CN107540308B - High-fluidity concrete and preparation method thereof - Google Patents
High-fluidity concrete and preparation method thereof Download PDFInfo
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Abstract
The invention relates to a high flowThe concrete consists of coarse aggregate, fine aggregate, a powder material, an additive and water, wherein the powder material comprises cement, fly ash and mineral powder; the additive comprises a water reducing agent and a tackifier; the coarse aggregate is 0.275m3/m3~0.300m3/m3(ratio of unit absolute volume) 166.4kg/m of water was used3~176.8kg/m3The water-powder ratio is 0.83-0.97, and the powder material is 510kg/m3~540kg/m3The sand rate is 53-55%, and the admixture dosage is 0.95-1.1 wt% of the powder material dosage. According to the concrete pouring construction process of the steel shell immersed tube bay, the performance index requirement of the high-fluidity concrete for filling the steel shell immersed tube bay is determined, and the high-fluidity concrete mixing proportion implementation method suitable for the steel shell immersed tube is formed through the research on the influence rule of various composition changes on the flowing performance, strength, hydration heat and shrinkage of the concrete.
Description
Technical Field
The invention relates to special concrete, in particular to high-fluidity concrete and a preparation method thereof, and particularly relates to concrete which is cast by adopting a pumping process, does not need vibration, is molded by self fluidity, is suitable for filling a steel shell immersed tube bulkhead, and has good filling property, clearance permeability, segregation resistance, high strength and lower hydration heat and shrinkage rate. The invention belongs to the field of buildings.
Background
The immersed tunnel can be divided into two types of reinforced concrete immersed tube and steel shell immersed tube according to the tube body material, wherein the former is widely used in europe, korea and China, and the latter is only used in japan. The steel shell immersed tube has obvious difference with the prior domestic reinforced concrete immersed tube structure no matter the appearance or the interior.
As for concrete materials, the steel shell immersed tube has the following characteristics: firstly, high-fluidity concrete is adopted, and a bin steel shell structure is uniformly filled without vibration; secondly, in the long-term service process, the concrete not only meets the technical requirements on basic physical mechanical properties, but also needs to maintain good cooperative deformability with the steel shell; thirdly, the concrete should have good volume stability.
The steel shell immersed tube is a combined structure and comprises a steel shell structure and concrete filled in the steel shell structure, wherein the steel shell structure is composed of hollow steel bays with different sizes, and the internal space of each bay is 0.5m3～13.5m3And the upper steel plate and the lower steel plate in the compartment are both provided with L-shaped steel and flat steel made steel ribs, the middle part of the upper top surface is provided with a concrete pouring opening with the diameter of 250mm, and the periphery is provided with exhaust holes with the diameter of 50 mm. High-fluidity concrete is poured into the steel bulkhead to uniformly fill the gap between the inner and outer steel shells, so that necessary pressure and weight support is generated, and the inner sides of the steel shells serving as permanent waterproof measures are protected from corrosion. The steel shell concrete mainly plays a role in anti-floating, stability and mechanical balance, and the concrete is required to have excellent workability and be capable of fully filling the corners inside the steel shell.
The steel bay is a closed space, concrete cannot be vibrated, the concrete molding state cannot be observed by naked eyes, and the filling condition of the hardened concrete is difficult to confirm, so that the concrete filling the steel bay is required to have good filling property and gap permeability, no external vibration is needed, and the concrete can flow under the action of self weight and fill the inner space of the steel bay. Meanwhile, the concrete also has good segregation resistance, and does not bleed and delaminate from top to bottom in the hardening process. In order to ensure that the gap between the steel shell and the concrete is not more than 5mm, the hydration heat and shrinkage rate of the concrete are lower and the volume stability is higher. The existing common concrete is difficult to meet the requirements of fluidity and self-compactness in steel shell immersed tube construction, and a high-fluidity concrete and a production preparation implementation method thereof are urgently needed.
Disclosure of Invention
The invention aims to fill the blank of the lack of special steel shell immersed tube filling concrete in China, provides high-fluidity concrete and is convenient for corresponding construction application requirements.
