CN110256016A - A kind of calculation method applied to water conservancy project concrete hydrating temperature rise value under adiabatic condition - Google Patents
A kind of calculation method applied to water conservancy project concrete hydrating temperature rise value under adiabatic condition Download PDFInfo
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
- C04B28/02—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
- C04B28/04—Portland cements
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- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D11/00—Control of flow ratio
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/00034—Physico-chemical characteristics of the mixtures
- C04B2111/00198—Characterisation or quantities of the compositions or their ingredients expressed as mathematical formulae or equations
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Abstract
The present invention provides a kind of calculation method of aquation temperature rise value under the adiabatic condition applied to concrete for hydraulic structure, comprising the following specific steps step 1. calculates the usage ratio of each cement and admixture: according to the quality of cement and admixture each in unit volume concrete for hydraulic structure, calculating separately out the ratio A that i-th kind of cement quality accounts for powder body material gross mass in unit volume concrete for hydraulic structureci, jth kind admixture quality accounts for the ratio A of powder body material gross mass in unit volume concrete for hydraulic structureai: the maximum temperature rise value of step 2. calculating concrete for hydraulic structure: the temperature rise value of step 3. calculating concrete for hydraulic structure each age: this method has preferable precision, the influence of type of raw materials and characteristic, construction parameter, curing age to temperature rise situation under concrete for hydraulic structure adiabatic condition is comprehensively considered, and calculating process is simple and convenient, utilizing works promote and apply.
Description
Technical field
The present invention relates to hydraulic engineering fields, in particular to a kind of to be applied to water conservancy project concrete hydrating temperature rise under adiabatic condition
The calculation method of value.
Background technique
Concrete is most widely used construction material in the world today, and within following predictable a period of time,
There has been no the status that other any materials can replace concrete.The hydraulic structure especially reservoir built using concrete is big
Dam has that structural strength height, good integrity, endurance be strong, each position cloth, it can be achieved that the functions such as dam crest overflow, dam body aperture
It sets the advantages that compact, thus has received widespread attention, form such as normality concrete gravity dam, RCC dam, panel
A series of dam types abundant such as concrete rock-fill dams.With the fields such as industrial premises, residential houses, highway bridge, construction manufacture
It is required that different, hydraulic engineering is usually large-scale, and the influence to people's life and property safety, social stability and economic development is all
It is larger therefore higher to the quality requirement of concrete, such as the quality of concrete raw material, the quality of construction casting, maintenance heat preservation
Quality etc., while having higher requirement to the military service performance and endurance of concrete, but to the intensity and mechanics of concrete
Performance requirement is not generally high, if the intensity of dam concrete is generally in C20, C25 and C30 or so, forms former material system, prepares
Method and performance characteristics etc. are compared with the discrepant concrete for hydraulic structure of other field.
Concrete for hydraulic structure generally faces climate control issues, this is related with the self attributes of concrete material.Concrete exists
It condenses in hardening process and is discharged with a large amount of heat, and the non-conductor as heat, a large amount of heat can not be evacuated timely
So that inside concrete generates biggish temperature stress, so that the anti-cracking ability to structure impacts, this point is in the big scale of construction
Concrete for hydraulic structure construction in it is more prominent.Therefore, temperature control is an important difficult point of concrete for hydraulic structure, since temperature control is asked
Concrete for hydraulic structure destruction can be found everywhere caused by topic, such as the dam Norris that Tenn flow management office, the U.S. builds, Russia
Dams, China's Danjiangkou Dam such as Gu Maji, Ma Makang, Bu Hetuoming, Bradley thatch gram all once there is extremely serious temperature
Crack.Therefore, the climate control issues for improving concrete for hydraulic structure using appropriate action are significant.
The measure of common control concrete for hydraulic structure temperature specifically include that reduce concrete for hydraulic structure pour placement temperature,
It adds mineral admixture and reduces the dosage of cement, uses the lower moderate-heat portland cement of thermal discharge or low-heat silicate water instead
Mud, later period water flowing cooling etc., wherein the placement temperature for reducing concrete for hydraulic structure is needed to raw material such as sandstone aggregate, mixing waters
Cooling processing is carried out, but the rise of temperature easily occurs in subsequent mix, transportational process；Adding mineral admixture can be reduced
The dosage of cement has preferable economic benefit and ecological benefits, and can improve the subsequent endurance quality of concrete for hydraulic structure, but lead
It is complicated to cause concrete mixing production line, and by the present of the factors such as region, haul distance, type, quality and the deliverability of admixture
Difference is larger；Using the lower moderate-heat portland cement of thermal discharge and low-heat portland cement water conservancy project coagulation can be reduced from source
The thermal discharge of soil, but the price of moderate-heat portland cement and low-heat portland cement is generally higher, but qualification constraint, market need
Ask, production and supply it is all smaller, therefore cement manufacturer production it is less and generally require customization supply；Later period leads to the method for cooling water
It needs in hydraulic engineering construction phase pre-buried water pipe, and cement injection net slurry is filled after cooling, this is to water conservancy project coagulation
The pouring construction and globality of soil will cause certain influence, but the later period leads to the method effect of cooling water obviously, intuitively, and can
It is adjusted to by the rate of temperature.
