearance without spending a large amount of capital for reinforcement treatment under various environmental conditions within a specified service life. Durability, as it were, determines the useful life of the engineered structure. The lightweight concrete not only bears the load effect, but also is influenced by various environmental factors, such as temperature change, freeze-thaw damage, acid-base corrosion and the like, so that the key for determining whether the durability is good or not is the compression resistance and the freezing resistance of the material. Due to the particularity of the internal structure of the lightweight concrete, a large number of pores formed by bubbles exist inside the lightweight concrete, the size and the distribution condition of the pore size greatly influence the stability of the internal structure, the compressive strength of the material is directly influenced, and the stable pore structure is also the key for improving the frost resistance of the concrete.

According to the polyether modified polycarboxylate water reducer in the light building material, anionic groups such as carboxylic groups on a molecular structure are adsorbed with cement particles due to electrostatic attraction, and oxazoline epoxy groups fully play a steric hindrance role, so that the cement particles are uniformly dispersed, the cement hydration reaction is delayed, and the water consumption for mixing cement is reduced. In addition, the prepared polyether-polycarboxylate superplasticizer has relatively high surface activity, so that the surface tension of the slurry can be well reduced, and the lower hydrophilic-hydrophobic balance value leads to better hydrophobicity, thereby being more beneficial to the dispersion of cement particles in the slurry. Due to the introduction of oxazoline epoxy polyether into the polyether modified polycarboxylic acid water reducing agent, the polyether modified polycarboxylic acid water reducing agent has good defoaming performance, and entrained air can be successfully eliminated in the mixing process. The air content in the slurry mixed after the polyether-polycarboxylic acid water reducing agent is added is basically the same as that of the mortar without any additive, which shows that the water reducing agent does not carry air into the slurry basically, so that the use amount of the defoaming agent can be saved, the barrier effect among cement particles is more uniform during mixing, the carboxylic acid groups on the molecular structure of the water reducing agent and the cement particles are adsorbed due to electrostatic attraction, and the oxazoline epoxy groups fully play the steric hindrance effect, so that the concrete has good dispersibility, good slump retention and good air entraining property and a firm and stable internal structure, and has good frost resistance and pressure resistance.

The technical scheme of the invention is as follows:

a light environment-friendly building material comprises the following raw materials in parts by weight: 5 to 45 portions of cement, 20 to 30 portions of water, 50 to 70 portions of ceramsite, 10 to 25 portions of slag, 10 to 15 portions of fly ash, 5 to 10 portions of hollow glass microsphere, 5 to 8 portions of superfine silicon powder, 1 to 3 portions of polyether modified polycarboxylic acid water reducing agent, 0.5 to 1.0 portion of foaming agent and 0.2 to 1.0 portion of air entraining agent.

The light environment-friendly building material and the preparation method thereof comprise the following steps:

s1, spraying adsorption water into the fly ash, wherein the water amount of the adsorption water is 30-40% of the weight of the fly ash, so as to obtain a mixed material A;

s2, uniformly mixing cement, the rest water, ceramsite, slag, hollow glass beads and superfine silicon powder to obtain a mixed material B;

s3, uniformly mixing the mixture A, the mixture B, the foaming agent, the air entraining agent and the polyether modified polycarboxylic acid water reducing agent to obtain the light environment-friendly building material.

Preferably, the cement is one of portland cement, sulfate cement and aluminate cement.

Preferably, the ceramsite is one of shale ceramsite, sludge ceramsite and coal gangue ceramsite.

The foaming agent is one of rosin resin type, surfactant type, protein type foaming agent and composite foaming agent.

Preferably, the air-entraining agent is one of rosin resins, alkyl benzene sulfonates and saponins.