The concrete mixing proportion scheme researched and provided by the invention is determined through a large amount of trial mixing adjustment, is suitable for pouring the steel shell immersed tube bulkhead, can fill the inner space of the steel bulkhead in a flowing manner under the action of self weight, and ensures that the gap between the steel shell and the concrete is not more than 5mm because the concrete has no phenomena of bleeding, upper and lower layering and the like. The concrete meets the concrete performance requirements applied in the preparation and processing of the steel shell concrete module in the Gangzhaoao bridge project.
In order to achieve the above object, the present invention provides a technical solution:
the high-fluidity concrete consists of coarse aggregates, fine aggregates, powder materials, additives and water, wherein the powder materials comprise cement, fly ash and mineral powder; the additive comprises a water reducing agent and a tackifier.
The coarse aggregate is 0.275m3/m3～0.300m3/m3(ratio per unit absolute volume),
the water consumption is 166.4kg/m3～176.8kg/m3，
The water-powder ratio is 0.83-0.97, the water-powder ratio is preferably 0.88-0.92,
powder material 510kg/m3～540kg/m3，
The sand rate is 53-55 percent,
the addition amount of the additive is 0.95 to 1.1 weight percent of the dosage of the powder material.
Preferably, the additive comprises a tackifier, the mixing amount of the tackifier is 0.6-0.8 wt% of the additive, and the rest of the components are water reducing agents.
The high-fluidity concrete has obvious difference with the prior common concrete, the application control range of the sand rate is 53-55 percent at a higher level, and the overall fluidity of the concrete is well controlled on the basis of improving the strength and the workability of the concrete. The optimal design of mixing water application is matched, and the proper amount of admixture is used for optimizing the overall fluidity of the concrete, so that the concrete has high fluidity, and the preparation requirement of the steel shell immersed tube is met.
wt%: i.e. mass percent.
The concrete inevitably contains partial air, the high-fluidity concrete is composed of powder materials, coarse aggregates, fine aggregates, additives, mixing water and a proper amount of air, and performance indexes meet the requirements of the high-fluidity concrete.
Further, in the powder material: the volume ratio of the cement is 45-50%, the volume ratio of the fly ash is 30-40%, and the volume ratio of the mineral powder is 14-15%. The sum of the total amount of all the components of the powder material is 100%, and if no other powder material is contained, the sum of the total amount of the three powder materials is 100%.
Preferably, the volume ratio of the cement is 45-50%, the volume ratio of the fly ash is 35-40%, and the volume ratio of the mineral powder is 14-15%.
Preferably, the volume ratio of the cement is 48-49%, the volume ratio of the fly ash is 36.5-38%, and the volume ratio of the mineral powder is 14.0-14.8%.
Most preferably, the volume ratio of the cement is 48.5%, the volume ratio of the fly ash is 37.1%, and the volume ratio of the mineral powder is 14.4%.
Further, the dosage of the coarse aggregate is 0.275m3/m3～0.293m3/m3. The unit absolute volume of the concrete coarse aggregate is controlled within the range, and the application amount of fine aggregate and powder materials can be well coordinated, so that the overall matching performance of the concrete is excellent and outstanding.
Furthermore, the coarse aggregate is broken stone, and the size of the broken stone is 5-20 mm.
Further, the amount of the water used was 166.4kg/m3～176.8kg/m3. The proportion of the mixing water is controlled within the range, and the unit water consumption of the concrete is one of basic factors for realizing good fluidity of concrete mixing, namely the mixing water and the admixture.
Further, the fine aggregate is river sand, medium sand.
Further, the water-powder ratio of the concrete is 0.88-0.92. The water-powder ratio refers to the volume ratio of water to powder, the powder refers to a cementing material and an inert (or semi-inert) mineral admixture (such as limestone powder and crushed stone powder), and the water-powder ratio has a large influence on the flowability of concrete.
Further, the cement is P.II 42.5 grade cement.
Further, the fly ash is I-grade fly ash.
Further, the additive is a polycarboxylic acid water reducing agent.
Further, the dosage of the concrete powder material is 510kg/m3～530kg/m3。
Preferably, the absolute volume of the unit powder material is 0.184m3/m3～0.191m3/m3。
Further preferably, the mixing amount of the concrete admixture is 0.95-1.0 percent (mass ratio) of the using amount of the powder material, 0.6-0.8 percent (mass ratio) of the admixture is a tackifier, and the rest of the admixture is a water reducing agent.