Later period leads to cooling water and cools down to concrete for hydraulic structure, controls the rate of cooling and selects the suitable water flowing time non-
Often important, key is accurately estimating to concrete for hydraulic structure temperature rise situation.The problem is not solved, numerous scholars are from different
Angle propose prediction concrete for hydraulic structure temperature rise situation method, as patent CN201520671659.X,
CN201420035766.9, CN200920205914.6, CN200920096110.7 etc. disclose Adiabatic temperature rise of concrete situation
Test and measuring device；The open coagulation such as CN201810826374.7, CN201410245084.5, CN201410086731.2
The inverting and calculation method of native adiabatic temperature rise；CN200910232705.5 disclose it is a kind of can be used for concrete cooling cooling lead
Flow fluid；Zhan Shulin has studied the influence of flyash, slag admixture to Adiabatic temperature rise of concrete and exothermic peak time of occurrence；
Zou Chuanxue etc. studies the distribution situation of internal temperature field under the conditions of concrete heat isolation, and related to the development of concrete strength foundation
Relationship；Li Xiaofang etc. establishes the prediction model of concrete temperature rise using the method for grey neural network prediction；Wang Chong etc. is from original
The angle of material is set out, and the influence of cement type and fineness to concrete temperature rise is had studied；He Jinren is done using simulation calculation
Method systematically has studied temperature field and the creep stress field of grinding coagulation soil from theory and practice；Zhao Zhong etc. is described in detail
Water flowing cooling parameter develops to Xiaowan Hydropower Station dam concrete later strength and the influence of endurance quality.The studies above is from difference
Angle inquired into prediction technique, measuring technique, cooling technique of concrete temperature rise etc., but in the prediction of concrete for hydraulic structure temperature rise
Aspect still has deficiency, in particular with a large amount of uses and cement type diversification of admixture, concrete for hydraulic structure temperature prediction
Deviation it is increasing, cause the determination of water flowing cooling system in practice, the selection on opportunity, the control of water temperature more and more difficult,
So that the system complexity of water flowing cooling means, technical costs are all continuously improved.
Summary of the invention
In order to overcome drawbacks described above, the present invention provides the meters for being applied to water conservancy project concrete hydrating temperature rise value under adiabatic condition
Calculation method can preferably calculate the temperature rise situation containing different cement types, the concrete for hydraulic structure of different admixtures,
To be conducive to the selection of concrete for hydraulic structure temperature control measures and the determination of temperature control system.
Technical solution of the present invention:
A kind of calculation method applied to water conservancy project concrete hydrating temperature rise value under adiabatic condition, this method include in detail below
Step:
Step 1. calculates the usage ratio of each cement and admixture:
According to the quality of cement and admixture each in unit volume concrete for hydraulic structure, i-th kind of cement quality is calculated separately out
Account for the ratio A of powder body material gross mass in unit volume concrete for hydraulic structureci, it is mixed that jth kind admixture quality accounts for unit volume water conservancy project
The ratio A of powder body material gross mass in solidifying soilai:
A in formula (1) and (2)ciPowder body material gross mass in unit volume concrete for hydraulic structure is accounted for for i-th kind of cement quality
Ratio；AajThe ratio of powder body material gross mass in unit volume concrete for hydraulic structure is accounted for for jth kind admixture quality；MciIt is i-th kind
Dosage of the cement in unit volume concrete for hydraulic structure；MajFor dosage of the jth kind admixture in unit volume concrete for hydraulic structure；
I=1~n, j=1~m, m and n are the positive integer more than or equal to 1；
The maximum temperature rise value of step 2. calculating concrete for hydraulic structure:
It is total that the quality of the various cement and admixture that are obtained according to step 1 accounts for powder body material in unit volume concrete for hydraulic structure
The ratio of quality calculates the maximum temperature rise value of concrete under adiabatic conditions:
K in formula (3)ciFor the conversion coefficient of i-th kind of cement；kajFor the conversion coefficient of jth kind admixture；QcemOn the basis of
Thermal discharge when the complete aquation of cement, Qcem=375kJ/kg；TporThe temperature put in storage is poured for concrete for hydraulic structure；ρconFor water conservancy project
The density of concrete, TmaxFor the maximum temperature rise value of concrete for hydraulic structure aquation under adiabatic condition；CconFor the ratio of concrete for hydraulic structure
Thermal capacitance；aciFor the conversion coefficient of cement type；
The temperature rise value of step 3. calculating concrete for hydraulic structure each age:
The maximum temperature rise value of aquation under the concrete for hydraulic structure adiabatic condition obtained according to step 2 calculates concrete for hydraulic structure and exists
The temperature rise situation of each age under adiabatic condition:
T in formula (4) and (5)ageFor temperature rise value of the concrete for hydraulic structure under adiabatic condition after the aquation t time；A is amendment
Coefficient；T is the hydration time of concrete；M is correction factor related with concrete for hydraulic structure pouring temperature；E is natural number, e=
2.718。
Cement type includes: ordinary portland cement, moderate-heat portland cement and low-heat silicate water in the step 1
Mud；Admixture kind includes: flyash, slag, mountain flour.