The preparation method of the polyether modified polycarboxylate water reducer comprises the following steps:

x1, weighing 2-3 parts by weight of methoxy polyethylene glycol and 1.4-2.0 parts by weight of polymethacrylic acid, adding into 2-3 parts by weight of water, heating to 80-90 ℃, stirring for 1-2 hours, vacuumizing the system to remove water, heating to 150-180 ℃, keeping the temperature for 4-6 hours, cooling the grafted product to-80-70 ℃ after the reaction is finished, adding 6-8 parts by weight of water, and diluting the pH to 2-3 to obtain a polyethylene glycol-polycarboxylic acid polymer solution;

x2, weighing 0.2-0.3 part by weight of oxazoline epoxy polyether and 0.3-0.4 part by weight of polyethylene glycol-polycarboxylic acid polymer solution, adding the mixture into 2-3 parts by weight of water, heating to 80-90 ℃, stirring for 1-2 h, vacuumizing the system to remove water, heating to 180-190 ℃, keeping the temperature for 4-6 h, cooling to room temperature after the reaction is finished, adding 30wt% of NaOH aqueous solution to adjust the pH value to 7, and obtaining the polyether modified polycarboxylic acid water reducer.

The preparation method of the oxazoline epoxy polyether comprises the following steps:

y1, weighing 5-6 parts by weight of glycolic acid and 7-8 parts by weight of isobutanol amine, adding into 100-120 parts by weight of xylene, heating to 150-170 ℃, stirring for 14-16 h, and carrying out reduced pressure concentration to remove xylene to obtain a white solid;

y2, weighing 0.6-1 part by weight of tetrabutylammonium hydrogen sulfate, adding 4-5 parts by weight of the white solid in the step Y1 into 30-40 parts by weight of 40wt% NaOH aqueous solution, stirring at 0-5 ℃ for 30-40 min, adding 4-5 parts by weight of epoxy chloropropane, stirring for 18-20 h, heating to room temperature, adding 30-40 parts by weight of ethyl acetate, extracting, separating, and concentrating an organic phase to dryness to obtain a yellow solid;

and Y3, weighing 0.1-0.2 part by weight of phosphazene base and 0.5-1 part by weight of benzyl alcohol, adding the phosphazene base and the benzyl alcohol into 2-5 parts by weight of toluene, stirring at 0-5 ℃ for 30-40 min, adding the yellow solid in the step Y2, stirring for 4-6 h, and concentrating to remove the solvent after the polymerization reaction is finished to obtain the oxazoline epoxy polyether.

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

(1) According to the polyether modified polycarboxylate water reducer prepared by the invention, as anionic groups such as carboxylic groups on a molecular structure and cement particles are adsorbed due to electrostatic attraction, oxazoline epoxy polyether fully exerts the steric hindrance effect, so that the cement particles are uniformly dispersed, the cement hydration reaction is delayed, and the water consumption for mixing cement is reduced;

(2) In addition, the prepared polyether-polycarboxylate superplasticizer has relatively high surface activity, so that the surface tension of the slurry can be well reduced, and the lower hydrophilic-hydrophobic balance value leads to better hydrophobicity, thereby being more beneficial to the dispersion of cement particles in the slurry. Due to the introduction of the oxazoline epoxy polyether side chain into the polyether modified polycarboxylic acid water reducing agent, the polyether modified polycarboxylic acid water reducing agent has good defoaming performance, air carried in the mixing process can be successfully eliminated, the using amount of a defoaming agent can be saved, the barrier effect among cement particles can be more uniform during mixing, the carboxylic acid groups on the molecular structure of the water reducing agent and the cement particles are adsorbed due to electrostatic attraction, and the oxazoline epoxy polyether fully exerts the steric hindrance effect, so that the concrete has good dispersibility, good slump retention and good air entraining performance and the internal structure is solid and stable, and therefore the polyether modified polycarboxylic acid water reducing agent has good freezing resistance and pressure resistance;

(3) The superfine silica powder added into the concrete can strengthen the closure of gas gaps in the concrete, so that the internal pores are smaller and more uniform, and the used slag, coal ash and the like are all recycled materials, thereby being green and environment-friendly.

Detailed Description

Hereinafter, the technical solution of the present invention will be described in detail by specific examples, but these examples should be explicitly proposed for illustration, but should not be construed as limiting the scope of the present invention.

The parameters of part of the raw materials in the embodiment of the invention are as follows:

portland cement, p.o.52.5, fineness (45 μm) screen residue: 5% and Yunnan Zhuoyi chemical industry.

