Summary of the invention
Technical problem to be solved by this invention is the deficiency that exists for above-mentioned prior art and provides a kind of high workability high-strength extra retarded set shape steel tube concrete additive and preparation method thereof, as the admixture of concrete filled steel tube, the serviceability of concrete filled steel tube can be improved and delay time of coagulation, significantly improve the intensity in concrete filled steel tube each length of time, especially early strength, can improve the volume stability of concrete filled steel tube simultaneously effectively.
The technical scheme that the problem that the present invention is the above-mentioned proposition of solution adopts is:
A kind of high workability high-strength extra retarded set shape steel tube concrete additive, it is mixed by metakaolin and composite modifier, the mass ratio of metakaolin and composite modifier is (50-20): 1, wherein said composite modifier is followed successively by 70%-90%, 5%-15% and 5%-15% mixed preparing by amino silane, epoxy radicals silicone hydride and methyl-silicone oil according to mass percent and forms, and the per-cent sum of each component is 100%.
By such scheme, the described metakaolin cooling that is kaolin behind at 500-1000 DEG C temperature lower calcination 0.5-6.0 hour of grinding is obtained.
By such scheme, SiO in described metakaolin
2with Al
2o
3mass percentage sum be more than or equal to 50wt%, specific surface area is more than or equal to 2300m
2/ kg.
The preparation method of above-mentioned high workability high-strength extra retarded set shape steel tube concrete additive, comprises the steps:
(1) be followed successively by 70%-90%, 5%-15% and 5%-15% according to mass percent, amino silane, epoxy radicals silicone hydride and organic silicone oil mixed, obtains composite modifier;
(2) be (50-20) according to the mass ratio of metakaolin and composite modifier: 1, metakaolin through drying is put into ceramic ball mill, add composite modifier, grinding 30-120min, namely obtains extra retarded set type high workability high strength steel pipe concrete additive.
By such scheme, the described metakaolin cooling that is kaolin behind at 500-1000 DEG C temperature lower calcination 0.5-6.0 hour of powder is obtained.
By such scheme, SiO in described metakaolin
2with Al
2o
3mass percentage sum be more than or equal to 50wt%, specific surface area is more than or equal to 2300m
2/ kg.
By such scheme, described amino silane is colourless to light yellow clear liquid, content >=95.0%, and density is 1.010 ± 0.005g/ml.
Compared with prior art, the invention has the beneficial effects as follows:
1) the present invention can significantly improve concrete early strength, when the volume of steel tube concrete soil additive of the present invention in ordinary mortar is 3wt%-15wt%, can significantly improve mortar 7d intensity more than 20%, and 28d strength growth rate still can remain on more than 15%; When the volume of steel tube concrete soil additive of the present invention is 8%, 7d ultimate compression strength increases by more than 30%, and for the metakaolin of equal volume, its rate of increase is 20%.Activated alumina and silicon-dioxide and hydrolysis product of cement calcium hydroxide generation secondary reaction of hydration in steel tube concrete soil additive of the present invention, its product (CSH gel and drated calcium aluminate etc.) effectively enhances the degree of compactness of system; And be combined in the interaction of the properties-correcting agent on metakaolin surface, the hydrated reaction product of properties-correcting agent forms locus effect and metakaolin is more effectively scattered in gelling material, meanwhile, properties-correcting agent improves metakaolin, bonding action between cement and hydrated product.Therefore, steel tube concrete soil additive of the present invention can significantly improve concrete early strength.
2) the present invention significantly delays concrete time of coagulation, and when the volume of steel tube concrete soil additive of the present invention in gelling material is 8%, time of coagulation delays about 17h.Because properties-correcting agent generates a large amount of hydroxyls in hydration process, formed adsorption film by the absorption of the calcium ion on cement particle surface and hinder aquation to carry out, or with the O on cement particle surface
2-form hydrogen bond and hinder hydration reaction, thus can effectively delay concrete time of coagulation.
