CN107382245A - A kind of fine coal sand-lime autoclave aerated concrete building block and preparation method thereof - Google Patents

Abstract

The invention discloses a fly ash-sand autoclaved aerated concrete block and a preparation method thereof. The raw materials include the following components in parts by weight: 39-60 parts of fly ash, 26-40 parts of sand, 20-30 parts of fine iron tailings powder, 23-43 parts of recycled fine aggregate from waste bricks, 12-22 parts of cement, 14-24 parts of lime, 5-10 parts of gypsum, 0.05-0.08 parts of aluminum powder . The fly ash-sand autoclaved aerated concrete block uses fly ash and sand to combine, mixes iron tailings fine powder, and replaces part of the sand with recycled fine aggregate from waste bricks as recycled aggregate. It has high strength and is easy to use. Good heat resistance, light weight, good thermal insulation performance and durability, and strong fire resistance. A large amount of industrial waste such as fly ash, iron tailings fine powder, and recycled fine aggregate from waste bricks is used, which has obvious economic advantages, energy saving and environmental protection, and low coal consumption.

Description

A kind of fly ash-sand autoclaved aerated concrete block and its preparation method

technical field

The invention relates to the technical field of concrete blocks, in particular to a fly ash-sand autoclaved aerated concrete block and a preparation method thereof.

Background technique

With the continuous increase in the promotion of new wall materials in China, the application of autoclaved aerated concrete blocks in my country's urban building wall materials has become very common, and the production technology level of autoclaved aerated concrete blocks has also improved significantly. Greatly improved, product performance and technical and economic indicators have been continuously optimized. As a load-bearing and non-load-bearing structural material and thermal insulation enclosure material, it has light weight, good thermal insulation and sound insulation performance, good fire resistance, slow water absorption, good durability, can be sawed and planed, has certain mechanical strength and machinability Wait. Compared with traditional clay bricks, autoclaved aerated concrete blocks can save land resources and improve building energy efficiency.

At present, there are mainly two types of autoclaved aerated concrete blocks produced in China: fly ash autoclaved aerated concrete blocks and sand autoclaved aerated concrete blocks. Among them, the body of the fly ash autoclaved aerated concrete block is easy to collapse, and the product is brittle and low in strength, but has good workability; the sand autoclaved aerated concrete block has poor grindability, which leads to large wear of equipment and damage to the mortar. The fineness and concentration are difficult to control, the bulk density of the embryo body tends to be heavy, and the product is prone to adhesion after leaving the kettle, especially the Baotou adhesion on the bottom surface of the flipping equipment is serious, resulting in a low pass rate and poor workability, but the product has high strength. . Therefore, it is necessary to develop an autoclaved aerated concrete block composed of fly ash and sand.

In addition, according to the statistics of the China Association of Metallurgical and Mine Enterprises, my country’s iron tailings output was about 400 million tons in 2005, and by 2015 the cumulative output was about 5.97 billion tons of iron tailings, of which the stockpiled iron tailings accounted for the total of all tailings stockpiles. It has become one of the industrial solid wastes with the largest stockpile and low utilization rate. Construction waste is the main part of urban waste, accounting for about 30% to 40% of the total amount of urban waste, of which concrete blocks and broken bricks account for about 80% to 90%, and are the main research objects for resource utilization of construction waste. The resource utilization of waste bricks is of great significance to the development of circular economy and environmental protection. Therefore, the comprehensive utilization of iron tailings and waste bricks is urgent.

Contents of the invention

The invention provides a fly ash-sand autoclaved aerated concrete block and its preparation method to solve the problem that the workability and strength of the autoclaved aerated concrete block cannot be balanced and the problems of fly ash, iron tailings, waste Technical problems with brick stockpiling.

The technical scheme that the present invention adopts is as follows:

A fly ash-sand autoclaved aerated concrete block, the raw materials include the following components in parts by weight: 39-60 parts of fly ash, 26-40 parts of sand, 20-30 parts of iron tailings fine powder 23-43 parts of recycled fine aggregate from waste bricks, 12-22 parts of cement, 14-24 parts of lime, 5-10 parts of gypsum, and 0.05-0.08 parts of aluminum powder.