Shale ceramisite, the type is as follows: a2020921-88, specification: 500 grade, hubei Huiweiji lightweight aggregate.

Slag, type: RX-240%, water content 0.1%, and mineral products of Lingzhou county.

Hollow glass beads, type: 3M S60HS, density: 0.60g/cm ³ External electric international chemical industry.

Superfine silica powder of CG-1250 mesh, water content 0.1%, jiangsu Zhongsheng Si material.

Sodium dodecyl benzene sulfonate, type: TD-228, pH = 5-7, shenzhen Taida chemical industry.

Polycarboxylic acid water reducing agent, type: SP-409 with gas content less than or equal to 2.7%, and refining chemical engineering of Kelong in Liaoning province.

Phosphazene base, 0.8mol/L n-hexane solution and alatin.

Methoxypolyethylene glycol, MPEG-2000, hydroxyl number: 25.5-31 mg KOH/g, jiangsu Haian petrochemical.

The composite foaming agent has the following model: HTW-1, henan Huatai building material.

The organic silicon defoamer adopted in the embodiment is a Dow organic silicon defoamer with the type number: AFE-3168, content: 30wt% of a new Suzhou antfu material.

Polymethacrylic acid, cat No.: AL670786017520, chemical engineering of orlilong, shandong.

Comparative example 1

A light environment-friendly building material and a preparation method thereof comprise the following steps:

s1, spraying 3kg of adsorption water into 10kg of fly ash, and uniformly mixing to obtain a mixed material A;

s2, uniformly mixing 45kg of Portland cement, 22kg of water, 50kg of shale ceramsite, 10kg of slag, 8kg of hollow glass beads and 5kg of superfine silicon powder to obtain a mixed material B;

s3, uniformly mixing the mixture A, the mixture B, 0.5kg of composite foaming agent, 0.8kg of sodium dodecyl benzene sulfonate and 2kg of polycarboxylic acid water reducing agent to obtain the light environment-friendly building material.

Example 1

A light environment-friendly building material and a preparation method thereof comprise the following steps:

s1, spraying 3kg of adsorption water into 10kg of coal ash, and uniformly mixing to obtain a mixed material A;

s2, uniformly mixing 45kg of Portland cement, 22kg of water, 50kg of shale ceramsite, 10kg of slag, 8kg of hollow glass microsphere and 5kg of superfine silicon powder to obtain a mixed material B;

s3, uniformly mixing the mixture A, the mixture B, 0.5kg of composite foaming agent, 0.8kg of sodium dodecyl benzene sulfonate and 2kg of polyether modified polycarboxylic acid water reducing agent to obtain the light environment-friendly building material.

The preparation method of the polyether modified polycarboxylate superplasticizer comprises the following steps:

x1, weighing 3kg of methoxy polyethylene glycol and 1.4kg of polymethacrylic acid, adding into 3L of water, heating to 80 ℃, stirring for 1h, vacuumizing the system, removing water, heating to 150 ℃, preserving heat for 4h, cooling the grafted product to-80 ℃ after the reaction is finished, adding 6L of water, and diluting the pH value to 3 to obtain a polyethylene glycol-polycarboxylic acid polymer solution;

and X2, weighing 0.2kg of oxazoline epoxy polyether and 0.3kg of polyethylene glycol-polycarboxylic acid polymer solution, adding the mixture into 2L of water, heating to 80 ℃, stirring for 1h, vacuumizing the system, removing water, heating to 180 ℃, preserving heat for 6h, cooling to room temperature after the reaction is finished, adding 30wt% of NaOH aqueous solution, and adjusting the pH value to 7 to obtain the polyether modified polycarboxylic acid water reducer.

