CN106777535B - Alkali-activated recycled concrete mix proportion design method and system - Google Patents

Abstract

The invention disclosesThe invention discloses a method and a system for designing the mixing proportion of alkali-activated recycled concrete, wherein the method comprises the following steps: determining the target compressive strength according to the performance requirements of an application scene, and selecting a corresponding alkali-cement ratio and a corresponding strength standard deviation; according to f_cu,0≥f_cu,k+1.645σ_kTo obtain f_cu,0A specific numerical value; obtaining corresponding regression coefficients and values of the compressive strength of the mortar 28d according to the alkali-cement ratio, and calculating to obtain the water-solid ratio according to the alkali-cement ratio, the trial strength, the regression coefficients and the compressive strength of the mortar 28 d; and calculating the content of each component by using a bone slurry mass ratio method according to the alkali-cement ratio, the water-solid ratio, the bone slurry mass ratio and the sand ratio. The invention has the beneficial effects that: the alkali-activated concrete using the recycled aggregate fully recycles waste resources, is beneficial to environmental protection, obtains a calculation model suitable for the alkali-activated recycled concrete through the water-solid ratio, calculates according to the actual mass relationship among the concrete components, and is more accurate in the obtained mixing ratio and wider in application range.

Description

Method and system for mix proportion design of alkali-stimulated recycled concrete

technical field

The invention relates to the field of concrete preparation, in particular to a method and a system for designing the mixing ratio of alkali-excited recycled concrete.

Background technique

Concrete is a general term for engineering composite materials in which aggregates are cemented into a whole by cementitious materials. The term concrete usually refers to cement concrete as cementing material, sand and stone as aggregate; it is mixed with water (may contain admixtures and admixtures) in a certain proportion, and the cement concrete obtained by stirring is also called ordinary concrete. Concrete, which is widely used in civil engineering. Recycled concrete means that after crushing, cleaning and grading waste concrete blocks, they are mixed with the gradation in a certain proportion, partially or completely replacing natural aggregates such as sand and gravel (mainly coarse aggregates), and then adding cement, water, etc. Made of new concrete. According to the combination of aggregates, recycled concrete can be in the following situations: all aggregates are recycled aggregates; coarse aggregates are recycled aggregates, and fine aggregates are natural sand; The raw material is regenerated aggregate; regenerated aggregate replaces part of coarse aggregate or fine aggregate.

With the continuous development of concrete technology, people's understanding of concrete as a building material is deepening, and the concept of considering sustainable development design concepts and the protection of ecological environment is deepening. However, due to the current large-scale application of traditional Portland cement, it not only consumes a large amount of natural resources, but also emits a large amount of gas during the preparation process and later use. According to the latest research, the cement industry alone produces 1.8Gt of emissions every year worldwide, accounting for about 5-7% of the total emissions from human production. The data shows that every ton of cement will produce 0.8t of emissions. Therefore, recycled concrete prepared from industrial waste residue and recycled aggregate from construction waste is of great significance. Recycled concrete means that after crushing, cleaning and grading waste concrete blocks, they are mixed with the gradation in a certain proportion, partially or completely replacing natural aggregates such as sand and gravel (mainly coarse aggregates), and then adding cement, water, etc. Made of new concrete. According to the combination of aggregates, recycled concrete can be in the following situations: all aggregates are recycled aggregates; coarse aggregates are recycled aggregates, and fine aggregates are natural sand; The raw material is regenerated aggregate; regenerated aggregate replaces part of coarse aggregate or fine aggregate. Compared with traditional Portland cement concrete, alkali-activated recycled concrete can not only effectively solve the problem of processing a large amount of construction waste, but also realize the recycling of waste to save natural resources and take into account ecological and environmental benefits. In addition, this kind of concrete uses alkali-excited cementitious materials to replace traditional cement cement materials, which can greatly reduce the carbon emissions caused by the use of cement cementitious materials in the process of concrete preparation, thus further embodying the idea of "green development".

So far, although scholars from all over the world have achieved many achievements in the research on alkali-excited concrete and proposed many mixing ratio design methods, reports on the preparation of alkali-excited concrete with completely recycled coarse aggregate instead of natural aggregate are still relatively rare. . The existing mix ratio design scheme has the problem of not taking into account the strength and durability of the final product, or simply setting the concrete density to a constant value to calculate the mix ratio. In addition, Obada Kayali pointed out that the most urgent task to promote the engineering application of alkali-induced concrete is to propose a suitable, simple and practical mix proportion design method.

