CN105777017A

CN105777017A - Concrete for steel reinforced concrete composite structure C250 strength grade

Info

Publication number: CN105777017A
Application number: CN201610217897.2A
Authority: CN
Inventors: 郑山锁; 董方园; 郑捷; 孙龙飞; 王斌; 张艺欣; 李磊; 王帆; 秦卿; 杨威; 左河山; 石磊; 郑淏; 张晓辉; 周炎
Original assignee: Xian University of Architecture and Technology
Current assignee: Xian University of Architecture and Technology
Priority date: 2016-04-08
Filing date: 2016-04-08
Publication date: 2016-07-20
Anticipated expiration: 2036-04-08
Also published as: CN105777017B

Abstract

The invention discloses concrete for the steel reinforced concrete composite structure C250 strength grade. The matching ratio of cement to fine aggregate to coarse aggregate to water to water reducing agent to antifoaming agent to silica powder to coal ash to exciting agent to expanding agent to composite plastic retaining agent is 504:769:1,308:102:21:1.5:100:125:11:52:0.65. A preparing method includes the steps that the water reducing agent, the exciting agent and the composite plastic retaining agent are evenly stirred into water to obtain a mixture, and the fine aggregate and 1/3 of the total mixture are sequentially added into a stirring machine according to the weight ratio and stirred to be even; the coarse aggregate and 1/3 of the total mixture are added and stirred to be even; the cement, the expanding agent, the silica powder and the coal ash are added and stirred to be even; the antifoaming agent and the residual mixture are added, and the mixture is stirred and discharged. By means of the concrete, the bonding performance between structural steel and the concrete can be remarkably improved under the natural state, the mechanical performance and the cooperative work performance of the steel and the concrete are effectively developed, the carrying capacity, the use performance and the durability of a structural element are greatly improved, and the concrete has the good high volume stability and the good economy.

Description

A kind of concrete for reinforced concrete composite structure C250 strength grade

Technical field

The invention belongs to building material technical field, relate to a kind of for special high-strength high-performance concrete that reinforced concrete composite structure strength grade is C250.

Background technology

The invention of Portland cement in 1824 makes concrete technology obtain rapid development, and its consumption is big, the scope of application extensively may occupy the first in the world.Although concrete is a kind of traditional manufactured construction materials, but because it has the continuous progressive of the superiority (abundant raw material, production technology simple, cost performance advantages of higher) do not replaced and concrete material science and technology, concrete has become the main body of civil engineering material, also will be one of indispensable main material in following civil engineering and nation-building.Simultaneously, continuous expansion along with city size, being on the increase of population, the continuous rising of land price, harshization of building local environment, the constantly progressive and rapid development of economy of Building technology, building is increasingly in the air, underground and water extend, namely building surpasses/extra-highization, super/Super-Long Span, underground, the development of lightweight and heavy type structure, especially steel reinforced concrete structure is in super/extra-highization, super/Super-Long Span, underground, marine or change under water, the application of the novelty such as lightweight or megaplex engineering field, the requirement of this construction material of concrete is also more and more higher.Therefore, concrete super/research and the practice of extra-high strengthening and super/special durableization will become the development trend in this field.

Reinforced concrete composite structure (abbreviation SRC structure) is a kind of principal mode of steel concrete combinative structure, owing to its bearing capacity is high, rigidity is big, ductility good, anti-seismic performance is superior, fire retardant anticorrosion, it is easy to the series of advantages such as construction, it is applied to big across, heavy type structure more and more widely, underground, under water or the high level of marine engineering and earthquake/typhoon zone and super/special skyscraper.Compared with steel construction, SRC structure can save great deal of steel, strengthens section rigidity, overcomes the shortcoming such as steel structure fire-resistant, corrosion resistance and poor durability and easy flexing unstability, makes the ability of steel be fully played；Compared with ordinary reinforced concrete structure (abbreviation reinforced concrete structure), reinforced concrete composite structure can reduce the sectional dimension of component, reduces shared space, thus increasing building to use space；In construction, the steel skeleton of steel reinforced concrete structure itself can hang the skeleton of mould, sliding formwork as concrete, not only enormously simplify formwork engineering, is also subject to the supporting system of whole construction loads (including extension, sliding formwork and institute's pouring concrete)；Further, since the SRC structure advantages such as to have globality strong, good working ductility, being substantially improved the brittleness of armored concrete sheared destruction, make the anti-seismic performance of structure be significantly improved, bearing capacity and ductility are all greatly improved than reinforced concrete structure.Therefore, in Japan and the developed country such as American-European, having the SRC structure of good anti-seismic performance has become a kind of generally acknowledged novel earthquake-proof structural system, and with steel construction, timber structure, reinforced concrete structure be called four big structures.China is also the country of earthquake more than, and most areas are earthquake territory, and part is positioned at highlight lines and frequently occurred earthquake district, promotes SRC structure in these areas and just has very important realistic meaning；On the other hand, owing to quickly increasing of population makes housing need amount also be on the increase, and land resource scarcity is valuable, and then promoted to build to the development of more high spatial, therefore build super/special skyscraper when economic condition and urban planning allow and also become saving fund and save the effective measures in soil.Therefore, SRC structure has boundless application prospect in China, constantly strengthening and the successful development of super/special high-strength steel and special high-strength high-performance concrete (they are putative 21 century materials) and application especially with China's economic strength, will be greatly facilitated popularization and application and the progress of this structural system.There are some researches prove, the intensity of special high-strength high-performance concrete is more high, and its fragility will increase, and ductility also can be poor, and under heavily stressed or complex stress condition, special high-strength high-performance concrete component will be controlled destructive process by fragility, and the reliability of work reduces.But, this novel High Technique Concrete is applied in reinforced concrete composite structure (being called for short SRC structure), i.e. shaped steel spy high-strength high-performance concrete combinative structure (being called for short SRUSUPC structure), can maximize favourable factors and minimize unfavourable ones, high-strength high-performance concrete fragility is big, ductility is poor and shaped steel is fire-resistant, the weakness of poor corrosion resistance to overcome spy so that it is superior function and economic benefit are given full play to.

In SRC structure, cementation good between shaped steel and concrete is to ensure that the basis of SRC component Shaped Steel and concrete co-ordination, shaped steel, reinforcing bar and three kinds of material elements collaborative works of concrete, to resist various action effect, can give full play to its advantage.But the cohesive force that the cohesive force that one of significant difference of SRC structure and reinforced concrete structure is in that between shaped steel and concrete is far smaller than the cohesive force between reinforcing bar and concrete, shaped steel and normal concrete is only about equivalent to the 45% of plain steel-bar cohesive force.Domestic and international many experimental studies show, there is bond-slip phenomenon between shaped steel and concrete, and the stress performance or even bearing capacity on SRC component has appreciable impact.Therefore, shaped steel and one of concrete emphasis becoming SRC structural research of collaborative work effectively how are ensured.At present, the processing method of bond-slip problem between shaped steel and concrete generally there are two kinds by engineering design: the first adds a number of shearing connecting piece by calculating in component surface, so certainly will cause the inconvenience in construction and improve cost, and easily causing the defects such as the congenital microcrack of inside concrete；It two is be not provided with or only arrange a small amount of shearing connecting piece, considers the impact of bond-slip, the corresponding bearing capacity reducing component, so certainly exist uneconomic factor in bearing capacity calculates.On the other hand, in Structural Design, ubiquity focuses on intensity and the phenomenon of light durability, the problem having occurred the safety in use of many xoncrete structures and durability aspect both at home and abroad.Namely some concrete structure engineerings completely lose use function or even bearing capacity in the not enough design period half of use due to the reason such as alkali-aggregate reaction, Chloride Attack, even there is partial collapse or total Collapse in indivedual engineerings, cause casualties or Architectural Equipment is destroyed.Therefore, in SRUSUPC structure, improve the natural adhesive property between shaped steel and special high-strength high-performance concrete, be not provided with on shaped steel surface or only arrange a small amount of shearing connecting piece by detailing requiments ensuring that the research of shaped steel and special high-strength high-performance concrete collaborative work effectively is significant；Meanwhile, the durability of concrete structure engineering also causes close attention and the great attention of people day by day, and becomes the problem that divination by means of the milfoil is to be solved.