Further, the raw materials include the following components in parts by weight: 45 to 55 parts of fly ash, 30 to 36 parts of sand, 22 to 28 parts of fine iron tailings powder, 30 to 35 parts of regenerated fine aggregate from waste bricks 16-20 parts of cement, 16-22 parts of lime, 6-9 parts of gypsum, and 0.05-0.08 parts of aluminum powder.

Further, the raw materials include the following components in parts by weight: 48 parts of fly ash, 32 parts of sand, 25 parts of iron tailings fine powder, 33 parts of recycled fine aggregate from waste bricks, 17 parts of cement, 19 parts of lime, 7 parts of gypsum part, 0.07 part of aluminum powder.

Further, the raw materials also include auxiliary agents, which are one or more of foam stabilizers, cellulose ethers, redispersible latex agents, expansion agents, and fibers.

Further, the sand is one or more of artificial sand, mountain sand, and river sand.

Further, the fineness modulus of the 80 μm square hole sieve of the sand is 18%-22%.

Further, the fineness modulus of the 45 μm square hole sieve of the fly ash is 8%-20%.

Further, the fineness modulus of the 0.15mm sieve hole of the waste brick regenerated fine aggregate is 11%-31%.

Further, the fineness modulus of the 45 μm square hole sieve of iron tailings fine powder is 5%-15%.

Further, the fineness modulus of the 80 μm square hole sieve of the aluminum powder is 0.5% to 1%.

Further, the cement is Portland cement, and the strength of the cement is ≥42.5MPa.

Further, the digestion time of lime powder is 16 minutes, the digestion temperature is 76°C, the effective CaO content is 75%-78.82%, the MgO content is 5.74%-10%, and the fineness modulus of the 45 μm square hole sieve is 10%-20 %.

According to another aspect of the present invention, there is also provided a method for preparing the above-mentioned fly ash-sand autoclaved aerated concrete, comprising the following steps: (1) regenerating fly ash, sand, iron tailings fine powder, and waste bricks The fine aggregate and aluminum powder are put into the ball mill respectively, and the required fineness modulus is reached after ball milling; the aluminum powder after ball milling is stirred and prepared as aluminum powder suspension; (2) the fly ash after ball milling in step (1) is , sand, iron tailings micropowder, recycled fine aggregate of waste bricks and other raw materials including cement, lime and gypsum. powder suspension, and then injected into the mould; the slurry is foamed to form a green body and then stopped and cut; (3) the cut green body obtained in step (2) is put into an autoclave for autoclave curing, to obtain Fly ash-sand autoclaved aerated concrete blocks.

Further, in step (2), the aluminum powder suspension is put in 0.5-1 min before the slurry is injected into the mould.

Further, the time for standing still is 1.5-2.5 hours, and the temperature during standing still is 50-80°C.

Further, the pressure of the autoclaved curing in step (3) is 0.8-1.5 MPa, and the time of the autoclaved curing is 6-12 hours.

The present invention has the following beneficial effects:

1. The fly ash-sand autoclaved aerated concrete block of the present invention uses fly ash and sand to combine, adds iron tailings micropowder, and replaces a part of sand with waste brick regeneration fine aggregate as recycled aggregate, the strength High, good workability, light weight, good thermal insulation performance and durability, strong fire resistance, can be used for frame structure or cast-in-place concrete structure building external wall filling, internal wall partition, and can also be used for seismic ring beam construction Exterior walls of multi-storey buildings or thermal insulation composite walls.

2. The fly ash-sand autoclaved aerated concrete block of the present invention has good toughness and is not easy to lose edges and corners; no adhesion will occur when it is discharged from the kettle, and the pass rate of the concrete block product is improved.