SUMMARY OF THE INVENTION

The main purpose of the present invention is to provide a method and system for designing the mix ratio of alkali-excited recycled concrete, which is calculated according to the actual relationship between the various components of the concrete, has a wider application range, and obtains an accurate mix ratio.

The present invention provides a method for designing the mix proportion of alkali-excited recycled concrete, which includes the following steps:

According to the performance requirements of the application scenario, determine the target compressive strength f _cu,k of the target alkali-excited recycled concrete, and select the appropriate alkali-binder ratio A/B and strength standard deviation σ _k ;

According to f _cu,0 ≥f _cu,k +1.645σ _k , the specific value of f cu, ₀ is obtained, where f _cu,0 is the trial strength of alkali-excited recycled concrete;

According to the alkali-binder ratio A/B, the corresponding regression coefficients α _a , α _b and the 28d compressive strength f _b of the mortar are obtained, and then according to the alkali-binder ratio A/B, trial strength f _cu,0 , regression coefficient α _a , α _b and the 28d compressive strength f _b of the mortar, the water-solid ratio W/GPS is calculated;

The content of each component in the alkali-excited recycled concrete was calculated according to the alkali-binder ratio A/B, water-solid ratio W/GPS, pulp-bone mass ratio and sand ratio using the pulp-bone mass ratio method.

Further, before the steps of determining the target compressive strength f _cu,k of the alkali-excited recycled concrete according to the performance requirements of specific application scenarios, and selecting a suitable alkali-to-binder ratio A/B and strength standard deviation σ, the steps include:

计算得到碱激发再生混凝土不同的抗压强度f_cu对应的强度标准差σ，并将抗压强度f_cu数值和与其对应的强度标准差σ一一对应存储为标准差数据库。According to the formula

The strength standard deviation σ corresponding to different compressive strength f _cu of alkali-excited recycled concrete is calculated, and the compressive strength f _cu value and its corresponding strength standard deviation σ are stored as a standard deviation database in one-to-one correspondence.

Further, according to the performance requirements of specific application scenarios, the steps of determining the target compressive strength f _cu,k of the alkali-excited recycled concrete, and selecting a suitable alkali-to-binder ratio A/B and strength standard deviation σ _k include:

Match the target compressive strength f cu, _k with the compressive strength f _cu data in the standard deviation database, and find the target strength standard deviation σ _k value corresponding to the target compressive strength f _cu,k value.

Further, according to the alkali to glue ratio A/B, obtain the corresponding regression coefficients α _a , α _b and the compressive strength f _b of the mortar 28d value, then according to the alkali glue ratio A/B, the trial strength f _{cu, 0} , the regression coefficients α _a , α _b and the 28d compressive strength f _b of the mortar, the water-solid ratio W/GPS is calculated, including:

计算得到水固比W/GPS。by formula

Calculate the water-solid ratio W/GPS.

Further, the step of calculating the content of each component in the alkali-excited recycled concrete according to the alkali-binder ratio A/B, the water-solid ratio W/GPS, the pulp-bone mass ratio and the sand ratio using the pulp-bone mass ratio method, comprising:

It is calculated using the following relational equation,

The amount of gelling components * alkali to glue ratio = alkali solution * alkali solid mass fraction;

Alkaline solution*(1-alkali solid mass fraction)+additional water=(amount of gelling component+alkali solution*alkali solid mass fraction)*water-solid ratio;

(amount of gelling component + alkali solution + additional water) * pulp-bone mass ratio = regenerated coarse aggregate + fine aggregate;

Fine aggregate = (recycled coarse aggregate + fine aggregate) * sand rate;

Regenerated coarse aggregate = (regenerated coarse aggregate + fine aggregate) - fine aggregate;

The amount of mineral powder = the amount of gelling components * 90%;

The amount of fly ash = the amount of cementitious components - the amount of mineral powder.

The present invention also proposes an alkali-excited recycled concrete mix ratio design system, including:

The target parameter unit is used to determine the target compressive strength f _cu,k of the target alkali-excited recycled concrete according to the performance requirements of the application scenario, and select a suitable alkali-to-binder ratio A/B and strength standard deviation σ _k ;

Trial strength calculation unit, used to obtain the specific value of f cu, ₀ according to f _cu,0 ≥f _cu,k +1.645σ _k , where f _cu,0 is the trial strength of alkali-excited recycled concrete;

The water-solid ratio calculation unit is used to obtain the corresponding regression coefficients α _a , α _b and the 28d compressive strength f _b of the mortar according to the alkali-binder ratio A/B, and then according to the alkali-binder ratio A/B, trial strength f _cu,0 , regression coefficients α _a , α _b and 28d compressive strength f _b of mortar, the water-solid ratio W/GPS is calculated;

The mixing ratio calculation unit is used to calculate the content of each component in the alkali-excited recycled concrete according to the alkali-binder ratio A/B, the water-solid ratio W/GPS, the pulp-bone mass ratio and the sand ratio using the pulp-bone mass ratio method.

