CN108709830A - The construction method of freezing-thawing damage regeneration concrete chloride diffusion coefficient multi-scale prediction model - Google Patents
The construction method of freezing-thawing damage regeneration concrete chloride diffusion coefficient multi-scale prediction model Download PDFInfo
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Abstract
The invention discloses a kind of construction methods of freezing-thawing damage regeneration concrete chloride diffusion coefficient multi-scale prediction model, it is characterized in that regeneration concrete to be considered as to the cement-base composite material being made of different scale material, since the hardened cement paste of small scale, gradually it is transitioned into the regeneration concrete of large scale, the chloride diffusion coefficient prediction model of different scale cement-based material is set up successively, then consider influence of the freezing-thawing damage to its chlorine ion binding capacity inside regeneration concrete, the final chloride diffusion coefficient multi-scale prediction model for establishing freezing-thawing damage regeneration concrete.The method has studied influence of the freezing-thawing damage to chlorine ion binding capacity from the Multi-scale model composition of cement-based material, is of great significance to the chloride-penetration resistance research of freezing-thawing damage regeneration concrete and durability Design.
Description
Technical field
The invention belongs to the prediction techniques of regeneration concrete chloride diffusion coefficient more particularly to a kind of freezing-thawing damage to regenerate
The construction method of Chloride Diffusion Coefficient in Concrete multi-scale prediction model.
Background technology
Regeneration concrete can be regarded as on meso-scale by original natural aggregate (NCA), old ITZ, old mortar (OM), new
ITZ and new mortar (NM) matrix composition, each constituent all affect the macro property of RC in various degree.Inside regeneration concrete
There are many holes and microcrack, these holes and crack enter inside concrete for harmful substance and provide channel, chlorion
It is carried out by these channels in regeneration concrete internal transmission, it is a complicated process, and transmission process is not only
Influenced by regeneration concrete mesostructure composition itself, and actual use process can by external environment, as load,
The influence of the effects that temperature and Frozen-thawed cycled.Therefore, from the thin sight Multi-scale model of regeneration concrete, it is each gradually to analyze it
Influence of the mesostructure to its chlorine ion binding capacity performance finally considers the damage that Frozen-thawed cycled generates, establishes one kind and meeting reality
The chloride diffusion coefficient multi-scale prediction model of the injury regeneration concrete of engineering specifications, is to study in actual use again
The effective way of growing concrete chlorine ion binding capacity characteristic and rule can provide new ginseng for the durable Journal of Sex Research of regeneration concrete
It examines and thinking.
Gap, microcrack and plane of weakness inside regeneration concrete constitute the internal flaw of concrete, commonly referred to as again
The damage of growing concrete.Transmission of the medium inside regeneration concrete has damaged direct relationship with it, and damage can be medium
Transmission more convenient path is provided.The king for causing concrete damage will be because being known as environmental activity (such as humidity, temperature and its friendship
For variation), load and its own in variation etc. for occurring in the process of military service, wherein lotus Frozen-thawed cycled effect is to cause to regenerate coagulation
The main reason for soil damages in use.
Freezing-thawing damage.Cement-based material can occur surface under subzero temperature and the ringing of positive warm (freeze and melt) and shell
Fall, crack, strength reduction, structure are loose so that the phenomenon that destroying, when concrete structure is subjected to Frozen-thawed cycled, the hole in concrete
Gap water volume in freezing process expands, and causes the destruction of concrete inner structure, and number of freezing and thawing is more, concrete destruction
It is more serious, after repeated freeze-thaw cycle, since the microcrack for freezing to generate interpenetrates in concrete, make concrete from outward appearance to inner essence
It wrecks, concrete strength is caused to decline, impermeability reduces, final to destroy completely, and the freeze thawing resistance of cement-based material damages energy
Power is to evaluate the important indicator of its durability.
The research of existing concrete freezing-thawing damage is concentrated mainly in the judgement of injury tolerance both at home and abroad, is damaged at present about freeze thawing
The correlative study for hindering the influence to concrete chloride ion diffusion property is also relatively fewer, and existing correlative study also only measures certain
Chlorine ion binding capacity characteristic of the concrete of one ratio of mud after the certain number of freeze thawing, such as foreign scholar G é rard study 0.45 water
Glue than the non-air-entraining concrete chloride diffusion coefficient after 31 times, 61 times and 95 times Frozen-thawed cycleds respectively, find through with
Corresponding chloride diffusion coefficient has increased separately 1.5,3.5,7.5 times after upper number of freezing and thawing, which can only illustrate that freeze thawing follows
Ring number is much bigger on the influence of the chlorine ion binding capacity of concrete, without establishing relevant theoretical formula.Domestic scholars flood brocade
Auspicious design is prepared for the concrete that water-cement ratio is 0.336, and the chlorion for then testing the concrete of different freezing-thawing damage degree expands
Coefficient is dissipated, carrying out regression analysis according to the data measured has obtained concrete freezing-thawing damage degree and chlorine from returning between diffusion system
It makes a public possession formula, what which can be relatively good illustrates that there are good non-between Chloride Ion in Concrete diffusion coefficient and freezing-thawing damage
Linear relationship, but due to the limitation of research itself, similar formula does not have universality.The Institute of Oceanology of the Chinese Academy of Sciences
Sun Congtao analyze influence of the freezing-thawing damage to Chloride Ion in Concrete distribution and diffusion coefficient, and injury tolerance concept is drawn
Enter, establishes the Chloride Ion in Concrete diffusion coefficient attenuation model for considering that freezing-thawing damage influences, in contrast, the research is one
Determine to have deepened correlative study in degree, however the model is established on the basis of studying normal concrete, therefore by the mould
Applicability of the type for regeneration concrete also needs to further study.
Summary it is found that due to freezing-thawing damage research limitation and regeneration concrete itself complexity, at present about
The correlation model of freezing-thawing damage regeneration concrete chloride diffusion coefficient, it is also necessary to which further research is established.
Invention content
The technical problem to be solved in the present invention is to provide a kind of more rulers of freezing-thawing damage regeneration concrete chloride diffusion coefficient
Spend the construction method of prediction model.
In order to solve the above technical problems, the present invention uses following technical scheme：
The construction method of freezing-thawing damage regeneration concrete chloride diffusion coefficient multi-scale prediction model, by regeneration concrete
It is considered as the cement-base composite material being made of different scale material, since the hardened cement paste of small scale, is gradually transitioned into
The regeneration concrete of large scale sets up the chloride diffusion coefficient prediction model of different scale cement-based material, then successively
Consider influence of the freezing-thawing damage to its chlorine ion binding capacity inside regeneration concrete, finally establishes the chlorine of freezing-thawing damage regeneration concrete
Ionic diffusion coefficient multi-scale prediction model.