Reference cement described in the step 2 is the ordinary portland cement that strength grade is 42.5.
The conversion coefficient k of cement described in the step 2ciIt is related with the strength grade of cement:
P is the strength grade of cement, respectively 32.5,42.5 and 52.5 in formula (6).
The conversion coefficient a of cement type described in the step 2ciIt is related with the kind of cement, silicate cement
Correction factor is 1.00, and the correction factor of moderate heat cement is 0.85, and the correction factor of low-heat cement is 0.79.
The conversion coefficient k of admixture described in the step 2aiIt is related with the activity index of admixture:
H is the 28d age activity index of admixture in formula (6), as activity index H < 0.7, shows admixture to mixed
The aquation for coagulating soil has retardation；When activity index H=0.7, shows that admixture is inert filler, do not have hydration activity；
As activity index H > 0.7, show that admixture can participate in the aquation of concrete, and is accompanied by exothermic effect in hydration process；
fcaFor the concrete for hydraulic structure 28d age compression strength containing 30% admixture；fcFor the concrete for hydraulic structure 28d age without admixture
Compression strength.
Correction factor M related with pouring temperature in the step 3 is calculated as follows:
Compared with prior art, the beneficial effects of the present invention are: (1) the application has fully considered admixture type and dosage
Influence to aquation temperature rise value under concrete for hydraulic structure adiabatic condition.In concrete for hydraulic structure common admixture be mainly flyash,
Slag and mountain flour, wherein flyash and slag can participate in the aquation of concrete, and the reaction product of formation is strong to later concrete
The growth of degree and the raising of durability are advantageous, and mountain flour cannot participate in the aquation of concrete, can only play the effect of filling, right
It is advantageous but unfavorable to concrete strength growth and the raising of durability to reduce cement consumption, the cost of reduction concrete.It is limited to
Flyash, the chemical component of slag, physical property, respond are all different from concrete, and can be with coagulation after the two incorporation
The aquation of soil influences each other, and whole hydration heat is caused to happen variation.Meanwhile fineness, the chemical component of mountain flour
The performance that will affect its Nucleation during concrete hydrating, dissolution and precipitating to concrete hydrating early stage ion
It impacts, and then whole hydration heat is caused to happen variation.Although in prior art to flyash, slag and
Mountain flour incorporation after concrete hydration heat situation changing rule and amplitude considered, but be normally based on chemical component,
The parameters such as fineness construct calculation method, and not only calculating process is complex, and the difficulty that engineer application is promoted is larger, such as " full dose type
Expression formula ", " incremental expression formula ", " three parameter hyperbola formula " etc., and effect is calculated by the admixture place of production, source, preparation
The factors such as technique are affected, and the application overcomes these problems, are directly modified, are made according to the living features of admixture
It obtains and the calculating error of concrete temperature rise is can be controlled within 8.3%.