计算得到碱激发再生混凝土不同的抗压强度f_cu对应的强度标准差σ，并将抗压强度f_cu数值和与其对应的强度标准差σ一一对应存储为标准差数据库。Further, it also includes a standard deviation database establishment unit, for according to the formula

The strength standard deviation σ corresponding to different compressive strength f _cu of alkali-excited recycled concrete is calculated, and the compressive strength f _cu value and its corresponding strength standard deviation σ are stored as a standard deviation database in one-to-one correspondence.

Further, the target parameter unit includes a target parameter module, which is used to match the target compressive strength f _cu,k with the compressive strength f _cu data in the standard deviation database, and find the target compressive strength f _{cu, k} value. Corresponding target intensity standard deviation σ _k value.

计算得到水固比W/GPS。Further, the water-solid ratio calculation unit includes a water-solid ratio W/GPS calculation module for passing the formula

Calculate the water-solid ratio W/GPS.

Further, the mixing ratio calculation unit includes a mixing ratio calculation module for calculating using the following relational equation:

The amount of gelling components * alkali to glue ratio = alkali solution * alkali solid mass fraction;

Alkaline solution*(1-alkali solid mass fraction)+additional water=(amount of gelling component+alkali solution*alkali solid mass fraction)*water-solid ratio;

(amount of gelling component + alkali solution + additional water) * pulp-bone mass ratio = regenerated coarse aggregate + fine aggregate;

Fine aggregate = (recycled coarse aggregate + fine aggregate) * sand rate;

Regenerated coarse aggregate = (regenerated coarse aggregate + fine aggregate) - fine aggregate;

The amount of mineral powder = the amount of gelling components * 90%;

The amount of fly ash = the amount of cementitious components - the amount of mineral powder.

The beneficial effects of the invention are as follows: the alkali-excited concrete using recycled aggregates such as construction waste instead of natural aggregates not only expands the use range of the alkali-excited concrete, but also fully recycles waste resources, which is beneficial to environmental protection; The water-solid ratio was used to obtain a calculation model suitable for alkali-excited recycled concrete, and the corresponding regression coefficients and 28d compressive strength of mortar under different alkali-binder ratios were established. According to the content of each component, the design method of alkali excited recycled concrete mix ratio is finally obtained. Calculated according to the actual quality relationship between the various components of concrete, the obtained mix ratio is more accurate and has a wider application range.

Description of drawings

Fig. 1 is a method flow diagram of an embodiment of a method for designing an alkali-excited recycled concrete mix ratio of the present invention;

Fig. 2 is a method flow chart of another embodiment of the alkali-excited recycled concrete mix proportion design method of the present invention;

3 is a structural block diagram of an embodiment of an alkali-excited recycled concrete mix ratio design system of the present invention.

The realization, functional characteristics and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments.

Detailed ways

It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

The following describes in detail the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, but not to be construed as a limitation of the present invention.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It should also be understood that terms, such as those defined in a general dictionary, should be understood to have meanings consistent with their meanings in the context of the prior art and, unless specifically defined as herein, should not be interpreted in idealistic or overly formal meaning to explain.

Referring to FIG. 1, an embodiment of the present invention is proposed, a method for designing the mix ratio of alkali-excited recycled concrete, including the following steps:

S2. According to the performance requirements of the application scenario, determine the target compressive strength f _cu,k of the target alkali-excited recycled concrete, and select a suitable alkali-binder ratio A/B and strength standard deviation σ _k .

S3. According to f _cu,0 ≥f _cu,k +1.645σ _k , the specific value of f cu, ₀ is obtained, where f _cu,0 is the trial strength of the alkali-excited recycled concrete.

S4. According to the alkali-binder ratio A/B, the corresponding regression coefficients α _a , α _b and the 28d compressive strength f _b of the mortar are obtained, and then according to the alkali-binder ratio A/B, trial strength f _cu,0 , regression The coefficients α _a , α _b and the 28d compressive strength f _b of the mortar can be calculated to obtain the water-solid ratio W/GPS.

S5. Calculate the content of each component in the alkali-excited recycled concrete according to the alkali-binder ratio A/B, the water-solid ratio W/GPS, the pulp-bone mass ratio and the sand ratio using the pulp-bone mass ratio method.