Above-mentioned construction method, includes the following steps：
<1>Establish cement paste chloride diffusion coefficient prediction model；
<2>Establish new mortar chloride diffusion coefficient prediction model；
<3>Establish regeneration concrete chloride diffusion coefficient multi-scale prediction model；
<4>Establish the chloride diffusion coefficient model of freezing-thawing damage regeneration concrete.
Bu Zhou <1>It is carried out by following operation：
The cement granules of different-grain diameter generate hardened cement net slurry after being reacted with water, and hardened cement net slurry is produced by various aquations
Object (C-S-H, CH, AF), unhydrated cement granules (can be approximately spherical) and many holes are constituted, each in cement paste
Volume fraction shared by component, changes with the ratio of mud and development of age, and various components are mutually mingled in slurry, and joint effect
Chloride diffusion coefficient after cement slurry hardening establishes hardened cement net slurry in conjunction with broad sense from Qia Fa and Moil-Tanaka methods
Chloride diffusion coefficient prediction model is：
In formula (35),Expression formula be：
In formula (36), DhCSHFor the diffusion coefficient of cement middle-high density C-S-H gel layers；DlCSHFor low-density C- in cement
The diffusion coefficient of S-H gel layers；VaThe volume point of total cement volume is accounted for for hardened cement paste middle-high density C-S-H gel layers
Number； VβFor the sum of the volume fraction of unhydrated cement granules in hardened cement paste and high density C-S-H gel layers；
Highdensity C-S-H gel layers contain hydrolysis product of cement (such as CH, AF) and highdensity C-S-H gel layers
Matrix, when hydrated product non-diffusing and it is relatively uniform be distributed in high density C-S-H gel layer matrixes when, according to matrix-folder
Parasitic mode type has DhCSHExpression formula be：
Wherein：
In formula (37)~(39),For by testing the chlorion being calculated with numerical value in high density C-S-H gels
Diffusion coefficient in layer, takesIt is CH, AF, highdensity C-S-H solidifying respectively
Volume fraction of the glue-line matrix in high density C-S-H gel layers；αh、βhFor intermediate variable；
The C-S-H gel layers of low-density had both contained hydrolysis product of cement (such as CH, AF) and the C-S-H gels of low-density
Layer matrix contains many pore holes again, consideration hydrated product, pore all non-diffusing and it is relatively uniform be distributed in it is low
In density C-S-H gel layer matrixes, the Mori-Tanaka methods being mingled with according to heterogeneous material have DlCSHExpression formula be：
Wherein：
ζ=Vcap(Dcap-D'lCSH) (45)
D&apos in formula (41)~(45);lCSHIt is uniform for hydrolysis product of cement (such as CH, AF) and low-density C-S-H gel layer matrixes
The effective diffusion cofficient of EFFECTIVE MEDIUM layer after being mingled with；For by testing the chlorion being calculated with numerical value in low-density
Diffusion coefficient in C-S-H gel layers, takesIt is CH, AF, hair respectively
Volume fraction of the C-S-H gel layers matrix in low-density C-S-H gel layers of pore, low-density；DcapFor the effective of pore
Diffusion coefficient takes Dcap=2.03 × 10-9m2/s；αl、βl, ξ, ζ be intermediate variable；
The volume fraction of the various hydrated products of hardened cement paste is respectively VCH、VAF、VCSH(VlCSHAnd VhCSH), it is unhydrated
Cement granules volume fraction be VU, the volume fraction of pore is Vcap, then have：
VCH+VAF+VlCSH+VhCSH+VU+Vcap=1 (46)
And have：
V in formula (36)a、VβExpression formula be respectively：
Composite type (35)~(49) can be able to the cement paste chloride diffusion coefficient that each volume parameter is variable and predict mould
Type is：
In formula (50),For the measured value tested and numerical value is calculated；It is assumed that saturation cement slurry
Quality is 1g, according to Portland cement chemical equation, obtains the prediction model of each volume fraction in net slurry, is：
In formula (51)~(56), the initial ratio of mud of n-cement slurry；T-age；ρc、ρlCSH、ρhCSH- cement it is close
The density of degree, the density of low-density C-S-H gels, high density C-S-H gels, takes ρlCSH=1.44g/cm3、ρhCSH=1.75g/
cm3, ρcIt is measured according to the cement material actually selected；p1、p2、p3、p4—C3S、C2S、C3A、C4Matter of the AF in clinker
Measure score.
Bu Zhou <2>It is carried out by following operation：
Can regard as on new mortar meso-scale by fine aggregate (sand grains, can be approximately spherical), hardened cement paste and
ITZ compositions between the two are predicted that establishing new mortar chloride diffusion coefficient prediction model is from being in harmony method using broad sense：
ξ in formula (57), ζ are intermediate variable, are had：
D in formula (58)HCPFor the chloride diffusion coefficient for the hardened cement paste that step 1 prediction obtains；DITZFor new mortar
The chloride diffusion coefficient of interfacial transition zone (ITZ) between middle fine aggregate and hardened cement paste；VAFor thin bone in new mortar
The volume fraction of material is obtained by the mix calculation of mortar；VITZFor the boundary in new mortar between fine aggregate and hardened cement paste
The volume fraction of face transition region (ITZ), value range 5%-30%；
Wherein, DITZInterfacial transition zone (ITZ) thickness and basis material between fine aggregate and hardened cement paste
Diffusion property is related, then using cement as the D of the new mortar of matrixITZExpression formula be：
DITZ=117.563DHCP·hITZ -0.8772 (59)
H in formula (59)ITZIt is related with the mean radius of cement particle for the thickness of new mortar median surface transition region, take hITZ
=25 μm.