3. The fly ash-sand autoclaved aerated concrete block of the present invention utilizes a large amount of industrial waste such as fly ash, iron tailings micropowder, waste brick regenerated fine aggregate, and has obvious economic advantages, energy saving and environmental protection, and low coal consumption .

4. The preparation method of the fly ash-sand autoclaved aerated concrete block of the present invention is simple and easy to operate, the slurry concentration and fineness are easy to control during the production process, the wear and tear on equipment is small, the body is easy to control and not easy to collapse mold.

In addition to the objects, features and advantages described above, the present invention has other objects, features and advantages. The present invention will be described in further detail below.

detailed description

It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below in conjunction with examples.

The present invention provides a fly ash-sand autoclaved aerated concrete block. The raw materials include the following components in parts by weight: 39-60 parts of fly ash, 26-40 parts of sand, iron tailings 20-30 parts of fine powder, 23-43 parts of recycled fine aggregate from waste bricks, 12-22 parts of cement, 14-24 parts of lime, 5-10 parts of gypsum, and 0.05-0.08 parts of aluminum powder.

In the fly ash-sand autoclaved aerated concrete block of the present invention, the fly ash has both the dual functions of aggregate and generation of cementitious material; the fly ash simultaneously provides SiO ₂ and Al ₂ O ₃ , and performs hydrothermal with lime React to produce hydrated silicate and hydrated aluminate, so that the block can gain strength; at the same time, it increases the workability of the autoclaved aerated concrete block, and solves the problem of fly ash storage.

In the fly ash-sand autoclaved aerated concrete block of the present invention, the main function of the sand is to provide _SiO2 , which can react with calcium oxide under autoclaved conditions to generate calcium silicate hydrate; at the same time, the sand is aerated under autoclaved The concrete cell wall can play the role of skeleton and aggregate.

Fly ash-sand autoclaved aerated concrete block of the present invention, the effect of iron tailings micropowder is as follows: 1, the density of iron tailings micropowder is bigger than admixtures such as fly ash, slag powder, can eliminate The disadvantage of poor homogeneity caused by the floating of admixtures in aerated concrete. 2. The water demand of iron tailings micropowder is relatively low, and the water consumption of autoclaved aerated concrete can be reduced after being mixed. 3. Improve the workability of the autoclaved aerated concrete mixture and increase the compressive strength. 4. Improve the utilization rate of iron tailings and solve the stockpiling problem of iron tailings.

The fly ash-sand autoclaved aerated concrete block and regenerated fine aggregate of waste bricks of the present invention are used to replace a part of sand, as regenerated aggregate and recycled building materials, so as to solve the problem of increasing accumulation of construction waste.

The fly ash-sand autoclaved aerated concrete block of the present invention uses fly ash and sand to combine, adds iron tailings micropowder, and replaces a part of sand with waste brick regenerated fine aggregate as regenerated aggregate, the above components Synergistic effect, the prepared fly ash-sand autoclaved aerated concrete block has high strength, good workability, light weight, good thermal insulation performance and durability, and strong fire resistance; and a large amount of fly ash, Industrial waste such as iron tailings powder, recycled fine aggregate of waste bricks, etc., has obvious economic advantages, energy saving and environmental protection, and low coal consumption; it can be used for external wall filling and internal wall partitioning of frame structures or cast-in-place concrete structures The anti-seismic ring beam constructs the outer wall of a multi-storey building or a thermal insulation composite wall.

In the fly ash-sand autoclaved aerated concrete block of the present invention, the main functions of lime are: 1. Release heat after decomposing with water, promote the reaction of aluminum powder and water to generate hydrogen, and form small and uniform air bubbles, thereby forming porous The body of the structure. 2. Under the condition of autoclaving and curing, it further reacts with silicon dioxide in the siliceous material to form calcium silicate hydrate. 3. Due to the high initial solubility of quicklime, it is beneficial to promote the consistency of the slurry and the hardening of the green body, which is conducive to improving the strength of the product.