Referring to FIG. 2, in another embodiment of the present invention, step S1 is further included before step S2, specifically:

计算得到碱激发再生混凝土不同的抗压强度f_cu对应的强度标准差σ，并将抗压强度f_cu数值和与其对应的强度标准差σ一一对应存储为标准差数据库。S1, according to the formula

The strength standard deviation σ corresponding to different compressive strength f _cu of alkali-excited recycled concrete is calculated, and the compressive strength f _cu value and its corresponding strength standard deviation σ are stored as a standard deviation database in one-to-one correspondence.

In step S1 as described above, the strength standard deviation σ corresponding to different compressive strengths f _cu is obtained by calculating the above-mentioned strength standard deviation σ calculation formula, and according to the one-to-one correspondence between the strength standard deviation σ and the compressive strength f _cu in Table 1 The form is recorded as a data table, the above-mentioned standard deviation database 5 is Table 1 in this embodiment, and Table 1 is shown below.

Table 1 Standard deviation σ of compressive strength of alkali-excited recycled concrete

In step S2 as described above, after determining the target compressive strength f _cu,k of concrete according to the actual application scenario, it is determined according to the strength index and the requirements of the ordinary concrete mix proportion design method JGJ55-2011 "Ordinary Concrete Mix Proportion Design Regulations" Alkali-binder ratio A/B; in addition, compare the target compressive strength f _cu,k with the compressive strength f _cu in Table 1, and find the compressive strength f cu with the same or similar value as the target compressive strength f _{cu ,k} , And select the value of the intensity standard deviation σ in a suitable range as the value of the intensity standard deviation σ _k for the next step of calculation. Specifically, according to the results in Table 1, when the standard strength value of alkali-excited recycled concrete is in the range of 45Mpa to 65Mpa, the standard deviation of its strength can be directly taken as 4.0Mpa. That is to say, it is not a table lookup. When in this range, the intensity standard deviation is directly taken as 4.0. When the standard value of alkali-excited recycled concrete strength is not within this range, its strength standard deviation can also be obtained by fitting.

计算得到水固比W/GPS。其中回归系数可以根据碱胶比A/B查表2得到，表2如下：Step S4 as described above, specifically through the formula

Calculate the water-solid ratio W/GPS. The regression coefficient can be obtained by looking up Table 2 according to the alkali to glue ratio A/B. Table 2 is as follows:

Table 2 Values of regression coefficients under different alkali-gel ratios

The above step S5, according to the alkali-binder ratio A/B, the water-solid ratio W/GPS, the pulp-bone mass ratio and the sand ratio, use the pulp-bone mass ratio method to calculate the content steps of each component in the alkali-excited recycled concrete, including :

Calculated using the following relational equation:

The amount of gelling components * alkali to glue ratio = alkali solution * alkali solid mass fraction;

Alkaline solution*(1-alkali solid mass fraction)+additional water=(amount of gelling component+alkali solution*alkali solid mass fraction)*water-solid ratio;

(amount of gelling component + alkali solution + additional water) * pulp-bone mass ratio = regenerated coarse aggregate + fine aggregate;

Fine aggregate = (recycled coarse aggregate + fine aggregate) * sand rate;

Regenerated coarse aggregate = (regenerated coarse aggregate + fine aggregate) - fine aggregate;

The amount of mineral powder = the amount of gelling components * 90%;

The amount of fly ash = the amount of cementitious components - the amount of mineral powder.

Table 3 Compressive strength of 28d mortar of alkali-excited rubber material within the test range

Among them, the alkali solution, alkali-binder ratio, alkali solid mass fraction, water-solid ratio, pulp-bone mass ratio and sand ratio are known parameters, and the remaining cementitious components dosage, additional water, recycled coarse aggregate, fine aggregate, mineral The amount of powder and the amount of fly ash are unknown parameters. By substituting each known parameter, the content of concrete components such as additional water, recycled coarse aggregate, fine aggregate, mineral powder amount and fly ash amount that we need can be calculated, and then the mix ratio of alkali-activated concrete can be obtained. (The above 28d refers to 28 days)

Finally, according to the obtained mixing ratio, the alkali-excited recycled concrete is prepared, and cured for 28 days under standard conditions. The average compressive strength of the test is obtained, and the average compressive strength is compared with the target compressive strength to see if it meets the target strength requirements. If it is not satisfied, adjust the concrete value of the slurry-bone ratio and/or the sand ratio and then calculate until a suitable mix ratio of alkali-excited recycled concrete is obtained.

