Two, background technology:
As everyone knows, the concrete cracking problem is the ubiquitous problem of engineering circle, and concrete crack has influenced concrete functions of use and work-ing life widely.Development concrete micro-expanding agent becomes the technique means that engineering circle generally adopts in order to solve concrete cracking, existing both at home and abroad a large amount of research, and lot of documents is arranged:
Major technique content in these documents is:
1, adopt gypsum phase material and aluminium mutually material chemical reaction takes place in the hydrated cementitious system, generate ettringite, produce the principle of volumetric expansion, prevent the crack that concrete produces owing to contraction.
2, gypsum phase material extensively adopts the gypsum ore that exploitation is come out, and aluminium phase material then comes from alunite, aluminate, aluminosulfate cement etc. in a large number.
Composite expansive agents for concrete and the manufacture method thereof announced of CN85100902A for example: mainly in calcareous expansive clinker, add a certain proportion of natural alumstone and gypsum, the common grinding of these mixtures formed.These technology can generate ettringite quickly in the hydrated cementitious system, expand obviously, but the ubiquity early expansion is bigger, the unconspicuous characteristics of delayed expansion.And owing to adopt materials such as alunite, aluminate, sulplo-aluminate to originate mutually in a large number as aluminium, in concrete, introduced a large amount of alkali on the one hand, the possibility that alkali takes place when containing activity and gather materials concrete is increased greatly, on the other hand in mixing the fresh concrete aquation system of high efficiency water reducing agent, accompany the carrying out of hydrated cementitious of aluminium salt aquation, a large amount of absorption high efficiency water reducing agent molecules, cause the actual usefulness of high efficiency water reducing agent to reduce, cause that the slump-loss of fresh concrete is obvious.With the cement expansive material function singleness of these technology preparations, only have the microdilatancy function usually in addition, can not satisfy of the requirement of modern concrete operating technique the Concrete Additive functional diversities.And production cost also remains further to be reduced.
Three, summary of the invention:
The objective of the invention is to overcome the existing concrete swelling agent and have above-mentioned shortcoming, provide a kind of and have good expansion rule, can obviously improve the fresh concrete serviceability, significantly improve concrete permeability resistance, the frost resistance endurance quality, and have the multifunctional mineral additive preparation technology and the method for early strong, low alkali content, characteristics such as with low cost.The present invention has industrial residue utilization rate height, improves concrete quality, and easy construction reduces the building maintenance expense, improves advantages such as buildings life-span.
The present invention adopts following technical proposals to realize:
A, at first prepare the function ingredients first: the M metal-powder with accounting for more than 90% below superfine pulverizing to the 2 μ particle diameter, is formed with the passive film of organism Passivation Treatment to suitable thickness then, make with the silica powder dilution again.
B, preparation function ingredients second: with the ferrous sulfate be the industrial waste of main component and sodium sulfate in proportion (0.5-1.5) combined grinding form.
C, be 4500-5500mm with the hard fluorgypsum oven dry of flyash, industrial waste, grinding to specific surface area
2/ g, water ratio is less than below 2%.
D, oven dry properties-correcting agent sugar calcium water reducer to water ratio are lower than 2%.
E, function of measuring component first is 3-5% (weight) respectively, function ingredients second is 3-5% (weight), properties-correcting agent sugar calcium water reducer is 1.2-2.4% (weight) and levigated flyash 55-60%, hard fluorgypsum 30-35%, mixes, and promptly makes the multifunctional concrete mineral additive.
Just Zhi Bei function ingredients first 3-5% and function ingredients second 3-5%, properties-correcting agent 1.2-2.4% be milled to the hard fluorgypsum 30-35% of industrial waste of certain fineness, flyash 55-60%, go into the ball mill grinding jointly and be mixed to evenly, promptly make Multifunction concrete mineral additive.
Flyash is the first level flour coal ash, and its performance should satisfy the CNS regulation.
Fluorgypsum is aluminium manufacturer's industrial waste, adopts hard fluorgypsum wherein, and its chemical ingredients is as shown in the table, and each group component fluctuates up and down and is no more than 1%.
