Core physical parameter-based lightweight aggregate concrete mix proportion design method and application

Abstract

The invention relates to the technical field of lightweight concrete, and provides a lightweight aggregate concrete mix proportion design method based on core physical parameters and application, the method comprises the following steps: setting target compressive strength fc and target density rho LC of lightweight aggregate concrete; obtaining all core physical parameters of the two components of the lightweight aggregate and the mortar; calculating the actual preparation density rho LC of the lightweight aggregate concrete according to a density formula; comparing the actual preparation density rho LC and actual density of the lightweight aggregate concrete with the target density rho LC, and if rho LC and actual density is less than or equal to rho LC, determining that the two components of the lightweight aggregate and the mortar meet the requirements; if rho LC, gt is set; if rho LC, the lightweight aggregate and the mortar do not meet the requirements, and new lightweight aggregate and mortar are selected again until rho LC is smaller than or equal to rho LC. The invention breaks through the limitation of a semi-quantitative mix proportion design method in the current standard, provides a novel mix proportion design method of the lightweight aggregate concrete based on any combination of the lightweight aggregate and the mortar, is high in design precision, and greatly reduces the workload.

Description

Technical Field

[0001] The present disclosure relates to the technical field of lightweight concrete, and in particular to a lightweight aggregate concrete mix design method based on core physical parameters and its application. Background Art

[0002] The improvement of bridge span capacity and the guarantee of existing bridge bearing capacity have put forward higher requirements for the lightweight of bridge materials. The development of high-performance lightweight materials is of great significance to bridge construction and maintenance. Lightweight aggregate concrete has the characteristics of light weight, high strength, heat preservation and fire resistance. It is an economically feasible lightweight material with broad application prospects in bridge engineering.

[0003] At present, the design method of lightweight aggregate concrete mix is ​​mainly based on experience. It is a semi-quantitative mix design method that only gives the approximate range of raw material usage. Accurate concrete mix ratios require a large amount of trial mixing tests, resulting in the use of traditional methods to obtain the target lightweight aggregate concrete. Usually, it takes a lot of work and a long time, and the design accuracy is low. At the same time, the current lightweight aggregate concrete mix design specifications only cover lightweight aggregate concrete of LC60 and below, and cannot directly guide the preparation of high-strength lightweight aggregate concrete, which to a certain extent restricts the application of high-strength lightweight aggregate concrete.

[0004] A lightweight aggregate concrete mix design method based on finite element analysis in the prior art is to carry out a large number of example calculations through finite elements to obtain the design curve for each specific lightweight aggregate and mortar strength combination, and establish a mathematical relationship expression between lightweight aggregate concrete strength and mortar strength, lightweight aggregate strength and lightweight aggregate content, so as to carry out lightweight aggregate concrete mix design for the specific mortar and lightweight aggregate strength combination. Although this method is highly practical, its scope of use is limited and it can only be used to guide lightweight aggregate concrete mix design under a specific mortar and lightweight aggregate strength combination.

[0005] Therefore, there is an urgent need for a lightweight aggregate concrete mix design method with a wider range of applications and higher design accuracy, breaking through the limitations of specific aggregate and mortar combinations, and proposing a lightweight aggregate concrete mix design method under any mortar and aggregate combination, so as to provide technical support for the application of lightweight aggregate concrete in bridge engineering. Summary of the invention

[0006] In view of this, the present disclosure provides a lightweight aggregate concrete mix design method based on core physical parameters and its application, so as to solve the problems of low accuracy and small application scope of existing lightweight aggregate concrete mix design methods.

[0007] In order to achieve the above-mentioned object, in one aspect, the present disclosure provides a lightweight aggregate concrete mix design method based on core physical parameters, wherein the lightweight aggregate concrete comprises two components, lightweight aggregate and mortar, and the method comprises:

[0008] S1: Set the target compressive strength f of lightweight aggregate concrete c and the target density ρ LC ;

[0009] S2: Obtain all core physical parameters of the two components of lightweight aggregate and mortar, wherein all core physical parameters of the two components of lightweight aggregate and mortar include: the volume dosage V of the lightweight aggregate component LWA , Lightweight aggregate apparent density ρ LWA , lightweight aggregate cylinder compressive strength f LWA , the mass water absorption rate of lightweight aggregate Φ, the compressive strength of mortar f motar and mortar density ρ motar ;

[0010] S3: Calculate the actual mix density ρ of lightweight aggregate concrete according to the density formula LC,实 =ρ LWA ·V LWA +ρ motar (1-V LWA )+ρ motar ·V LWA ·Φ·ρ LWA / ρ water ;

[0011] S4: Compare the actual density of lightweight aggregate concrete ρ LC,实 With the target density ρ LC , if LC,实 ≤ρ LC , then the lightweight aggregate and mortar components meet the requirements, and the target lightweight aggregate concrete mix design is completed; if ρ LC,实 >ρ LC , then the lightweight aggregate and mortar components do not meet the requirements, then reselect new lightweight aggregate and mortar, and repeat steps S2 to S4 until ρ LC,实 ≤ρ LC until.