The preparation method of the oxazoline epoxy polyether comprises the following steps:

weighing 5kg of glycolic acid and 7kg of isobutanol amine in Y1, adding into 12.5L of dimethylbenzene, heating to 170 ℃, stirring for 16h, and concentrating at-0.9 MPa and 45 ℃ after the reaction is finished to remove the dimethylbenzene to obtain a white solid;

y2, weighing 0.6kg of tetrabutylammonium hydrogen sulfate, adding 4kg of the white solid obtained in the step Y1 into 30kg of 40wt% NaOH aqueous solution, stirring at 0 ℃ for 30min, adding 4kg of epoxy chloropropane, stirring for 18h, heating to room temperature, adding 30kg of ethyl acetate, extracting, separating, and concentrating an organic phase at-0.9MPa and 45 ℃ until the organic phase is dried to obtain a yellow solid;

and Y3, weighing 0.1kg of phosphazene base and 0.6kg of benzyl alcohol, adding into 3kg of toluene, stirring at 0 ℃ for 30min, adding the yellow solid in the step Y2, stirring for 6h, and concentrating at-0.9MPa and 45 ℃ after the polymerization reaction is finished to remove the solvent to obtain the oxazoline epoxy polyether.

Example 2

A light environment-friendly building material and a preparation method thereof comprise the following steps:

s1, spraying 3kg of adsorption water into 10kg of fly ash, and uniformly mixing to obtain a mixed material A;

s2, uniformly mixing 45kg of Portland cement, 22kg of water, 50kg of shale ceramsite, 10kg of slag, 8kg of hollow glass microsphere and 5kg of superfine silicon powder to obtain a mixed material B;

s3, uniformly mixing the mixture A, the mixture B, 0.5kg of composite foaming agent, 0.8kg of sodium dodecyl benzene sulfonate, 2kg of polycarboxylic acid water reducing agent and 0.5kg of organic silicon defoaming agent to obtain the light environment-friendly building material.

Example 3

A light environment-friendly building material and a preparation method thereof comprise the following steps:

s1, spraying 3kg of adsorption water into 10kg of fly ash, and uniformly mixing to obtain a mixed material A;

s2, uniformly mixing 45kg of Portland cement, 22kg of water, 50kg of shale ceramsite, 10kg of slag and 8kg of hollow glass beads to obtain a mixed material B;

s3, uniformly mixing the mixture A, the mixture B, 0.5kg of composite foaming agent, 0.8kg of sodium dodecyl benzene sulfonate and 2kg of polyether modified polycarboxylic acid water reducing agent to obtain the light environment-friendly building material.

The preparation method of the polyether modified polycarboxylate superplasticizer comprises the following steps:

x1, weighing 3kg of methoxy polyethylene glycol and 1.4kg of polymethacrylic acid, adding into 3L of water, heating to 80 ℃, stirring for 1h, vacuumizing the system, removing water, heating to 150 ℃, preserving heat for 4h, cooling the grafted product to-80 ℃ after the reaction is finished, adding 6L of water, and diluting the pH value to 3 to obtain a polyethylene glycol-polycarboxylic acid polymer solution;

and X2, weighing 0.2kg of oxazoline epoxy polyether and 0.3kg of polyethylene glycol-polycarboxylic acid polymer solution, adding the mixture into 2L of water, heating to 80 ℃, stirring for 1h, vacuumizing the system, removing water, heating to 180 ℃, preserving heat for 6h, cooling to room temperature after the reaction is finished, adding 30wt% of NaOH aqueous solution, and adjusting the pH value to 7 to obtain the polyether modified polycarboxylic acid water reducer.

The preparation method of the oxazoline epoxy polyether comprises the following steps:

y1, weighing 5kg of glycolic acid and 7kg of isobutanol amine, adding into 12.5L of dimethylbenzene, heating to 170 ℃, stirring for 16h, and concentrating at-0.9MPa and 45 ℃ after the reaction to remove the dimethylbenzene to obtain a white solid;

weighing 0.6kg of tetrabutylammonium hydrogen sulfate and 4kg of the white solid in the step Y1 into 30kg of 40wt% NaOH aqueous solution, stirring at 0 ℃ for 30min, adding 4kg of epoxy chloropropane, stirring for 18h, heating to room temperature, adding 30kg of ethyl acetate, extracting, separating, and concentrating the organic phase at-0.9 MPa and 45 ℃ to dryness to obtain a yellow solid;

and Y3, weighing 0.1kg of phosphazene base and 0.6kg of benzyl alcohol, adding into 3kg of toluene, stirring at 0 ℃ for 30min, adding the yellow solid in the step Y2, stirring for 6h, and concentrating at-0.9MPa and 45 ℃ after the polymerization reaction is finished to remove the solvent to obtain the oxazoline epoxy polyether.

