CN102390963A - Recycled aggregate medium-dry hard concrete prepared by using building waste and preparation method of recycled aggregate medium-dry hard concrete - Google Patents

Abstract

The invention discloses a recycled aggregate medium-dry hard concrete prepared by using building waste, which comprises the following raw materials of coarse aggregate, fine aggregate, a gelatinizing agent, a water reducing agent and water, wherein the gelatinizing agent comprises cement and coal ash, and the coarse aggregate comprises 50-100 percent of recycled coarse aggregate prepared from the building waste. A preparation method of the recycled aggregate medium-dry hard concrete comprises the following steps of: pretreating the building waste, removing impurities, remaining waste concrete, waste bricks and the like; crushing and screening to prepare the recycled coarse aggregate; mixing the recycled coarse aggregate, natural sand, cement and water according to the proportion, adding the coal ash and the water reducing agent, stirring uniformly to obtain a mixture; and squeezing and forming the mixture, curing for 2 days to obtain the recycled aggregate medium-dry hard concrete. The invention solves the problems of worsening ecological environment and the like caused by difficulty in treating the building waste; and the building wastes are used for manufacturing the recycled aggregate for replacing natural aggregate, the increasingly deficient natural aggregate and damage degree to the ecological environment are reduced, and the living environment of human beings is protected. The recycled aggregate medium-dry hard concrete prepared by using the method has high strength and high abrasive resistance, and can be used for building base installations such as city roads, housing constructions and the like.

Description

Utilize half-dried rigid concrete of regeneration aggregate of building castoff preparation and preparation method thereof

Technical field

The present invention relates to a kind of half-dried rigid concrete and preparation method thereof, specifically is a kind of half-dried rigid concrete of regeneration aggregate and method thereof of utilizing the building castoff preparation.

Background technology

Concrete is pressed the workability branch of mix, and several kinds of low, half-dried rigid concrete, plastic concrete, mobile concrete, high-flowing concrete and chutable concretes etc. are arranged.Generally the call ultra-dry stiff concrete of concrete mix consistometric value greater than 30s, to the low that is called between the 30s, consistometric value is less than half-dried rigid concrete of being called of 20s at 20s for consistometric value.The construction work normal concrete was called the normal concrete mixture before setting and harden not.It must have good denseness is workability, is convenient to constructing operation such as mix, transportation, pouring, tamping, has the performance that quality is even, moulding is closely knit.After the normal concrete mix setting and harden, should have enough intensity, with the weather resistance of bearing design load and should have that guarantees that buildings can be safe.Workability is comprehensive technological property of normal concrete mix, and it comprises the implication of three aspects such as flowability, glutinous gathering property and full water-based.

Along with the development quickening of urbanization process of China's modernization construction, large-scale new town construction and reconstruction of the old city town cause the increasing of building castoff.The waste that building castoff is produced when being meant construction, repairerment and demolition of buildings has useless tile block, barren rock material, concrete blocks, sand-lime soil usually.Present most of waste concrete all is unprocessed direct stacking or landfill, has not only taken a large amount of soils, contaminate environment, and has caused a large amount of wastes of resource.Because China built in the last few years on a large scale, had expended material of construction such as a large amount of sand, stone and cement always.Natural resource such as a large amount of exploitation sand, stone cause resource nervous, environmental degradation.People inquire into waste concrete are utilized again, mainly are to be prepared as regeneration aggregate or building slab.Because the physicals of waste concrete and natural building material has than big-difference, and is bigger like the waste concrete water-intake rate, is generally 3.6～8%, and the water-intake rate of natural aggregate can not guarantee construction quality and work-ing life less than 3% as adopting usual method.

" constructional method of low " patent No. 201010501877.0 of Chinese patent reported in literature; " a kind of preparation method of low test block " patent No. 201010501859; All are low constructional methods; Half-dried rigid concrete, the particularly patent report of the half-dried rigid concrete construction method of regeneration aggregate are not also arranged.Half-dried rigid concrete generally is used in foundation works, and usage quantity is very big.

Summary of the invention

The objective of the invention is to for the building castoff resource utilization; Be prepared as coarse aggregate with building castoff; Prepare half-dried rigid concrete with this coarse aggregate, a kind of half-dried rigid concrete of regeneration aggregate of building castoff preparation and technical scheme of method thereof utilized is provided.

For realizing the foregoing invention purpose, the present invention adopts following technical scheme to be achieved: utilize the half-dried rigid concrete of regeneration aggregate of building castoff preparation, it is characterized in that; Raw material by following weight parts is formed, and coarse aggregate 1200～1320, fine aggregate 580～620, jelling agent 320～420, water reducer and water, described jelling agent are cement and flyash; Cement account for jelling agent 60～90%, flyash accounts for 10～40% of jelling agent; Water reducer is a cement amount 0.3～0.5%, and water is 150 ± 10, contains 50～100% regenerated coarse aggregates processed by building castoff in the described coarse aggregate; Described fine aggregate is a natural matter; Half-dried rigid concrete ultimate compression strength is more than or equal to 30Mpa, and its slump value is less than 10mm, and consistometric value is less than 20s.