[0012] In the above scheme, the target compressive strength f of the lightweight aggregate concrete in step S1 is c The value range is 30~120MPa, and the target density ρ LC The value range is 1400~1950kg / m 3 .

[0013] In the above scheme, the step S2 of obtaining all the core physical parameters of the two components of lightweight aggregate and mortar includes:

[0014] S21: Determine whether the core physical parameters of the two components, lightweight aggregate and mortar, are all known. If yes, execute step S22; otherwise, execute step S23;

[0015] S22: Determination of the core physical parameters of lightweight aggregate and mortar, including the apparent density of lightweight aggregate ρ LWA , lightweight aggregate cylinder compressive strength f LWA , the mass water absorption rate of lightweight aggregate Φ, the compressive strength of mortar f motar and mortar density ρ motar ; Then calculate the volume of lightweight aggregate component V according to the strength formula LWA , obtain all the core physical parameters of lightweight aggregate and mortar;

[0016] S23: Determine the known core physical parameters of the lightweight aggregate and mortar components, and estimate the volumetric dosage V of the lightweight aggregate component LWA Then, based on the known core physical parameters of the two components of lightweight aggregate and mortar, the estimated volume dosage V of the lightweight aggregate component LWA , as well as the density formula and strength formula, the remaining unknown core physical parameters of lightweight aggregate and mortar are calculated, and all the core physical parameters of lightweight aggregate and mortar are obtained.

[0017] In the above scheme, the density formula is: LC =ρ LWA ·V LWA +ρ motar (1-V LWA )+ρ motar ·V LWA ·Φ·ρ LWA / ρ water , where the density of water is water =1000kg / m3;

[0018] The strength formula is:

[0019] In the above scheme, the step S21 is to determine whether the core physical parameters of the two components, lightweight aggregate and mortar, are all known. If the core physical parameters of the lightweight aggregate component are known and the core physical parameters of the mortar component are unknown, then step S23 includes: determining the core physical parameters of the lightweight aggregate component, including the lightweight aggregate density ρ LWA , lightweight aggregate cylinder compressive strength f LWA , the mass water absorption rate of lightweight aggregate Φ; temporarily estimate or assume the unit volume dosage of lightweight aggregate component V LWA ; Calculate the mortar density ρ according to the density formula motar ; Calculate the compressive strength f of the mortar according to the strength formula motar .

[0020] In the above scheme, the step S21 is to determine whether the core physical parameters of the two components, lightweight aggregate and mortar, are all known. If the core physical parameters of the mortar are known and the core physical parameters of the lightweight aggregate are unknown, then step S23 includes: determining the core physical parameters of the mortar components, including the compressive strength f of the mortar. motar 、Mortar density ρ motar ; Temporarily estimate or assume the volume of lightweight aggregate component V LWA ; Calculate the cylinder compressive strength f of lightweight aggregate according to the strength formula LWA ; Temporarily estimate or assume the mass water absorption rate Φ of lightweight aggregate, and calculate the apparent density ρ of lightweight aggregate according to the density formula LWA .

[0021] In the above scheme, the step S21 is to determine whether the core physical parameters of the two components of lightweight aggregate and mortar are all known. If the core physical parameters of lightweight aggregate and mortar are unknown, step S23 includes: temporarily estimating or assuming the unit volume consumption V of the lightweight aggregate component. LWA ; Temporarily estimate or assume the compressive strength of the mortar f motar ; Calculate the cylinder compressive strength f of lightweight aggregate according to the strength formula LWA ; Temporarily estimate or assume the mass water absorption rate Φ of lightweight aggregate and the density ρ of mortar motar , the apparent density of lightweight aggregate ρ is calculated according to the density formula LWA .