This method is based on the relationship of each component under the condition that the cementitious material is dominated by mineral powder and mixed with 10% fly ash. Therefore, the mix ratio of the alkali-excited recycled concrete obtained by this method is the same as the fly ash in the cementitious raw material. To keep 10% of the content, finally get the alkali excited recycled concrete mix ratio that meets the strength requirements.

The specific cases are as follows:

The mixing ratio design method proposed in the present invention is designed for alkali excited recycled concrete, and it is required that the target compressive strength reaches f _cu,k =50MPa, and the construction workability is good. The specific design steps are as follows:

(1) First determine the ratio of alkali to glue. According to the requirements of strength index and ordinary concrete mix proportion design method JGJ55-2011 "Ordinary concrete mix proportion design regulations", the target compressive strength and other comprehensive properties are preliminarily selected as alkali-binder ratio A/B=0.24.

(2) According to the ratio of alkali to glue A/B, the corresponding regression coefficient can be obtained, that is, the relationship between compressive strength and water-solid ratio can be clearly defined. The alkali to glue ratio A/B=0.24, which can be obtained from Table 2, and the corresponding regression coefficients are α _a =0.2227, α _b =-1.5245. In addition, according to Table 3, it can be obtained that under the condition that the ratio of alkali to glue is 0.24, the compressive strength f _b =58.2MPa of the mortar 28d.

(3) According to the preparation target, the target compressive strength _fcu,k = 50MPa, according to the results in Table 1, when the target strength is between 45Mpa and 65Mpa, the standard deviation of the target strength can be taken as σ _k = 4.0Mpa, and the concrete is obtained from this The trial strength f _cu,0 =f _cu,k +1.645σ=50+1.645*4.0=56.58MPa.

并求解，可以得到水固比W/GPS＝0.352。Substitute the specific values of f _cu,0 , f _b , α _a , α _b into the formula

And solve it, we can get the water-solid ratio W/GPS=0.352.

(4) Look up Table 3 and take the amount of cementitious component = 600 + 66 = 666 kg/ ^m3 as the reference value, through the preliminary experiment, and then select the sand ratio of 0.45 according to the working performance and strength requirements of alkali-induced recycled concrete, and the mortar bone The mass ratio is 0.99, and the content of each component is calculated. The specific calculation process is as follows:

The first step is to calculate the water glass content, the amount of gelling components * alkali to glue ratio = alkali solution * alkali solid mass fraction, this test selects water glass with a modulus of 1.95, in which the mass fraction of Na ₂ O is 14.26%, and the mass fraction of SiO ₂ The mass fraction is 26.92%, so the alkali solid mass fraction of water glass is 41.18%, which can be substituted into:

666*0.24=alkali solution*0.412,

Alkali solution (water glass) = 387.96 kg/m ³ by calculation.

The second step is to calculate the additional water content, alkali solution*(1-base solid mass fraction)+additional water=(amount of gelling component+alkali solution*base solid mass fraction)*water-solid ratio, and substituting the known component specific The number is worth:

387.96*(1-0.412)+extra water=(666+387.96*0.412)*0.352,

Calculated extra water = 62.57 kg/m.

The third step is to calculate the sum of fine aggregate and recycled coarse aggregate, (amount of gelling component + alkaline solution + additional water) * pulp-bone mass ratio = recycled coarse aggregate + fine aggregate, and substitute the specific values of the relevant components :

(666+387.96+62.57)*0.99=recycled coarse aggregate+fine aggregate, from this, regenerated aggregate+fine aggregate total=1127.81 kg/m ³ .

The fourth step is to calculate the fine aggregate, fine aggregate=(regenerated coarse aggregate+fine aggregate)*sand rate; fine aggregate=1127.81*0.45=507.51kg/m ³ , wherein the fine aggregate is natural sand.

The fifth step, calculate the regenerated coarse aggregate, regenerated coarse aggregate = (regenerated coarse aggregate + fine aggregate) - fine aggregate, substitute the specific values of the relevant components, and calculate the regenerated coarse aggregate = 1127.81-507.51 = 620.30kg /m ³ .

The sixth step is to calculate the amount of mineral powder, the amount of mineral powder = the amount of cementitious components * 90%, and substituting the specific values of the relevant components, the calculation is obtained, the amount of mineral powder = 666 * 0.9 = 599.4 kg/m ³ .

Step 7: Calculate the amount of fly ash, the amount of fly ash = the amount of cementitious components - the amount of slag powder, substituting the specific data of the relevant components, the calculation is obtained, the amount of fly ash = 666-599.4 = 66.6kg/m ³ .