The fly ash-sand autoclaved aerated concrete block of the present invention has the main functions of gypsum as follows: 1. It can participate in the hydration reaction of cement and adjust the final setting time of cement. In the early stage of cement hydration reaction, gypsum mainly acts as an inhibitor to prevent false setting of cement. 2. It can affect and inhibit the digestion process of lime, prolong its digestion time, and reduce its final digestion temperature. 3. Participate in the outgassing reaction of aluminum powder. Gypsum can react with aluminum hydroxide, the reaction product of aluminum powder and water, to produce calcium sulfoaluminate. 4. Increase the strength of green bodies and products and reduce the shrinkage value.

In the fly ash-sand autoclaved aerated concrete block of the present invention, the main function of the aluminum powder is to carry out a chemical reaction in the slurry, release gas and form small and uniform bubbles, so that the autoclaved aerated concrete block is formed with porous structure.

The fly ash-sand autoclaved aerated concrete block of the invention has good toughness and is not easy to lose edges and corners; no adhesion will occur when it is discharged from the kettle, and the qualified rate of the concrete block product is improved.

Preferably, the raw materials include the following components in parts by weight: 45 to 55 parts of fly ash, 30 to 36 parts of sand, 22 to 28 parts of fine iron tailings powder, 30 to 35 parts of regenerated fine aggregate from waste bricks 16-20 parts of cement, 16-22 parts of lime, 6-9 parts of gypsum, and 0.05-0.08 parts of aluminum powder. The fly ash-sand autoclaved aerated concrete block prepared by adopting the above-mentioned ratio of each component in the raw material has high strength, good workability, good heat preservation performance and durability, and good heat preservation and heat insulation performance.

Preferably, the raw materials include the following components in parts by weight: 48 parts of fly ash, 32 parts of sand, 25 parts of fine iron tailings powder, 33 parts of recycled fine aggregate from waste bricks, 17 parts of cement, 19 parts of lime, and 7 parts of gypsum part, 0.07 part of aluminum powder. The fly ash-sand autoclaved aerated concrete block prepared by adopting the above ratio of each component in the raw material has the highest strength, the best workability, and the highest qualified rate of the product.

Preferably, the raw materials also include auxiliary agents, and the auxiliary agents are one or more of foam stabilizers, cellulose ethers, redispersible latex agents, swelling agents, and fibers. The foam stabilizer can significantly improve the pouring stability, improve its pore structure, reduce large pores, and reduce the difference in bulk density between the upper, middle and lower parts of the product. Cellulose ether has excellent thickening and water retention effects. Redispersible latex can significantly improve the bond strength. When the above additives are added to the prepared autoclaved aerated concrete block raw materials, corresponding functions can be realized. The above-mentioned additives play an auxiliary role in the preparation process of autoclaved aerated concrete blocks, and have the functions of improving pouring stability, improving pore structure, reducing bulk density difference, water retention, and improving bond strength, so that the preparation can be obtained The block performance is better.

Preferably, the sand is one or more of artificial sand, mountain sand, and river sand. The above-mentioned sands can be used to provide silicon dioxide, which reacts with calcium oxide under autoclaved conditions to generate calcium silicate hydrate.

Preferably, the fineness modulus of the 80 μm square hole sieve of the sand is 18%-22%. Selecting the sand with the above fineness can enhance the skeleton effect of the sand in the product and increase the strength of the fly ash-sand autoclaved aerated concrete block.

Preferably, the fineness modulus of the 45 μm square hole sieve of the fly ash is 8% to 20%. The water demand of the above-mentioned fly ash is 92%-96%, and the loss on ignition is 0%-8%. Selecting the fly ash with the above-mentioned fineness can improve the workability of the prepared autoclaved aerated concrete block.

Preferably, the fineness modulus of the 0.15mm mesh of the regenerated fine aggregate of waste bricks is 11%-31%. Selecting the above-mentioned fineness of waste brick recycled fine aggregate can better replace sand as recycled aggregate.