[0022] In the above scheme, among all the core physical parameters of the two components of lightweight aggregate and mortar described in step S2, the apparent density of lightweight aggregate ρ LWA The value range is 1000~1500kg / m 3 , lightweight aggregate cylinder compressive strength f LWA The value range is 3~20MPa, the mass water absorption rate of lightweight aggregate is Φ≤15%, and the compressive strength of mortar is f motar ≤150MPa, mortar density ρ motar The value range is 1300~2200kg / m 3 , light bone mass single volume dosage V LWA <0.5.

[0023] In the above scheme, the lightweight aggregate component material is spherical lightweight aggregate.

[0024] In order to achieve one aspect of the above-mentioned purpose, the present disclosure also provides a lightweight aggregate concrete, which is obtained by applying the lightweight aggregate concrete mix design method based on core physical parameters.

[0025] It can be seen from the above technical solutions that the lightweight aggregate concrete mix design method based on core physical parameters and its application provided by the present disclosure have at least the following beneficial effects:

[0026] 1. The lightweight aggregate concrete mix design method and application based on core physical parameters provided in the present disclosure sets the target compressive strength f of lightweight aggregate concrete. c and the target density ρ LC ; Obtain all the core physical parameters of the two components of lightweight aggregate and mortar; Calculate the actual mix density ρ of lightweight aggregate concrete according to the density formula LC,实 ; Compare the actual density of lightweight aggregate concrete ρ LC,实 With the target density ρ LC , if LC,实 ≤ρ LC , then the lightweight aggregate and mortar components meet the requirements; if ρ LC,实 >ρ LC , then the lightweight aggregate and mortar components do not meet the requirements, then new lightweight aggregate and mortar are selected until ρ LC,实 ≤ρ LC So far; the problems of low accuracy and small application scope of existing lightweight aggregate concrete mix design methods have been solved.

[0027] 2. The lightweight aggregate concrete mix design method and application based on core physical parameters provided by the present invention breaks through the limitations of the semi-quantitative mix design method in the current standard, and provides a new lightweight aggregate concrete mix design method based on any combination of lightweight aggregate and mortar, with high design accuracy and greatly reduced workload.

[0028] 3. The lightweight aggregate concrete mix design method and application based on core physical parameters provided in the present invention obtains the core physical parameters and the unit volume usage of lightweight aggregate under any lightweight aggregate and mortar combination according to the density formula and the strength formula, completes the mix design of lightweight aggregate concrete, breaks through the limitation of specific aggregate and mortar combination, is simple to operate and easy to use.

[0029] 4. The lightweight aggregate concrete mix design method and application based on core physical parameters provided in the present disclosure can achieve a designed lightweight aggregate concrete with a strength of up to 120 MPa. Compared with the current lightweight aggregate concrete mix design specification which only covers lightweight aggregate concrete of LC60 and below, the designed strength can be significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above contents and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0031] Figure 1 The present invention is a flowchart of a lightweight aggregate concrete mix design method based on core physical parameters according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0033] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0034] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0035] In order to solve the problems of low precision and small application scope of existing lightweight aggregate concrete mix design methods, Figure 1 As shown, the present disclosure provides a lightweight aggregate concrete mix design method based on core physical parameters, wherein the lightweight aggregate concrete comprises two components, lightweight aggregate and mortar, and optionally, the lightweight aggregate component is spherical lightweight aggregate. The method comprises the following steps:

[0036] S1: Set the target compressive strength f of lightweight aggregate concrete c and the target density ρ LC ;

[0037] In this step, the target compressive strength of the lightweight aggregate concrete is c The value range is 30~120MPa, and the target density ρ LC The value range is 1400~1950kg / m 3 .

[0038] S2: Obtain all core physical parameters of the two components of lightweight aggregate and mortar, wherein all core physical parameters of the two components of lightweight aggregate and mortar include: the volume dosage V of the lightweight aggregate component LWA , Lightweight aggregate apparent density ρ LWA , lightweight aggregate cylinder compressive strength f LWA , the mass water absorption rate of lightweight aggregate Φ, the compressive strength of mortar f motar and mortar density ρ motar ;

[0039] In this step, all the core physical parameters of the two components of lightweight aggregate and mortar are obtained, including:

[0040] S21: Determine whether the core physical parameters of the two components, lightweight aggregate and mortar, are all known. If yes, execute step S22; otherwise, execute step S23;