Further, the concrete performance index is controlled as follows:
slump spread: the thickness of the glass is 650mm plus or minus 50mm,
T500and (3) reaching time: the time of the reaction lasts for 3s to 15s,
V75funnel outflow time: the time of the reaction lasts for 5s to 15s,
the filling height of the U-shaped instrument is not less than 300mm,
the gas content is not more than 5 percent,
volume weight not less than 2300kg/m3，
The normal-pressure bleeding rate is 0,
the 28d compressive strength was C50.
The high-fluidity concrete mixing proportion and the implementation method thereof are suitable for filling the steel-shell immersed tube compartment, adopt the pumping process for pouring, do not need vibration, are molded by self fluidity, and have the characteristics of good filling property, good clearance passing property and segregation resistance, high strength and lower hydration heat and shrinkage rate.
The high-fluidity concrete determines the performance index requirement of the high-fluidity concrete for filling the steel shell immersed tube bay according to the concrete pouring construction process of the steel shell immersed tube bay, preferentially determines the mix proportion of the high-fluidity concrete through the research on the influence rule of various composition changes on the fluidity, the strength, the hydration heat and the shrinkage of the concrete, and forms the implementation method of the mix proportion of the high-fluidity concrete suitable for the steel shell immersed tube.
The new technical scheme provided by the invention can mainly realize the following technical effects:
1. compared with the existing common concrete, the high-fluidity concrete has the characteristics of high concrete strength and good workability, has excellent overall fluidity, and can be used for well filling a steel shell structure and preparing a high-quality steel shell immersed tube.
2. The application proportion of the coarse aggregate and the fine aggregate in the high-fluidity concrete is good in matching relation, and the overall fluidity of the concrete is better and better than that of common concrete.
3. The invention optimizes the application relation of each component of the concrete, and the application amounts of sand rate, water-powder ratio, admixture, tackifier and the like are mutually coordinated and matched to achieve the optimal concrete flow property.
Description of the drawings:
FIG. 1 is a water-powder volume ratio T500The extent-to-time effect.
FIG. 2 is the effect of the ratio of the water powder volume to the outflow time of the V-funnel.
Figure 3 is the effect of coarse aggregate unit volume on the fill height of the U-shaped instrument.
FIG. 4 is gas content vs. T500The extent-to-time effect.
Figure 5 is the effect of gas content on the outflow time of the V-funnel.
FIG. 6 is a graph of the effect of viscosifier on slump spread versus fill height of a clevis.
FIG. 7 is the change rule of the compressive strength of the concrete with different water-cement ratios in standard curing.
FIG. 8 is the change rule of the compressive strength of concrete cured under the same conditions and different water-cement ratios.
FIG. 9 is the hydration exotherm rate for the hydration exotherm for the cement system.
FIG. 10 is the hydration exotherm for the cement system.
Figure 11 is the adiabatic temperature rise of concrete.
FIG. 12 shows the shrinkage of the concrete on drying.
Detailed Description
The present invention will be described in further detail with reference to test examples and specific embodiments. It should be understood that the scope of the above-described subject matter is not limited to the following examples, and any techniques implemented based on the disclosure of the present invention are within the scope of the present invention.
The specifications/properties of the various raw materials used in the examples of the present invention are as follows:
cement: P.II 42.5; fly ash: i level; slag powder: stage S95; river sand: carrying out medium sand; crushing stone: the particle size is 5-20 mm; additive: a polycarboxylic acid water reducing agent. The above specification/property grades of raw materials are used unless otherwise specified.
< example 1>
Preparing high-fluidity concrete
The concrete is prepared from the following raw materials in parts by weight per cubic meter:
765.9kg/m of broken stone3(ii) a (apparent density of crushed stone 2700kg/m3)
863.6kg/m river sand3(ii) a (river)The apparent density of the sand is 2640kg/m3Sand rate 53%)
286kg/m of cement3(ii) a (the apparent density of the cement is 3140kg/m3)
156kg/m of fly ash3(ii) a (the apparent density of the fly ash was 2240kg/m3)
78kg/m ore powder3(ii) a (apparent density of ore powder 2900kg/m3)
171.6kg/m water3；
Additive 5.2kg/m3Wherein the tackifier accounts for 8.0 percent, and the balance is the water reducing agent.