Preferably, the fineness modulus of the 45 μm square hole sieve of iron tailings fine powder is 5%-15%. The water requirement of the iron tailings fine powder is 91%-96%, and the loss on ignition is 0%-3%. The use of the iron tailings fine powder improves the workability of the autoclaved aerated concrete mixture and increases the compressive strength of the product.

Preferably, the fineness modulus of the 80 μm square hole sieve of the aluminum powder is 0.5% to 1%. The use of aluminum powder with the above fineness makes it easier to carry out chemical reactions in the slurry and release hydrogen to form bubbles, so that the autoclaved aerated concrete forms a more uniform porous structure.

Preferably, the cement is Portland cement, and the strength of the cement is ≥42.5MPa. Using Portland cement with the above-mentioned strength can increase the strength of the slurry. The main function of Portland cement is to ensure the pouring stability and the hardening speed of the green body in the initial stage of production, and it also plays an important role in the reaction in the later autoclaved curing.

Preferably, the digestion time of lime powder is 16 minutes, the digestion temperature is 76°C, the effective CaO content is 75%-78.82%, the MgO content is 5.74%-10%, and the fineness modulus of the 45 μm square hole sieve is 10%-20 %.

The present invention also provides a method for preparing the above-mentioned fly ash-sand autoclaved aerated concrete block, comprising the following steps: (1) mixing fly ash, sand, iron tailings micropowder, waste brick regenerated fine aggregate, The aluminum powder is put into the ball mill respectively, and reaches the required fineness modulus after the ball milling; the aluminum powder after the ball milling is stirred and prepared as an aluminum powder suspension; (2) the fly ash, sand and iron after the ball milling in step (1) are Tailings fine powder, waste brick recycled fine aggregate and other raw materials including cement, lime and gypsum are measured according to the weight ratio, put into the pouring car, stirred to obtain the slurry, and aluminum powder suspension is added to the slurry before being injected into the mold. Then inject mould; static stop and cut after slurry foaming forms green body; (3) the green body after cutting obtained in step (2) is put into autoclave and carry out autoclave curing, promptly obtains fly ash- Sand autoclaved aerated concrete blocks.

The preparation method of the above-mentioned fly ash-sand autoclaved aerated concrete block is simple and easy to operate, the concentration and fineness of the slurry are easy to control during the production process, the wear and tear on equipment is small, the body is easy to control and the mold is not easy to collapse.

Preferably, in step (2), the aluminum powder suspension is put in 0.5-1 min before the slurry is injected into the mould. In the above steps, the aluminum powder should be put in 0.5 to 1 minute before the slurry is injected into the mold, so that the reaction between the aluminum powder and water proceeds in the mold to form a uniform porous structure in the green body.

Preferably, the time for standing still is 1.5-2.5 hours, and the temperature during standing still is 50-80°C.

Preferably, the pressure of autoclaved curing in step (3) is 0.8-1.5 MPa, and the time of autoclaved curing is 6-12 hours.

Example

The reagents used in the following examples are all commercially available.

Example 1

The preferred embodiment of the present invention discloses a fly ash-sand autoclaved aerated concrete block. The raw materials include the following components in parts by weight: 48 parts of fly ash, 32 parts of sand, and 25 parts of iron tailings fine powder , 33 parts of recycled fine aggregate from waste bricks, 17 parts of cement, 19 parts of lime, 7 parts of gypsum, and 0.07 parts of aluminum powder.

The preferred embodiment of the present invention also discloses the preparation method of the above-mentioned fly ash-sand autoclaved aerated concrete block, comprising the following steps: (1) regenerating fine bone with fly ash, sand, iron tailings fine powder and waste bricks Material, aluminum powder are put into ball mill respectively, reach the required fineness modulus after ball milling; The aluminum powder after the ball milling is stirred and prepared as aluminum powder suspension; (2) fly ash, sand after ball milling in step (1) , iron tailings micropowder, recycled fine aggregate of waste bricks and other raw materials including cement, lime and gypsum are measured according to the proportion by weight, put into the pouring car, stirred to obtain slurry, and aluminum is added to the slurry 0.5 minutes before injection into the mold. The powder suspension is then injected into the mould; the slurry is foamed to form a green body and then stopped and cut. The time of static stop is 2.5h, and the temperature during static stop is 50°C. (3) put the green body after the cutting that obtains in step (2) into autoclave and carry out autoclaving curing, the pressure of autoclaving curing is 1.2MPa, and the time of autoclaving curing is 10h, promptly obtains fly ash- Sand autoclaved aerated concrete blocks.