(2) the application has fully considered influence of the cement type to temperature rise situation under concrete for hydraulic structure adiabatic condition.Cement
Meeting water reaction can discharge with a large amount of heat, and the exothermic phenomenon in cement and water reaction process is to lead to concrete heat isolation temperature
The main reason for rising.The size of hydrated cementitious thermal discharge and chemical component, grain fineness, crystallization degree, mineral phase composition etc. have
Much relations；The chemical reaction energy barrier of variety classes cement, ion-solubility rate difference are larger, and the hydration rate of cement is caused to produce
Raw very big difference, and then the hydration heat characteristic of concrete entirety is impacted.Therefore, accurate evaluation cement is exhausted in concrete
Status in hot temperature rise is extremely important.Due to the coagulating hardening performance of different cement, later strength development and the energy of resistance to environmental disruption
Power difference is larger, be used in combination a plurality of types of cement can realize to concrete coagulating time, gain in strength, endurance quality tune
Whole and raising, while there is also mutual effects between different type cement, this leads to the accurate description in composite system
Influence of the cement to Adiabatic temperature rise of concrete is relatively difficult, and so Piao etc. has found the rate of heat release of cement itself to concrete totality
Adiabatic temperature rise also have a significant impact, Yang Jin etc. then thinks cement type to the temperature rise and temperature under the conditions of mortar and concrete heat isolation
Raising speed rate all has an impact.However, existing method is less from the aspect of temperature rise under the conditions of cement type is on concrete heat isolation influences,
Lack the report of temperature rise situation under the conditions of concrete heat isolation when for the effect of different type cementitious composite.The application combination water conservancy work
The actual conditions of Cheng Jianshe have fully considered cement type, volume and strength grade to temperature rise situation under the conditions of concrete heat isolation
Influence, and do not pay attention on these influences in existing report.The application is counted mainly for silicate cement
It calculates, the calculation formula and related coefficient of disclosure can have preferable effect to commercially available cement under 95% fraction.
(3) the application has fully considered influence of the environment temperature to temperature rise situation under the conditions of concrete heat isolation.Zhu Baifang institute
Scholar once pointed out " rate of change of temperature value and the temperature of concrete are related under the conditions of concrete heat isolation, and the temperature of concrete is higher,
Temperature rate-of-rise is bigger, but not in a linear relationship between the two, and existing Adiabatic temperature rise of concrete calculation formula is not
It pays attention to this, causes its computational accuracy poor ".In view of this, to ring by the way of correction factor in the calculation method of part
The influence of border temperature is described, aquation dynamic method, Zhang Ziming such as Yao Wu et al. based on Tomosawa model et al. base
In the equivalent time model etc. of Arrhenius theory, but these calculation methods are related to multiple steps such as derivation, partial differential calculating,
Solution procedure complicated difficult is to promote and apply.The environment temperature being directed in the application is alternatively referred to as the placing temperature of concrete, puts in storage
Temperature, initial temperature etc., calculation method is simple and convenient.
Detailed description of the invention
Fig. 1 is flow chart of the method for the present invention.
Specific embodiment
Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, complete
Site preparation description, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.It is based on
Embodiment in the present invention, it is obtained by those of ordinary skill in the art without making creative efforts every other
Embodiment shall fall within the protection scope of the present invention.
The present invention provides a kind of technical solution:
A kind of calculation method applied to water conservancy project concrete hydrating temperature rise value under adiabatic condition, it is characterised in that this method can
To be realized by following steps:
Step 1. calculates the usage ratio of each cement and admixture
According to the quality of cement and admixture each in unit volume concrete for hydraulic structure, i-th kind of cement quality is calculated separately out
Account for the ratio A of powder body material gross mass in unit volume concrete for hydraulic structureci, it is mixed that jth kind admixture quality accounts for unit volume water conservancy project
The ratio A of powder body material gross mass in solidifying soilai:
A in formula (1) and (2)ciI-th kind of cement quality accounts for the ratio of powder body material gross mass in unit volume concrete for hydraulic structure
Example, %；AajJth kind admixture quality accounts for the ratio of powder body material gross mass in unit volume concrete for hydraulic structure, %；MciIt is i-th
Dosage of the kind cement in unit volume concrete for hydraulic structure, kg；MajIt is jth kind admixture in unit volume concrete for hydraulic structure
Dosage, kg.
The maximum temperature rise value of step 2. calculating concrete for hydraulic structure
It is total that the quality of the various cement and admixture that are obtained according to upper step accounts for powder body material in unit volume concrete for hydraulic structure
The ratio of quality calculates the maximum temperature rise value of concrete under adiabatic conditions:
K in formula (3)ciFor the conversion coefficient of i-th kind of cement；kajFor the conversion coefficient of jth kind admixture；QcemOn the basis of
Thermal discharge when the complete aquation of cement, Qcem=375kJ/kg；TporThe temperature put in storage is poured for concrete for hydraulic structure, DEG C；ρconFor water
The density of work concrete, kg/m3。TmaxFor the maximum temperature rise value of concrete for hydraulic structure aquation under adiabatic condition, DEG C；Ccon is water
The specific heat capacity of work concrete, J/ (kg DEG C)；aciFor the conversion coefficient of cement type.