Stirring and mixing evenly to obtain the high-fluidity concrete.
TABLE 1 high flow mix ratios
TABLE 2 workability of high-fluidity concrete
TABLE 3 other Properties of the high-fluidity concrete
According to the concrete shrinkage and the adiabatic temperature rise, calculating the gap between the concrete and the steel shell in the concrete hardening process under the most adverse conditions according to the following formula:
μ＝(Tα+ζ)·h
in the above formula: mu-gap between concrete and steel shell, mm;
t-adiabatic temperature rise, DEG C, of the concrete;
α——coefficient of linear expansion of concrete, 10X 10-6℃-1；
Zeta-shrinkage of cured concrete under the same conditions, x 10-6；
h-maximum height of steel bay, mm.
The design index that the gap between the concrete and the steel shell under the most adverse condition is 1.4mm and is not more than 5mm is calculated according to the formula, and the filling requirement of the steel shell concrete is met.
From the results of the concrete test performances in tables 2 to 3, it can be seen that the high fluidity concrete of the present invention satisfies the overall performance of each requirement, the slump spread, V75Time of funnel, T500The filling height, bleeding rate, air content, volume weight, strength, drying shrinkage rate, heat insulation temperature rise and the like of the U-shaped line all meet the design requirements of steel shell concrete at the position of the immersed tube joint of the Gangzhaomu bridge. The high-fluidity concrete prepared in the embodiment is the best scheme of the invention, and is the high-fluidity concrete finally applied to the immersed tube joint.
< example 2>
Preparing concrete: the volume ratio of the water powder is 0.83-0.97, and the dosage of the cementing material is 520kg/m3The cement, the fly ash and the mineral powder are mixed according to the volume ratio of the cementing material of 48.5 percent, 37.1 percent and 14.4 percent, the sand rate is 52 to 54 percent, the water-gel ratio is 0.30 to 0.35, and the mixing amount of the additive is 0.8 to 1.2 percent (0.8 percent of the additive is a tackifier). Working Performance of formulated concrete (T)500Extension time, V-funnel flow time), water-powder volume ratio versus T of high-fluidity concrete500The degree of expansion has an important influence, and as a result, as shown in FIG. 1, T is increased with the water-to-powder volume ratio500The time is rapidly reduced, the flowing speed is increased, the fluidity is enhanced, the water-powder volume ratio is increased to 0.89, T500The time is reduced to below 5 s.
The water-powder volume ratio has a significant influence on the outflow time of the V-shaped funnel of the high-fluidity concrete, and as a result, as shown in fig. 2, with the increase of the water-powder volume ratio, the outflow time of the V-shaped funnel is reduced, the water-powder volume ratio is increased to 0.89, the outflow time of the V-shaped funnel is reduced to below 15s, the water-powder ratio is continuously increased, the outflow time reduction rate of the V-shaped funnel is slowed down, the water-powder volume ratio reaches a minimum value when being 0.94, the water-powder ratio is increased thereafter, the cohesiveness and the segregation resistance of the concrete are reduced, the concrete cannot continuously flow out of the funnel, the intermittent stuck phenomenon is presented, and the outflow time of the V-shaped funnel is increased on the contrary. During the test, it was also found that slight bleeding occurred when the water/powder volume ratio was increased to 0.97.
Therefore, the water-powder ratio is preferably controlled to be 0.88 to 0.92.
< example 3>
Preparing concrete: the water-gel ratio is 0.33, and the dosage of the cementing material is 520kg/m3The cementing material is 48.5 percent of cement, 37.1 percent of fly ash and 14.4 percent of mineral powder in volume ratio, and the unit volume consumption of the coarse aggregate is 0.26-0.33 m3/m30.9-1.1% of additive (0.8% of additive is tackifier).
