CN1040780A - Cementless powdered coal ash concrete - Google Patents

Abstract

A kind of improved Cementless powdered coal ash concrete, it is made by flyash, lime, gypsum and rubble etc., by its component concentration of choose reasonable and technology, can be made into the concrete that ultimate compression strength surpasses 20MPa.Thereby saved a large amount of cement, utilized the flyash that is regarded as refuse in a large number, had remarkable economic efficiency and social benefit.

Description

Cementless powdered coal ash concrete

A kind of improved Cementless powdered coal ash concrete belongs to building material technical field.

The concrete of architectural use generally is hybridly prepared into by a certain percentage by cement, sand and rubble.Along with progress of science and technology, people seek the surrogate of cement gradually, and are wherein successful with development and use flyash again.For example in the dam concrete of the Sanmenxia Gorge, mix flyash; Shanghai utilizes flyash mixed vitrified bond brickmaking; Hebei province utilizes flyash to produce air-entrained concrete building block or the like.In addition, the conspicuous work of Soviet Union K.B. lattice rad base, (China Construction Industry Press publishes " waste residue and powder ash air-entrained concrete goods " book that Chen Zhenji translates, in June, 1979 first version, P44, P63.) in point out: " peracidity (CaO＜10%) flyash; the agglutinate proportioning is: flyash: lime: gypsum=60: 35: 5; the agglutinate label during 95-98 ℃ of vapor cure temperature is 100, and the aerated concrete compressive strength of producing with it is 0.6-6MPa ".These concrete utilize flyash to make the cement surrogate, thereby have saved the more expensive cement of a large amount of prices, have reduced cost.But all these utilize in the known technology of flyash, or still need mix cement to improve goods ultimate compression strength.Do not mix cement, but the product strength that makes is too low.The product strength that provides as above-mentioned Soviet Union prescription only is 0.6-6MPa, the lime-powder ash air-entrained concrete building block of Shijiazhuang City, Hebei Province city building materials two factories development, its unit weight 500 ± 50kg/M ³, ultimate compression strength is 2.7MPa.(seeing " national scientific and technological achievement database " data) can only be used as non-bearing wall body.

The object of the present invention is to provide a kind of new Cementless powdered coal ash concrete.Be characterized in that intensity is higher without cement.Its label can reach more than No. 200.Can replace portland cement concrete with it.In addition, more and more many along with big industrial development, coal-fired waste flyash.With China is example, and the whole nation is about 500,000,000 tons of large power plant flyash reserves only, 180,000 mu of floor spaces.Nearly 5,000 ten thousand tons of year ash discharge amount, and also with year 5000000 tons of ash discharge amounts increase progressively.And the utilization of coal ash rate only accounts for 22.7% of ash discharge amount, and handling these flyash is big problems anxious to be solved, and purpose of the present invention also is to open up more wide road for the comprehensive utilization of flyash on the other hand.Turn waste into wealth.Relax the state of cement strained market supply.

The objective of the invention is on the method basis of making portland cement concrete, to realize by each components contents of reasonable apolegamy agglutinate wherein.

The main raw material(s) of making Cementless powdered coal ash concrete has four kinds of flyash, lime, gypsum and rubbles etc.Main technique is divided into raw material processing, blunge, the dress mould operations such as moulding, vapor cure, the goods demoulding of vibrating.Wherein, the agglutinate that plays cementation is mixed by flyash, lime powder and terra alba etc. and forms, and each components contents is:

Flyash: 70-83%;

Lime powder: 15-27%;

Terra alba: 2-5%;

Glue (agglutinate) bone (rubble) is than being 1: 2.0-2.6.

Water-cement ratio and portland cement concrete are basic identical, are about 0.46-0.50.

" starting material processing " in the above-mentioned technological process is meant original state unslaked lime, gypsum etc. through the meal of making such as broken, levigate, its particle diameter should be able to be by the sieve in every square centimeter 4900 hole, screen over-size is no more than 6% concerning lime powder, concerning terra alba, be no more than 36%, rubble then gets final product through the water flushing, other operation such as blunge, the moulding of vibrating of dress mould, the goods demoulding is then identical with ordinary process:

The vapor cure system is divided into: four steps such as constant temperature is quiet to stop, intensification, constant temperature, cooling.Per step temperature and time parameter is as follows:

Constant temperature is quiet to stop: 43-50 ℃, and 2.8-3.2 hour;

Heat up: 43-101 ℃, 3.6-4.5 hour;

Constant temperature: 95-101 ℃, 8-10 hour;

Cooling: 101-32 ℃, 2.8-3.2 hour.

Below provide by above-mentioned technology and starting material and make concrete four embodiment (because technology and water-cement ratio, glue bone ratio etc. are basic identical.So only provide the component concentration that is mixed of agglutinate):

1, flyash: 82%

Lime powder: 15%

Terra alba: 3%;

The actual measurement ultimate compression strength of corresponding concrete product is 21.1MPa.

2, flyash: 78%;

Lime powder: 20%

Terra alba: 2%;

The actual measurement ultimate compression strength of corresponding concrete product is 22.2MPa.

3, flyash: 70%;

Lime powder: 25%;

Terra alba: 5%;

The actual measurement ultimate compression strength of corresponding concrete product is 20.2MPa.

4. flyash: 83%;

Lime powder: 15%;

Terra alba: 3%;

The actual measurement ultimate compression strength of corresponding concrete product is 21.3MPa.

By the Cementless powdered coal ash concrete that the present invention makes, its technical indicator is: unit weight: 2080kg/M ³, go out chamber ultimate compression strength more than 20MPa; Tensile strength is: 1.5MPa; Folding strength is 2.8MPa; Static(al) pressure-proof elasticity modulus 16000MPa; With reinforcing bar bond stress 1.9MPa; Frost resistance: freeze-thaw cycle 50 times, loss of strength 1%; Freeze-thaw cycle 100 times, loss of strength 8%; Anti-penetration grade is B8; Sulfuric-resisting sodium corrosion factor 0.96 soaked 28 days in the water, and intensity increases by 6%, and tends towards stability; Deposited in the air 28 days, intensity increases by 3%, and tends towards stability.By the concrete product that the present invention makes, save 390 kilograms of cement for every cubic metre, owing to saved the more expensive cement of price,,, reduce cost 20% than portland cement concrete pipe as tubing so cost significantly reduces; Give panel, cost reduces by 26% than the portland cement concrete plate.By the concrete product that the present invention makes, every cubic metre can be utilized flyash to be about 451 kilograms, makes the flyash that accumulates in a large number turn waste into wealth, turn harm into good, and decontamination has been opened up more wide approach for utilizing flyash in a large number.

Claims (2)

1, a kind of Cementless powdered coal ash concrete, it utilizes four kinds of raw materials such as flyash, lime, gypsum and rubble, through the moulding of vibrating of raw material processing, blunge, dress mould, operations such as vapor cure, the goods demoulding are made, it is characterized by, the agglutinate that plays cementation is mixed by flyash, lime powder and terra alba etc. and forms, and each component concentration is:

Flyash: 70-83%;

Lime powder: 15-27%;

Terra alba: 2-5%.

2, Cementless powdered coal ash concrete according to claim 1 is characterized in that, in four steps such as its conservation system is divided into that constant temperature quietly stops, intensification, constant temperature and cooling, per step temperature and time parameter is:

Constant temperature is quiet to stop: 43-50 ℃, and 2.8-3.2 hour;

Heat up: 43-101 ℃, 3.6-4.5 hour;

Constant temperature: 95-101 ℃, 8-10 hour;

Cooling: 101-32 ℃, 2.8-3.2 hour.