Main chemical constitution CaF
2Al
2O
3SO
3CaO
Percentage composition (%) 6.0-7.0 18.5-19.5 21-22 39-40
The multifunctional concrete mineral additive produces the microdilatancy effect in the hydrated cementitious system, three expansion sources are arranged: one of them is the generation of ettringite, the effect of fluorgypsum in Multifunction concrete mineral additive: the one, for the generation of ettringite provides the gypsum phase, the 2nd, fluorgypsum is aluminium manufacturer's industrial waste, wherein contain a large amount of active aluminum phases, thereby aluminium phase material can be provided for the generation of ettringite.
The effect of high-quality fly ash in the multifunctional concrete mineral additive: the one, help improving the serviceability of fresh concrete, the 2nd, make fluorgypsum, function ingredients first, function ingredients second, the properties-correcting agent etc. can homodisperse, the 3rd, reduce the production cost of Multifunction concrete mineral additive.And the adding of flyash can also bring into play its micro aggregate effect, increases concrete density, can bring into play its volcanic ash effect, reduces alkali content in the concrete, reduces the cement heat-transmission, improves endurance performance of concrete.
The effect of function ingredients first in the multifunctional concrete mineral additive: in the hydrated cementitious system along with the carrying out of hydrated reaction of cement, its surperficial passive film dissolves gradually, certain the time with the material generation chemical reaction of hydrated cementitious in mutually, generate a large amount of equally distributed small closed bubbles, produce volumetric expansion, this is second expansion sources of Multifunction concrete mineral additive.Simultaneously, a large amount of equally distributed small closed bubble of generation can play good ball lubrication, helps the mutual slippage between cement particle and other mineral admixture particles, thus the slump of controlling fresh concrete effectively through the time lose.And a large amount of equally distributed small closed bubble of generation can play the effect of endurance qualities such as significantly improving concrete permeability resistance, frost resistance.The function ingredients first in the hydrated cementitious system reaction times and speed of reaction can be by controlling its surface passivated membrane filmogen and the thickness of film controlled.
The effect of function ingredients second in the multifunctional concrete mineral additive: produce chemical reaction in the hydrated cementitious system, generate Fe (OH)
3Gel, favourable to concrete early strength on the one hand, produce volumetric expansion on the other hand, form the 3rd expansion sources of multifunctional concrete mineral additive.And Fe (OH)
3The generation of gel can refinforced cement stone degree of compactness, thereby improve durability of concrete.
The effect of properties-correcting agent sugar calcium water reducer in the multifunctional concrete mineral additive: the effect of slow setting is arranged on the one hand, the slump that helps fresh concrete through the time loss control, the effect of diminishing is arranged on the other hand, make the fresh concrete workability keep under the situation of certain level, can reduce water consumption, thereby increase concrete density, improve concrete strength.
Said components and proportioning are prepared the Multifunction concrete mineral additive that just obtains a kind of excellent performance by processing requirement, when take outer doping to add among the concrete with the weight percent of cement consumption 10-14% after, can obtain good technology economic.For example: 1, can keep 2/10000ths degree of free swelling during the 28 day length of time, the contraction that produces owing to a variety of causes of compensating concrete effectively; 2, obviously improve the serviceability of fresh concrete, effectively control the fresh concrete slump through the time lose, can control 2 hours slump-loss of C60 strength grade without vibration high performance concrete in 5cm.3, significantly improve endurance qualities such as concrete impermeability, frost resistance, as mix and C60 without vibration concrete frost resistance can be brought up to more than the F300.4, when reaching above-mentioned technical indicator, concrete physical and mechanical property is unaffected.5, utilize industrial residue in a large number, production technique is simple, and production cost per ton can be controlled at about 250 yuan.In a word, the development of Multifunction concrete mineral additive can solve present concrete micro-expanding agent function singleness well with application, alkali content is big, influence the problem of endurance performance of concrete, serviceability and physical and mechanical property, can also reduce the pollution of industrial waste, the significant social economic benefit is arranged environment.