Example 2

The preferred embodiment of the present invention discloses a fly ash-sand autoclaved aerated concrete block. The raw materials include the following components in parts by weight: 39 parts of fly ash, 26 parts of sand, and 30 parts of iron tailings fine powder , 43 parts of waste brick recycled fine aggregate, 22 parts of cement, 24 parts of lime, 5 parts of gypsum, 0.05 part of aluminum powder, 0.03 part of foam stabilizer, 0.2 part of cellulose ether, 0.3 part of redispersible latex powder, 0.3 part of fiber , 1 part of expansion agent.

The preferred embodiment of the present invention also discloses the preparation method of the above-mentioned fly ash-sand autoclaved aerated concrete block, comprising the following steps: (1) regenerating fine bone with fly ash, sand, iron tailings fine powder and waste bricks Material, aluminum powder are put into ball mill respectively, reach the required fineness modulus after ball milling; The aluminum powder after the ball milling is stirred and prepared as aluminum powder suspension; (2) fly ash, sand after ball milling in step (1) , iron tailings fine powder, recycled fine aggregate of waste bricks and other raw materials including cement, lime, gypsum and additives, after being measured according to the weight ratio, put into the pouring car, stir to obtain the slurry, and pour it into the slurry 1 minute before injecting the mold Add the aluminum powder suspension, and then pour it into the mold; the slurry foams to form a green body, then stops and cuts. The time of static stop is 1.5h, and the temperature during static stop is 80°C. (3) put the green body after the cutting obtained in step (2) into the autoclave and carry out autoclaving curing, the pressure of autoclaving curing is 1.5MPa, and the time of autoclaving curing is 6h, promptly obtains fly ash- Sand autoclaved aerated concrete blocks.

Example 3

The preferred embodiment of the present invention discloses a fly ash-sand autoclaved aerated concrete block. The raw materials include the following components in parts by weight: 60 parts of fly ash, 40 parts of sand, and 20 parts of iron tailings fine powder , 23 parts of waste brick recycled fine aggregate, 12 parts of cement, 14 parts of lime, 10 parts of gypsum, 0.08 part of aluminum powder, 0.05 part of foam stabilizer, and 0.5 part of redispersible latex powder.

The preferred embodiment of the present invention also discloses the preparation method of the above-mentioned fly ash-sand autoclaved aerated concrete block, comprising the following steps: (1) regenerating fine bone with fly ash, sand, iron tailings fine powder and waste bricks Material, aluminum powder are put into ball mill respectively, reach the required fineness modulus after ball milling; The aluminum powder after the ball milling is stirred and prepared as aluminum powder suspension; (2) fly ash, sand after ball milling in step (1) , iron tailings micropowder, recycled fine aggregate of waste bricks and other raw materials including cement, lime, gypsum, additives, after proportioning by weight, put them into the pouring car, stir to obtain slurry, and pour into the slurry 0.5min before injecting into the mold Add aluminum powder suspension to the slurry, and then pour it into the mold; the slurry foams to form a green body, then stops and cuts. The time of static stop is 2.5h, and the temperature during static stop is 50°C. (3) put the green body after the cutting obtained in step (2) into the autoclave and carry out autoclaving curing, the pressure of autoclaving curing is 0.8MPa, and the time of autoclaving curing is 12h, promptly obtains fly ash- Sand autoclaved aerated concrete blocks.