[0041] S22: Determination of the core physical parameters of lightweight aggregate and mortar, including the apparent density of lightweight aggregate ρ LWA , lightweight aggregate cylinder compressive strength f LWA , the mass water absorption rate of lightweight aggregate Φ, the compressive strength of mortar f motar and mortar density ρ motar ; Then calculate the volume of lightweight aggregate component V according to the strength formula LWA , obtain all the core physical parameters of lightweight aggregate and mortar;

[0042] S23: Determine the known core physical parameters of the lightweight aggregate and mortar components, and estimate the volumetric dosage V of the lightweight aggregate component LWA Then, based on the known core physical parameters of the two components of lightweight aggregate and mortar, the estimated volume dosage V of the lightweight aggregate component LWA , as well as the density formula and strength formula, the remaining unknown core physical parameters of lightweight aggregate and mortar are calculated to obtain all the core physical parameters of lightweight aggregate and mortar.

[0043] Wherein, the density formula is: LC =ρ LWA ·V LWA +ρ motar (1-V LWA )+ρ motar ·V LWA ·Φ·ρ LWA / ρ water , the density of water ρ water =1000kg / m3;

[0044] The strength formula is:

[0045] S3: Calculate the actual mix density ρ of lightweight aggregate concrete according to the density formula LC,实 =ρ LWA ·V LWA +ρ motar (1-V LWA )+ρ motar ·V LWA ·Φ·ρ LWA / ρ water ;

[0046] S4: Compare the actual density of lightweight aggregate concrete ρ LC,实 With the target density ρ LC , if LC,实 ≤ρ LC , then the lightweight aggregate and mortar components meet the requirements, and the target lightweight aggregate concrete mix design is completed; if ρ LC,实 >ρ LC , then the lightweight aggregate and mortar components do not meet the requirements, then reselect new lightweight aggregate and mortar, and repeat steps S2 to S4 until ρ LC,实 ≤ρ LC until.

[0047] In order to verify the accuracy and reliability of the lightweight aggregate concrete mix design method based on core physical parameters provided by the present disclosure, the lightweight aggregate concrete mix design method based on core physical parameters provided by the present disclosure will be further described in detail in combination with Examples 1-4 below.

[0048] Example 1

[0049] In this embodiment, the core physical parameters of the two components, lightweight aggregate and mortar, are known. The lightweight aggregate concrete mix design method based on the core physical parameters provided in this embodiment comprises the following specific steps:

[0050] S101: Setting target compressive strength f of lightweight aggregate concrete c =60MPa and target density

[0051] ρ LC =1850kg / m 3 .

[0052] S102: Determination of the core physical parameters of lightweight aggregate and mortar, including the apparent density of lightweight aggregate ρ LWA =1546kg / m 3 , lightweight aggregate cylinder compressive strength f LWA =13.5MPa, mass water absorption rate of lightweight aggregate Φ = 8.77%, compressive strength of mortar f motar =72.5, mortar density ρ motar =1850kg / m 3 .

[0053] S103: Calculate the volume of lightweight aggregate component V according to the strength formula LWA ;

[0054] In this step, the target compressive strength f c =60Mpa, compressive strength of mortar f motar =72.5 and lightweight aggregate cylinder compressive strength f LWA =13.5Mpa Substitute into strength formula fc = Calculate the volume of lightweight aggregate component V LWA =0.293;

[0055] S104: Calculate the actual mix density ρ of lightweight aggregate concrete according to the density formula LC,实 ;

[0056] In this step, the apparent density of lightweight aggregate ρ LWA =1546kg / m 3 , Volume of lightweight aggregate component V LWA =0.285, mortar density ρ motar =1850kg / m 3 , the mass water absorption rate of lightweight aggregate Φ = 8.77% and the density of water ρ water =1000kg / m3Substitute into the density formula ρ LC,实 =ρ LWA ·V LWA +ρ motar (1-V LWA )+ρ motar ·V LWA ·Φ·ρ LWA / ρ water , the actual mix density ρ of lightweight aggregate concrete is calculated LC, Actual = 1834.42kg / m 3 ;

[0057] S105: Comparison of actual density of lightweight aggregate concrete ρ LC,实 With the target density ρ LC , we know that LC, Actual = 1834.42kg / m 3 < LC =1850kg / m 3 , that is, LC, Real<ρ LC , the determined lightweight aggregate and mortar can meet the requirements, and the target lightweight aggregate concrete mix design is completed.