Test example 1

The frost resistance test method of the light concrete has no clear standard specification in China at present, but the frost resistance test method of the concrete material is mature and can be referred to for a certain extent. In the current standard of testing methods for long-term performance and durability of common concrete (GB/T50082-2009) on concrete frost resistance, two methods are provided: slow freezing and fast freezing. The experiment is carried out by referring to a slow freezing method, and the specific method comprises the following steps: lightweight concrete slurry is prepared according to the mixing proportion, and is poured into a mould with the size of 100mm multiplied by 100mm according to the requirement, 4 groups of anti-freezing tests are performed in total, and each group has 5 samples. And (4) curing the sample for 1 day in a chamber with a mold, then removing the mold, and then carrying the sample to a curing chamber for standard curing. And when the maintenance age is 24 days, taking out the test piece, numbering the test piece by using a paint pen, then soaking the test piece in water at 20 ℃, taking out the test piece from the water when the test piece reaches the 28-day maintenance age, immediately wiping off redundant water on the surface by using a wet rag after the appearance of the test piece is checked, immediately weighing, and tightly wrapping the test piece after the test piece is weighed. And (3) putting the wrapped test piece into a freezing box, performing a freezing test, reducing the temperature by 10 ℃ every 1h until the temperature is reduced to-20 ℃, and keeping the temperature constant. After the freezing, the sample is taken out from the freezing box immediately, is put into water with the temperature of 20 ℃ for melting, and after a few minutes, the surface ice layer is melted, the preservative film and the sample can be peeled off, and the sample is continuously melted in the water, wherein the melting time is 12 hours. After a specified number of freeze-thaw cycles, the samples were weighed and the mass loss rate was calculated.

TABLE 1 Experimental results of freezing resistance

When the external temperature of the lightweight concrete is lower, moisture in the small holes in the lightweight concrete is frozen to generate ice expansion pressure, when the moisture is expanded to be higher than the tensile strength of the hole walls, the hole walls are damaged, the temperature rises again, frozen water is melted, and a part of precipitates are carried, so that the phenomenon is called freeze-thaw damage of the lightweight concrete. The frost resistance of lightweight concrete refers to the property of resisting multiple freeze-thaw cycles without damage under a water-absorbing saturated state. When the pores in the concrete are large and the pores are not uniformly distributed, the thinner the pore walls in the concrete are, the more easily the concrete is damaged in the freeze-thaw process, and the more the absorbed moisture is, the polyether modified polycarboxylate water reducing agent added in the embodiment 1 can reduce the water content of the cement during mixing, and the uniform and stable micro pores are formed in the concrete through the polyether modified polycarboxylate water reducing agent and the air entraining agent, so that the pores in the concrete are uniformly distributed, and the gas gaps in the concrete are better in sealing property due to the addition of the superfine silicon powder, so that the concrete is firm and firm in interior and is not easily damaged in the freeze-thaw process. Although the water content in the cement can also be reduced to a certain extent by the polycarboxylic acid water reducing agent used in comparative example 1, the air entrained by the polycarboxylic acid water reducing agent during mixing causes too large air pore space inside the concrete, so that water can easily enter the air pore space during freeze thawing, and the structure of the concrete is damaged from inside due to freezing at low temperature, so that the freezing resistance performance is poor.