Bu Zhou <3>It is carried out by following operation：
It can be regarded as regeneration concrete, on meso-scale by original natural aggregate (OA), old interfacial transition zone
(OITZ), the cement-based material of the small dimensional materials such as old mortar (OM), new interfacial transition zone (NITZ) and new mortar (NM) composition,
Volume fraction joint effect shared by each component the chloride diffusion coefficient of regeneration concrete；Regeneration concrete simplification is regarded as
Multiple dimensioned composite sphere is regenerated according to porous material penetration theory with reference to broad sense from Qia Fa and Moil-Tanaka methods
The chloride diffusion coefficient multi-scale prediction model of concrete is：
In formula (60), DNMFor the chloride diffusion coefficient for the new mortar that step 2 prediction obtains；φ1For natural aggregate, always
ITZ, old mortar, the sum of the volume fraction of new ITZ, i.e. φ1=φOA+φOITZ+φOM+φNITZ；φNMFor the volume point of new mortar
Number； D4For the combination diffusion coefficient of recycled aggregate (natural aggregate+old interface+old mortar) and new interface；
Recycled aggregate is embedded in new interface, D is obtained according to the effective diffusion cofficient calculation formula of composite sphere4Expression formula
For：
In formula (61), DNITZFor the diffusion coefficient of new interface (new ITZ), calculating formula is shown in formula (62)；φ2For natural aggregate,
The sum of the volume fraction of old ITZ, old mortar, i.e. φ2=φOA+φOITZ+φOM；φNITZThe volume of new mortar in regeneration concrete
Score；D3For the diffusion coefficient of recycled aggregate (natural aggregate+old interface+old mortar)；Remaining symbolic indication meaning is same as above；
DNITZ=117.563DNM·hNITZ -0.8772 (62)
In formula (62), hNITZFor the thickness (m) of new interfacial transition zone in regeneration concrete, h is takenNITZ=45 μm；
Natural aggregate and old interface are considered as in entirety, then embedded old mortar, according to the effective diffusion cofficient of composite sphere
Calculation formula can obtain D3Expression formula be：
(63), D in formulaOMFor the diffusion coefficient of old mortar, D is takenOM=6.9DNM；φ3For original natural aggregate, old ITZ
The sum of volume fraction, i.e. φ2=φOA+φOITZ；φOMThe volume fraction of old mortar is adhered on recycled aggregate surface；D2For nature bone
The diffusion coefficient of material and the combination at old interface；Remaining symbolic indication meaning is same as above；
Natural aggregate is chimeric with old interface, D can be obtained according to the effective diffusion cofficient calculation formula of composite sphere2Expression
Formula is：
In formula (64), DOITZFor the diffusion coefficient at old interface, calculating formula is shown in formula (65)；φOMIt is old in regeneration concrete
The volume fraction of mortar；φOITZThe volume fraction of old mortar；DOAFor the diffusion coefficient of natural aggregate, D is takenOA=0.210-12m2/
s；Remaining symbolic indication meaning is same as above；
DOITZ=117.563DOM·hOITZ -0.8772 (65)
In formula (65), hOITZFor the thickness (m) of new interfacial transition zone in regeneration concrete, h is takenOITZ=55 μm；
In formula (60)~(64), φNITZValue range is 0.5%-2.0%, takes 0.75%, the volume point of remaining each component
Count the volume fraction φ with recycled aggregateRCA(can be acquired according to match ratio) and change, the correlation computations formula of each volume fraction
For：
In formula (66), ψ is the volume fraction (related with recycled aggregate grain size) for adhering to old mortar in recycled aggregate, value model
It encloses for 30%-45%, is taken as 34.7%；Remaining symbolic indication meaning is same as above.
Bu Zhou <4>It is carried out by following operation：
Regeneration concrete will appear internal injury under the external influences such as Frozen-thawed cycled, and internal injury can be to regeneration concrete
Chloride ion permeability generates large effect, according to freezing-thawing damage theory, considers the correlation of chlorine ion binding capacity and freezing-thawing damage,
Establishing freezing-thawing damage regeneration concrete chloride diffusion coefficient prediction model is：
In formula (67), DRCFor the chloride diffusion coefficient of regeneration concrete；After regeneration concrete freeze-thaw damage
Chloride diffusion coefficient takesk1For freezing-thawing damage degree；k1Expression formula be：
Wherein, d is specimen thickness；N is freezing-thawing cycles.
Application of the above-mentioned construction method in terms of freezing-thawing damage mixture ratio design of recycled aggregate concrete regenerates freezing-thawing damage mixed
The chloride diffusion coefficient multi-scale prediction model and concrete life prediction theory for coagulating soil are combined, and obtaining makes in varying environment
With the match ratio under grade, meeting the regeneration concrete that different service lives require.
In view of the problems of the existing technology, it is based on existing theoretical research, inventor establishes a kind of freezing-thawing damage again
The construction method of growing concrete chloride diffusion coefficient multi-scale prediction model, it is characterised in that regeneration concrete is considered as by not
The cement-base composite material constituted with sized materials is gradually transitioned into large scale since the hardened cement paste of small scale
Regeneration concrete sets up the chloride diffusion coefficient prediction model of different scale cement-based material successively, then considers regeneration
Influence of the inside concrete freezing-thawing damage to its chlorine ion binding capacity, finally establishes the chlorine ion binding capacity of freezing-thawing damage regeneration concrete
Coefficient multi-scale prediction model.The method from the Multi-scale model composition of cement-based material, have studied freezing-thawing damage to chlorine from
The influence of son diffusion has the chloride-penetration resistance research of freezing-thawing damage regeneration concrete and durability Design highly important
Meaning.
Compared with existing concrete chloride diffusion coefficient assay method, outstanding advantage of the invention is：
(1) regeneration concrete Na Guan, thin sight, the influence of its pairs of chlorine ion binding capacity of microcosmic and macrostructure group are had studied,
The chloride diffusion coefficient prediction model of multiple dimensioned cement-based material is constructed, which analyzes comprehensively, fit from microcosmic to macroscopic view
It is wide with range, reference can be provided to study the durability of regeneration concrete from microcosmic angle.
(2) the freezing-thawing damage regeneration concrete multi-scale prediction model established is from the Multi-scale model angle of concrete material
Degree analyzes the Diffusion Law and influence factor of chlorion in freezing-thawing damage regeneration concrete, establishes the freeze thawing of regeneration concrete
Quantitative relationship between injury tolerance and its chlorine ion binding capacity performance compensates for the research defect of related fields, can be that regeneration is mixed
The freeze proof Journal of Sex Research for coagulating soil provides new reference and reference.
(3) prediction model through the invention can be according to the cooperation of existing cement-based material when relevant material parameters ratio
Its chloride diffusion coefficient is accurately predicted, without passing through special test device real-time testing, Ke Yijie every time
About research cost promotes the development of the durable Journal of Sex Research of cement-based material.
(4) prediction model of the present invention and existing concrete life design theory are combined, it can be according to concrete structure
Service life require, calculate and acquire the match ratio of the regeneration concrete for meeting requirement, be the match ratio of concrete structure
Design provides new approaches.
Description of the drawings
Fig. 1 is the flow of freezing-thawing damage regeneration concrete chloride diffusion coefficient multi-scale prediction model construction of the present invention
Figure.
Fig. 2 is hardened cement paste micro-scale structures model schematic.
Fig. 3 is the relation curve (ratio of mud n=0.5) that various volume parameters change with age t in cement paste.
Fig. 4 is the relation curve (age t=28d) that various volume parameters change with ratio of mud n in cement paste.
Fig. 5 is the meso-scale structural schematic diagram of new mortar.
Fig. 6 is that the ratio of mud is 0.5, sand volume score VANew mortar chlorion expands when taking definite value 0.3,0.42,0.5 respectively
Dissipate coefficient DNMWith interfacial transition zone volume fraction VITZThe relation curve of variation.