Finally, a suitable specific mix ratio of alkali-excited recycled concrete is obtained, as shown in Table 4:

Table 450MPa alkali excited recycled concrete mix ratio

(5) Alkali-excited recycled concrete was prepared according to the mixture ratio obtained in (4), the slump of the fresh concrete was 172 mm, no segregation or bleeding occurred, and the construction workability was good. After curing for 28 days under standard conditions, the average compressive strength is 53.1MPa after testing, which meets the requirements.

(6) Since the characteristics of the water absorption rate, gradation, and crushing index of the aggregate used have a direct impact on the performance of the concrete, the properties of the raw materials must be tested before the design of the mix ratio.

The beneficial effects of the invention are as follows: the alkali-excited concrete using recycled aggregates such as construction waste instead of natural aggregates not only expands the use range of the alkali-excited concrete, but also fully recycles waste resources, which is beneficial to environmental protection; The water-solid ratio was used to obtain a calculation model suitable for alkali-excited recycled concrete, and the corresponding regression coefficients and 28d compressive strength of mortar under different alkali-binder ratios were established. According to the content of each component, the design method of alkali excited recycled concrete mix ratio is finally obtained. Calculated according to the actual quality relationship between the various components of concrete, the obtained mix ratio is more accurate and has a wider application range.

The present invention also proposes an alkali-excited recycled concrete mix ratio design system, including:

计算得到碱激发再生混凝土不同的抗压强度f_cu对应的强度标准差σ，并将抗压强度f_cu数值和与其对应的强度标准差σ一一对应存储为标准差数据库。Standard deviation database establishment unit 1, for according to the formula

The strength standard deviation σ corresponding to different compressive strength f _cu of alkali-excited recycled concrete is calculated, and the compressive strength f _cu value and its corresponding strength standard deviation σ are stored as a standard deviation database in one-to-one correspondence.

The target parameter unit 2 is used to determine the target compressive strength f _cu,k of the target alkali-excited recycled concrete according to the performance requirements of the application scenario, and select a suitable alkali-binder ratio A/B and strength standard deviation σ _k ;

Trial strength calculation unit 3 is used to obtain the specific value of f cu, ₀ according to f _cu,0 ≥ f _cu,k +1.645σ _k , where f _{cu, 0} is the trial strength of alkali-excited recycled concrete;

The water-solid ratio calculation unit 4 is used to obtain the corresponding regression coefficients α _a , α _b and the compressive strength f _b of the mortar 28d according to the alkali-binder ratio A/B, and then according to the alkali-binder ratio A/B, trial mix Strength f _{cu, 0} , regression coefficients α _a , α _b and 28d compressive strength f _b of mortar, the water-solid ratio W/GPS is calculated;

The mixing ratio calculation unit 5 is used for calculating the content of each component in the alkali-excited recycled concrete according to the alkali-binder ratio A/B, the water-solid ratio W/GPS, the pulp-bone mass ratio and the sand ratio using the pulp-bone mass ratio method.

The standard deviation database establishment unit 1 is used to calculate the strength standard deviation σ corresponding to different compressive strength f _cu through the above-mentioned strength standard deviation σ calculation formula, and according to the strength standard deviation σ in Table 1 and the compressive strength f _cu one by one The corresponding form is recorded as a data table, and the above-mentioned standard deviation database is Table 1 in this embodiment.

Among them, the target parameter unit 2 includes a target parameter module 201, which is used to determine the target compressive strength f _{cu, k} of concrete according to the actual application scenario, according to the strength index and the design method of ordinary concrete mix ratio JGJ55-2011 "General In addition, the target compressive strength f _{cu, k} is compared with the data of compressive strength f _cu in Table 1, and it is found that the value of the target compressive strength f _{cu, k} is the same as that of the target compressive strength f cu, k The compressive strength f _cu , and the value of the strength standard deviation σ corresponding to the compressive strength f _cu is selected as the value of the strength standard deviation σ _k for the next step of calculation.

计算得到水固比W/GPS。水固比，为水与固体材料的比值。Among them, the water-solid ratio calculation unit 4 includes a water-solid ratio calculation module 401, which is used for formulating

Calculate the water-solid ratio W/GPS. The water-solid ratio is the ratio of water to solid materials.