Test example 2

The concrete prepared in the comparative examples and examples was tested for compressive strength by the test method referred to the method for testing autoclaved aerated concrete Performance (GB/T11969-2020), the concrete was mixed and placed in a cubic test mold of 100mm x 100mm, and the test mold was then set on a vibrating table for vibration until no slurry was present on the surface of the test mold and no significant air bubbles were released. And covering the surface of the test piece with a plastic film after forming and plastering, standing for 2d in an environment with the temperature of 20 ℃ and the relative humidity of more than or equal to 50 percent, and immediately placing the test piece into a curing room with the temperature of 20 ℃ and the relative humidity of more than or equal to 95 percent for curing after the number is coded and the mold is removed. Before testing, a bottom plate and a top plate of a compressor are wiped clean by using dry towels, a sample is placed in the center of a bottom plate of an electronic universal testing machine, the compression direction is perpendicular to the pouring direction of the sample, the testing machine is started, a base is adjusted to enable the top surface of the sample to be parallel to the surface of a pressing plate, so that the sample can be fully contacted in the compression process, when the sample is about to be contacted, a program is started, the pressing machine is enabled to be loaded at the speed of 2kN/s, the deformation condition of the sample is observed at any time in the compression process, the test is stopped until the sample is damaged, and test data are stored. Each group of compression experiments has 3 samples, the compressive strength of each sample is calculated according to formula 1, and the average value of 3 times of test results is taken as the strength value of the group of samples.

f _cu = F/A-formula 1

f _cu -compressive strength of the sample, in MPa;

f is the breaking load in kN;

a-area under pressure of sample, mm ² 。

TABLE 2 compression Strength test values

Experimental protocol	Compressive strength/MPa
		Comparative example 1	38.6
Example 1	43.2
		Example 2	37.4
Example 3	36.7

The water reducing agent is one of main components that act on concrete, and its action on lightweight concrete is mainly expressed as an influence on concrete dispersibility, slump retention, and air permeability. Fluidity is the most basic, central property of concrete. The water reducing agent is added into the concrete, so that the dispersibility of the slurry can be obviously improved, and the workability and the homogeneity of the fresh concrete slurry in the engineering application process are improved. These effects greatly affect the internal structure of the concrete and thus the compressive strength of the concrete. As can be seen from Table 2, the concrete material prepared in example 1 has the best compressive strength, which is probably due to the relatively high surface activity of the prepared polyether-polycarboxylate water reducing agent, which can well reduce the surface tension of the slurry, and the lower hydrophilic-hydrophobic balance value leads to better hydrophobicity, thus being more beneficial to the dispersion of cement particles in the slurry. The carboxylic group on the molecular structure of the water reducing agent and cement particles are adsorbed due to electrostatic attraction, and oxazoline epoxy polyether fully exerts the steric hindrance effect, so that the concrete has good dispersibility, good slump retention and air entraining performance and a firm and stable internal structure, thereby having good pressure resistance.

Test example 3

The concrete prepared in the comparative examples and examples was subjected to air inclusion measurement by the following specific test method: 2kg of the uncured concrete slurry prepared in each example is put into a stirrer to be uniformly stirred and then put into a container, the balance is filled with water through vibration compaction, the water is poured out after the balance is filled, the volume fraction of the poured water in the container is calculated, namely the air content in the material, and specific test results are shown in table 3.

TABLE 3 air inclusion amount test result table

Experimental protocol	Air content/vol%
		Comparative example 1	14.5
Example 1	4.1
		Example 2	4.3
Example 3	4.2

From the test results in table 3, it can be seen that the air entrainment of the concrete prepared in the comparative example is significantly higher than that in examples 1 to 3, while the entrainment of the polyether modified polycarboxylate water reducer used in example 1 is significantly less, which is substantially the same as the effect of the defoamer used in example 2, probably because the oxazoline epoxy polyether side chain is introduced into the polyether modified polycarboxylate water reducer, the polyether modified polycarboxylate water reducer has good defoaming performance, and the entrained air can be successfully eliminated in the blending process, which is not only beneficial to the formation of the internal pore structure of the concrete, but also can reduce the use of the defoamer, and reduce the cost.

Claims (9)

1. A light environment-friendly building material is characterized by mainly comprising the following raw materials: cement, water, ceramsite, slag, fly ash, hollow glass beads, superfine silicon powder, a polyether modified polycarboxylic acid water reducing agent, a foaming agent and an air entraining agent.

2. A light environment-friendly building material is characterized by mainly comprising the following raw materials in parts by weight: 5 to 45 portions of cement, 20 to 30 portions of water, 50 to 70 portions of ceramsite, 10 to 25 portions of slag, 10 to 15 portions of fly ash, 5 to 10 portions of hollow glass microsphere, 5 to 8 portions of superfine silicon powder, 1 to 3 portions of polyether modified polycarboxylic acid water reducing agent, 0.5 to 1.0 portion of foaming agent and 0.2 to 1.0 portion of air entraining agent.