[0058] Example 2

[0059] In this embodiment, the core physical parameters of the lightweight aggregate component are known, and the core physical parameters of the mortar component are unknown. The lightweight aggregate concrete mix design method based on the core physical parameters provided in this embodiment comprises the following specific steps:

[0060] S201: Setting the target compressive strength f of lightweight aggregate concrete c =70MPa and target density ρ LC =2000kg / m 3 .

[0061] S202: Determination of core physical parameters of lightweight aggregate components, including lightweight aggregate density ρ LWA =1546kg / m 3 , lightweight aggregate cylinder compressive strength f LWA =13.5MPa, mass water absorption rate of lightweight aggregate Φ=8.77%.

[0062] S203: Estimate or assume the volume of lightweight aggregate component V LWA =0.285.

[0063] S204: Calculate the mortar density ρ according to the density formula motar ;

[0064] In this step, the target density ρ LC =2000kg / m 3 , lightweight aggregate density ρ LWA =1546kg / m 3 , Volume dosage of lightweight aggregate component V LWA =0.285, mass water absorption rate of lightweight aggregate Φ = 8.77%, density of lightweight aggregate ρ LWA =1546kg / m 3 and the density of water ρ water =1000kg / m3Substitute into the density formula ρ LC =ρ LWA ·V LWA +ρ motar ·(1-ρV LWA )+ρ motar ·V LWA ·Φ·ρ LWA / ρ water , calculate the mortar density ρ motar =2069kg / m 3 ;

[0065] S205: Calculate the compressive strength f of the mortar according to the strength formula motar ;

[0066] In this step, the target compressive strength f c =70MPa, volume dosage of lightweight aggregate component V LWA =0.285, lightweight aggregate cylinder compressive strength f LWA =13.5MPaSubstitute into the strength formula Calculate the compressive strength of the mortar f motar =87.41;

[0067] S206: Calculate the actual mix density ρ of lightweight aggregate concrete according to the density formula LC,实 ;

[0068] In this step, the density of lightweight aggregate ρ LWA =1546kg / m 3 , Volume dosage of lightweight aggregate component V LWA =0.285, mortar density ρ motar =2069kg / m 3 , lightweight aggregate mass water absorption Φ = 8.77%, lightweight aggregate density ρ LWA =1546kg / m 3 and the density of water ρ water =1000kg / m3Substitute into the density formula ρ LC,实 =ρ LWA ·V LWA +ρ motar (1-V LWA )+ρ motar ·V LWA ·Φ·ρ LWA / ρ water , the actual mix density ρ of lightweight aggregate concrete is calculated LC, Actual = 2000kg / m 3 ;

[0069] S207: Comparison of actual density of lightweight aggregate concrete ρ LC,实 With the target density ρ LC , ρ LC, Actual = 2000kg / m 3 =ρ LC =2000kg / m 3 , that is, LC,实 =ρ LC , the determined lightweight aggregate and mortar can meet the requirements, and the target lightweight aggregate concrete mix design is completed.

[0070] Example 3

[0071] In this embodiment, the core physical parameters of the mortar are known, and the core physical parameters of the lightweight aggregate are unknown. The lightweight aggregate concrete mix design method based on the core physical parameters provided in this embodiment comprises the following specific steps:

[0072] S301: Setting the target compressive strength f of lightweight aggregate concrete c =50MPa and target density ρ LC =1900kg / m 3 .

[0073] S302: Determine the core physical parameters of the mortar components, including the compressive strength of the mortar motar =61.2MPa, mortar density ρ motar =1840kg / m 3.

[0074] S303: Estimate or assume the volume of lightweight aggregate component V LWA =0.285.

[0075] S304: Calculate the lightweight aggregate cylinder compressive strength f according to the strength formula LWA ;

[0076] In this step, the target compressive strength f c =50MPa, compressive strength of mortar f motar =61.2MPa, volume dosage of lightweight aggregate component V LWA =0.285Substitute into the strength formula Calculate the lightweight aggregate cylinder compressive strength f LWA =10.517MPa;

[0077] S305: Temporarily estimate or assume that the mass water absorption rate of lightweight aggregate Φ = 10%, and then calculate the apparent density ρ of lightweight aggregate according to the density formula LWA ;

[0078] In this step, the target density ρ LC =1900kg / m 3 , Volume dosage of lightweight aggregate component V LWA =0.285, mortar density ρ motar =1840kg / m 3 , the mass water absorption rate of lightweight aggregate Φ = 10% and the density of water ρ water =1000kg / m 3 Substitute into the density formula ρ LC =ρ LWA ·V LWA +ρ motar (1-V LWA )+ρ motar ·V LWA ·Φ·ρ LWA / ρ water , the apparent density of lightweight aggregate ρ is calculated LWA =1731.87kg / m 3 ;

[0079] Therefore, the cylinder pressure strength should be ≥10.517MPa, the mass water absorption rate should be ≤10%, and the apparent density should be ≤1731.87kg / m 3 The lightweight aggregate is used as the lightweight aggregate in the target lightweight aggregate concrete.