Prior art has C30 for the concrete strength grade of reinforced concrete composite structure, C35, C40, C45, the low-strength HPC of C50 and C55, C60, C70, C80, the high-strength high-performance concrete of C90 and C100 and C110, C120, C130, the super high strength high performance concrete of C140 and C150, also has follow-up C160, C170, C180, C190 and C200 super/technology of preparing of special high-strength high-performance concrete, above-mentioned each strength grade concrete significantly improves the adhesive property between shaped steel and (surpassing) high-strength concrete, and improve the durability of structure；But, there is also the special high-strength high-performance concrete that can not thereby extend into higher intensity, and the problem that the natural adhesive property between shaped steel and special high-strength high-performance concrete is poor when using it for reinforced concrete composite structure, can not be solved, therefore civil engineering work can not be met and extend in aerial, underground and water, namely building surpasses/extra-highization, super/Super-Long Span, underground, marine or change under water, the application such as super-durable and heavy, huge and novel Structural Engineering and develop the requirement of this trend.It addition, prior art there is also the part technology of preparing by super for concrete/extra-high strengthening, super/special durableization, but they be all not directed to or unresolved for SRC structure time shaped steel and special high-strength high-performance concrete between the problem of natural adhesive property difference.

Summary of the invention

It is an object of the invention to provide a kind of for special high-strength high-performance concrete that reinforced concrete composite structure strength grade is C250.This concrete is applied in reinforced concrete composite structure, the adhesive property that can significantly improve between shaped steel and concrete under naturalness (that is shaped steel surface is not provided with or only arranges a small amount of shearing connecting piece by detailing requiments), effectively play steel and the respective mechanical property of concrete bi-material and mutual cooperative work performance, thus the significantly bearing capacity of lift structure component and serviceability；It addition, this concrete can improve the durability of structure, and there is good service behaviour, high volume stability and economy.

For solving above-mentioned technical problem, the present invention is achieved in that

A kind of concrete for reinforced concrete composite structure C250 strength grade, this concrete match ratio is (unit: kg/m³):

Cement: fine aggregate: coarse aggregate: water: water reducer: defoamer: silica flour: flyash: exciting agent: extender: compound plasticity-maintaining agent=504: 769: 1308: 102: 21: 1.5: 100: 125: 11: 52: 0.65.

Described cement selects steady quality, better performances, P I 62.5R portland cement that intensity is higher, need before using to carry out compatibility test between the two with poly carboxylic acid series concrete high-performance water reducing agent, test method adopts the method in existing building material industry standard " cement with water reducer compatibility test method " JC/T1083-2008, and selects and cement type that the poly carboxylic acid series concrete high-performance water reducing agent compatibility is good.Selected cement performance index (includes fineness, SO₃Content, content of MgO, presetting period, final setting time, 3 days intensity, 28 days intensity) requirement of national existing relevant criterion should be not less than, and select the cement type that alkali content is few, the heat of hydration is low, water requiremen is also low.

The granule that described fine aggregate adopts mass ratio to be 8:2 is round and smooth, quality is hard, grating good in partially thick fluvial sand and quality is consummate, grating is good quartz sand.Wherein, the quality of sand should be not less than in existing building material industry standard " regular concrete sand, stone quality and test method standard " JC/T52-2006 and national standard " building sand " GB/T14684-2011 the high-quality sand standard of regulation.Its modulus of fineness is between 2.8～3.2, and clay content and clod content should be not more than for 0.3% (in mass), and chloride ion content should be not more than 0.02% (quality in dry sand), SO₃Content should be not more than 0.5%.In quartz sand, dioxide-containing silica should be not less than 99%, and ferric oxide content should be not more than 0.005%, and the metals content impurity such as chromium, titanium should be not more than 0.01%.

Described coarse aggregate adopts the artificial rubble being main component with basalt, granite that quality densification is hard, intensity is high, rough surface, particle shape are almost spherical, elongated particles is little, grating is good, feeds intake according to continuous size fraction rubble Φ 5～Φ 10；The quality of rubble should be not less than the regulation requirement of the relevant criterion such as existing building material industry standard " regular concrete sand, stone quality and test method standard " JC/T52-2006 and " cobble for building, rubble " GB/T14685-2011.The cubic compressive strength of its parent rock of coarse aggregate should be not less than 300MPa, and maximum particle diameter should control at 10mm；By quality ratio, its SO₃Content should be not more than 0.5%, and clay content should be not more than 0.2%, and clod content should be not more than 0.1%, and pin, sheet-like particle content should be not more than 0.5%, and must not be mixed into air slaking granule.When carrying out this Concrete, continuous size fraction rubble Φ 5～Φ 10 is adopted to feed intake.

Through a large amount of tentative contrast tests and with cement compatibility test, high efficiency water reducing agent selected by this invention is poly carboxylic acid series concrete high-performance water reducing agent, its quality should be not less than the regulation requirement of the relevant criterion such as existing national standards " Technical code for application of admixture in concrete " GB50119-2013 and " concrete admixture " GB8076-2008, and the water-reducing rate of selected high efficiency water reducing agent should be greater than 30%.The maximum saturation volume of selected high efficiency water reducing agent is not less than the 2.5% of whole binder total amount, adopts with mixing method, and needs to carry out compatibility test with selected cement type before use.

Described defoamer selects AGITANP803 powder defoamer.

30nm nano silica fume and the sub-micro silica flour that described silica flour adopts mass ratio to be 3:2, its quality should be not less than the regulation requirement of the relevant criterion such as national standard " mineral admixture for high-strength high-performance concrete " GB/T18736-2002, simultaneously, the moisture content of 30nm nano silica fume and (Asia) SILICA FUME all should be not more than 1%, loss on ignition all should be not more than 3%, chloride ion content all should be not more than 0.01%, and pozzolanic activity index all should be greater than 95%.Wherein, the specific surface area of 30nm nano silica fume should be not less than 40000m²/ kg, silicone content should be not less than 99.9%；The specific surface area of (Asia) micron silica flour should be not less than 25000m²/ kg, dioxide-containing silica should be not less than 95%.

I grade of special fine powdered coal of high-quality that the power plant that described flyash adopts coal burning process advanced produces.Its quality should be not less than the regulation requirement of the relevant criterion such as national standard " flyash in cement and concrete " GB/T1596-2005, and its fineness (0.045mm square hole screen tails over, %) should be not more than 10%, and loss on ignition should be not more than 3%, SO₃Content should be not more than 2%, and water content should be not more than 1%, and water demand ratio should be not more than 95%, and specific surface area should be greater than 700m²/kg。

Described exciting agent is by the efficient flyash excitant (FAEA) of inventor place research team independent development, the activity that Ultrafine Grinding pulverized burned coal ash hydration mixed with nano silica fume and sub-micro silica flour is reacted by this exciting agent excites further, and it is formulated according to the raw material compound of following mass percent:

The waterglass (utilizing solid sheet NaOH and commercially available sodium silicate water glass to be modulated into the waterglass that modulus is about 1.0 in proportion) of inorganic material 65%～73%, 23%～30% common dihydrate gypsum (CaSO₄·2H₂O) and organic material 3%～5% triethanolamine (TEA) compound formulated.

Preparation method is as follows: first make certain density alkaline solution by soluble in water for solid sheet NaOH, then and the sodium silicate water glass of known modulus (between the modulus general 2.4～3.3 of commercial water glass) be modulated into the waterglass that the test that modulus is 1.0 needs, finally prepare, with common dihydrate gypsum and TEA compound, the composite exciting agent (FAEA) becoming required again.