Fig. 7 is regeneration concrete meso-scale structural model schematic diagram.
Fig. 8 is volume fraction φOM,φOITZ,φOA,φNMWith the volume fraction φ of recycled aggregateRCAThe relationship of variation is bent
Line.
Fig. 9 is the cylinder test specimen (upper left) for RCM methods machined and regeneration concrete chlorine ion binding capacity system
The offset relation curve of number predicted value and test value
Figure 10 is two kinds of model predication values of injury regeneration Chloride Diffusion Coefficient in Concrete and the offset relation song of test value
Line.
In figure：1 C-S-H layers of high density；2 C-S-H layers of low-density；3 equivalent spherical unhydrated cement granules；4 is unhydrated
Cement granules；5 hardened cement pastes；6 natural sand grains；7 equivalent spherical natural sand grains；Between 8 natural sand grains and cement slurry
ITZ；9 natural coarse aggregates；10 equivalent spherical natural coarse aggregates；11 old interfacial transition zones (ITZ)；12 old mortars；13 New Territory
Face transition region (ITZ)；14 new mortars.
Specific implementation mode
In order to verify the superiority of aforementioned construction method and its related prediction model, inventor is multiple dimensioned pre- according to having been established
It surveys model and further designs the regeneration concrete of different chloride diffusion coefficients, and carry out verification experimental verification.The selection of material and cooperation
Than the cement-based material that design prepares different chloride diffusion coefficients, according to material parameter and the more rulers of the mix-design present invention
Prediction model is spent, calculates chloride diffusion coefficient predicted value, and by the pre- of its measured value with RCM methods and existing theoretical model
Measured value does comparative analysis.In order to illustrate the practical engineering application meaning of model, in conjunction with prediction model and existing concrete structure
Life prediction is theoretical, is required according to the service life in not the same year of concrete structure, and solution meets actually required regeneration concrete
Match ratio.Specific embodiment process is：
(1) according to the multi-scale prediction model established, pre-selected material parameter, design mixture proportion prepares different chlorions and expands
Dissipate the multiple dimensioned cement-based material of coefficient
(2) cement paste prepared, new mortar, regeneration concrete test specimen are chosen and carries out the regeneration after freezing and thawing test
Concrete sample measures its corresponding chloride diffusion coefficient by RCM methods.
(3) test value that the design value of different scale cement-based material chloride diffusion coefficient and RCM methods measure is carried out
Comparison illustrates the multi-scale prediction model of the present invention to each scale cement-based material chloride diffusion coefficient forecasting reliability.
(4) it introduces and has freezing-thawing damage Chloride Diffusion Coefficient in Concrete prediction model, the freeze thawing that the present invention is established is damaged
Hinder regeneration concrete chloride diffusion coefficient prediction model, the prediction model of introducing, freezing-thawing damage regeneration concrete RCM methods chlorine from
Sub- diffusion coefficient test value compares and analyzes, and illustrates the superiority of model of the present invention.
(5) according to existing Forecast of concrete structural life theory, the regeneration coagulation of different service life requirements is solved
The chloride diffusion coefficient acquired is substituted into regeneration concrete multi-scale prediction model, must provided by the chloride diffusion coefficient of soil
The mix-design of body can provide reference for the regeneration concrete of actual engineering design difference durability demand.
It is described in detail and how to implement by the following examples.
Embodiment one predicts the chloride diffusion coefficient of different cement-based materials
In order to verify the reliability of multi-scale prediction model of the present invention, relevant raw materials are preselected, given correlation match ratio is set
Meter, each scale cement material chloride diffusion coefficient prediction model then established according to step 1 to step 4 calculate relevant
At the same time chloride diffusion coefficient prepares cement-based material according to selected raw material and match ratio, and carries out the quick chlorine of RCM
Ion diffusion test obtains chloride diffusion coefficient test value, and is compared with modelling value.
Correlation test raw material it is selected as follows：
Cement：P42.5 Portland cements, clinker chemical composition and mineral composition are as shown in table 1, cement density
For ρc=3.15g/cm3。
Fine aggregate：Natural river sand, grain size are 0.16~5.00mm, and fineness modulus 3.0, grade is associated with sand in IIth area；
Coarse aggregate：Limestone gravel, grain size are 16~20mm, and grain shape is close to square and spherical shape.
Regenerated coarse aggregate：Effective ratio of mud obtains to be sieved after 0.4 normal concrete jaw crushing crusher machine, and grain size is
16~20mm, grain shape is close to square and spherical shape.
The chemical composition of 1 clinker of table and mineral composition
Mix-design：
The material drafted is selected, Variable Parameters Design is carried out, for three kinds of cement paste, cement mortar, regeneration concrete water
Cement-based material, devises different match ratios, and specific mix-design is as shown in table 2:
2 each scale cement-base composite material material utilization amount of table
Chloride diffusion coefficient predictor calculation：
The flow of multi-scale prediction model construction of the present invention as shown in Figure 1, next coming in order from the cement paste mistake of small scale
The regeneration concrete to large scale is crossed, the chloride diffusion coefficient that each match ratio cement-based material is calculated according to prediction model value is set
Evaluation.
Fig. 2 is hardened cement net slurry micro-scale structures model schematic.It is predicted by cement paste chloride diffusion coefficient
Cement paste chloride diffusion coefficient known to modular form (50) is related with each volume parameter, and the calculation formula of each volume parameter is shown in formula
(51)~(56), in formula (51)~(56) known to the performance parameter of material ρc=3.15g/cm3, and have ρlCSH=1.44g/
cm3、ρhCSH=1.75g/cm3、p1、p2、p3、p4When taking 0.499,0.243,0.075,0.11 respectively according to table 1, formula (51)~
(each volume parameter is only related with ratio of mud n and age t in 56.Fig. 3 be when ratio of mud n is 0.5, it is various in cement paste
The relation curve that volume parameter changes with age t；Fig. 4 is when age t is 28 days, and various volume parameters are with water in cement paste
The relation curve of gray scale n variations.For the ease of follow-up test comparative analysis, when calculating each subitem volume fraction according to prediction model
It is 28 days uniformly to take curing age, and the prediction of the cement paste chloride diffusion coefficient under different mixture ratio is calculated by formula (50)
Design value DHCP, as shown in table 3.