The density of concrete and raw material used have compared with Important Relations, and wherein the influence of aggregate is maximum.Hydraulic engineering construction
Main feature is exactly that material has region.It is limited to the limitation of the factors such as transportation range, material utilization amount, economic cost, water
Sharp engineering construction is often drawn materials nearby, causes the former material group phase-splitting difference of different engineering concrete larger, aggregate characteristics have larger difference
It is different, so that the density of concrete is in 2300-2400kg/m3Between.Engineer application and computational accuracy are considered, by concrete for hydraulic structure
Density is set to 2350kg/m3The calculating demand when fraction is not less than 95% can be met.
Specific heat capacity reaction is the case where concrete is risen by temperature after heat transfer effect.The thermal conduction characteristic of concrete with
The factors such as material component, pore size distribution and architectural characteristic, saturation state are related.In general, concrete for hydraulic structure former material component is more
Based on cement, admixture, sandstone aggregate, the material that can significantly affect concrete thermal characteristic mixed with other is less.Therefore,
Consider engineer application and computational accuracy, by the specific heat capacity of concrete for hydraulic structure be set to 0.96kJ/ (kgK) can meet fraction not
Calculating demand in the case of lower than 95%.
The temperature rise value of step 3. calculating concrete for hydraulic structure each age
The maximum temperature rise value of aquation under the concrete for hydraulic structure adiabatic condition obtained according to upper step calculates concrete for hydraulic structure exhausted
The temperature rise situation of each age in hot situation:
T in formula (4) and (5)ageFor temperature rise value of the concrete for hydraulic structure under adiabatic condition after the aquation t time, DEG C；A is to repair
Positive coefficient；T is the hydration time of concrete；M is correction factor related with concrete for hydraulic structure pouring temperature；E is natural number, e
=2.718.
Cement type includes: ordinary portland cement, moderate-heat portland cement and low-heat portland cement in step 1；It mixes
It include: flyash, slag, mountain flour with item kind.Ordinary portland cement, moderate-heat portland cement and low-heat portland cement are equal
For cement type common in concrete for hydraulic structure.Flyash, slag are as admixture using relatively wide, energy in concrete for hydraulic structure
The aquation of concrete for hydraulic structure is enough participated in, corresponding hydration activity has the military service performance and endurance that improve concrete for hydraulic structure
Benefit.Mountain flour is as inertia admixture, though the aquation of concrete for hydraulic structure cannot be participated in, has very much to the heat release for reducing concrete for hydraulic structure
Meaning.
According in claim 1 it is a kind of applied under adiabatic condition water conservancy project concrete hydrating temperature rise value calculate method,
It is characterized in that reference cement described in the step (2) is the ordinary portland cement that strength grade is 42.5, the production
Product are also to sell most, most widely used, the maximum cement type of usage amount currently on the market.
The conversion coefficient k of cement described in step 2ciIt is related with the strength grade of cement:
P is the strength grade of cement, respectively 32.5,42.5 and 52.5 in formula (6).The related rule of national cement products
Fan Zhong has done detailed regulation to strength grade, and strength of cement grade mentioned herein is consistent with the requirement in national regulation.
The conversion coefficient a of cement type described in step 2ciIt is related with the kind of cement, the amendment of silicate cement
Coefficient is 1.00, and the correction factor of moderate heat cement is 0.85, and the correction factor of low-heat cement is 0.79.Cement type correction factor
Determination, comprehensively considered mineral phase composition, the water of commercially available portland cement, moderate-heat portland cement and low-heat portland cement
The problems such as change feature and law of heat release, can make formula have preferable calculating effect in the case where fraction is 95%.
The conversion coefficient k of admixture described in step 2aiIt is related with the activity index of admixture,
H is the 28d age activity index of admixture in formula (6), as activity index H < 0.7, shows admixture to mixed
The aquation for coagulating soil has retardation；When activity index H=0.7, shows that admixture is inert filler, do not have hydration activity；
As activity index H > 0.7, show that admixture can participate in the aquation of concrete, and is accompanied by exothermic effect in hydration process；
fcaFor the concrete for hydraulic structure 28d age compression strength containing 30% admixture；fcFor the concrete for hydraulic structure 28d age without admixture
Compression strength.
In general, the activity index of admixture is according to the intensity containing admixture test group and without admixture test group
The ratio of intensity determines.Also become strength activity index according to the calculated activity index of Strength Changes situation.According to coagulation
Correlativity between native intensity and degree of hydration, activity index can intuitively reflect special to concrete hydrating after admixture is added
The influence of property.