Five, embodiment:
Blain specific surface 4500-5500mm is dried, measures, is crushed to the flyash that meets the demands, hard fluorgypsum respectively
2/ g fineness is controlled its material composite water cut less than standby below 2%.The preparation of function ingredients first: certain metal-powder is accounted for more than 90% with the following particle diameter of airflow milling superfine pulverizing to 2 μ, carry out surface passivation with alkali lye and organism then and handle, form passive film, with the silica powder dilution, make the function ingredients first again on its surface.Accurate function of measuring component first, function ingredients second, properties-correcting agent sugar calcium water reducer (the control water ratio is lower than 2%), with its with the coal ash that is milled to certain fineness, grinding is even again for hard fluorgypsum, obtains multifunctional concrete mineral additive proposed by the invention behind the test package.
Further specify the application's invention below in conjunction with embodiment, but embodiment should not regard the qualification to right of the present invention as.
Embodiment:
Table 1 multifunctional mineral additive formulations
The multifunctional mineral additive is formed and the volume sequence number
Fluorgypsum+flyash+second+first+properties-correcting agent volume (cement weight %) H 35%+52%+5%+3%+5% 12I 30%+56%+5%+4%+5% 12G 33%+57%+3%+4%+3% 12
Table 2 is mixed multifunctional mineral additive H concrete test proportioning
Each component concentration (kg/m
3) sample
Cement sand stone water FDN mineral additive H UEAA0 439 478 1,188 195 3.95 0 0A1 386 478 1,188 195 3.95 0 5,3A2 386 478 1,188 195 3.95 53 0
The free linear expansivity of table 3 glue sand test specimen
Degree of free swelling (* 10
-4) sequence number swelling agent (volume)
1d??????3d??????5d??????7d?????11dB0???????0????????????-1.8????-1.8????-1.9????-1.9???-2.0B1???????UEA(12%)????-0.4????0.6?????2.6?????2.6????2.6B2???????H(12%)??????0.9?????1.5?????2.4?????2.3????2.3
Table 4 is blank and mix multifunctional mineral additive concrete and newly mix the characteristic index sample expanding value slump (mm)
The doff that decays flows down the time (S)
(cm) initial 1h 1.5hA0 60 210 204 199 1,6A1 57.5 201 122 82 2,0A2 59.5 215 201 194 14
Table 5 is blank and mix multifunctional mineral additive concrete physical and mechanical property
Folding strength (Mpa) ultimate compression strength (Mpa) sample
3d??????7d?????28d?????????3d??????7d?????28dA0????????5.40????6.49????9.78???????36.2????41.1????50.0A1????????4.97????5.70????9.40???????33.2????42.1????48.9A2????????5.75????6.62????9.69???????39.5????43.0????50.8
Table 6 is blank and mix multifunctional mineral additive endurance performance of concrete
Sample | Impervious (permeated height cm) | Freeze the back and freeze preceding compressive strength rate (%) | 28d chloride-penetration resistance value (coulomb) | ??????????Na
2SO
4Corrode
|
???f
0 | ????f | Coefficient against corrosion |
?A0 | Water oozes out | ????84.5 | ????1500 | ???50.0 | ??41.2 | ??0.824 |
?A1 | ????8.5 | ????91.3 | ????420 | ???48.9 | ??45.3 | ??0.926 |
?A2 | ????7.4 | ????99.4 | ????280 | ???50.8 | ??48.8 | ??0.961 |
Table 7 multifunctional mineral additive H composite of performance index
Project | Desired value | Measured value |
Chemical ingredients | Magnesium oxide % water ratio % total alkali content % chlorion % | ????≤ ????????≤ ????????≤ ????????≤ | ????5.0 ????3.0 ????0.75 ????0.05 | ????1.10 ????2.2 ????0.20 ????0.01 |
Physicals | Fineness | Specific surface area m
2/ kg 0.08mm tails over % 1.25mm and tails over %
| ????250 ????10 ????0.5 | ????550 ????8.6 ????0 |
Time of coagulation | Initial set min 〉=final set h≤ | ????45 ????10 | ????170 ????4.5 |
Ultimate compression strength Mpa | ????7d???????≥ ????????28d??????≥ | ????25.0 ????45.0 | ????35.0 ????53.0 |
Folding strength Mpa | ????7d???????≥ ????????28d??????≥ | ????4.5 ????6.5 | ????5.5 ????9.0 |