The regular influence of the unit volume of the coarse aggregate on the workability of the high-fluidity concrete is mainly reflected on the wrapping property of the concrete discharged from the machine and the filling height of a U-shaped instrument. The effect of coarse aggregate unit volume on the fill height of the U-shaped instrument is shown in figure 3. Along with the reduction of the unit volume of the coarse aggregate, the filling height of the U-shaped instrument is gradually increased, the filling property, the segregation resistance and the clearance passing property of the concrete are improved, and when the unit volume of the coarse aggregate is reduced to 0.29m3/m3When the filling height is increased to 331mm, the height difference of the fillers on two sides of the U-shaped instrument is reduced to 18 mm. The unit volume of coarse aggregate has a significant influence on the filling property and the gap permeability of the concrete mixture, and it is necessary to control the unit volume to an appropriate range.
< example 4>
Preparing concrete: the water-to-glue ratio is 0.33, and the water consumption is 171.6kg/m3The dosage of the cementing material is 520kg/m3The cementing material comprises 48.5% of cement, 37.1% of fly ash and 14.4% of mineral powder in volume ratio, 53% of sand rate and 0.9-1.1% of additive (0.8% of additive is tackifier). Air entraining and defoaming components are additionally added, and the air content of the concrete mixture is controlled within the range of 1.6-4.5%.
Gas content to T500The effect of the time to reach the extension is shown in FIG. 4, which basically shows that as the gas content increases, the flow speed increases, T500With a gradual reduction in the reach time of the expansionThe tendency is that the concrete rapidly reaches 500mm spread as the slump cone lifts the concrete, but the flow time is not long lasting and the flow stops very quickly. In particular, when the gas content is increased to 4.5%, the state of "fast flow, but not far flow" is exhibited.
The influence of the air content on the outflow time of the V-shaped funnel is shown in figure 5, the linear correlation is realized, the wrapping property and the cohesiveness of concrete are improved along with the increase of the air content, the segregation resistance is enhanced, concrete fillers can continuously and quickly pass through the outlet of the V-shaped funnel, and the outflow time of the V-shaped funnel is greatly reduced. Generally, the influence of air content change on the workability of the high-fluidity concrete is complex, the air content is increased, the wrapping property of slurry and coarse and fine aggregates is enhanced, the segregation resistance of the concrete is improved, and meanwhile, the flowing distance of the concrete is weakened to a certain extent due to the enhancement of the wrapping property.
The air content of the high-fluidity concrete is controlled to be below 4% by adding air-entraining and defoaming components.
< example 5>
Preparing concrete: the water-gel ratio is 0.33, and the dosage of the cementing material is 520kg/m3The cementing material comprises 48.5% of cement, 37.1% of fly ash and 14.4% of mineral powder in volume ratio, the sand rate is 55%, and the additive is 0.9-1.1%. The mixing amount of the tackifier component in the admixture is changed within the range of 0.4-1.2%, the influence of the mixing amount of the tackifier on the slump expansion degree and the filling height of the U-shaped instrument is shown in figure 6, the tackifier is anionic and is compounded into the water reducing agent, the mixing amount accounts for the mass percent of the using amount of the water reducing agent, the cohesiveness and the segregation resistance of concrete are enhanced along with the increase of the mixing amount of the tackifier, the filling height of the U-shaped instrument is increased, but the slump expansion degree is reduced. In the concrete mixing process, the concrete bleeding is obviously improved along with the increase of the mixing amount of the tackifier, when the mixing amount is increased to 0.6 percent, the standing bleeding rate of the concrete is 0.5 percent, and after the mixing amount is increased to 0.8 percent or more, the concrete does not bleed any more.
< example 6>
Preparing concrete: the dosage of the cementing material is kept to 520kg/m3The cementing material comprises the following components in percentage by volume: 48.5% cement and 37.1% powderThe sand ratio is finely adjusted within the range of the sand ratio of 52-54% by adding 14.4% of coal ash and mineral powder, the additive is 0.8-1.2% (0.8% of the additive is a tackifier), the water-cement ratio is changed from 0.31-0.35, and the influence of the water-cement ratio on the concrete strength is contrastively analyzed.