Correction factor M related with pouring temperature described in the step 3 is calculated as follows:
Temperature has the hydration rate of concrete for hydraulic structure, gain in strength and largely influences, main reason is that improving
Temperature can increase the rate of dissolution of ion, promote the progress of chemical reaction.Therefore, it is mixed to will lead to water conservancy project for the difference of placing temperature
The solidifying soil time required when reaching identical degree of hydration changes.
Embodiment (1): the meter of temperature rise under High Altitude in West China severe cold area hydraulic engineering mass concrete adiabatic condition
It calculates and temperature control measures suggestion.Certain hydraulic engineering is located at China High Altitude in West China severe cold area, and the geological environment at engineered locations is multiple
Miscellaneous, climatic environment is severe, and concrete service environment is harsh, and winter severe cold is dry, and summer is windy and day and night temperature is larger, to dam
Concrete pour and conserve and temperature control measures propose higher requirement.
According to design, which mainly uses moderate-heat portland cement and flyash as cementitious material, folk prescription concrete
The dosage of middle cementitious material is 280kg/m3, used in cement type be moderate-heat portland cement, strength grade 42.5
Grade, the dosage in folk prescription concrete is 224kg/m3；Use the flyash that activity index is 83% as admixture, folk prescription coagulation
Dosage in soil is 56kg/m3.Corresponding cement accounts for the mass fraction A of powder body materialcIt is 80%, flyash accounts for powder body material
Mass fraction AaIt is 20%.
According to the cement type and strength grade of selection, corresponding cement type conversion coefficient acIt is 0.85, corresponding water
The conversion coefficient k of mudcIt is 0.0043.
According to the admixture type of selection and active situation, the conversion coefficient k of corresponding admixtureaIt is 0.43.
Pre-cooling measure is taken when cast-in-place concrete, the placing temperature of concrete is 21.2 DEG C, corresponding placing temperature
Correction factor m is -5.67 × 10-5, negative value illustrates that the placing temperature is unfavorable to the control of temperature rise under the conditions of concrete heat isolation.
According to above- mentioned information, can calculate the temperature rise of concrete used in the engineering under adiabatic conditions is 45.4 DEG C, is poured
The temperature rise situation of each age is as shown in Table 1 and Table 2 afterwards.
In 1 embodiment 1 of table under each age concrete for hydraulic structure adiabatic condition of certain Engineering Projects temperature rise situation calculated value
| Age/d | 0 | 1 | 2 | 3 | 5 | 7 |
| Temperature rise/DEG C | 21.2 | 36.7 | 42.2 | 35.8 | 31.3 | 28.1 |
In 2 embodiment 1 of table under each age concrete for hydraulic structure adiabatic condition of certain Engineering Projects temperature rise situation measured value
| Age/d | 0 | 1 | 2 | 3 | 5 | 7 |
| Temperature rise/DEG C | 21.2 | 37.2 | 41.3 | 37.1 | 33.4 | 28.9 |
The calculated value and measured value of concrete for hydraulic structure each age temperature rise situation under adiabatic conditions are respectively such as table 1 in the engineering
With shown in table 2.Since the maximum temperature rise of concrete for hydraulic structure under adiabatic conditions differs larger with placing temperature, it is proposed that take guarantor
Temperature, moisturizing means simultaneously add Temperature Control Measures.
Embodiment (2): the calculating of temperature rise under northwest cold and dry region hydraulic engineering mass concrete adiabatic condition
With temperature control measures suggestion.Certain hydraulic engineering is located at northwest China cold and dry region, concrete service environment winter at engineered locations
Ji Hanleng low temperature, summer windy drying, to dam concrete pour and conserve and temperature control measures propose higher requirement.
It is limited by former material supply, which mainly uses ordinary portland cement and slag as cementitious material, folk prescription
The dosage of cementitious material is 325kg/m in concrete3, used in cement type be ordinary portland cement, strength grade
It is 42.5 grades, the dosage in folk prescription concrete is 221kg/m3；Use the flyash that activity index is 89% as admixture, it is single
Dosage in square concrete is 74kg/m3.Corresponding cement accounts for the mass fraction A of powder body materialcIt is 75%, flyash accounts for powder
The mass fraction A of materialaIt is 25%.
According to the cement type and strength grade of selection, corresponding cement type conversion coefficient acIt is 1.00, corresponding water
The conversion coefficient k of mudcIt is 0.043.
According to the admixture type of selection and active situation, the conversion coefficient k of corresponding admixtureaIt is 0.63.
Pre-cooling measure is taken when cast-in-place concrete, the placing temperature of concrete is 18.4 DEG C, corresponding placing temperature
Correction factor m is 7.67 × 10-5, which is advantageous the control of temperature rise under the conditions of concrete heat isolation.