Through test determination, this exciting agent and early strength silicate cement, poly carboxylic acid series concrete high-performance water reducing agent have the good compatibility.

The calcium sulphoaluminate class high-efficiency expanding agent being applicable to special high-strength high-performance concrete selected by described extender, its quality should be not less than the regulation requirement of the relevant criterion such as national standard " cement expansive material " GB23439-2009, and its fineness (0.08mm square hole screen tails over, %) should being not more than 10%, specific surface area should be greater than 300m²/ kg, limited expansion rate (in water 7 days) should be not less than 0.05%, and 28d comprcssive strength should be not less than 50MPa, and content of MgO should be not more than 3%, and alkali content should be not more than 0.5%.

Described plasticity-maintaining agent selects the composite highly effective plasticity-maintaining agent being applicable to special high-strength high-performance concrete, and this plasticity-maintaining agent includes the raw material of following mass ratio:

Concrete plasticity-maintaining agent 5%～15%；Hydroxyl hydroxy acid salt retarder 45%～55%；Macromolecule economization agent 35%～40%；

Described concrete plasticity-maintaining agent is the plasticity-maintaining agent of the market sale of the stable in properties with poly-hydroxy acid series high-efficiency water-reducing agent with the better compatibility；

Described hydroxyl hydroxy acid salt retarder is the one in sodium gluconate, sodium potassium tartrate tetrahydrate, sodium citrate, sodium salicylate；

Described macromolecule economization agent is the comb polymer containing polyoxyalkylene chain, containing the one in the organic polymer of polyethers and aliphatic category, copolymer containing methyl ether based polyalcohol/methyl ether based polyalcohol；

The described comb polymer containing polyoxyalkylene chain is the JM-SRA series concrete economization agent that Jiangsu Subotexin Material Co., Ltd develops, and it is mainly composed of alkyl polyoxyethylene ether；

The described organic polymer containing polyethers and aliphatic category is the JSJ type economization agent that Metallurgical Research Institute, Department of Architecture is developed, and its main component is polyethers and aliphatic category Organic substance；

The described copolymer containing methyl ether based polyalcohol/methyl ether based polyalcohol is that the institute of civil engineering of Zhejiang University develops ZZD-A type economization agent, and its main component is methyl ether based polyalcohol and methyl ether based polyalcohol.

Through a large amount of tentative contrast tests and with the high-performance water reducing agent used by cement compatibility test, this plasticity-maintaining agent and portland cement and the present invention, there is the good compatibility.Its quality should be not less than the regulation of the relevant criterion such as existing national standards " Technical code for application of admixture in concrete " GB50119-2013.

Described mixing water selects tap water, and its quality should be not less than the regulation requirement of the relevant criterion such as nation-building ministerial standard " the reinforcement of concrete water quality standard " JGJ63-2006, and requires that the alkali content of selected tap water is not more than 1000mg/L.

The present invention gives the concrete preparation method for reinforced concrete composite structure C250 strength grade, and the method adopts the cement improved to wrap up in sandstone method concrete stirring technology, and concrete technology step is as follows:

1) first by water reducer 21kg/m³, exciting agent 11kg/m³With compound plasticity-maintaining agent 0.65kg/m³Uniformly admix load weighted water 102kg/m³In, obtain mixture；

2) then according to weight proportion adds 615.2kg/m in forced mixer³Fluvial sand, 153.8kg/m³Quartz sand and step 1) amount of the mixture 1/3, uniform stirring 1～2min；

3) 1308kg/m is added³Φ 5～Φ 10 continuous size fraction rubble coarse aggregate and step 1) amount of the mixture 1/3, uniform stirring 2～4min；

4) it is subsequently added into whole cementing material: 504kg/m³Cement, 52kg/m³Extender, 60kg/m³Nano silica fume, 40kg/m³Sub-micro silica flour and 125kg/m³Flyash, uniform stirring 3～4min；

5) it is eventually adding 1.5kg/m³Defoamer and remaining step 1) mixture, uniform stirring 2～3min, be stirred for 2～3min after stopping 3 minutes to uniformly, discharging, obtain the concrete mix of C250 strength grade.

Described preparation is the concrete mix of C250 for reinforced concrete composite structure strength grade, its maintenance process adopts the steam curing in heating curing, its maintenance flow process is: quiet stop that (4～6 hours) → heating up, (relative humidity is more than 95% for → heated at constant temperature in heating (programming rate for per hour 10 DEG C), 80 DEG C～90 DEG C, 48～72 hours) → lower the temperature and heat (cooling rate is 10 DEG C per hour) → standard curing to 28 days.

The invention has the beneficial effects as follows:

1. the concrete that the present invention produces is a kind of suitable in the special high-strength high-performance concrete that reinforced concrete composite structure strength grade is C250.This concrete is at mechanical property (the i.e. C250 strength grade that can ensure that it should possess, plasticity etc.) and there is high-durability, high workability, on the basis of high volume stability and economy, it is significantly improved the natural adhesive property between this concrete and shaped steel, make it be applied in steel reinforced concrete structure design and add shearing connecting piece without (or only needing by detailing requiments a little) on shaped steel surface, shaped steel and this concrete effective collaborative work can be ensured, thus decreasing working procedure, steel are saved, improve efficiency of construction, and avoid and shearing connecting piece is set in a large number on shaped steel surface and easily causes the defects such as this congenital microcrack of inside concrete, there is significant economic benefit and construction quality improvement effect, its mechanical property comparative test result is in Table 4.

2. the high efficiency water reducing agent used in the present invention selects poly carboxylic acid series concrete high-performance water reducing agent (water-reducing rate should be greater than 30%), compares other type of water reducer, and the compatibility with early strength silicate cement is good, and it is without Na₂SO₄, can further improve this concrete durability.

3. the defoamer used in the present invention selects powder defoamer, model is AGITANP803, the a large amount of microvesicles formed in concrete-agitating process and remain in concrete after vibration compacting can be carried out deaeration so that it is degree of compaction is effectively improved, and enhances concrete durability and shear stability.

4. the composite exciting agent used in the present invention selects the alkaline composite exciting agent (FAEA) of independent development, can promote the generation of entringite, makes have certain micro-expansibility mixed with the concrete of flyash and silicon ash, improves concrete shrinkage.By composite exciting agent by flyash Watch glass body network structure depolymerization, thus exciting the lateral reactivity of flyash, the Vitrea corrosiveness of three-D space structure being main aquation component with aluminosilicate in flyash hydro-combination process can be strengthened, improve the power of forward hydration reaction, generate more C-S-H gel, the crystal such as drated calcium aluminate and hydrated calcium silicate, promote that flyash participates in early hydration process, make full use of the gap between flyash activity micro aggregates and ball effect and silicon ash filler particles, improve the performance of cementing material and reduce water consumption, and secondary hydration product fill concrete internal voids, early strength to institute's concrete batching, later strength and corrosion resistance increase significantly；On the other hand, the effect of composite exciting agent has promoted the formation of silicon ash-fly ash based mineral polymer, also significantly improves the adhesive property between shaped steel and special high-strength high-performance concrete while improving concrete durability.

null5. what the present invention produced is by adding active mineral additives (special fine powdered coal for the high performance concrete that reinforced concrete composite structure strength grade is C250、Nano silica fume and sub-micro silica flour)，Equivalent method of substitution is adopted to replace part of cement，Utilize the pozzolanic reaction of active mineral admixture、Enhancement effect、Filling effect、Durability improves the warm peak subtractive effect of effect and hydration heat of concrete，And make full use of active mineral admixture compound and mix and over-superimposed effect produced by the composite blend of active mineral admixture and high efficiency water reducing agent，According to them and cement granules、Coarse-fine aggregate particle diameter is the grain composition of Binder Materials part in the feature optimised coagulation soil material of same one-level not，Flyash and silicon ash can the intergranular holes of filling concrete，Not only make concrete gathers materials and the pore structure of interfacial structure between Behavior of Hardened Cement Paste and Behavior of Hardened Cement Paste all obtains and greatly improves，Improve the consistency of Behavior of Hardened Cement Paste、Impervious，Typical compact texture can expand to aggregate surface simultaneously，So that concrete is more closely knit hard，Concrete mechanical property (adhesive property especially and between shaped steel)、Endurance quality and service behaviour all improve a lot.