[0080] S306: Determine the actual mix density ρ of lightweight aggregate concrete according to the density formula LC,实 ;

[0081] In this step, the apparent density of lightweight aggregate ρ LWA =1731.87kg / m 3 , Volume of lightweight aggregate component V LWA =0.285, mortar density ρ motar =1840kg / m 3 , the mass water absorption rate of lightweight aggregate Φ = 10% and the density of water ρ water =1000kg / m 3 Substitute into the density formula ρ LC,实 =ρ LWA ·V LWA +ρ motar (1-V LWA )+ρ motar ·V LWA ·Φ·ρ LWA / ρ water , the actual mix density ρ of lightweight aggregate concrete is calculated LC, Actual = 1900kg / m 3 ;

[0082] S307: Comparison of actual density of lightweight aggregate concrete ρ LC,实 With the target density ρ LC , ρ LC, Actual = 1900kg / m 3 =ρ LC =1900kg / m 3 , that is, LC,实 =ρ LC , the determined lightweight aggregate and mortar can meet the requirements, and the target lightweight aggregate concrete mix design is completed.

[0083] Example 4

[0084] In this embodiment, the core physical parameters of lightweight aggregate and mortar are unknown. The lightweight aggregate concrete mix design method based on core physical parameters provided in this embodiment comprises the following specific steps:

[0085] S401: Setting the target compressive strength f of lightweight aggregate concrete c =40MPa and target density

[0086] ρ LC =1950kg / m 3 .

[0087] S402: Estimate or assume the volume of lightweight aggregate component V LWA =0.285.

[0088] S403: Estimate or assume the compressive strength of mortar f motar =f c+20=60.0MPa

[0089] S404: Calculate the lightweight aggregate cylinder compressive strength f according to the strength formula LWA ;

[0090] In this step, the target compressive strength f c =40MPa, compressive strength of mortar f motar =60.0MPa, volume dosage of lightweight aggregate component V LWA =0.285Substitute into the strength formula Calculate the lightweight aggregate cylinder compressive strength f LWA =5.066MPa;

[0091] S405: Temporarily estimate or assume that the mass water absorption rate of lightweight aggregate Φ = 10%, mortar density ρ motar =2000kg / m 3 , then the apparent density ρ of lightweight aggregate is calculated according to the density formula LWA =1520.47kg / m 3 ;

[0092] In this step, the target density ρ LC =1950kg / m 3 , Volume dosage of lightweight aggregate component V LWA =0.285, mortar density ρ motar =2000kg / m 3 , the mass water absorption rate of lightweight aggregate Φ = 10% and the density of water ρ water =1000kg / m 3 Substitute into the density formula ρ LC =ρ LWA ·V LWA +ρ motar (1-V LWA )+ρ motar ·V LWA ·Φ·ρ LWA / ρ water , the apparent density of lightweight aggregate ρ is calculated LWA =1520.47kg / m 3 ;

[0093] Therefore, the cylinder pressure strength is ≥5.066MPa, the mass water absorption rate is ≤10%, and the apparent density is ≤1520.47kg / m 3 The lightweight aggregate is selected as the lightweight aggregate in the target lightweight aggregate concrete, with a compressive strength of ≥60.0MPa and a density of ≤2000kg / m 3 The mortar is used as the mortar in the target lightweight aggregate concrete.

[0094] S406: Determine the actual density of lightweight aggregate concrete according to the density formula LC,实 ;

[0095] In this step, the apparent density of lightweight aggregate ρ LWA =1520.47kg / m 3 , Volume dosage of lightweight aggregate component V LWA =0.285, mortar density ρ motar =2000kg / m 3 , the mass water absorption rate of lightweight aggregate Φ = 10% and the density of water ρ water =1000kg / m3Substitute into the density formula ρ LC,实 =ρ LWA ·V LWA +ρ motar (1-V LWA )+ρ motar ·V LWA ·Φ·ρ LWA / ρ water , the actual mix density ρ of lightweight aggregate concrete is calculated LC, Actual = 1950kg / m 3 ;

[0096] S407: Comparison of actual density of lightweight aggregate concrete ρ LC,实 With the target density ρ LC , ρ LC, Actual = 1950kg / m 3 =ρ LC =1950kg / m 3 , that is, LC,实 =ρ LC , the determined lightweight aggregate and mortar can meet the requirements, and the target lightweight aggregate concrete mix design is completed.