According to above- mentioned information, can calculate the temperature rise of concrete used in the engineering under adiabatic conditions is 47.2 DEG C, is poured
The temperature rise situation of each age is as shown in Table 3 and Table 4 afterwards.
In 3 embodiment 2 of table under each age concrete for hydraulic structure adiabatic condition of certain Engineering Projects temperature rise situation calculated value
| Age/d | 0 | 1 | 2 | 3 | 5 | 7 |
| Temperature rise/DEG C | 18.4 | 38.6 | 44.3 | 37.6 | 32.9 | 29.5 |
In 4 embodiment 2 of table under each age concrete for hydraulic structure adiabatic condition of certain Engineering Projects temperature rise situation measured value
| Age/d | 0 | 1 | 2 | 3 | 5 | 7 |
| Temperature rise/DEG C | 18.4 | 29.3 | 45.6 | 38.7 | 33.4 | 28.2 |
The calculated value and measured value of concrete for hydraulic structure each age temperature rise situation under adiabatic conditions are respectively such as table 3 in the engineering
With shown in table 4.Since the maximum temperature rise of concrete for hydraulic structure under adiabatic conditions differs larger with placing temperature, it is proposed that take guarantor
Temperature, moisturizing means and the control measure cooling using pre-buried water pipe early period, later period water flowing.
Embodiment (3): the calculating of temperature rise under certain hydraulic engineering mass concrete adiabatic condition of southeast high temperature and humidity area
With temperature control measures suggestion.Certain hydraulic engineering is located at China, high temperature and humidity area, the southeast, and concrete durability is wanted at engineered locations
Ask higher, but fight Frozen-thawed cycled damage capability require it is lower, and to dam concrete pour and conserve and temperature control measures
Propose higher requirement.
Since the region aggregate has certain basic active, which mainly uses low-heat portland cement and mountain flour conduct
Cementitious material, the dosage of cementitious material is 330kg/m in folk prescription concrete3, used in cement type be low-heat silicate
Cement, strength grade are 42.5 grades, and the dosage in folk prescription concrete is 231kg/m3；Use and does not have active mountain flour as mixing
And material, the dosage in folk prescription concrete are 99kg/m3.Corresponding cement accounts for the mass fraction A of powder body materialcIt is 70%, flyash
Account for the mass fraction A of powder body materialaIt is 30%.
According to the cement type and strength grade of selection, corresponding cement type conversion coefficient acIt is 0.79, corresponding water
The conversion coefficient k of mudcIt is 0.043.
According to the admixture type of selection and active situation, the conversion coefficient k of corresponding admixtureaIt is 0.
Pre-cooling measure is taken when cast-in-place concrete, the placing temperature of concrete is 23.6 DEG C, corresponding placing temperature
Correction factor m is -0.00017, illustrates that the placing temperature is unfavorable to the control of temperature rise under the conditions of concrete heat isolation, but passed through
The limitation for cost of helping, needs the later period to take Temperature Control Measures.
According to above- mentioned information, can calculate the temperature rise of concrete used in the engineering under adiabatic conditions is 48.3 DEG C, is poured
The temperature rise situation of each age is as shown in table 5 and table 6 afterwards.
In 5 embodiment 3 of table under each age concrete for hydraulic structure adiabatic condition of certain Engineering Projects temperature rise situation calculated value
| Age/d | 0 | 1 | 2 | 3 | 5 | 7 |
| Temperature rise/DEG C | 23.6 | 39.1 | 44.9 | 38.2 | 33.3 | 29.9 |
In 6 embodiment 3 of table under each age concrete for hydraulic structure adiabatic condition of certain Engineering Projects temperature rise situation measured value
| Age/d | 0 | 1 | 2 | 3 | 5 | 7 |
| Temperature rise/DEG C | 23.6 | 38.4 | 45.6 | 37.7 | 31.5 | 28.4 |
The calculated value and measured value of concrete for hydraulic structure each age temperature rise situation under adiabatic conditions are respectively such as table 3 in the engineering
With shown in table 4.Since the maximum temperature rise of concrete for hydraulic structure under adiabatic conditions differs larger with placing temperature, it is proposed that reinforce early period
The cooling control measure of pre-buried water pipe, later period water flowing.
It although an embodiment of the present invention has been shown and described, for the ordinary skill in the art, can be with
Understand without departing from the principles and spirit of the present invention can to these embodiments carry out it is a variety of variation,
Modification, replacement and variant, the scope of the present invention is defined by the appended.