The change rule of the compression strength of the standard curing condition different water-cement ratio high-fluidity concrete along with the age is shown in figure 7, the strength of each group of concrete along with the age is gradually increased, the 7d strength is greater than 40MPa, the 28d strength is greater than 50MPa, and the 56d strength is greater than 60 MPa. The compressive strength of the concrete at each age basically follows the rule that the lower the cement ratio, the higher the strength, wherein the strength of the cement ratio of 0.31 to the concrete at the age of 28d exceeds 70MPa, the strength at the age of 56d exceeds 80MPa, and the strength margin is too high. The compression strength of the concrete with the water-cement ratio of 0.35 in the 28d age period is far lower than that of other groups of concrete, and is only 55.6MPa, and the strength margin is lower.
The law of the change of the compressive strength of the concrete with different water-cement ratios and high fluidity under the same condition along with the age is shown in figure 8, the curing under the same condition is to simulate the sealed environment in a steel shell, and the concrete is immediately sealed and cured after being formed and has no moisture exchange with the outside. The change rule of the compressive strength of the concrete cured under the same condition is not much different from the standard curing condition, but the strength of the concrete with the water-cement ratio of 0.31-0.34 is relatively close to that of the concrete cured under the same condition within the age of 3 d-7 d, and the strength of the concrete with the water-cement ratio of 0.31 is rapidly increased after 28d and is obviously higher than that of other concrete groups. In the whole, the compressive strength of the concrete in each age is slightly lower than that of the standard curing test piece due to no external curing moisture supplement of the same-condition curing test piece, the strength difference before 28d is slightly larger, and the strength difference between the age of 28d and the later period is slightly smaller.
Therefore, the water-glue ratio is controlled not to exceed 0.34.
< example 7>
Preparing concrete: the water-gel ratio is 0.33, and the dosage of the cementing material is kept at 520kg/m3The cementing material is composed of a pure cement system A, a cement system B with the volume ratio of 48.5 percent, 37.1 percent of fly ash and 14.4 percent of mineral powder system, fine sand adjustment rate within the sand rate range of 55 percent, and an additive of 0.9 to 1.1 percent.
The exothermic performance of the cementing material system is improved by blending the fly ash and the mineral powder, and the exothermic rate and the exothermic quantity change rule are shown in figures 9-10. Compared with a pure cement system, the coal ash and mineral powder are adopted to replace cement, the hydration heat release rate and the heat release total amount of the cementing material system are obviously reduced, the heat release rate increases and decreases slowly before and after the maximum heat release rate occurs, a heat release secondary peak occurs after a main heat release peak, and the heat release rate curve of the whole heat release process also tends to be smooth. The heat release of the mixed fly ash and mineral powder system for 72 hours is 65 percent of that of a pure cement system, and the maximum heat release rate is about 45 percent of that of the pure cement system, so that the hydration heat of concrete can be reduced, and the temperature shrinkage of the concrete can be controlled. Therefore, the cementing material combined system adopting part of fly ash and mineral powder to replace cement is more beneficial to pouring high-fluidity concrete in a closed steel shell for application, the effect of controlling the temperature shrinkage of the concrete is better, and the realized quality is better.
< example 8>
The concrete is prepared by a system of 48.5 percent of cement, 37.1 percent of fly ash and 14.4 percent of mineral powder, the water-cement ratio is 0.33, and the dosage of a cementing material is 470kg/m3～570kg/m3Adjusting the sand rate within the range of 47-55%, fine adjusting the dosage of the water reducing agent within the range of 0.90-1.05%, and testing the influence of the change of the cementing material on the adiabatic temperature rise of the concrete by using a temperature stress testing machine, which is specifically shown in FIG. 11.
The change of the dosage of the cementing material has good linear correlation with the adiabatic temperature rise of the concrete, the adiabatic temperature rise is increased along with the increase of the dosage of the cementing material, and the calculation is carried out according to a linear fitting formula, wherein the increase is 10kg/m each time3The concrete adiabatic temperature rise of the gelled material of the same system is improved by 1.4 ℃.
< example 9>
Testing a 48.5% cement, 37.1% fly ash and 14.4% mineral powder system, wherein the dosage of the cementing material is 490kg/m3～540kg/m3The drying shrinkage change law of the high-fluidity concrete in the standard curing and the curing under the same conditions is shown in FIG. 12.