6. the nano silica fume used in the present invention, is a kind of nontoxic, tasteless, pollution-free, high-purity, pure nano material.The particle size of nano silica fume is little, and specific surface area is big, it is possible to give full play to its micro-packing effect；There is a large amount of unsaturated residual bond and the hydrogen-based of different bond styles in nano silica fume surface, or for deviateing the silica structure of steady statue because of anoxia, can consume and refine Ca (OH)₂Crystal, promotes hydration rate and degree of hydration, and the hydrated calcium silicate gel making formation is finer and close；Compared to (Asia) SILICA FUME, there is higher activity (particularly induced activity) and free energy state, the improvement of concrete microstructure and the raising (i.e. C250 strength grade, plasticity etc.) of mechanical property all there are is no small facilitation, the adhesive property improved between shaped steel and special high-strength high-performance concrete is also created remarkable result simultaneously.

7. the present invention fills appropriate flyash and can improve concrete and mix and stir the mobility of material, cohesiveness and water-retaining property, but flyash replaces part of cement can reduce concrete early strength to a certain extent, and mix appropriate silicon ash, it is remarkably improved concrete intensity and durability, and secondary reaction of hydration can be there is with hydrolysis product of cement Ca (OH) 2, form gelled product, filling concrete stone structure, improve the microstructure of slurry, improve mechanical property and the durability of hardenite.Flyash and grey being used in conjunction with of silicon, can improve concrete substrate degree of compaction, thus the adhesive property improved between shaped steel and concrete.

8. the extender used in the present invention, is a kind of calcium sulphoaluminate class concrete high-efficiency expanding agent.Calcium sulphoaluminate class concrete high-efficiency expanding agent generates entringite swelling water compound crystal (c with hydrate₃A·3CaSO₄·32H₂O), the volume contraction cracking caused by chemical reaction, physical reactions and thermodynamical reaction can be prevented from or reduce in concrete hydrating, hardening compensate, and can fill, block various capillary slit and make concrete inner structure finer and close, not only substantially increase concrete anti-crack and anti-seepage performance and volume stability, and concrete density and intensity can be made to be further improved.

9. the plasticity-maintaining agent used in the present invention, is a kind of composite highly effective plasticity-maintaining agent formulated by concrete high-efficiency plasticity-maintaining agent, mineral acid salt retarder, macromolecule economization agent compound.This efficient plasticity-maintaining agent can effectively slow down the aquation of cement granules when appropriate admixture, therefore there is high slump holding capacity, and make the early-age shrinkage rate of special high-strength high-performance concrete decrease, it is favorably improved concrete crack resistance, thus enhancing concrete durability；Under the combined effect with high-performance water reducing agent, the shortcoming that concrete early strength is relatively low can not only be improved, moreover it is possible to significantly improve the mechanical property (adhesive property etc. between plasticity, comprcssive strength, shaped steel and concrete) of type steel performance.

10. the quartz sand used in the present invention is the silicate mineral of a kind of hard, wear-resisting, stable chemical performance.Its main mineral constituent is silicon dioxide, has certain acid-resisting erosion medium resistance ability, it is possible to makes up the shortcoming that fluvial sand is inert material and participates in hydration reaction and reduce the heat of hydration, improves concrete durability and intensity.

11. what the present invention produced is under normal concrete manufacturing condition for the special high-strength high-performance concrete that reinforced concrete composite structure strength grade is C250, and adopt and reduce the cement that cement granules, additive granule and superfine active mineral grain fly upward everywhere when concrete-agitating as far as possible and wrap up in what the feeding method of sandstone stirring technique realized, preparation technology is simple and is easily achieved, it is suitable for through engineering approaches and industrialization, it is easy to large-scale promotion application, there is good social benefit.

12. what the present invention produced is used in the raw material of the special high-strength high-performance concrete that reinforced concrete composite structure strength grade is C250 containing substantial amounts of flyash, silica flour; they are industrial waste and garbage; it is dissolved and environmental conservation can be made tremendous contribution; meet the requirement of sustainable development; it is a kind of green concrete, a kind of environment-friendly material.

13. the raw material (including industrial waste) that the present invention selects be in a large number, the market circulation of large-scale production, buys and sell product, raw material is easy to get.

14. the steam heating curing adopted in the present invention can accelerate the process of cement and active mineral admixture hydration reaction and the performance of volcano ash effect, concrete microstructure can be improved, improve its interfacial adhesion and intensity.It addition, the steam heating curing technology of concrete or concrete component is already ripe, and easily grasping, the popularization and application for this invention are laid a good foundation.

null15. what the present invention produced is disastrously expect (superfined flyash and Ultrafine Grinding silica flour) by addition superfine active mineral for the special high-strength high-performance concrete that reinforced concrete composite structure strength grade is C250，Equivalent method of substitution is adopted to replace part of cement，Utilize the pozzolanic reaction of active mineral admixture、Enhancement effect、Filling effect、Durability improves effect and the warm peak subtractive effect of the special high-strength high-performance concrete heat of hydration，And make full use of active mineral admixture compound and mix and over-superimposed effect produced by the composite blend of active mineral admixture and high efficiency water reducing agent，According to them and cement granules、Coarse-fine aggregate particle diameter does not optimize the grain composition of Binder Materials part in extra-high strong high-performance concrete material in the feature of same one-level，In this proportioning，Aggregate accounting about 75%，Suitably reduce sand coarse aggregate ratio，Namely improve rubble accounting；Not only make special high-strength high-performance concrete gathers materials and the pore structure of interfacial structure between Behavior of Hardened Cement Paste and Behavior of Hardened Cement Paste all obtains and greatly improves, improve the consistency of Behavior of Hardened Cement Paste, impermeability, typical compact texture can expand to aggregate surface simultaneously, so that special high-strength high-performance concrete is more closely knit hard, the special mechanical property (adhesive property especially and between shaped steel) of high-strength high-performance concrete, endurance quality and service behaviour all improve a lot.

The present invention is the adhesive property to significantly improve between shaped steel and concrete under naturalness (that is shaped steel surface is not provided with or only arranges a small amount of shearing connecting piece by detailing requiments), effectively play steel and the respective mechanics of concrete bi-material and cooperative work performance, thus the significantly bearing capacity of lift structure component and performance, and the durability improving structure is objective, study the technology of preparing for the special high-strength high-performance concrete that reinforced concrete composite structure strength grade is C250.At present, the quality and the intensity that make special portland cement used by high-strength high-performance concrete both at home and abroad are more and more higher, the process technology of active mineral admixture (silica flour, flyash etc.) used is updated with quality, in addition the research of the concrete admixture such as high-performance water reducing agent, high-efficiency expanding agent, efficient plasticity-maintaining agent and application are all achieved with bigger progress, and the research that defoamer and exciting agent are in concrete also just progressively develops with application, thus the realization for the studies above objective identifies basis.Meanwhile, the cement consumption of the requirement of special high-strength high-performance concrete is relatively fewer, and produces cement and mean a large amount of discharges of carbon dioxide, therefore alleviates the greenhouse effect that the earth is caused to a certain extent；It requires there is sufficient amount and accounts for the active mineral additives of the high-qualitys such as the bigger flyash of cementing material proportion, silica flour; mean the reasonable treatment and use of industrial waste; it is beneficial to form good production cycle and environmental conservation, and the active mineral additives of these high-qualitys improves required for concrete material self performance just.In a word, the special high-strength high-performance concrete of application can be saved cement, turned waste into wealth by industrial waste, extending structure engineering service life, and finally preserves the ecological environment and natural resources.In sum, research and development for the special high-strength high-performance concrete of reinforced concrete composite structure will walk out the road of a sustainable development for use concrete better, it is by the integration capability of lift structure engineering and performance, promote that steel-concrete combined structure is in China, especially the high level in highlight lines and frequently occurred earthquake area, super/special skyscraper, offshore platform or submerged structure, hypogee, super/Super-Long Span, popularization and application in super/extra-heavy duty type structure, improve the scientific and technological content of building structure in infrastructure and human settlement, and play it there is bigger bearing capacity and rigidity, good anti-seismic performance, construction speed is fast, the unique advantages such as durable good with fire resistance and significant Social and economic benef@.Therefore, shaped steel spy high-strength high-performance concrete combinative structure has significantly high engineer applied value and wide market prospect.