[0097] Furthermore, in order to further verify the accuracy and reliability of the lightweight aggregate concrete mix design method based on core physical parameters provided by the present disclosure, the present disclosure also provides a lightweight aggregate concrete, which is obtained by applying the lightweight aggregate concrete mix design method based on core physical parameters.

[0098] Based on the core physical parameters of lightweight aggregate and mortar obtained according to the method of the present disclosure in Examples 1 to 4 and the volumetric dosage of lightweight aggregate per cubic meter, lightweight aggregate concrete was tested, and the compressive strength and density properties of lightweight aggregate concrete were tested according to the GB / T50081-2019 method, and compared with the target lightweight aggregate. The test and comparison results are shown in the following table

[0099]

[0100] It can be seen that the lightweight aggregate concrete obtained by using the lightweight aggregate concrete mix design method based on core physical parameters disclosed in the present invention basically matches the performance of the target lightweight aggregate, thereby verifying the accuracy and practicality of the lightweight aggregate concrete mix design method based on core physical parameters provided by the present invention.

[0101] At the same time, the lightweight aggregate concrete mix design method based on core physical parameters provided by the present invention breaks through the limitations of specific aggregate and mortar combinations, and can obtain the core physical parameters and the unit volume consumption of lightweight aggregate under any lightweight aggregate and mortar combination according to the density formula and the strength formula, thereby completing the mix design of lightweight aggregate concrete. The method is simple to operate and easy to use, and covers a wider range of lightweight aggregate concrete strengths, and is no longer limited to the design of traditional lightweight aggregate concrete of 60MPa and below.

[0102] It will be appreciated by those skilled in the art that the features described in the various embodiments of the present disclosure may be combined and / or combined in a variety of ways, even if such combinations or combinations are not explicitly described in the present disclosure. In particular, without departing from the spirit and teachings of the present disclosure, the features described in the various embodiments of the present disclosure may be combined and / or combined in a variety of ways. All of these combinations and / or combinations fall within the scope of the present disclosure.

[0103] The embodiments of the present disclosure are described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present disclosure. Although the embodiments are described above, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. Without departing from the scope of the present disclosure, those skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A method for designing a mix ratio of lightweight aggregate concrete based on core physical parameters, wherein the lightweight aggregate concrete comprises two components: lightweight aggregate and mortar. The method comprises: S1: Set the target compressive strength f of lightweight aggregate concrete c and the target density ρ LC ; S2: Obtain all core physical parameters of the two components of lightweight aggregate and mortar, wherein the core physical parameters of the two components of lightweight aggregate and mortar include: the volume dosage V of the lightweight aggregate component LWA , Lightweight aggregate apparent density ρ LWA , lightweight aggregate cylinder compressive strength f LWA , the mass water absorption rate of lightweight aggregate Φ, the compressive strength of mortar f motar and mortar density ρ motar ; S3: Calculate the actual mix density ρ of lightweight aggregate concrete according to the density formula LC,实 =ρ LwA ·V LWA +ρ motar ·(1-V LWA )+ρ motar ·V LWA ·Φ·ρ LWA / ρ water ; S4: Compare the actual density of lightweight aggregate concrete ρ LC,实 With the target density ρ LC , if LC,实 ≤ρ LC , then the lightweight aggregate and mortar components meet the requirements, and the target lightweight aggregate concrete mix design is completed; if ρ LC,实 >ρ LC , then the lightweight aggregate and mortar components do not meet the requirements, then reselect new lightweight aggregate and mortar, and repeat steps S2 to S4 until ρ LC,实 ≤ρ LC until.

2. The lightweight aggregate concrete mix design method based on core physical parameters according to claim 1 is characterized in that: The target compressive strength f of the lightweight aggregate concrete in step S1 is c The value range is 30~120MPa, and the target density ρ LC The value range is 1400~1950kg / m 3 .