Described cement is general purpose portland cement strength grade 32.5, and water reducer is commercially available high efficiency water reducing agent.

Utilize the half-dried rigid concrete preparation method of regeneration aggregate of building castoff preparation, it is characterized in that concrete steps are following:

1) building castoff is carried out pre-treatment, remove foreign material, keep waste concrete, useless brick, waste mortar;

2) to waste concrete, useless brick, broken, the screening of waste mortar, making particle diameter is regenerated coarse aggregate at the PM for particulate matter of 4.75～31.5mm;

3) according to proportioning regenerated coarse aggregate, natural sand, cement, water are mixed, other adds a small amount of flyash, water reducer, stirs to obtain mixture;

4) above-mentioned mixture is molded through shaking, maintenance in 28 days promptly gets the half-dried rigid concrete material of regeneration aggregate.

Waste concrete, useless brick, waste mortar account for more than 70% in building castoff, and these waste compositions are complicated, and enormous amount is emphasis and a difficult point of handling building castoff.Half-dried rigid concrete foundation works in construction work is occupied significant proportion, and foundation works adopts half-dried rigid concrete usually.The present invention is for the building castoff resource utilization, and building castoff is used for preparing the coarse aggregate of half-dried rigid concrete, because foundation works materials amount is big, can consume a large amount of coarse aggregates.The coarse aggregate of building castoff preparation is compared with the coarse aggregate of natural materials preparation, and it is strong to have water-absorbent, the characteristics that ash is many; The half-dried rigid concrete of regeneration aggregate of the present invention is compared with common regenerated aggregate concrete, has certain difference in intensity and aspect of performance, but because of the adding of flyash and water reducer; Half-dried rigid concrete water consumption of regeneration aggregate and cement consumption are all less, and ultimate compression strength and folding strength are higher, and shrinkage strain is little; Disconnected plate rate is little; Can be used to prepare pavement material, and brick uses materials for wall, have highly application value.The present invention can substitute natural coarse aggregate 50～100% with the coarse aggregate of building castoff preparation, makes jelling agent 10-40% with coal ash instead cement.One aspect of the present invention has solved a large amount of building castoff difficult treatment, and by problems such as the ecotope that it causes go from bad to worse; On the other hand; Make regeneration aggregate with building castoff and substitute natural aggregate, can reduce construction industry to natural resource consumption, thereby reduce exploitation to natural sandstone; Reduce the deficient day by day and a large amount of sandstones of natural aggregate and exploited the destructiveness that ecotope is caused; Protect existent environment of people, guaranteed the Sustainable development of human society, met the requirement of Sustainable development.The half-dried rigid concrete of the regeneration aggregate that the present invention prepares has HS, high-wearing feature, can be used for the construction of Infrastructure such as urban road and building construction.

Embodiment

Below in conjunction with embodiment the present invention is done further detailed, complete explanation:

Utilize the half-dried rigid concrete of regeneration aggregate of building castoff preparation.According to " design of common concrete proportioning rules " (JGJ55-2000); With the C30 concrete mix is benchmark, with reference to " highway cement concrete pavement construction technique normalizing " (JTG F30-2003), " general purpose portland cement " (GB 175-2007) and " flyash concrete utilisation technology standard " (GBJ 146-90).

1, raw material

Raw material by following weight is formed; Coarse aggregate 1200～1320, fine aggregate 580～620, jelling agent 320～420, water reducer and water; Described jelling agent is cement and flyash; Cement account for jelling agent 60～90%, flyash accounts for 10～40% of jelling agent, water reducer is a cement amount 0.3～0.5%, water is 150 ± 10.The concrete raw material of each embodiment is seen table 1.Contain 50～100% regenerated coarse aggregates processed by building castoff in the described coarse aggregate, described fine aggregate is a natural matter, and half-dried rigid concrete ultimate compression strength is more than or equal to 30 Mpa, its slump value is less than 10mm, and consistometric value is less than 20s.The half-dried rigid concrete proportioning of regeneration aggregate calculates by " design of common concrete proportioning rules ", about 1 cube of concrete.