3) the present invention significantly improves concrete serviceability, and when in normal concrete, the volume of metakaolin is 5wt%-10wt%, when polycarboxylate water-reducer volume is 0.5%, its slump declines at about 40mm-100mm.But when mixing the steel tube concrete soil additive of the present invention of equal volume, its degree of mobilization can remain unchanged substantially, and without the need to additional water reducer.Metakaolin particle surface due to properties-correcting agent generation Chemical bond or physisorption, properties-correcting agent forms the cage construction of oligopolymer in hydration process, makes its space forming surface steric hindrance, thus effectively improves rheological property.
4) the present invention can improve concrete volume stability, after adding metakaolin in normal concrete, due to volcano ash effect and the micro-packing effect of metakaolin, can greatly improve concrete compactness, thus effectively reduce volume of concrete contraction.But, adding of steel tube concrete soil additive of the present invention, improve concrete serviceability and the active reaction rate that improve metakaolin, be more conducive to reducing concrete volumetric shrinkage.Therefore, steel tube concrete soil additive of the present invention can improve concrete volume stability significantly, improves concrete endurance quality.
5) the present invention to different types of cement and concrete additive adaptability good; water reducer is usually there will be and the phenomenon that consistency is bad appears in cement in engineering reality, and the problem that steel tube concrete soil additive of the present invention there will not be adaptability bad for the kind of various admixture and cement.
Embodiment
In order to understand the present invention better, illustrate content of the present invention further below in conjunction with embodiment, but content of the present invention is not only confined to the following examples.
embodiment 1:
A kind of high workability high-strength extra retarded set shape steel tube concrete additive, it is prepared at grinding in ball grinder 30min by metakaolin, composite modifier, wherein, the mass ratio of metakaolin and composite modifier is 20:1, and described properties-correcting agent has amino silane, epoxy radicals silicone hydride and methyl-silicone oil to be followed successively by 90%, 5% and 5% mixed preparing according to mass percent to form.Wherein, SiO in described metakaolin
2with Al
2o
3mass percentage sum be more than or equal to 50wt%, specific surface area is more than or equal to 2300m
2/ kg; Described amino silane is colourless to light yellow clear liquid, content>=95.0%, and density is 1.010 ± 0.005g/ml.
The preparation method of above-mentioned high workability high-strength extra retarded set shape steel tube concrete additive, comprises the steps:
(1) be followed successively by 90%, 5% and 5% according to mass percent, amino silane, epoxy radicals silicone hydride and organic silicone oil mixed, obtains composite modifier;
(2) be 20:1 according to the mass ratio of metakaolin and composite modifier, the metakaolin through drying put into ceramic ball mill, adding composite modifier, grinding 30min, namely obtains extra retarded set type high workability high strength steel pipe concrete additive.
embodiment 2:
A kind of high workability high-strength extra retarded set shape steel tube concrete additive, it is prepared at grinding in ball grinder 75min by metakaolin, composite modifier, wherein, the mass ratio of metakaolin and composite modifier is 20:1, and described properties-correcting agent has amino silane, epoxy radicals silicone hydride and methyl-silicone oil to be followed successively by 90%, 5% and 5% mixed preparing according to mass percent to form.Wherein, SiO in described metakaolin
2with Al
2o
3mass percentage sum be more than or equal to 50wt%, specific surface area is more than or equal to 2300m
2/ kg; Described amino silane is colourless to light yellow clear liquid, content>=95.0%, and density is 1.010 ± 0.005g/ml.
The preparation method of above-mentioned high workability high-strength extra retarded set shape steel tube concrete additive, comprises the steps:
(1) be followed successively by 90%, 5% and 5% according to mass percent, amino silane, epoxy radicals silicone hydride and organic silicone oil mixed, obtains composite modifier;
(2) be 20:1 according to the mass ratio of metakaolin and composite modifier, the metakaolin through drying put into ceramic ball mill, adding composite modifier, grinding 75min, namely obtains extra retarded set type high workability high strength steel pipe concrete additive.
embodiment 3:
A kind of high workability high-strength extra retarded set shape steel tube concrete additive, it is prepared at grinding in ball grinder 120min by metakaolin, composite modifier, wherein, the mass ratio of metakaolin and composite modifier is 20:1, and described properties-correcting agent has amino silane, epoxy radicals silicone hydride and methyl-silicone oil to be followed successively by 90%, 5% and 5% mixed preparing according to mass percent to form.Wherein, SiO in described metakaolin
2with Al
2o
3mass percentage sum be more than or equal to 50wt%, specific surface area is more than or equal to 2300m
2/ kg; Described amino silane is colourless to light yellow clear liquid, content>=95.0%, and density is 1.010 ± 0.005g/ml.