3. The lightweight aggregate concrete mix design method based on core physical parameters according to claim 1 is characterized in that: The step S2 of obtaining all the core physical parameters of the two components of lightweight aggregate and mortar includes: S21: Determine whether the core physical parameters of the lightweight aggregate and mortar components are all known. If yes, execute step S22; otherwise, execute step S23; S22: Determination of the core physical parameters of lightweight aggregate and mortar, including the apparent density of lightweight aggregate ρ LWA , lightweight aggregate cylinder compressive strength f LWA , the mass water absorption rate of lightweight aggregate Φ, the compressive strength of mortar f motar and mortar density ρ motar ; Then calculate the volume of lightweight aggregate component V according to the strength formula LWA , obtain all the core physical parameters of lightweight aggregate and mortar; S23: Determine the known core physical parameters of the lightweight aggregate and mortar components, and estimate the volumetric dosage V of the lightweight aggregate component LWA Then, based on the known core physical parameters of the two components of lightweight aggregate and mortar, the estimated volume dosage V of the lightweight aggregate component LWA , as well as the density formula and strength formula, the remaining unknown core physical parameters of lightweight aggregate and mortar are calculated to obtain all the core physical parameters of lightweight aggregate and mortar.

4. The lightweight aggregate concrete mix design method based on core physical parameters according to claim 3 is characterized in that: The density formula is: LC =ρ LWA ·V LWA +ρ motar ·(1-V LWA )+ρ motar ·V LWA ·Φ·ρ LWA / ρ water , where the density of water is water =1000kg / m 3 ; The strength formula is:

5. The lightweight aggregate concrete mix design method based on core physical parameters according to claim 4 is characterized in that: The step S21 is to determine whether the core physical parameters of the two components, lightweight aggregate and mortar, are all known. If the core physical parameters of the lightweight aggregate component are known and the core physical parameters of the mortar component are unknown, then step S23 includes: Determine the key physical parameters of lightweight aggregate components, including lightweight aggregate density ρ LWA , lightweight aggregate cylinder compressive strength f LWA , mass water absorption rate of lightweight aggregate Φ; Estimate or assume the volume of lightweight aggregate component V LWA ; Calculate the mortar density ρ according to the density formula motar ; Calculate the compressive strength f of mortar according to the strength formula motar .

6. The lightweight aggregate concrete mix design method based on core physical parameters according to claim 4 is characterized in that: The step S21 is to determine whether the core physical parameters of the two components, lightweight aggregate and mortar, are all known. If the core physical parameters of the mortar are known and the core physical parameters of the lightweight aggregate are unknown, then step S23 includes: Determination of key physical parameters of mortar components, including the compressive strength of the mortar motar 、Mortar density ρ motar ; Estimate or assume the volume of lightweight aggregate component V LWA ; Calculate the cylinder compressive strength f of lightweight aggregate according to the strength formula LWA ; Temporarily estimate or assume the mass water absorption rate Φ of lightweight aggregate, and calculate the apparent density ρ of lightweight aggregate according to the density formula LWA .

7. The lightweight aggregate concrete mix design method based on core physical parameters according to claim 4 is characterized in that: The step S21 is to determine whether the core physical parameters of the two components, lightweight aggregate and mortar, are all known. If the core physical parameters of the lightweight aggregate and mortar are all unknown, then step S23 includes: Estimate or assume the volume of lightweight aggregate component V LWA ; Estimate or assume the compressive strength of the mortar f motar ; Calculate the cylinder compressive strength f of lightweight aggregate according to the strength formula LWA ; Temporarily estimate or assume the mass water absorption rate Φ of lightweight aggregate and the density ρ of mortar motar , the apparent density of lightweight aggregate ρ is calculated according to the density formula LWA .

8. The lightweight aggregate concrete mix design method based on core physical parameters according to claim 1, characterized in that: Among all the core physical parameters of the lightweight aggregate and mortar components described in step S2, the apparent density of the lightweight aggregate is LWA The value range is 1000~1500kg / m 3 , lightweight aggregate cylinder compressive strength f LWA The value range is 3~20MPa, the mass water absorption rate of lightweight aggregate is Φ≤15%, and the compressive strength of mortar is f motar ≤150MPa, mortar density ρ motar The value range is 1300~2200kg / m 3 , light bone mass single volume dosage V LWA <0.

5.

9. The lightweight aggregate concrete mix design method based on core physical parameters according to claim 1, characterized in that: The light aggregate component material is spherical light aggregate.

10. A lightweight aggregate concrete obtained by applying the lightweight aggregate concrete mix design method based on core physical parameters as claimed in any one of claims 1 to 9.

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