Wherein:

(1) coarse aggregate does, the building castoff of villages within the city's transformation grades technology and the regenerated coarse aggregate of particle diameter in 4.75mm～31.5mm scope that obtain through artificial separation, jaw crushing, vibratory screening apparatus, and major ingredient is waste concrete, useless brick, waste mortar.The regenerated coarse aggregate grating is, particle diameter 4.75 mm～9.5 mm account for 22%, and particle diameter 9.5mm～19.0mm accounts for 53%, and particle diameter 19.0mm～31.5 mm account for 25%.Natural aggregate is cobble, rubble.The grating such as the table 1 of coarse aggregate,

(2) the natural fine aggregate be common building with river sand, mountain sand or stone flour, maximum particle diameter 4.75mm, continuous grading, it is 2.500,1.250,0.630,0.315 with the summation of the sieve accumulated retained percentage in five kinds of apertures such as 0.160mm.

(3) cement is Portland blast; Strength grade 32.5,28 days ultimate compression strength of cement is 32.5 Mpa, cement is as concrete gelling material; Cement coagulates slurry to the quality of concrete decisive role, and its main effect is: the hole that is wrapped in aggregate surface and filler aggregate; At concrete coagulation sclerosis previous crops is the lubricant lubricate between gathering materials, and makes the concrete mix have the workability that is suitable for constructing; When concrete coagulation hardens, strengthen the cohesive force between the aggregate, make mixed mirror soil reach needed intensity, weather resistance etc.

(4) flyash is that ash discharge is done in Yang Zonghai power station, Yunnan Province.Flyash mixes in the concrete in right amount; Can partly replace cement; Can not only save cement consumption, reduce the concrete cost, and can also improve the workability of concrete mix, because flyash has activation; The hydration reaction of regeneration aggregate surface residual cement mortar can be strengthened, performances such as concrete density, impermeability and chemical resistance can also be improved.

(5) water reducer does, the good growing concrete admixture in Kunming is sold the sky skill board FDN-2 high efficiency water reducing agent that Ltd sells, and major ingredient is: the high condenses of β-naphthalenesulfonateformaldehyde formaldehyde.Water reducer can be saved the mixing water amount, increases concrete flowability, improves concrete workability, the reduction of erection time, accelerate works progress, and also can save the engineered cementitious consumption, have good economic benefits.Simultaneously can also strengthen concrete intensity.

2, preparation method:

(1) regenerated coarse aggregate, fine aggregate, cement, water are mixed, other adds a small amount of flyash, water reducer, stirs, and wherein: water-cement ratio is 0.3～0.5, the water reducer volume is a cement amount 0.3～0.5%.

(2) adopt the molded technology of shaking, frequency be 2860 minutes/inferior, amplitude is 0.5mm, upper surface pressure is 0.6Mpa, time of vibration is under the condition of 15s, carries out maintenance, promptly can obtain the half-dried rigid concrete of regeneration aggregate.

(3) check: before maintenance, detect the slump, denseness.28 days compression strength value 39.54Mpa of the half-dried rigid concrete of prepared regeneration aggregate, its slump value 8mm, consistometric value 14s.

3, purposes

Utilize the half-dried rigid concrete of regeneration aggregate of building castoff preparation to can be used to prepare regenerated aggregate concrete pavement material and the regenerated aggregate concrete brick of ultimate compression strength in C30 and following requirement of strength.

Table 1

Table 2

Claims (3)

1. utilize the half-dried rigid concrete of regeneration aggregate of building castoff preparation, it is characterized in that, form by the raw material of following weight parts; Coarse aggregate 1200～1320, fine aggregate 580～620, jelling agent 320～420, water reducer and water; Described jelling agent is cement and flyash, cement account for jelling agent 60～90%, flyash accounts for 10～40% of jelling agent, water reducer is a cement amount 0.3～0.5%; Water is 150 ± 10; Contain 50～100% regenerated coarse aggregates processed by building castoff in the described coarse aggregate, described fine aggregate is a natural matter, and half-dried rigid concrete ultimate compression strength is more than or equal to 30Mpa; Its slump value is less than 10mm, and consistometric value is less than 20s.

2. the half-dried rigid concrete of regeneration aggregate that utilizes the building castoff preparation according to claim 1 is characterized in that described cement is general purpose portland cement strength grade 32.5, and water reducer is commercially available high efficiency water reducing agent.

3. the half-dried rigid concrete preparation method of regeneration aggregate who utilizes the building castoff preparation as claimed in claim 1 is characterized in that concrete steps are following:

1) building castoff is carried out pre-treatment, remove foreign material, keep waste concrete, useless brick, waste mortar;

2) to waste concrete, useless brick, broken, the screening of waste mortar, making particle diameter is regenerated coarse aggregate at the PM for particulate matter of 4.75～31.5mm;

3) according to proportioning regenerated coarse aggregate, natural sand, cement, water are mixed, other adds a small amount of flyash, water reducer, stirs to obtain mixture;

4) above-mentioned mixture is molded through shaking, maintenance in 28 days promptly gets the half-dried rigid concrete material of regeneration aggregate.