3. The lightweight, environmentally friendly building material of claim 1 or 2, wherein: the cement is one of portland cement, sulfate cement and aluminate cement.

4. The lightweight, environmentally friendly building material of claim 1 or 2, further comprising: the ceramsite is one of shale ceramsite, sludge ceramsite and coal gangue ceramsite.

5. The light environment-friendly building material as claimed in claim 1 or 2, wherein the preparation method of the polyether modified polycarboxylic acid water reducing agent comprises the following steps:

x1, weighing 2-3 parts by weight of methoxy polyethylene glycol and 1.4-2.0 parts by weight of polymethacrylic acid, adding into 2-3 parts by weight of water, heating to 80-90 ℃, stirring for 1-2 hours, vacuumizing the system to remove water, heating to 150-180 ℃, keeping the temperature for 4-6 hours, cooling the grafted product to 80-70 ℃ after the reaction is finished, adding 6-8 parts by weight of water, and diluting the pH to 2-3 to obtain a polyethylene glycol-polycarboxylic acid polymer solution;

x2, weighing 0.2-0.3 part by weight of oxazoline epoxy polyether and 0.3-0.4 part by weight of polyethylene glycol-polycarboxylic acid polymer solution, adding the mixture into 2-3 parts by weight of water, heating to 80-90 ℃, stirring for 1-2 h, vacuumizing the system to remove water, heating to 180-190 ℃, preserving heat for 4-6 h, cooling to room temperature after the reaction is finished, adding 30wt% of NaOH aqueous solution to adjust the pH value to 7, and obtaining the polyether modified polycarboxylic acid water reducer.

6. The lightweight, environmentally friendly building material of claim 5, wherein the oxazoline epoxy-based polyether is prepared by a method comprising the steps of:

y1, weighing 5-6 parts by weight of glycolic acid and 7-8 parts by weight of isobutanol amine, adding into 100-120 parts by weight of xylene, heating to 150-170 ℃, stirring for 14-16 h, and carrying out reduced pressure concentration to remove xylene to obtain a white solid;

y2, weighing 0.6-1 part by weight of tetrabutylammonium hydrogen sulfate, adding 4-5 parts by weight of the white solid obtained in the step Y1 into 30-40 parts by weight of 40wt% NaOH aqueous solution, stirring at 0-5 ℃ for 30-40 min, adding 4-5 parts by weight of epoxy chloropropane, stirring for 18-20 h, heating to room temperature, adding 30-40 parts by weight of ethyl acetate, extracting, separating, and concentrating an organic phase to be dry to obtain a yellow solid;

and Y3, weighing 0.1-0.2 part by weight of phosphate and 0.5-1 part by weight of benzyl alcohol, adding the phosphate and the benzyl alcohol into 2-5 parts by weight of toluene, stirring at 0-5 ℃ for 30-40 min, adding the yellow solid in the step Y2, stirring for 4-6 h, and concentrating to remove the solvent after the polymerization reaction is finished to obtain the oxazoline epoxy polyether.

7. The lightweight, environmentally friendly building material of claim 1 or 2, wherein: the foaming agent is one of rosin resin type, surfactant type, protein type foaming agent and composite foaming agent.

8. The lightweight, environmentally friendly building material of claim 1 or 2, further comprising: the air entraining agent is one of rosin resins, alkylbenzene sulfonates and saponins.

9. The method for preparing a lightweight, environmentally friendly building material as claimed in any one of claims 1 to 8, comprising the steps of:

s1, spraying adsorption water into the fly ash, wherein the water amount of the adsorption water is 30-40% of the weight of the fly ash, so as to obtain a mixed material A;

s2, uniformly mixing cement, the rest water, ceramsite, slag, hollow glass beads and superfine silicon powder to obtain a mixed material B;

s3, uniformly mixing the mixture A, the mixture B, the foaming agent, the air entraining agent and the polyether modified polycarboxylic acid water reducing agent to obtain the light environment-friendly building material.