Claims (7)
1. a kind of calculation method applied to water conservancy project concrete hydrating temperature rise value under adiabatic condition, which is characterized in that this method packet
Include step in detail below:
Step 1. calculates the usage ratio of each cement and admixture:
According to the quality of cement and admixture each in unit volume concrete for hydraulic structure, calculates separately out i-th kind of cement quality and account for list
The ratio A of powder body material gross mass in the volume concrete for hydraulic structure of positionci, jth kind admixture quality accounts for unit volume concrete for hydraulic structure
The ratio A of middle powder body material gross massai:
A in formula (1) and (2)ciThe ratio of powder body material gross mass in unit volume concrete for hydraulic structure is accounted for for i-th kind of cement quality
Example；AajThe ratio of powder body material gross mass in unit volume concrete for hydraulic structure is accounted for for jth kind admixture quality；MciFor i-th kind of water
Dosage of the mud in unit volume concrete for hydraulic structure；MajFor dosage of the jth kind admixture in unit volume concrete for hydraulic structure；i
=1~n, j=1~m, m and n are the positive integer more than or equal to 1；
The maximum temperature rise value of step 2. calculating concrete for hydraulic structure:
The quality of the various cement and admixture that are obtained according to step 1 accounts for powder body material gross mass in unit volume concrete for hydraulic structure
Ratio, calculate concrete maximum temperature rise value under adiabatic conditions:
K in formula (3)ciFor the conversion coefficient of i-th kind of cement；kajFor the conversion coefficient of jth kind admixture；QcemFor benchmark cement
Thermal discharge when complete aquation, Qcem=375kJ/kg；TporThe temperature put in storage is poured for concrete for hydraulic structure；ρconFor water conservancy project coagulation
The density of soil, TmaxFor the maximum temperature rise value of concrete for hydraulic structure aquation under adiabatic condition；CconFor the specific heat capacity of concrete for hydraulic structure；
aciFor the conversion coefficient of cement type；
The temperature rise value of step 3. calculating concrete for hydraulic structure each age:
The maximum temperature rise value of aquation under the concrete for hydraulic structure adiabatic condition obtained according to step 2 calculates concrete for hydraulic structure and is being insulated
In the case of each age temperature rise situation:
T in formula (4) and (5)ageFor temperature rise value of the concrete for hydraulic structure under adiabatic condition after the aquation t time；A is correction factor；
T is the hydration time of concrete；M is correction factor related with concrete for hydraulic structure pouring temperature；E is natural number, e=2.718.
2. a kind of calculation method applied to water conservancy project concrete hydrating temperature rise value under adiabatic condition according to claim 1,
It is characterized in that, cement type includes: ordinary portland cement, moderate-heat portland cement and low-heat silicate in the step 1
Cement；Admixture kind includes: flyash, slag, mountain flour.
3. a kind of calculation method applied to water conservancy project concrete hydrating temperature rise value under adiabatic condition according to claim 1,
It is characterized in that, reference cement described in the step 2 is the ordinary portland cement that strength grade is 42.5.
4. a kind of calculation method applied to water conservancy project concrete hydrating temperature rise value under adiabatic condition according to claim 1,
It is characterized in that, the conversion coefficient k of cement described in the step 2ciIt is related with the strength grade of cement:
P is the strength grade of cement, respectively 32.5,42.5 and 52.5 in formula (6).
5. a kind of calculation method applied to water conservancy project concrete hydrating temperature rise value under adiabatic condition according to claim 1,
It is characterized in that, the conversion coefficient a of cement type described in the step 2ciIt is related with the kind of cement, silicate cement
Correction factor be 1.00, the correction factor of moderate heat cement is 0.85, and the correction factor of low-heat cement is 0.79.
6. a kind of calculation method applied to water conservancy project concrete hydrating temperature rise value under adiabatic condition according to claim 1,
It is characterized in that, the conversion coefficient k of admixture described in the step 2aiIt is related with the activity index of admixture:
H is that the 28d age activity index of admixture shows admixture to concrete as activity index H < 0.7 in formula (6)
Aquation have retardation；When activity index H=0.7, shows that admixture is inert filler, do not have hydration activity；Work as work
When sex index H > 0.7, show that admixture can participate in the aquation of concrete, and is accompanied by exothermic effect in hydration process；fcaFor
Concrete for hydraulic structure 28d age compression strength containing 30% admixture；fcFor the concrete for hydraulic structure 28d age resistance to compression without admixture
Intensity.
7. a kind of calculation method applied to water conservancy project concrete hydrating temperature rise value under adiabatic condition according to claim 1,
It is characterized in that, the correction factor M related with pouring temperature in the step 3 is calculated as follows:
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