The preparation method of above-mentioned high workability high-strength extra retarded set shape steel tube concrete additive, comprises the steps:
(1) be followed successively by 90%, 5% and 5% according to mass percent, amino silane, epoxy radicals silicone hydride and organic silicone oil mixed, obtains composite modifier;
(2) be 20:1 according to the mass ratio of metakaolin and composite modifier, the metakaolin through drying put into ceramic ball mill, adding composite modifier, grinding 120min, namely obtains extra retarded set type high workability high strength steel pipe concrete additive.
embodiment 4:
A kind of high workability high-strength extra retarded set shape steel tube concrete additive, it is prepared at grinding in ball grinder 90min by metakaolin, properties-correcting agent, wherein, the mass ratio of metakaolin and composite modifier is 30:1, and described properties-correcting agent has amino silane, epoxy radicals silicone hydride and methyl-silicone oil to be followed successively by 80%, 15% and 5% mixed preparing according to mass percent to form.Wherein, SiO in described metakaolin
2with Al
2o
3mass percentage sum be more than or equal to 50wt%, specific surface area is more than or equal to 2300m
2/ kg; Described amino silane is colourless to light yellow clear liquid, content>=95.0%, and density is 1.010 ± 0.005g/ml.
The preparation method of above-mentioned high workability high-strength extra retarded set shape steel tube concrete additive, comprises the steps:
(1) be followed successively by 80%, 15% and 5% according to mass percent, amino silane, epoxy radicals silicone hydride and organic silicone oil mixed, obtains composite modifier;
(2) be 30:1 according to the mass ratio of metakaolin and composite modifier, the metakaolin through drying put into ceramic ball mill, adding composite modifier, grinding 90min, namely obtains extra retarded set type high workability high strength steel pipe concrete additive.
embodiment 5:
A kind of high workability high-strength extra retarded set shape steel tube concrete additive, it is prepared at grinding in ball grinder 90min by metakaolin, properties-correcting agent, wherein, the mass ratio of metakaolin and composite modifier is 50:1, and described properties-correcting agent has amino silane, epoxy radicals silicone hydride and methyl-silicone oil to be followed successively by 70%, 15% and 15% mixed preparing according to mass percent to form.Wherein, SiO in described metakaolin
2with Al
2o
3mass percentage sum be more than or equal to 50wt%, specific surface area is more than or equal to 2300m
2/ kg; Described amino silane is colourless to light yellow clear liquid, content>=95.0%, and density is 1.010 ± 0.005g/ml.
The preparation method of above-mentioned high workability high-strength extra retarded set shape steel tube concrete additive, comprises the steps:
(1) be followed successively by 70%, 15% and 15% according to mass percent, amino silane, epoxy radicals silicone hydride and organic silicone oil mixed, obtains composite modifier;
(2) be 50:1 according to the mass ratio of metakaolin and composite modifier, the metakaolin through drying put into ceramic ball mill, adding composite modifier, grinding 90min, namely obtains extra retarded set type high workability high strength steel pipe concrete additive.
application testing (one)
Using mortar specimen as investigation object, metakaolin and the preparation-obtained additive of embodiment 1-3 are all with 6%, 8%, 10% equivalent replace gelling material configuration mortar.Choose river sand (crossing 2.36mm sieve), water cement ratio is 0.45, and cement mortar rate is 1:3, and water reducer is wooden sodium sulfonate's pulvis water reducer.According to the degree of mobilization of GB/T 2429-2005 " Test method for fluidity of cement mortar " test benchmark sample, metakaolin sample, embodiment 1-3 sample; According to GB/T 17671-1999 " Test method for strength of hydraulic cement mortar ", by 7 days and 28 days ultimate compression strength of omnipotent pressure testing machine test benchmark sample and example.The degree of mobilization of mortar specimen and strength test results are in table 1.