3 hardened cement net slurry chloride diffusion coefficient predictor calculation of table
Fig. 5 is the meso-scale structural schematic diagram of new mortar.The chlorion of new mortar expands known to prediction model formula (57)
Dissipate coefficient DNMWith the volume fraction V of fine aggregateAAnd the body of the interfacial transition zone (ITZ) between fine aggregate and hardened cement paste
Fraction VITZIt is related, when the ratio of mud is 0.5, VAD when taking definite value 0.3,0.42,0.5 respectivelyNMWith VITZThe relationship of variation such as Fig. 6
It is shown.As setting VA=0.42, VITZWhen=0.0991, D can be calculated by formula (59)ITZValue, then D that table 1 is calculatedHCP
And the parameter value of setting substitutes into formula (57) and new mortar chloride diffusion coefficient predicted value D is calculatedNM, correlation calculation result is shown in Table
4。
4 new mortar chloride diffusion coefficient predictor calculation of table
Fig. 7 is the meso-scale structural schematic diagram of regeneration concrete.Coagulation is regenerated known to prediction model formula (60)-(65)
The chloride diffusion coefficient D of soilRCWith the volume fraction φ of original natural coarse aggregateOA, the volume fraction φ of old ITZOITZ, old mortar
Volume fraction φOM, the volume fraction φ of new ITZNITZ, the volume fraction φ of new mortarNMIt is related.Fig. 8 is volume fraction φOM,
φOITZ,φOA,φNMWith the volume fraction φ of recycled aggregateRCAThe relation curve of variation.Each subitem can be calculated by formula (60)-(65)
The chloride diffusion coefficient D of parameter and regeneration concreteRC, specific result of calculation is shown in Table 5.
5 regeneration concrete chloride diffusion coefficient predictor calculation of table
The chloride diffusion coefficient D of freezing-thawing damage regeneration concrete known to prediction model (67), (68)FRCWith with freeze thawing
Injury tolerance k1It is related, as size (thickness) timing for test specimen, k1It is only related to freezing-thawing cycles n.The ratio of mud is 0.5 again
When growing concrete damages under Frozen-thawed cycled effect, chloride diffusion coefficient model prediction design value is as shown in table 6.
6 freezing-thawing damage regeneration concrete chloride diffusion coefficient predictor calculation of table
The quick chlorine ion binding capacity experiments of cement-based material RCM：
In order to verify the reliability that the present invention designs a model, according to optional test material and mix-design, prepare each
The cement-based material of scale, and the quick chlorine ion binding capacity experiment of RCM methods is carried out, measure the chlorine ion binding capacity of corresponding cement-based material
Ratio test value compares itself and modelling value, and analysis model predicts error, illustrates foundation of the present invention on this basis
Multi-scale prediction model, can be used for designing the regeneration concrete for preparing different life requirements, be the resistance to of regeneration concrete
Long Journal of Sex Research provides new reference.
Test specimen makes.Machine is stirred using HJW-60 forced action type list horizontal axis concrete to be stirred cement-base composite material, it will
The mixture that stirring is completed is packed into the cylindrical pvc pipe that size is Φ 100mm × 250mm, and every group of match ratio makes 6 standards
Test specimen is vibrated on shocking platform to the closely knit molding of test specimen, is covered preservative film in port after specimen molding and is moved to standard curing room
Maintenance, which is immersed in afterwards for 24 hours in the pond of fog room, continues maintenance to 28d, will be tried using stonecutter when reaching before testing age 7 days
Part cuts into a diameter of (100 ± 1) mm, the highly cylinder test specimen for (50 ± 2) mm, with sand paper polishing light after taking test specimen to process
Sliding, test specimen (see Fig. 9) after processing is completed continues curing in water to age is tested, in order to study inside concrete freezing-thawing damage
Influence to its chloride diffusion coefficient, every group of match ratio take point three groups of carry out Frozen-thawed cycled processing of 9 cylinder test specimens, every group
Freezing-thawing cycles are followed successively by 10,25,50 times.
The quick chlorine ion binding capacity experiment of RCM methods.The quick chloride permeability test basis GBT50082- of RCM methods carried out
2009 《Normal concrete long-term behaviour and durability performance test method standard》It carries out, method chlorion suitable for measuring
Unstable state transport coefficient in cement-base composite material.Cement-based material per group # takes 3 cylinder test specimens to test it
Chloride diffusion coefficient, however take the average value of 3 experimental test values as the chloride diffusion coefficient of this group of cement-based material,
Experimental test result is shown in Table 7.
Test value and predicted value comparative analysis：
In order to illustrate the reliability of prediction model of the present invention, by the model prediction of each cement-based material chloride diffusion coefficient
Value, is compared, model predication value and test value comparing result are as shown in table 7 with RCM method measured values.
7 different scale cement-based material model predication value of table and test value comparing result
The predicted value and test value of comparative analysis C0.4, C0.5, C0.6 can be found that hardened cement paste chlorion in table 7
Diffusion coefficient prediction result and experiment degree of agreement are preferable, and deviation maximum value is only 5.16%, minimum value 3.28%, illustrates this
The hardened cement paste chloride diffusion coefficient prediction technique that invention proposes is effective.
The cement bonded sand that can illustrate to be prepared according to prediction model design by tri- groups of correction datas of M0.4, M0.5, M0.6 in table 7
The maximum deviation of the predicted value and test value of starching its chloride diffusion coefficient is no more than 7%, it is contemplated that the prediction deviation of new mortar
Further comprise the prediction deviation of hardened cement paste, although so the deviation is big compared with the deviation of cement slurry, the value according to
It is old in the reasonable scope, illustrate that new mortar chloride diffusion coefficient multi-scale prediction method proposed by the present invention is effective.
RC0.4, RC 0.5, RC 0.6 respectively represent the regeneration concrete of three kinds of different mixture ratios design in table 7, from its its
Correction data can be found that the maximum deviation of regeneration concrete chloride diffusion coefficient predicted value and its test value is 8.63%.It examines
The prediction deviation for considering regeneration concrete chloride diffusion coefficient had not only contained the prediction deviation of hardened cement paste but also had contained
The prediction deviation of new mortar, and the factors such as discreteness due to regeneration concrete itself bigger and test error, so even if should
Prediction deviation value be more than hardened cement paste prediction deviation, be also acceptable, regeneration concrete chlorine proposed by the present invention from
Sub- diffusion coefficient multi-scale prediction model is similarly effective.The offset relation of predicted value and test value is as shown in Figure 9.
By the comparing result of last three groups of data in table 7 it is found that being regenerated by the freezing-thawing damage that prediction model is calculated mixed
The deviation of solidifying soil chloride diffusion coefficient predicted value and its test value is maintained within 10%, the prediction deviation with regeneration concrete
Value is closer to, and illustrates freezing-thawing damage regeneration concrete chloride diffusion coefficient prediction proposed by the present invention no more than 10% deviation
Model remains reliable.