Example 4

The preferred embodiment of the present invention discloses a fly ash-sand autoclaved aerated concrete block. The raw materials include the following components in parts by weight: 45 parts of fly ash, 30 parts of sand, and 22 parts of iron tailings fine powder , 35 parts of waste brick recycled fine aggregate, 20 parts of cement, 22 parts of lime, 6 parts of gypsum, 0.05 part of aluminum powder, 0.3 part of cellulose ether, and 0.2 part of redispersible latex powder.

The preferred embodiment of the present invention also discloses the preparation method of the above-mentioned fly ash-sand autoclaved aerated concrete block, comprising the following steps: (1) regenerating fine bone with fly ash, sand, iron tailings fine powder and waste bricks Material, aluminum powder are put into ball mill respectively, reach the required fineness modulus after ball milling; The aluminum powder after the ball milling is stirred and prepared as aluminum powder suspension; (2) fly ash, sand after ball milling in step (1) , iron tailings micropowder, recycled fine aggregate of waste bricks and other raw materials including cement, lime, gypsum, additives, after proportioning by weight, put them into the pouring car, stir to obtain slurry, and pour into the slurry 0.5min before injecting into the mold Add aluminum powder suspension to the slurry, and then pour it into the mold; the slurry foams to form a green body, then stops and cuts. The static stop time is 2 hours, and the temperature at the static stop is 60°C. (3) put the green body after the cutting obtained in step (2) into the autoclave and carry out autoclaving curing, the pressure of autoclaving curing is 1.5MPa, and the time of autoclaving curing is 6h, promptly obtains fly ash- Sand autoclaved aerated concrete blocks.

Example 5

The preferred embodiment of the present invention discloses a fly ash-sand autoclaved aerated concrete block. The raw materials include the following components in parts by weight: 55 parts of fly ash, 36 parts of sand, and 28 parts of iron tailings fine powder , 30 parts of recycled fine aggregate from waste bricks, 16 parts of cement, 16 parts of lime, 9 parts of gypsum, 0.08 parts of aluminum powder, 0.02 parts of foam stabilizer, 0.2 parts of fiber, and 2 parts of expansion agent.

The preferred embodiment of the present invention also discloses the preparation method of the above-mentioned fly ash-sand autoclaved aerated concrete block, comprising the following steps: (1) regenerating fine bone with fly ash, sand, iron tailings fine powder and waste bricks Material, aluminum powder are put into ball mill respectively, reach the required fineness modulus after ball milling; The aluminum powder after the ball milling is stirred and prepared as aluminum powder suspension; (2) fly ash, sand after ball milling in step (1) , iron tailings fine powder, recycled fine aggregate of waste bricks and other raw materials including cement, lime, gypsum and additives, after being measured according to the weight ratio, put into the pouring car, stir to obtain the slurry, and pour it into the slurry 1 minute before injecting the mold Add the aluminum powder suspension, and then pour it into the mold; the slurry foams to form a green body, then stops and cuts. The static stop time is 2.5 hours, and the temperature at the static stop is 65°C. (3) put the green body after the cutting that obtains in step (2) into autoclave and carry out autoclaving curing, the pressure of autoclaving curing is 1.2MPa, and the time of autoclaving curing is 10h, promptly obtains fly ash- Sand autoclaved aerated concrete blocks.

The fly ash-sand autoclaved aerated concrete blocks of the above-mentioned Examples 1-5 were tested according to the method specified in GB/T11969-2008, and the test results are shown in Table 1.

Table 1 Example 1-5 Fly ash-sand autoclaved aerated concrete block performance test results

Example 1 Example 2 Example 3 Example 4 Example 5 Average bulk density (kg/m ³ ) 618 616 620 615 616 Compressive strength (MPa) 5.68 5.56 5.63 5.6 5.65 Slump after 1h (mm) 190 180 189 185 183

The compressive strength of fly ash autoclaved aerated concrete blocks is generally 4.39MPa, the compressive strength of sand autoclaved aerated concrete blocks is 5.5MPa, and the dry shrinkage value is 0.27mm/m. Compared with the above test results, it can be seen that the fly ash-sand autoclaved aerated concrete block of the present invention is light in weight, high in strength, good in workability, good in durability, and not easy to collapse.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. a kind of flyash-sand autoclave aerated concrete building block, it is characterised in that raw material includes following group in parts by weight Point：

39 parts~60 parts of flyash, 26 parts~40 parts of sand, 20 parts~30 parts of iron tailings micro mist, give up brick recycled fine aggregate 23 parts~43 Part, 12 parts~22 parts of cement, 14 parts~24 parts of lime, 5 parts~10 parts of gypsum, 0.05 part~0.08 part of aluminium powder.