Detailed description of the invention

What the present invention developed is used for the special high-strength high-performance concrete that reinforced concrete composite structure strength grade is C250, except the material cement similar with normal concrete employing, sand, rubble, water, it is also added into its indispensable component: concrete high-performance water reducer, concrete high-efficiency expanding agent and active mineral admixture (silica flour, flyash), additionally also it is mixed with powder defoamer, exciting agent and composite highly effective plasticity-maintaining agent.Special high-strength high-performance concrete is different from normal concrete, and its intensity and performance are all more common to be greatly improved with high-strength concrete.The ratio of mud of special high-strength high-performance concrete is generally less than 0.22, and its water-cement ratio is less than 0.15, and common and high-strength concrete the ratio of mud is typically in more than 0.30, and the maximum size of coarse aggregate of special high-strength high-performance concrete is also smaller than common and high-strength concrete.Above-mentioned every difference result in special high-strength high-performance concrete has very big difference with common and high-strength concrete in performance, disastrously expect by adding superfine active mineral, utilize the pozzolanic reaction of superfine active mineral spike, (micro-) filling effect and plasticization effect, optimize the grain composition of Binder Materials part in extra-high strong high-performance concrete material, not only make special high-strength high-performance concrete gathers materials and the pore structure of interfacial structure between Behavior of Hardened Cement Paste and Behavior of Hardened Cement Paste all obtains and greatly improves, improve the consistency of Behavior of Hardened Cement Paste, impervious, typical compact texture can expand to aggregate surface simultaneously, so that special high-strength high-performance concrete is more closely knit hard, mechanical property (adhesive property especially and between shaped steel) and the endurance quality of special high-strength high-performance concrete all improve a lot.Simultaneously, by mixing of powder defoamer, the a large amount of bubbles forming and remaining in concrete after vibration compacting the transition zone, interface in cement slurry or between cement slurry and aggregate in concrete-agitating process can be reduced and carry out deaeration, make its degree of compaction be effectively improved, the special mechanical property (including the adhesive property between shaped steel) of high-strength high-performance concrete and the raising of endurance quality are all made that no small contribution.It addition, by the admixture of exciting agent, concrete can be made to have certain micro-expansibility, improve concrete shrinkage；The Vitrea corrosiveness with aluminosilicate for main aquation component in water of coal ash and process can be strengthened, increase the activity of flyash, improve the power of forward hydration reaction, generating the crystal such as more C-S-H gel, drated calcium aluminate and hydrated calcium silicate, intensity and corrosion resistance to institute's concrete batching increase significantly.And the admixture of concrete high-efficiency expanding agent, the produced volume contraction cracking of concrete hardening reaction can be compensated, it is possible to the various capillary slit filled, block in concrete, improve concrete anti-crack and anti-seepage performance, density, intensity and volume stability.Admixture for high-performance water reducing agent and composite highly effective plasticity-maintaining agent, decrease cement water consumption, cement granules is had certain dispersion and wetting action, concrete early-age shrinkage rate is made to decrease, it is effectively reduced carrying out of early cracks of concrete, the shortcoming that concrete early strength is relatively low can not only be improved, moreover it is possible to significantly improve durability and the mechanical property (adhesive property etc. between plasticity, comprcssive strength, shaped steel and concrete) of type steel performance.

With bonding between plain bar to concrete is similar, the cohesive force between shaped steel and concrete is also mainly made up of chemical bond power, frictional resistance and mechanical snap power three part.Each ingredient of the cohesive force between shaped steel and concrete is all closely related with concrete performance.

Chemical bond power is the chemical adhesion strength that produces on shaped steel surface of the cement gel body in concrete or absorption affinity, and its (shearing resistance) ultimate value depends on the character of cement and the degree of roughness on shaped steel surface.During casting concrete, cement slurry produces surface tension at steel surface, and under capillary effect, the cement slurry on steel surface will form self-balancing；Cast concrete generally to vibrate, and power of vibrating (disturbance) can strengthen and accelerate the cement slurry infiltration to steel surface oxide layer；Cement slurry crystallization in maintenance processes, cement crystal forms chemical bond power.Chemical bond power only exists under the state that is originally formed of Steel Reinforced Concrete Members, once there is (locally) bond-slip on joint face, cement crystal will be cut off and attrition crushing, and chemical bond power is then lost.The principal element affecting chemical bond power has concrete strength, shaped steel steel surface degree of roughness, test specimen to build mode and the maintenance in the degree of vibrating and later stage and concrete contraction situation etc..

After chemical bond power is lost, steel surface changed condition (steel surface is uneven) caused by the rough of steel surface and other reason, make it be interlocked with the concrete crystal grain on contact surface, material is thus formed mechanical snap power.For shaped steel such as the rolled steel joists that plant produced postmenstruation process, once bond-slip development is accelerated, the crushed integration of concrete crystal on shaped steel and concrete surface, at this moment mechanical snap power also substantial loss.Affect the degree of roughness that principal element is shaped steel steel surface of mechanical snap power and the force way etc. of surface appearance (corrosion degree etc.), aggregate grating, concrete strength and Steel Reinforced Concrete Members.

The frictional resistance of shaped steel is also formed after the bond failure between shaped steel and concrete by shaped steel surrounding concrete, and mainly just plays a role after mechanical snap power is lost substantially.When chemical bond power; especially after mechanical snap power is lost; owing to being cut off with the concrete crystal on shaped steel contact surface, crushed and being expanded; in addition the lateral confinement such as protective layer and stirrup; normal pressure will be produced on shaped steel with concrete joint face; relatively big plus coefficient of friction on joint face, thus defining frictional resistance.Frictional resistance all exists after chemical bond power is lost always, is the major part of later stage cohesive force between shaped steel and concrete.Affect frictional resistance because have the size of adhesive surface, member stress mode, aggregate grating between shaped-steel layout and surface character, shaped steel and the concrete of shaped steel and affecting the factor (thickness of concrete cover of shaped steel, stirrup ratio, concrete shrinkage) etc. of lateral confinement.