Have model formation and prediction model comparative analysis of the present invention：
In order to illustrate the superiority of model prediction of the present invention, it is further introduced into existing freezing-thawing damage concrete chloride ion diffusion
Coefficient prediction model is compared.The Sun Congtao of the Institute of Oceanology of the Chinese Academy of Sciences analyze freezing-thawing damage to chlorine in concrete from
The influence of son distribution and diffusion coefficient, and injury tolerance concept is introduced, establish chlorine in the concrete for considering freezing-thawing damage influence
The factor of the considerations of ionic diffusion coefficient attenuation model, the model is similar with prediction model of the present invention, can as contrast model,
Shown in the freezing-thawing damage Chloride Diffusion Coefficient in Concrete attenuation model such as formula (69) that Sun Congtao is established.
In formula Chinese style:DFThe chloride diffusion coefficient of concrete after being acted on for Frozen-thawed cycled；DF0For not by Frozen-thawed cycled
The chloride diffusion coefficient of action concrete；N is freezing-thawing cycles.
For regeneration concrete, for the ease of comparative analysis, D in formula (69)F0Value be prediction model of the present invention calculate
Chloride diffusion coefficient when obtained regeneration concrete is without by freeze thawing ringing takes D when the ratio of mud is 0.5F0=
12.89×10-12m2/ s, this up-to-date style (69) can be rewritten as：
For freezing-thawing damage regeneration concrete chloride diffusion coefficient prediction model of the present invention, formula (67), (68) Zhong Dangshui
Gray scale is 0.5 (DRC=12.89 × 10-12m2/ s), when specimen thickness d=50mm, formula (67) formula is reduced to：
DFRC=136.15-123.26 (1+97.656 (1-41666.66e-0.0159n+0.0000240+41666.66e-0.0159n
)5)-1 (71)
Formula (70), (71) indicate that grandson's freezing-thawing damage from great waves model and multi-scale prediction model of the present invention regenerates coagulation respectively
The relationship that native chloride diffusion coefficient changes with freezing-thawing cycles, physical relationship curve is as shown in Figure 10, distinguishes in Fig. 10
The chloride diffusion coefficient RCM method measured values after regeneration concrete Frozen-thawed cycled 10 times, 25 times, 50 times are added, by score
It can be found that prediction model of the present invention and measured value degree of agreement are higher, grandson then occurs larger inclined from great waves model and measured value for analysis
Difference, and it is bigger with freezing-thawing cycles increase deviation, illustrate model of the present invention in prediction freezing-thawing damage regeneration concrete chlorion
More superiority when diffusion coefficient.
Embodiment two designs the regeneration concrete of different service lives
Prediction model of the present invention can be the regeneration concrete for instructing practice of engineering design different service lives to require.According to
Existing Forecast of concrete structural life is theoretical, in conjunction with prediction model of the present invention, it is established that regeneration concrete chlorine ion binding capacity system
The relationship that number changes over time solves the chloride diffusion coefficient for the regeneration concrete that different service lives requires, will acquire
Chloride diffusion coefficient substitute into regeneration concrete multi-scale prediction model of the present invention, obtain specific mix-design, can be with
Regeneration concrete for actual engineering design difference durability demand provides reference.
Yang Lvfeng etc. considers that age attenuation coefficient, the concrete chloride ion of foundation corrode according to the second diffusion laws of fick
Life prediction formula is：
It can be with the limiting expression formula of the chloride diffusion coefficient of concrete by formula (72)：
In formula (72), (73), T is design life；D0It is concrete in t0The chlorine ion binding capacity system at (initial) moment
Number, referred to as initial propagations coefficient, the concrete sample that 28d ages are measured by RCM methods obtain；N decays for diffusion coefficient age
Coefficient is generally taken as 0.3 for non-mineral admixture concrete；D is protective layer thickness；csIt is dense for the surface chlorion of concrete
Degree；c0For initial chlorine ion concentration；crFor the criticality chlorine ion concentration of removing blunt of reinforcing steel bar；erf-1() is the inverse letter of error function
Number.
C can be obtained after the bar in chlorine salt solution function grade of known concrete structures、c0、crAnd the design parameter of d, if
Given design service life T again can calculate different designs service life, different villaumites when taking n=0.3 according to formula (73)
The first diffusion chloride diffusion coefficient limit value of concrete under environmental activity grade is more further combined with regeneration concrete of the present invention
Scale prediction model, mix-design and the preparation of the concrete which can require for different service lives provide quantization according to
According to.
The c obtained according to the relevant regulations of durability specification and guides、c0、cr, the design parameters such as d it is as shown in table 8.
Design parameter under 8 varying environment function grade of table and design life
When design period being respectively 30 years, 50 years, 100 years, in different environmental activity grades, can be counted by formula (73)
It calculates and obtains the limit value of each horizontal lower initial chloride diffusion coefficient of concrete, as shown in table 9.
The limit value of the initial chloride diffusion coefficient D0 of 9 concrete of table
Below in conjunction with prediction model of the present invention, it is III-C to choose environment function grade in table 9, and design life is 30 years
The initial chloride diffusion coefficient limit value of concrete structure calculate the match ratio of regeneration concrete met the requirements.
Regeneration concrete chloride diffusion coefficient increases with the increase of RCA volume fractions and water-cement ratio, it is contemplated that low water
Glue than it is too low when, the working performance of concrete is difficult to meet the requirements, therefore in order to prepare high-durability (low chlorine is from diffusion coefficient)
Regeneration concrete, first consider reduce regeneration concrete in recycled aggregate volume fraction, if taking φRCA=10%, by formula
(66) each volume fraction φ is calculatedOA、φOITZ、φOM、φNITZ、φNMNumerical value it is as shown in table 10, if recycled aggregate select
Grain size is the simple grain diameter aggregate of 10-15mm, and recycled aggregate source is identical with case one, when water-cement ratio is 0.38, if regeneration
Concrete by related prediction model of the present invention without that by freeze thawing ringing, then can be further calculated and obtain each subitem chlorion
Diffusion coefficient DOITZ、DOM、DNITZ、DNMNumerical value it is as shown in table 10, by the evaluation of each volume fraction and each chlorine ion binding capacity
It is D that factor v, which substitutes into formula (60) and the chloride diffusion coefficient of regeneration concrete can be calculated,RC=5.98 × 10-12m2/s≤
6.1×10-12m2/ s, it is III-C which, which meets environmental activity grade, is designed with initial to concrete chloride ion when being limited in year 30 years
The requirement of diffusion coefficient limit value can assume that design mixture proportion, specific mix-design are as shown in table 11 by correlation.More than if
The D obtained is assumed in designRCMore than defined limit value, then water-cement ratio and recycled aggregate volume fraction are adjusted according to predictor formula, directly
To DRCLess than defined limit value.