2. flyash according to claim 1-sand autoclave aerated concrete building block, it is characterised in that raw material is included with weight Measure the following component of part meter：

45 parts~55 parts of flyash, 30 parts~36 parts of sand, 22 parts~28 parts of iron tailings micro mist, give up brick recycled fine aggregate 30 parts~35 Part, 16 parts~20 parts of cement, 16 parts~22 parts of lime, 6 parts~9 parts of gypsum, 0.05 part~0.08 part of aluminium powder.

3. flyash according to claim 2-sand autoclave aerated concrete building block, it is characterised in that raw material is included with weight Measure the following component of part meter：

48 parts of flyash, 32 parts of sand, 25 parts of iron tailings micro mist, give up 33 parts of brick recycled fine aggregate, 17 parts of cement, 19 parts of lime, stone 7 parts of cream, 0.07 part of aluminium powder.

4. flyash according to any one of claim 1 to 3-sand autoclave aerated concrete building block, it is characterised in that

The sand is the one or more in artificial sand, mountain sand, river sand；And/or

Modulus of fineness more than 80 μm of square hole screens of the sand is 18%~22%.

5. flyash according to any one of claim 1 to 3-sand autoclave aerated concrete building block, it is characterised in that

Modulus of fineness more than 45 μm of square hole screens of the flyash is 8%~20%；And/or

The modulus of fineness of the 0.15mm sieve apertures of the useless brick recycled fine aggregate is 11%~31%.

6. flyash according to any one of claim 1 to 3-sand autoclave aerated concrete building block, it is characterised in that

Modulus of fineness more than 45 μm of square hole screens of the iron tailings micro mist is 5%~15%；And/or

Modulus of fineness more than 80 μm of square hole screens of the aluminium powder is 0.5%~1%.

7. flyash according to any one of claim 1 to 3-sand autoclave aerated concrete building block, it is characterised in that

The cement is portland cement, intensity >=42.5MPa of the cement.

8. a kind of preparation method of flyash-sand autoclave aerated concrete building block any one of claim 1 to 7, its It is characterised by, comprises the following steps：

(1) flyash, sand, iron tailings micro mist, useless brick recycled fine aggregate, aluminium powder are put into ball mill respectively, after ball milling Reach defined modulus of fineness；Aluminium powder stirring after ball milling is formulated as aluminium powder suspension；

(2) by the flyash after ball milling in the step (1), sand, iron tailings micro mist, useless brick recycled fine aggregate and other originals Material includes cement, lime, gypsum, after measuring by weight ratio, puts into pouring truck, and stirring obtains slurry, before injection mould to The aluminium powder suspension is added in the slurry, is then injected into mould；The slurry, which foams to be formed, quiet after base substrate to stop and cuts；

(3) base substrate after the cutting that will be obtained in the step (2), which is put into still kettle, carries out steam press maintenance, that is, obtains the powder Coal ash-sand autoclave aerated concrete building block.

9. the preparation method of flyash according to claim 8-sand autoclave aerated concrete building block, it is characterised in that

In the step (2), the aluminium powder suspension 0.5~1min before the slurry injects mould is put into；And/or

The quiet time stopped is 1.5~2.5h, and the temperature in quiet stopping time is 50~80 DEG C.

10. the preparation method of flyash according to claim 8-sand autoclave aerated concrete building block, it is characterised in that

The pressure of steam press maintenance is 0.8~1.5MPa in the step (3), and the time of steam press maintenance is 6~12h.