Key technical problem to be solved by this invention is, guaranteeing mechanical property (i.e. intensity and plasticity) that special high-strength high-performance concrete should possess and there is high-durability, high workability, on the basis of high volume stability and economy, it is significantly improved (nature) adhesive property between concrete and shaped steel, make to add shearing connecting piece without (or only needing by detailing requiments a little) on shaped steel surface in steel reinforced concrete structure designs, can ensure to have between shaped steel and concrete bonding and anchoring reliably, make both energy under load action harmonious, cooperation.

nullThe present invention is from principle and design principle，Break the restriction of " full sieve rice " formula，By orthogonal experiment and contrast experiment's method，Consider concrete high-performance water reducer、Concrete high-efficiency expanding agent、Defoamer、Exciting agent、Between efficient plasticity-maintaining agent and with the compatibility of cement，Maximum size of coarse aggregate、Between coarse aggregate different-grain diameter and and fine aggregate particle diameter between level pairing concrete strength and (micro-) filling effect of the impact of performance and active mineral additives、The performance factors such as pozzolanic activity，Select high-quality coarse-fine aggregate and control particle diameter and grating，Special high-strength high-performance concrete its preparing materials mixes appropriate concrete high-performance water reducer、Concrete high-efficiency expanding agent、Concrete composite highly effective plasticity-maintaining agent and high-quality active mineral micropowder，And consider the addition of defoamer and exciting agent，Reduce the ratio of mud，Based on the local existing material that is easy to get，Do not change conventional production process，For reducing cement granules as far as possible、Additive granule and superfine active mineral grain fly upward the feeding method adopting cement to wrap up in sandstone stirring technique everywhere when concrete-agitating，Utilize the pozzolanic reaction of active mineral admixture、Enhancement effect、(micro-) filling effect、Durability improves effect and the warm peak subtractive effect of the special high-strength high-performance concrete heat of hydration，And make full use of active mineral admixture compound and mix and over-superimposed effect produced by the composite blend of active mineral admixture and concrete high-performance water reducer、The deaeration effect of defoamer、The compensation contraction of extender and filling effect、The activity excitation effect of exciting agent、The guarantor of composite highly effective plasticity-maintaining agent moulds and reduces and deferred action，Make mechanical property (adhesive property especially and between shaped steel) good、Service behaviour is excellent、Excellent in durability、The strength grade suitable in reliability application steel reinforced concrete structure of advantage of lower cost is the special high-strength high-performance concrete of C250.The mechanical property test comparing result of the present invention is as shown in table 4.

When the present invention selects raw material, not requiring nothing more than raw material is high-quality, also requires that the special raw material used by high-strength high-performance concrete of preparation is that locality is easy to get.Furthermore, it is contemplated that the intensity of institute's concrete batching is significantly high, according to maximum density theory, the grain composition of coarse-fine aggregate in concrete material is optimized, makes large or fine granule have mutually good filling, to reduce the voidage of aggregate；Simultaneously, the mean diameter of general cement is 20～30 μm, granule less than 10 μm is also few, and the grain diameter of active mineral admixture is tiny more than cement granules particle diameter, the mean diameter of superfined flyash is 3～6 μm, space between energy filling concrete granule, the mean diameter of SILICA FUME is also only small, it it is 0.10～0.26 μm, space between energy filling concrete granule and superfined flyash granule and between superfined flyash particle, the mean diameter of nanometer SILICA FUME is less, for 10nm～0.1 μm, can fill between gel particles and and interfacial structure between fine gap or space, so the grain composition of Binder Materials part being optimized also most important in the extra-high strong high-performance concrete material prepared.And concrete aggressivity is heavily dependent on concrete pore structure by the outside deterioration factor (such as factors such as sulfate), and this causes the main cause of Durability of Concrete just.Mixing of active mineral admixture, reduce the voidage with interface between cement granules, make water mudrock structure and interfacial structure more fine and close, block the permeation pathways being likely to be formed, so that the impermeability of the special high-strength high-performance concrete prepared increases substantially, water and other various etching medium (CL^-、SO4^2-, CO2 etc.) be all difficult to enter inside concrete, and the occurrence probability of Alkali-silica reaction and the generation probability of calcium hypochlorite can be reduced, its intensity and endurance quality are greatly improved.Namely when in water mudrock structure and interfacial structure, macropore content more than 0.1 μm is relatively low, it is beneficial to be prepared the improvement of the properties of special high-strength high-performance concrete, otherwise, all unfavorable to being prepared the special intensity of high-strength high-performance concrete, anti-permeability performance, corrosion resistance and endurance quality.

After replacing part of cement with active mineral admixture, it is also possible to make the portion of water in cement granules space be filled its interior mineral admixture and cement out, the fluidity of cement paste can be made to increase.But also not all mineral admixture all has this significant plasticization effect, specific surface area mainly due to amount of activated mineral admixture is too big or itself has loose structure, although it can displace the portion of water in cement paste after replacing cement, but owing to itself water suction or wetting surface need more free water, cause that the mobility of cement paste does not increase.In order to ensure to be developed the high workload performance of special high-strength high-performance concrete, the present invention adopts the method that concrete high-performance water reducer and active mineral admixture compound are mixed, under both collaborative works, the subparticle of active mineral additives has not only given full play to their (micro-) filling effect, and the moisture being filled among space is cemented out, between making between granule, water barrier thickeies；Additionally, the subparticle of active mineral admixture has adsorbed concrete high-performance water reducer molecule, produced by the electric double layer current potential that its surface is formed, electrostatic repulsion is more than the gravitation between powder particle, powder granule is promoted to disperse, and it is further exacerbated by the dispersion of cement granules, the mobility making cement paste increases, thus effectively improving the mobility of compound；Meanwhile, the compound of super fine active mineral admixture is mixed and is reduced the heat of hydration, can improve concrete volume stability.

Higher inherent strength, toughness and stability should be had for preparing the aggregate in the raw material of special high-strength high-performance concrete, so that various static state and dynamic stress, impact and corrasion can be resisted, the decline of concrete batching performance without causing.Owing to the apparent condition of different aggregates is different, causing that the adhesion strength between cement slurry and aggregate also differs, rubble has higher adhesion strength compared with cobble under normal circumstances；On the other hand, in cement slurry, silicon ash content ratio asynchronous adhesion strength difference is also very big, and during mixing silica, the adhesion strength between cement slurry and aggregate is more much higher than when not mixing.Normal concrete is when destroying, cement slurry and the bonding interface of aggregate are weak links, crack is to occur along the interface of cement slurry with aggregate, aggregate generally will not destroy, and external world's erosion also tends to from then on interface and starts development, and the bonding interface of the cement slurry in special high-strength high-performance concrete and aggregate is no longer weak link, its destruction is also no longer along interface and occurs, but cause due to the destruction of aggregate, therefore the performance of special high-strength high-performance concrete is had large effect by the performance of aggregate.The fine aggregate selected in the research of the present invention adopts that granule is round and smooth, quality is hard, grating is good, clay content little in thick fluvial sand；The artificial rubble being main component with granite, basalt that coarse aggregate is rough surface, fine quality, grating is good, its maximum particle diameter should control at 10mm.So, concrete uniformity has been got back further lifting, so that concrete is more closely knit, intensity also can be further enhanced.

The present invention adopts cement to wrap up in sandstone method (the SEC method also known as improving) concrete stirring technology in the preparation, forced mixer is stirred, its feeding sequence is: first poly carboxylic acid series concrete high-performance water reducing agent, exciting agent and composite highly effective plasticity-maintaining agent is uniformly admixed in load weighted water, obtains mixture；It is subsequently adding fine aggregate and is mixed with 1/3 → stir (1～2 minute) → the additions coarse aggregate of high-performance water reducing agent and exciting agent amount of the mixture and 1/3 → stir (2～4 minutes) being mixed with high-performance water reducing agent and exciting agent amount of the mixture → add whole cementing material (cement, extender, silicon ash and flyash) → stir (3～4 minutes) → add be stirred for after defoamer and residue are mixed with high-performance water reducing agent and exciting agent mixture → uniform stirring (2～3 minutes) → stops 3 minutes to uniform (2～3 minutes) → discharging.This technique can reduce cement granules as far as possible and superfine active mineral grain flies upward everywhere when concrete-agitating, and can improve prepared concrete intensity, and segregation phenomenon should not occur in prepared concrete, and bleeding is few, and service behaviour is relatively better.

The present invention adopts the steam curing in heating curing when maintenance, its maintenance flow process is: quiet stop that (4～6 hours) → heating up, (relative humidity is more than 95% for → heated at constant temperature in heating (programming rate for per hour 10 DEG C), 80 DEG C～90 DEG C, 48～72 hours) → lower the temperature and heat (cooling rate is 10 DEG C per hour) → standard curing to 28 days.This maintenance process can accelerate the process of cement and active mineral admixture hydration reaction and the performance of volcano ash effect, can improve concrete microstructure, improves its interfacial adhesion and intensity.