As shown in Table 1, when in the first, embodiment 1-3 sample, water reducer consumption is reduced to 0.2%, the degree of mobilization of mortar specimen compares the metakaolin sample of equal volume, all still improve, illustrate that additive of the present invention is to the serviceability effect of having greatly improved; The second, embodiment 1-3 sample and metakaolin sample are for benchmark sample, 7d and 28d intensity all shows obvious growth; And the 7d intensity of comparative example 1-3 sample and equal volume metakaolin sample, strength growth rate is respectively 11.6%, 20.2% and 10.4%, illustrate that additive of the present invention has stronger promoter action to early strength, 28d intensity shows to there is no impact to later strength development simultaneously.
application testing (two)
Select the proportioning of embodiment 2, only to starch as investigation object, with reference to the measuring method of cement setting time in GB/T1346-2001 " cement normal consistency water consumption, time of coagulation, the stability method of inspection ", first, the final setting time of assay standard sample (new P.I 52.5 cement of China), metakaolin sample and embodiment 2 sample respectively, measurement result is as shown in table 2, wherein in metakaolin sample, metakaolin is that the quality such as 8% replaces cement according to volume, and additive described in embodiment 2 sample is that the quality such as 8% replaces cement according to volume.
As shown in Table 2 metakaolin mix make slurry just, all corresponding shortening of final setting time.But adding of additive described in embodiment 2 has but delayed the time of coagulation of gelling material widely, and wherein the presetting period is for benchmark sample, has delayed about 17h, illustrates that additive of the present invention has stronger delayed coagulation to concrete.
Select the proportioning of embodiment 2, with reference to JCJ/T 70-2009 standard, all test specimens are shaping in the die trial of 3 25mm × 25mm × 280mm is placed on that temperature is 20 DEG C, relative humidity is greater than maintenance under the condition of 90%RH.Form removal is placed on that temperature is 20 DEG C, relative humidity is maintenance in the environment of 60%RH, after this surveys its 3d, 5d, 7d, 14d and 28d length respectively.The rate of expansion following formula of test specimen calculates:
, in formula:
-test specimen is in the rate of expansion (%) in the t days length of time;
-test specimen is in the length (mm) in the t days length of time;
the datum length (mm) of-test specimen;
the length (mm) of-gauge head (namely burying nail).
As shown in Figure 1, when the volume of steel tube concrete soil additive described in embodiment 2 is 8%, for metakaolin, steel tube concrete soil additive of the present invention significantly reduces the dry shrinkage of mortar specimen, is more conducive to the volume stability of mortar.
application testing (three)
Be investigate object with concrete sample, metakaolin and embodiment 4 gained additive are all with 8% equivalent replace gelling material configuration concrete, and water reducer is polycarboxylic acids dehydragent.According to the slump of GB/T 50080-2002 " Standard for test methods of properties of ordinary concrete mixture standard " test benchmark sample, metakaolin sample and embodiment 4 sample, as shown in table 3; According to GB/T 50081-2002 " standard for test methods of mechanical properties of ordinary concrete ", by 7 days and 28 days ultimate compression strength of omnipotent pressure testing machine test benchmark sample, metakaolin sample and embodiment 4 sample, as shown in Figure 2; According to GB/T 50089-2009 " Standard for test methods of longterm performance and durability of ordinary concrete standard ", contact process is adopted to measure concrete dry shrinkage, as shown in Figure 3.
As shown in Table 3, when described in embodiment 4, the volume of steel tube concrete soil additive is 8%, when not adding water reducer, it is for the metakaolin of the improvement result of rheological property relative to equal volume, still obvious; Meanwhile, as can be seen from Figure 2, with regard to 7d intensity, embodiment 4 reaches 9.6% relative to the metakaolin rate of increase of equal volume, and within 28 days, strength growth rate is 12.4%.Illustrate that steel tube concrete soil additive of the present invention can not only improve serviceability, and the growth of early strength can be promoted.
As shown in Figure 3, the drying shrinkage of mixing rear concrete sample of metakaolin has significant reduction compared with benchmark sample, and contrast embodiment 4 sample of equal volume, its drying shrinkage is further reduced, and this illustrates that steel tube concrete soil additive of the present invention can significantly improve concrete volume stability.