The result of calculation of each relevant parameter in 10 prediction model of table
11 environmental activity grade of table is III-C, the mixture ratio design of recycled aggregate concrete that design life is 30 years
To sum up, the chloride diffusion coefficient predicted value that prediction model of the present invention is calculated is with RCM methods measured value and
There is model predication value to be compared, model predication value of the present invention is good with the test value goodness of fit, illustrates the excellent of model of the present invention
Property.At the same time, according to the prediction model established, in conjunction with according to life prediction theory, it is contemplated that Practical Project is to concrete
The regeneration coagulation for meeting different service lives requirements can be calculated in the different demands of durability, preselected portions model parameter
The specific match ratio of soil.Therefore, one aspect of the present invention can be selected according to associated materials and mix-design is predicted again well
Growing concrete chloride diffusion coefficient, the regeneration concrete being had excellent performance for design resisting chloride ion penetration provide reference；It on the other hand can
To combine concrete life prediction theory, design meets different service lives and requires the regeneration concretes to be, regeneration concrete it is resistance to
Long Journal of Sex Research research provides new reference.In addition, model of the present invention can also further characterize regeneration concrete injury tolerance and its
Relationship schedule between chlorine ion binding capacity is conducive to the chloride-penetration resistance research for promoting freezing-thawing damage regeneration concrete.
In short, the present invention considers multiphase, the multiple dimensioned characteristic of concrete material, the damage that Frozen-thawed cycled generates then is considered
Hinder influence to regeneration concrete chloride diffusion coefficient, each Correlative Influence Factors of analysis that can be careful preselect associated materials,
It carries out mix-design and the regeneration concrete of different life requirements is accurately prepared according to actual requirement of engineering, and
The accurately relationship schedule between characterization regeneration concrete freezing-thawing damage and its chlorine ion binding capacity, it is excellent to obtain durability
Good regeneration concrete, and study its anti-freezing property and new thinking is provided.
Claims (10)
1. a kind of construction method of freezing-thawing damage regeneration concrete chloride diffusion coefficient multi-scale prediction model, it is characterised in that
Regeneration concrete is considered as to the cement-base composite material being made of different scale material, is opened from the hardened cement paste of small scale
Begin, is gradually transitioned into the regeneration concrete of large scale, sets up the chloride diffusion coefficient of different scale cement-based material successively
Then prediction model considers influence of the freezing-thawing damage to its chlorine ion binding capacity inside regeneration concrete, finally establishes freezing-thawing damage
The chloride diffusion coefficient multi-scale prediction model of regeneration concrete.
2. construction method according to claim 1, it is characterised in that include the following steps：
<1>Establish cement paste chloride diffusion coefficient prediction model；
<2>Establish new mortar chloride diffusion coefficient prediction model；
<3>Establish regeneration concrete chloride diffusion coefficient multi-scale prediction model；
<4>Establish the chloride diffusion coefficient model of freezing-thawing damage regeneration concrete.
3. construction method according to claim 2, it is characterised in that Bu Zhou <1>It is carried out by following operation：
In conjunction with broad sense from Qia Fa and Moil-Tanaka methods, establishing hardened cement net slurry chloride diffusion coefficient prediction model is：
In formula (1), φ,Expression formula be：
In formula (2), DhCSHFor the diffusion coefficient of cement middle-high density C-S-H gel layers；DlCSHIt is solidifying for low-density C-S-H in cement
The diffusion coefficient of glue-line；VαThe volume fraction of total cement volume is accounted for for hardened cement paste middle-high density C-S-H gel layers；VβFor
The sum of the volume fraction of unhydrated cement granules and high density C-S-H gel layers in hardened cement paste；
Being mingled with model according to matrix-has DhCSHExpression formula be：
Wherein：
In formula (3)~(5),For by testing the chlorion being calculated with numerical value in high density C-S-H gel layers
Diffusion coefficient；VhCSHIt is CH, AF, highdensity C-S-H gel layers matrix respectively in high density C-S-H gel layers
Volume fraction；αh、βhFor intermediate variable；
The Mori-Tanaka methods being mingled with according to heterogeneous material have DlCSHExpression formula be：
Wherein：
ζ=Vcap(Dcap-D′lCSH) (11)
D ' in formula (6)~(11)lCSHAfter being uniformly mingled with for hydrolysis product of cement (such as CH, AF) and low-density C-S-H gel layer matrixes
EFFECTIVE MEDIUM layer effective diffusion cofficient；For by testing the chlorion being calculated with numerical value in low-density C-S-H
Diffusion coefficient in gel layer；Vcap、VlCSHIt is the C-S-H gel layer matrixes of CH, AF, pore, low-density respectively
Volume fraction in low-density C-S-H gel layers；DcapFor the effective diffusion cofficient of pore；αl、βl, x, ζ be intermediate variable；
The volume fraction of the various hydrated products of hardened cement paste is respectively VCH、VAF、VCSH(VlCSHAnd VhCSH), unhydrated water
The volume fraction of mud particle is VU, the volume fraction of pore is Vcap, then have：
VCH+VAF+VlCSH+VhCSH+VU+Vcap=1 (12)
And have：
V in formula (2)α、VβExpression formula be respectively：
Composite type (1)~(15), can be able to the cement paste chloride diffusion coefficient prediction model that each volume parameter is variable is：
In formula (16),DcapFor the measured value tested and numerical value is calculated；It is assumed that the quality of saturation cement slurry is
1g obtains the prediction model of each volume fraction in net slurry, is according to Portland cement chemical equation：
In formula (17)~(22), the initial ratio of mud of n- cement slurries；T- ages；ρc、ρlCSH、ρhCSHIt is the density of cement, low close
Density, the density of high density C-S-H gels for spending C-S-H gels, take ρlCSH=1.44g/cm3、ρhCSH=1.75g/cm3, ρcRoot
The cement material that factually border is selected measures；p1、p2、p3、p4-C3S、C2S、C3A、C4Mass fractions of the AF in clinker.
4. construction method according to claim 3, it is characterised in that：Diffusion of the chlorion in high density C-S-H gel layers
CoefficientDiffusion coefficient of the chlorion in low-density C-S-H gel layers
The effective diffusion cofficient D of porecapTake Dcap=2.03 × 10-9m2/ s, the density p of high density C-S-H gelshCSH=1.75g/
cm3, low-density C-S-H gels density plCSH=1.44g/cm3。
5. construction method according to claim 2, it is characterised in that Bu Zhou <2>It is carried out by following operation：
Predicted that establishing new mortar chloride diffusion coefficient prediction model is from being in harmony method using broad sense：
ξ in formula (23), ζ are intermediate variable, are had：
D in formula (24)HCPFor the chloride diffusion coefficient for the hardened cement paste that step 1 prediction obtains；DITZIt is thin in new mortar
The chloride diffusion coefficient of interfacial transition zone ITZ between aggregate and hardened cement paste；VAFor the body of fine aggregate in new mortar
Fraction；VITZFor the volume fraction of the interfacial transition zone ITZ in new mortar between fine aggregate and hardened cement paste, value model
It encloses for 5%-30%；
Wherein, using cement as the D of the new mortar of matrixITZExpression formula be：
DITZ=117.563DHCP·hITZ -0.8772 (25)
H in formula (25)ITZFor the thickness of new mortar median surface transition region.