Embodiment:

(1) raw material

1. cement

Select the Qinling Mountains board P I 62.5R cement of steady quality, better performances, compatibility test between the two is carried out with poly carboxylic acid series concrete high-performance water reducing agent before using, test method adopts the method in existing building material industry standard " cement and water reducer compatibility test method " JC/T1083-2008, good with the poly carboxylic acid series concrete high-performance water reducing agent compatibility.Selected cement performance index meets the requirement of the national existing relevant criterion such as " portland cement, Portland cement " GB175-2007, and its alkali content is few, the heat of hydration is low, water requiremen is also low.

2. aggregate

Sand and the quartz sand adopting mass ratio to be 8:2.

Sand adopts that granule is round and smooth, quality is hard, grating good in partially thick, Ba fluvial sand, the quality of sand meets the high-quality sand standard of regulation in existing building material industry standard " regular concrete sand, stone quality and test method standard " JC/T52-2006 and national standard " building sand " GB/T14684-2011.Its modulus of fineness is 3.0, clay content and clod content all control 0.3% (in mass) below, chloride ion content controls in 0.02% (quality in dry sand) below, SO₃Content should be not more than 0.5%.

Select the quartz sand that quality is consummate, grating is good.Its dioxide-containing silica should be not less than 99%, and ferric oxide content should be not more than 0.005%, and the metals content impurity such as chromium, titanium should be not more than 0.01%.When carrying out this Concrete, adopt different-grain diameter specification (2-4mm, 1-2mm, 0.63-1mm, 0.315-0.63mm, 0.16-0.315mm, < 0.16mm) many gratings feed intake.

3. flyash

I grade of special fine powdered coal of high-quality that the power plant adopting coal burning process advanced produces.Its quality meets the regulation requirement of the relevant criterion such as national standard " flyash in cement and concrete " GB/T1596-2005, and its fineness (0.045mm square hole screen tails over, %) is not more than 5%, and loss on ignition is 2.2%, SO₃Content is 1.5%, and water demand ratio is less than 95%, and specific surface area is about 1000m²/kg。

4. silica flour

30nm nano silica fume and the sub-micro silica flour adopting mass ratio to be 3:2, the 30nm nano silica fume selected and the quality of (Asia) SILICA FUME meet the regulation requirement of the relevant criterion such as national standard " mineral admixture for high-strength high-performance concrete " GB/T18736-2002, the moisture content of 30nm nano silica fume and (Asia) SILICA FUME is respectively less than 1%, loss on ignition is no more than 3%, chloride ion content is no more than 0.01%, and pozzolanic activity index is all higher than 95%.Wherein, the specific surface area of 30nm nano silica fume is about 42000m²/ kg, silicone content is not less than 99.9%；The specific surface area of (Asia) micron silica flour is about 27000m²/ kg, dioxide-containing silica is not less than 99%.

5. concrete high-performance water reducer

Through a large amount of tentative contrast tests and with cement compatibility test, high efficiency water reducing agent selected by this invention is poly carboxylic acid series concrete high-performance water reducing agent, its quality meets the regulation requirement of the relevant criterion such as existing national standards " concrete admixture " GB8076-2008, and the water-reducing rate of selected high efficiency water reducing agent is more than 30%.Maximum doping quantity is whole binder total amount the 2.5% of selected high efficiency water reducing agent, adopts with mixing method, carries out compatibility test with selected cement type and the compatibility is good before using.

6. exciting agent

Select by the efficient flyash excitant (FAEA) of inventor place research team independent development, it is passing through the research to the Ultrafine Grinding pulverized burned coal ash hydration reaction characteristics mixed with nano silica fume and sub-micro silica flour and recognizing on the basis that its activity needs to excite further and utilize, by the waterglass (utilizing solid sheet NaOH and commercially available sodium silicate water glass to be modulated into the waterglass that modulus is about 1.0 in proportion) of inorganic material 65%～75%, 23%～30% common dihydrate gypsum (CaSO₄·2H₂O) and organic material 3%～5% triethanolamine (TEA) compound formulated.Preparation method is as follows: first make certain density alkaline solution by soluble in water for solid sheet NaOH, then and the sodium silicate water glass of known modulus (between the modulus general 2.4～3.3 of commercial water glass) be modulated into modulus be 1.0 test need waterglass, finally prepare, with common dihydrate gypsum and TEA compound, the composite exciting agent (FAEA) becoming required again, refer to table 1.Through test determination, this exciting agent and early strength silicate cement, poly carboxylic acid series concrete high-performance water reducing agent have the good compatibility.

The different ratio of table 1FAEA exciting agent

7. extender

Through a large amount of tentative contrast tests and with cement compatibility test, extender selected by this invention is the calcium sulphoaluminate class concrete high-efficiency expanding agent being applicable to special high-strength high-performance concrete, its quality meets the regulation requirement of the relevant criterion such as national standard " cement expansive material " GB23439-2009, and its fineness (0.08mm square hole screen tails over, %) being not more than 10%, specific surface area is about 400m²/ kg, limited expansion rate (in water 7 days) is not less than 0.05%, and 28d comprcssive strength is more than 55MPa, and content of MgO is not more than 2%, and alkali content is not more than 0.3%.

8. plasticity-maintaining agent

Selecting the composite highly effective plasticity-maintaining agent being applicable to special high-strength high-performance concrete, this plasticity-maintaining agent includes the raw material of following mass ratio:

Concrete plasticity-maintaining agent 5%～15%；Hydroxyl hydroxy acid salt retarder 45%～55%；Macromolecule economization agent 35%～40%.

Wherein, concrete plasticity-maintaining agent is the plasticity-maintaining agent of the market sale of the stable in properties with poly-hydroxy acid series high-efficiency water-reducing agent with the better compatibility.Hydroxyl hydroxy acid salt retarder is the one in sodium gluconate, sodium potassium tartrate tetrahydrate, sodium citrate, sodium salicylate.Macromolecule economization agent is the comb polymer containing polyoxyalkylene chain, containing the one in the organic polymer of polyethers and aliphatic category, copolymer containing methyl ether based polyalcohol/methyl ether based polyalcohol.

Wherein, the comb polymer containing polyoxyalkylene chain is the JM-SRA series concrete economization agent that Jiangsu Subotexin Material Co., Ltd develops, and it is mainly composed of alkyl polyoxyethylene ether；The organic polymer containing polyethers and aliphatic category is the JSJ type economization agent that Metallurgical Research Institute, Department of Architecture is developed, and its main component is polyethers and aliphatic category Organic substance；Copolymer containing methyl ether based polyalcohol/methyl ether based polyalcohol is that the institute of civil engineering of Zhejiang University develops ZZD-A type economization agent, and its main component is methyl ether based polyalcohol and methyl ether based polyalcohol.

The different ratio of table 2 plasticity-maintaining agent

9. mixing water

Selection tap water is mixing water, and its quality meets the regulation requirement of the relevant criterion such as Minstry of Housing and Urban-Rural Development of People Republic of China's ministerial standard " concrete mixing water supply standard " JGJ63-2006, and alkali content is less than 800mg/L.

(2) match ratio

The match ratio that the special high-strength high-performance concrete that the present invention is C250 for the strength grade that will apply in steel reinforced concrete structure provides is as shown in table 3.