Wherein, the mixing ratio calculation unit 5 includes a mixing ratio calculation module 501, which is used for calculation using the following relational equation:

The amount of gelling components * alkali to glue ratio = alkali solution * alkali solid mass fraction;

Alkaline solution*(1-alkali solid mass fraction)+additional water=(amount of gelling component+alkali solution*alkali solid mass fraction)*water-solid ratio;

(amount of gelling component + alkali solution + additional water) * pulp-bone mass ratio = regenerated coarse aggregate + fine aggregate;

Fine aggregate = (recycled coarse aggregate + fine aggregate) * sand rate;

Regenerated coarse aggregate = (regenerated coarse aggregate + fine aggregate) - fine aggregate;

The amount of mineral powder = the amount of gelling components * 90%;

The amount of fly ash = the amount of cementitious components - the amount of mineral powder.

Alkali-excited concrete that uses recycled aggregates such as construction waste instead of natural aggregates not only expands the use range of alkali-excited concrete, but also fully reuses waste resources, which is conducive to environmental protection; the use of water-solid ratio to obtain suitable alkali The calculation model of stimulated recycled concrete was established, and the corresponding regression coefficient and 28d compressive strength of mortar under different alkali-binder ratios were established. Finally, the slurry-bone mass ratio method was used to calculate the content of each component that meets the strength of alkali-excited recycled concrete, and finally obtained Alkali-induced recycled concrete mix ratio design method is calculated according to the actual quality relationship between the various components of concrete, and the obtained mix ratio is more accurate and has a wider range of applications.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of the present invention, or directly or indirectly applied to other related All technical fields are similarly included in the scope of patent protection of the present invention.

Claims (8)

1. A design method for the mixing proportion of alkali-activated recycled concrete is characterized by comprising the following steps:

determining the target compressive strength f of the target alkali-activated recycled concrete according to the performance requirements of the application scene_cu,kAnd selecting proper alkali-binder ratio A/B and standard deviation sigma of strength_k；

According to f_cu,0≥f_cu,k+1.645σ_kTo obtain f_cu,0Specific numerical values, wherein f_cu,0The strength of the alkali-activated recycled concrete is trial-prepared;

obtaining corresponding regression coefficient α according to the alkali-glue ratio A/B_a、α_bCompressive strength f of sand 28d_bTaking value according to the alkali-binder ratio A/B and the trial strength f_cu,0Regression coefficient α_a、α_bCompressive strength f of sand 28d_bCalculating to obtain a water-solid ratio W/GPS;

calculating the content of each component in the alkali-activated recycled concrete by using a slurry-to-bone mass ratio method according to the alkali-to-cement ratio A/B, the water-to-solid ratio W/GPS, the slurry-to-bone mass ratio and the sand rate;

the alkali-activated recycled concrete comprises components of alkali solution, additional water, recycled coarse aggregate, fine aggregate, mineral powder and fly ash; and calculated using the following relationship:

the gelling component is used in the mass fraction of alkali gel to alkali solution;

alkali solution (1-alkali solid mass fraction) + additional water (gelling component amount + alkali solution alkali solid mass fraction) × water-solid ratio;

(the amount of the gelling component plus the alkali solution plus the additional water) and the mass ratio of the slurry to the bone are regenerated coarse aggregate plus fine aggregate;

fine aggregate (recycled coarse aggregate + fine aggregate) sand fraction;

the recycled coarse aggregate (recycled coarse aggregate + fine aggregate) -fine aggregate;

the using amount of the mineral powder is 90 percent of the using amount of the gelling component;

the using amount of the fly ash is equal to the using amount of the gelling component-the using amount of the mineral powder;

and preparing alkali-activated recycled concrete according to the content of each component in the alkali-activated recycled concrete, testing the actual strength of the alkali-activated recycled concrete, adjusting the mass ratio and/or sand rate of the mortar when the actual strength does not meet the target compressive strength, and calculating the content of each component in the alkali-activated recycled concrete according to the adjusted mass ratio and/or sand rate of the mortar.

2. The method for designing the mix proportion of the alkali-activated recycled concrete according to claim 1, wherein the target compressive strength f of the alkali-activated recycled concrete is determined according to the performance requirements of an application scene_cu,kAnd selecting proper alkali-binder ratio A/B and standard deviation sigma of strength_kBefore the steps, the method comprises the following steps:

according to the formula

Calculating to obtain different compressive strengths f of the alkali-activated recycled concrete_cuCorresponding standard deviation sigma of strength, and the compressive strength f_cuThe numerical values and the intensity standard deviations σ corresponding thereto are stored in a standard deviation database in one-to-one correspondence.