The drying shrinkage of the 90d age standard curing and same-condition curing concrete basically follows the rule which is increased along with the increase of the dosage of the cementing materialAccording to the method, the cured test piece under the same condition has no moisture exchange with the outside, and the shrinkage caused by moisture loss is basically avoided in the concrete hardening process, so that the drying shrinkage of the cured test piece is obviously smaller than that of a standard cured test piece. When the dosage of the cementing material is 520kg/m3The relative treatment range of the dry shrinkage of the concrete in standard curing and under the same condition curing is lower, the influence of the strength of the concrete is comprehensively considered, and 520kg/m is selected3The cementing material is ideal for preparing high-fluidity concrete.
Claims (4)
1. The high-fluidity concrete consists of coarse aggregates, fine aggregates, powder materials, additives and water, wherein the powder materials are cement, fly ash and mineral powder; the additive comprises a water reducing agent and a tackifier;
the coarse aggregate is 0.275m3/m3~0.293m3/m3The ratio of the unit absolute volume,
the water consumption is 166.4kg/m3~176.8kg/m3，
The water-powder volume ratio is 0.88-0.92,
powder material 520kg/m3Wherein the volume ratio of the cement is 45-50%, the volume ratio of the fly ash is 30-40%, and the volume ratio of the mineral powder is 14-15%; the sum of the total amount of the three powder materials is 100 percent;
the sand rate is 53% -55%,
the mixing amount of the additive is 0.95-1.0 wt% of the powder material,
the additive comprises a tackifier, the mixing amount of the tackifier is 0.6-0.8 wt% of the additive, and the rest of the additive is a water reducing agent; the tackifier is an anionic tackifier;
the concrete performance index is controlled as follows:
slump spread: the thickness of the glass is 650mm plus or minus 50mm,
T500and (3) reaching time: the time of the reaction is 3s to 15s,
V75funnel outflow time: the time of the reaction is 5s to 15s,
the filling height of the U-shaped instrument is not less than 300mm,
the gas content is not more than 5 percent,
the unit weight is notLess than 2300kg/m3，
The normal-pressure bleeding rate is 0,
the 28d compressive strength was C50.
2. The high-fluidity concrete according to claim 1, wherein the volume ratio of the cement is 45% to 50%, the volume ratio of the fly ash is 35% to 40%, and the volume ratio of the mineral powder is 14% to 15%.
3. The high fluidity concrete according to claim 1, wherein the coarse aggregate is crushed stone having a size of 5 to 20 mm.
4. The high fluidity concrete according to claim 1, wherein the cement is a P-II 42.5 grade cement.
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| CN102276224A (en) * | 2011-07-22 | 2011-12-14 | 中交上海三航科学研究院有限公司 | Marine engineering self-compacting high-performance concrete and preparation method thereof |
| CN102320803A (en) * | 2011-09-10 | 2012-01-18 | 中国十七冶集团有限公司 | Self-compacting concrete prepared from iron ore tailings, and preparation method thereof |
| CN106946523A (en) * | 2017-03-20 | 2017-07-14 | 中交武汉港湾工程设计研究院有限公司 | Fill concrete after a kind of foundation for laid pipe |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100893495B1 (en) * | 2008-01-09 | 2009-04-17 | 한일시멘트 (주) | The manufacturing method and composition of low-heat, high-strength concrete for self compaction |
| CN101274829A (en) * | 2008-05-08 | 2008-10-01 | 同济大学 | High-early-strength high-slump-retaining shrinkage-compensating self-compaction C60 concrete |
| CN102276224A (en) * | 2011-07-22 | 2011-12-14 | 中交上海三航科学研究院有限公司 | Marine engineering self-compacting high-performance concrete and preparation method thereof |
| CN102320803A (en) * | 2011-09-10 | 2012-01-18 | 中国十七冶集团有限公司 | Self-compacting concrete prepared from iron ore tailings, and preparation method thereof |
| CN106946523A (en) * | 2017-03-20 | 2017-07-14 | 中交武汉港湾工程设计研究院有限公司 | Fill concrete after a kind of foundation for laid pipe |
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