6. construction method according to claim 5, it is characterised in that：The thickness h of new mortar median surface transition regionITZ
Take hITZ=25 μm.
7. construction method according to claim 2, it is characterised in that Bu Zhou <3>It is carried out by following operation：
Regard regeneration concrete simplification as multiple dimensioned composite sphere, according to porous material penetration theory, with reference to broad sense from being in harmony method
With Moil-Tanaka methods, the chloride diffusion coefficient multi-scale prediction model for obtaining regeneration concrete is：
In formula (26), DNMFor the chloride diffusion coefficient for the new mortar that step 2 prediction obtains；φ1For natural aggregate, old ITZ, old
The sum of the volume fraction of mortar, new ITZ, i.e. φ1=φOA+φOITZ+φOM+φNITZ；φNMFor the volume fraction of new mortar；D4
For the combination diffusion coefficient of recycled aggregate and new interface；
Recycled aggregate is embedded in new interface, D is obtained according to the effective diffusion cofficient calculation formula of composite sphere4Expression formula be：
In formula (27), DNITZFor the diffusion coefficient at new interface, calculating formula is shown in formula (28)；φ2For natural aggregate, old ITZ, old sand
The sum of volume fraction of slurry, i.e. φ2=φOA+φOITZ+φOM；φNITZThe volume fraction of new mortar in regeneration concrete；D3For again
The diffusion coefficient of raw aggregate；Remaining symbolic indication meaning is same as above；
DNITZ=117.563DNM·hNITZ -0.8772 (28)
In formula (28), hNITZFor the thickness of new interfacial transition zone in regeneration concrete；
D can be obtained according to the effective diffusion cofficient calculation formula of composite sphere3Expression formula be：
(29), D in formulaOMFor the diffusion coefficient of old mortar；φ3For original natural aggregate, the sum of the volume fraction of old ITZ, i.e. φ2
=φOA+φOITZ；φOMThe volume fraction of old mortar is adhered on recycled aggregate surface；D2For natural aggregate and the combination at old interface
Diffusion coefficient；Remaining symbolic indication meaning is same as above；
D can be obtained according to the effective diffusion cofficient calculation formula of composite sphere2Expression formula be：
In formula (30), DOITZFor the diffusion coefficient at old interface, calculating formula is shown in formula (31)；φOMFor old mortar in regeneration concrete
Volume fraction；φOITZThe volume fraction of old mortar；DOAFor the diffusion coefficient of natural aggregate；Remaining symbolic indication meaning is same as above；
DOITZ=117.563DOM·hOITZ -0.8772 (31)
In formula (31), hOITZFor the thickness of new interfacial transition zone in regeneration concrete；
In formula (26)~(30), φNITZValue range is 0.5%-2.0%, and the volume fraction of remaining each component is with recycled aggregate
Volume fraction φRCAAnd change, the correlation computations formula of each volume fraction is：
In formula (32), y is the volume fraction for adhering to old mortar in recycled aggregate, value range 30%-45%；Remaining symbol table
Signal justice is same as above.
8. construction method according to claim 7, it is characterised in that：The thickness of new interfacial transition zone in the regeneration concrete
Spend hNITZTake hNITZ=45 μm, the diffusion coefficient D of old mortarOMTake DOM=6.9DNM, the diffusion coefficient D of natural aggregateOATake DOA=
0.210-12m2/ s, the thickness h of new interfacial transition zone in regeneration concreteOITZTake hOITZ=55 μm, φNITZ0.75% is taken, regeneration
The volume fraction y for adhering to old mortar in aggregate is taken as 34.7%.
9. construction method according to claim 2, it is characterised in that Bu Zhou <4>It is carried out by following operation：
According to freezing-thawing damage theory, considers the correlation of chlorine ion binding capacity and freezing-thawing damage, establish freezing-thawing damage regeneration concrete
Chloride diffusion coefficient prediction model is：
In formula (33), DRCFor the chloride diffusion coefficient of regeneration concrete；For the chlorion after regeneration concrete freeze-thaw damage
Diffusion coefficient takesk1For freezing-thawing damage degree；k1Expression formula be：
Wherein, d is specimen thickness；N is freezing-thawing cycles.
10. application of the construction method described in claim 1 in terms of freezing-thawing damage mixture ratio design of recycled aggregate concrete, feature exist
It is mutually tied with concrete life prediction theory in by the chloride diffusion coefficient multi-scale prediction model of freezing-thawing damage regeneration concrete
It closes, obtains under varying environment service rating, meet the match ratio for the regeneration concrete that different service lives require.
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| CN110737967A (en) * | 2019-09-10 | 2020-01-31 | 上海交通大学 | concrete structure durability prediction method, system and terminal |
| CN111797519A (en) * | 2020-06-24 | 2020-10-20 | 河海大学 | GEM equation-based calculation method for depassivation time of concrete reinforcement |
| CN112949192A (en) * | 2021-03-05 | 2021-06-11 | 南京工程学院 | Concrete freeze-thaw life prediction method for deterministic resampling particle filtering |
| CN113049452A (en) * | 2021-04-15 | 2021-06-29 | 中国水利水电科学研究院 | Device and method for measuring and controlling diffusion range of cement-based grout in grouting of covering layer |
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| CN109472107A (en) * | 2018-11-23 | 2019-03-15 | 上海理工大学 | A method of establishing regeneration concrete damage ratio Evolution Model under freeze thawing |
| CN110568165A (en) * | 2019-07-30 | 2019-12-13 | 深圳大学 | Concrete mesoscopic chloride ion diffusion coefficient prediction method |
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| CN111797519B (en) * | 2020-06-24 | 2022-10-14 | 河海大学 | GEM equation-based calculation method for depassivation time of concrete reinforcement |
| CN112949192A (en) * | 2021-03-05 | 2021-06-11 | 南京工程学院 | Concrete freeze-thaw life prediction method for deterministic resampling particle filtering |
| CN112949192B (en) * | 2021-03-05 | 2023-08-11 | 南京工程学院 | Concrete freeze-thawing life prediction method for deterministic resampling particle filtering |
| CN113049452A (en) * | 2021-04-15 | 2021-06-29 | 中国水利水电科学研究院 | Device and method for measuring and controlling diffusion range of cement-based grout in grouting of covering layer |
| CN113049452B (en) * | 2021-04-15 | 2021-10-26 | 中国水利水电科学研究院 | Device and method for measuring and controlling diffusion range of cement-based grout in grouting of covering layer |
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