3. The method for designing the mix proportion of the alkali-activated recycled concrete according to claim 2, wherein the target compressive strength f of the alkali-activated recycled concrete is determined according to the performance requirements of an application scene_cu,kAnd selecting proper alkali-binder ratio A/B and standard deviation sigma of strength_kThe method comprises the following steps:

the compressive strength f of the target_cu,kCompressive strength f in the sum standard deviation database_cuMatching the data to find the target compressive strength f_cu，kNumerical value corresponding target intensity standard deviation sigma_kNumerical values.

4. The method as claimed in claim 1, wherein the regression coefficient α is obtained according to the alkali-binder ratio A/B_a、α_bCompressive strength f of sand 28d_bTaking value according to the alkali-binder ratio A/B and the trial strength f_cu,0Regression coefficient α_a、α_bCompressive strength f of sand 28d_bAnd calculating to obtain the water-solid ratio W/GPS, comprising the following steps:

by the formula

And calculating to obtain the water-solid ratio W/GPS.

5. An alkali-activated recycled concrete mix proportion design system, comprising:

a target parameter unit for determining the target compressive strength f of the target alkali-activated recycled concrete according to the performance requirements of the application scene_cu,kAnd selecting proper alkali-binder ratio A/B and standard deviation sigma of strength_k；

A trial-fitting intensity calculating unit for calculating the trial-fitting intensity according to f_cu,0≥f_cu,k+1.645σ_kTo obtain f_cu,0Specific numerical values, wherein f_cu,0The strength of the alkali-activated recycled concrete is trial-prepared;

a water-solid ratio calculation unit for obtaining corresponding regression coefficient α according to the alkali-glue ratio A/B_a、α_bCompressive strength f of sand 28d_bTaking value according to the alkali-binder ratio A/B and the trial strength f_cu,0Regression coefficient α_a、α_bCompressive strength f of sand 28d_bCalculating to obtain a water-solid ratio W/GPS;

the mixing proportion calculation unit is used for calculating the content of each component in the alkali-activated recycled concrete by using a slurry-bone mass ratio method according to the alkali-cement ratio A/B, the water-solid ratio W/GPS, the slurry-bone mass ratio and the sand rate;

the alkali-activated recycled concrete comprises components of alkali solution, additional water, recycled coarse aggregate, fine aggregate, mineral powder and fly ash; the mix proportion calculating unit comprises a mix proportion calculating module which is used for calculating by using the following relation equation:

the gelling component is used in the mass fraction of alkali gel to alkali solution;

alkali solution (1-alkali solid mass fraction) + additional water (gelling component amount + alkali solution alkali solid mass fraction) × water-solid ratio;

(the amount of the gelling component plus the alkali solution plus the additional water) and the mass ratio of the slurry to the bone are regenerated coarse aggregate plus fine aggregate;

fine aggregate (recycled coarse aggregate + fine aggregate) sand fraction;

the recycled coarse aggregate (recycled coarse aggregate + fine aggregate) -fine aggregate;

the using amount of the mineral powder is 90 percent of the using amount of the gelling component;

the using amount of the fly ash is equal to the using amount of the gelling component-the using amount of the mineral powder;

the mixing proportion calculation unit is also used for preparing the alkali-activated recycled concrete according to the content of each component in the alkali-activated recycled concrete, testing the actual strength of the alkali-activated recycled concrete, adjusting the mortar-bone mass ratio and/or the sand rate when the actual strength does not meet the target compressive strength, and calculating the content of each component in the alkali-activated recycled concrete according to the adjusted mortar-bone mass ratio and/or the adjusted sand rate.

6. The alkali-activated recycled concrete mix proportion designing system as set forth in claim 5, further comprising a standard deviation database creating unit for creating a standard deviation database according to a formula

Calculating to obtain different compressive strengths f of the alkali-activated recycled concrete_cuCorresponding standard deviation sigma of strength, and the compressive strength f_cuThe numerical values and the intensity standard deviations σ corresponding thereto are stored in a standard deviation database in one-to-one correspondence.

7. The system for designing mix proportion of alkali-activated recycled concrete according to claim 6, wherein said target parameter unit comprises a target parameter module for setting a target compression strength f_cu,kCompressive strength f in the sum standard deviation database_cuMatching the data to find the target compressive strength f_cu，kNumerical value corresponding target intensity standard deviation sigma_kNumerical values.

8. The system for designing mix proportion of alkali-activated recycled concrete according to claim 5, wherein said water-to-solid ratio calculation unit comprises a water-to-solid ratio W/GPS calculation module for calculating the water-to-solid ratio by formula

And calculating to obtain the water-solid ratio W/GPS.

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