Table 3 is for extra-high strong high-performance concrete mix (unit: the kg/m of reinforced concrete composite structure³)

(3) stirring technique

This invention adopts cement to wrap up in sandstone method concrete stirring technology, and concrete technology step is as follows:

First by poly carboxylic acid series concrete high-performance water reducing agent 21kg/m³, exciting agent 11kg/m³With composite highly effective plasticity-maintaining agent 0.65kg/m³Uniformly admix load weighted water 102kg/m³In, obtain mixture；Then according to weight proportion adds 615.2kg/m in forced mixer³Fluvial sand, 153.8kg/m³Quartz sand and be mixed with the 1/3 of high-performance water reducing agent, exciting agent and composite highly effective plasticity-maintaining agent amount of the mixture, uniform stirring is after 1～2 minute, adds 1308kg/m³Coarse aggregate (Φ 5～Φ 10 continuous size fraction rubble) and be mixed with the 1/3 of high-performance water reducing agent, exciting agent and composite highly effective plasticity-maintaining agent amount of the mixture, after uniform stirring 2～4 minutes, add whole cementing material (including extender): 504kg/m³Cement, 52kg/m³Extender, 60kg/m³Nano silica fume, 40kg/m³(Asia) SILICA FUME and 125kg/m³Flyash, uniform stirring is after 3～4 minutes, adds 1.5kg/m³AGITANP803 powder defoamer and residue be mixed with the mixture of high-performance water reducing agent and exciting agent, uniform stirring 2～3 minutes, be stirred for 2～3 minutes after having a rest 3 minutes to uniform, discharging, obtain the concrete mix of C250 strength grade.

This technique can reduce cement granules, additive granule and superfine active mineral grain as far as possible and fly upward everywhere when concrete-agitating, and prepared concrete intensity can be improved, and segregation phenomenon should not occur in prepared concrete, bleeding is few, and service behaviour is relatively better.

(4) maintenance process

This invention adopts the steam curing in heating curing, and concrete maintenance flow process is as follows:

Quiet stop that (4～6 hours) → heating up, (relative humidity is more than 95% for → heated at constant temperature in heating (programming rate for per hour 10 DEG C), 80 DEG C～90 DEG C, 48～72 hours) → lower the temperature and heat (cooling rate is 10 DEG C per hour) → standard curing to 28 days.

This maintenance process can accelerate the process of cement and active mineral admixture hydration reaction and the performance of volcano ash effect, can improve prepared concrete microstructure, improve its interfacial adhesion and intensity.

(5) mechanical property test Comparative result

The special high-strength high-performance concrete that strength grade is C250 being applicable to reinforced concrete composite structure prepared according to above-mentioned match ratio is as shown in table 4 with the mechanical property comparative test result of general super high strength concrete (strength grade is the concrete of C250).

Table 4 mechanical performance of concrete comparative test result

As can be seen from Table 4, the strength grade prepared by this technology is the special high-strength high-performance concrete of C250, achieve can ensure that mechanical property (i.e. C250 strength grade, plasticity etc.) that it should possess and there is high-durability, high reliability, high workability, high volume stability and economy basis on, being significantly improved (nature) adhesive property between concrete and shaped steel, adhesion strength improves 1.75 times.Make to add shearing connecting piece without (or only needing by detailing requiments a little) on shaped steel surface in steel reinforced concrete structure designs, shaped steel and concrete effective collaborative work can be ensured, thus decreasing working procedure, steel are saved, improve efficiency of construction, and avoid and shearing connecting piece is set in a large number on shaped steel surface and easily causes the defects such as the congenital microcrack of inside concrete, significant economic benefit and construction quality improvement effect can be brought, there is higher engineer applied and be worth and wide market prospect.

Claims

1. the concrete for reinforced concrete composite structure C250 strength grade, it is characterised in that this concrete is according to kg/m³Match ratio be:

2. a kind of concrete for reinforced concrete composite structure C250 strength grade according to claim 1, it is characterized in that, described fine aggregate adopts mass ratio to be that the ratio granule of 8:2 is round and smooth, quality is hard, grating good in partially thick fluvial sand and quality is consummate, grating is good high grade quartz sand；Its modulus of fineness is between 2.8～3.2；By quality ratio, its clay content and clod content should be not more than 0.3%；In the mass ratio of dry sand, its chloride ion content should be not more than 0.02%, SO₃Content should be not more than 0.5%；In quartz sand, dioxide-containing silica should be not less than 99%, and ferric oxide content should be not more than 0.005%, and chromium, titanium impurity content should be not more than 0.01%.

3. a kind of concrete for reinforced concrete composite structure C250 strength grade according to claim 1, it is characterized in that, described coarse aggregate adopts the artificial rubble being main component with basalt, granite that quality densification is hard, intensity is high, rough surface, particle shape are almost spherical, elongated particles is little, grating is good, feeds intake according to continuous size fraction rubble Φ 5～Φ 10；The cubic compressive strength of its parent rock of coarse aggregate should be not less than 300MPa, and maximum particle diameter should control at 10mm；By quality ratio, its SO₃Content should be not more than 0.5%, and clay content should be not more than 0.2%, and clod content should be not more than 0.1%, and pin, sheet-like particle content should be not more than 0.5%, and must not be mixed into air slaking granule.

4. a kind of concrete for reinforced concrete composite structure C250 strength grade according to claim 1, it is characterized in that, described concrete high-performance water reducer selects poly carboxylic acid series concrete high-performance water reducing agent, water-reducing rate should be greater than 30%, and maximum saturation volume should be not less than the 2.5% of whole binder total amount.

5. a kind of concrete for reinforced concrete composite structure C250 strength grade according to claim 1, it is characterised in that described cement selects P I 62.5R portland cement；

Described defoamer selects AGITANP803 powder defoamer.

6. the concrete for reinforced concrete composite structure C250 strength grade according to claim 1, it is characterized in that, 30nm nano silica fume and the sub-micro silica flour that described silica flour adopts mass ratio to be 3:2, the moisture content of 30nm nano silica fume and sub-micro silica flour all should be not more than 1%, loss on ignition all should be not more than 3%, chloride ion content all should be not more than 0.01%, and pozzolanic activity index all should be greater than 95%；Wherein, the specific surface area of 30nm nano silica fume should be not less than 40000m²/ kg, silicone content should be not less than 99.9%；The specific surface area of submicron silica flour should be not less than 25000m²/ kg, dioxide-containing silica should be not less than 95%；

Described flyash adopts I grade of special fine powdered coal of high-quality, and 0.045mm square hole screen tails over and should be not more than 10%, and its loss on ignition should be not more than 3%, SO₃Content should be not more than 2%, and water content should be not more than 1%, and water demand ratio should be not more than 95%, and specific surface area should be greater than 700m²/kg。

7. the concrete for reinforced concrete composite structure C250 strength grade according to claim 1, it is characterised in that described exciting agent is flyash excitant FAEA, it is formulated according to the raw material compound of following mass percent:

The waterglass of 65%～73%；The dihydrate gypsum of 23%～30%；The triethanolamine of 3%～5%；

Described waterglass is to utilize solid sheet NaOH and commercially available sodium silicate water glass to be modulated into the waterglass that modulus is 1.0 in proportion.

8. the concrete for reinforced concrete composite structure C250 strength grade according to claim 1, it is characterized in that, calcium sulphoaluminate high-efficiency expanding agent selected by described extender, 0.08mm square hole screen tails over and should be not more than 10%, its specific surface area should be greater than 300m2/kg, and in water, 7 days limited expansion rates should be not less than 0.05%, and 28d comprcssive strength should be not less than 50MPa, content of MgO should be not more than 3%, and alkali content should be not more than 0.5%.

9. the concrete for reinforced concrete composite structure C250 strength grade according to claim 1, it is characterised in that described compound plasticity-maintaining agent is composite highly effective plasticity-maintaining agent, and this plasticity-maintaining agent includes the raw material of following mass ratio:

The described comb polymer containing polyoxyalkylene chain is JM-SRA series concrete economization agent；

The described organic polymer containing polyethers and aliphatic category is JSJ type economization agent；

The described copolymer containing methyl ether based polyalcohol/methyl ether based polyalcohol is ZZD-A type economization agent.

10. for the concrete preparation method of reinforced concrete composite structure C250 strength grade, it is characterised in that the method adopts the cement improved to wrap up in sandstone method concrete stirring technology, and concrete technology step is as follows: