scholarly journals Fractal dimension of concrete mix gradation: a quantitative parameter for some concrete properties

2020 ◽  
Vol 307 ◽  
pp. 01049
Author(s):  
Soumia Kheira Sebsadji ◽  
Kaddour Chouicha
Keyword(s):  
Fractal Dimension ◽  
Design Method ◽  
Fine Fraction ◽  
Concrete Mixture ◽  
Fine Aggregate ◽  
Concrete Properties ◽  
Average Grain Size ◽  
Concrete Mix ◽  
Analytical Formulas ◽  
Coarse To Fine

This study is based upon the fractal feature of ideal Particle Size Distributions (PSD) suggested by numerous concrete mix designs, i.e. ideal PSD can be shown to be equivalent to a power law distributions EC(ϕi) ∝ ϕi− DF, EC(ϕi) is the number of grains of size greater than ϕi, and DF is a nonwhole number called fractal dimension. This fact allows us to analyze the solid skeleton of a concrete mix (all solid components of the mixture) as a fractal structure, thus to determine some of physical properties of the concrete mixture. For DF ranging from 2.5 to 3, and based upon many parameters of the concrete mix (as the granular range, the volumetric fraction of solids in the concrete mixture…), analytical formulas have been proposed relating DF and some properties of the concrete in the solid state. The required properties are the coarse-to-fine aggregate ratio, the fineness modulus of the sand fraction, the average grain size and volume of the fine fraction in the concrete mix. The focus of this research is to develop formulas by which concrete properties can be predicted knowing the concrete mix gradation, i.e. the mix design method used.

scholarly journals Concrete Mix Design for Completely Recycled Fine Aggregate by Modified Packing Density Method

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3535
Author(s):  
Yibo Yang ◽  
Baixi Chen ◽  
Yan Su ◽  
Qianpu Chen ◽  
Zhiji Li ◽  
...  
Keyword(s):  
Packing Density ◽  
Unit Price ◽  
Mix Design ◽  
Concrete Mixture ◽  
Fine Aggregate ◽  
Density Method ◽  
Concrete Mix Design ◽  
Recycled Fine Aggregate ◽  
Concrete Mix ◽  
Aggregate System

The undesirable properties of conventional recycled fine aggregate (RFA) often limit its application in the construction industry. To overcome this challenge, a method for preparing completely recycled fine aggregate (CRFA), which crushes all concrete waste only into fine aggregate, was proposed. The obtained CRFA had high apparent density, and its water absorption was lower than that of the conventional RFA. To take advantage of the CRFA, this paper introduced the modified packing density method for the CRFA concrete mix design. The modified packing density method took account of the powder with a particle size of smaller than 75 μm in the CRFA and balanced both the void ratio and the specific surface area of the aggregate system. Concrete (grade C55) was prepared using the CRFA to validate the feasibility of the proposed method. The unit price of the prepared CRFA concrete was around 12.7% lower than that of the natural aggregate concrete. Additionally, the proposed procedure for the concrete mixture design could recycle all concrete waste into the new concrete and replace all the natural fine aggregate in the concrete mixture.

Experimental Research on Grading of Fine Aggregate in Frame Concrete

2010 ◽  
Vol 163-167 ◽  
pp. 1085-1089 ◽  
Author(s):  
Zhen Shuang Wang ◽  
Li Jiu Wang ◽  
Hao Lin Su
Keyword(s):  
Fractal Dimension ◽  
Coarse Aggregate ◽  
Design Method ◽  
Fractal Theory ◽  
Uniform Design ◽  
Fine Aggregate ◽  
N Value ◽  
Uniform Design Method ◽  
The Relationship ◽  
Mortar Matrix

According to frame concrete theory, Concrete was composed of mortar matrix, coarse aggregate, and transition zone between mortar matrix and coarse aggregate. Proper particle grading of fine aggregate can not only save cement, but also increase comprehensive properties of mortar matrix. Uniform design method was used to study the relationships between the grading of fine aggregate and workability, and the relationship with mechanic properties of mortar matrix and concrete. Based on fractal theory, the relationship between fractal dimension and modulus of fineness, and the relationship between fractal dimension and n value in Fuller equation were researched. It concluded that grading of fine aggregate affects the workability and mechanic properties of mortar matrix and concrete, significantly. There was a good linear relation between fractal dimension and n value in Fuller Equation, and fratatal dimension decreased with modulus of fineness increasing.

Influence of “MC-Bauchemie” Additions on the Fine-Grained Concrete Properties

2020 ◽  
Vol 309 ◽  
pp. 114-119
Author(s):  
Ekaterina S. Gerasimova ◽  
Elizaveta Gumirova
Keyword(s):  
Cement Stone ◽  
Hardened Cement ◽  
Fine Aggregate ◽  
Fine Grained ◽  
Concrete Properties ◽  
Concrete Mix ◽  
Materials Used ◽  
Effective Additive ◽  
Optimal Quantity

The paper is devoted to research of influence of “MC-Bauchemie” additions on the fine-grained concrete properties, namely compressive strength. The results of testing of fine-grained concrete made on the basis of two different natural sands are presented. Characteristics of the initial materials used in the work (Portland cement, sands and additions-plasticizers) are given. The basic methods of preparation of mixes and testing of hardened cement stone and concrete are described. The optimal quantity of the selected additions on the example of cement paste and stone are established. Mobility dependences of concrete mixes on a type and quantity of plasticizers are received. The dependence of the additions effectiveness on the mobility of the concrete mix on the quality of the fine aggregate is shown. It is established that the most effective additive is PowerFlow 3100, its optimal amount for obtaining fine-grained concrete on the basis of JSC “Kar’er Myisyi” sand is 0.2 %.

Study on concrete proportioning methods: a qualitative and economical perspective

2021 ◽  
Vol 12 (1) ◽  
pp. 20
Author(s):  
Shoib Bashir Wani ◽  
Tahir Hussain Muntazari ◽  
Nusrat Rafique
Keyword(s):  
Design Method ◽  
Concrete Strength ◽  
Performance Criteria ◽  
Mix Design ◽  
Design Parameters ◽  
Fine Aggregate ◽  
Aggregate Content ◽  
Concrete Mix Design ◽  
Concrete Mix ◽  
Moderate Climate

The various approaches, established for concrete mix design, are not universal because design mixes are explicit to local climate, available materials, and type of exposure. The new-generation mix design method should be developed based on the performance criteria. The concrete strength obtained from the designed concrete mix and optimum cement content should not be considered as the only parameter for the suitability of the concrete mix. This study was carried to compare the proportioning of concrete mixes obtained by following procedures of Indian Standard (IS), American Concrete Institute (ACI) and British Standard (BS) of concrete mix design without the use of admixtures to validate for use in a moderate climate like Kashmir, India. The concrete mixes have been prepared with the necessary 28 days resistance in compression as “15 MPa, 20 MPa, 25 MPa, 30 MPa and 35 MPa”. The assessment of water-cement (w/c) ratio; cement, water, fine aggregate (FA) and coarse aggregate (CA) proportion was carried. The w/c ratio among all formulated mixes is significantly high in the BS method and low for IS method. The BS method uses less quantity and IS method uses the maximum quantity of cement. In addition, the ratio of total aggregate content (TAC) and the aggregate-cement ratio is higher in BS design method as compared to IS and ACI design methods. The aggregate content in ACI mix design appears to be consistent and it added to the relative high compressive strength. The specimens cast following BS guidelines failed to attain the target mean strength (TMS) due to a higher volume of aggregate content, high w/c proportion, less quantity of cement in the mix. The specimens cast by ACI and IS mix design upon compression testing showed higher results than the calculated TMS. The cost analysis per cubic meter of concrete revealed that IS and ACI mix proportioning are expensive than BS method. The IS procedure results in dense concrete followed by ACI procedure. It is expected that with a comprehensive investigation on selected design parameters concentrating more on local challenges, the present study will floor the way for the development and adoption of performance-based design mix selection for moderate climate.

scholarly journals Performance Evaluation of Soft Computing for Modeling the Strength Properties of Waste Substitute Green Concrete

2021 ◽  
Vol 13 (5) ◽  
pp. 2867
Author(s):  
Muhammad Izhar Shah ◽  
Muhammad Nasir Amin ◽  
Kaffayatullah Khan ◽  
Muhammad Sohaib Khan Niazi ◽  
Fahid Aslam ◽  
...  
Keyword(s):  
Predictive Models ◽  
Parametric Study ◽  
Cross Validation ◽  
Strength Properties ◽  
Fine Aggregate ◽  
Agricultural Industry ◽  
Green Concrete ◽  
Concrete Properties ◽  
Water To Cement Ratio ◽  
Sugarcane Bagasse Ash

The waste disposal crisis and development of various types of concrete simulated by the construction industry has encouraged further research to safely utilize the wastes and develop accurate predictive models for estimation of concrete properties. In the present study, sugarcane bagasse ash (SCBA), a by-product from the agricultural industry, was processed and used in the production of green concrete. An advanced variant of machine learning, i.e., multi expression programming (MEP), was then used to develop predictive models for modeling the mechanical properties of SCBA substitute concrete. The most significant parameters, i.e., water-to-cement ratio, SCBA replacement percentage, amount of cement, and quantity of coarse and fine aggregate, were used as modeling inputs. The MEP models were developed and trained by the data acquired from the literature; furthermore, the modeling outcome was validated through laboratory obtained results. The accuracy of the models was then assessed by statistical criteria. The results revealed a good approximation capacity of the trained MEP models with correlation coefficient above 0.9 and root means squared error (RMSE) value below 3.5 MPa. The results of cross-validation confirmed a generalized outcome and the resolved modeling overfitting. The parametric study has reflected the effect of inputs in the modeling process. Hence, the MEP-based modeling followed by validation with laboratory results, cross-validation, and parametric study could be an effective approach for accurate modeling of the concrete properties.

Sludge Ash as Fine Aggregate for Concrete Mix

1995 ◽  
Vol 121 (9) ◽  
pp. 633-638 ◽  
Author(s):  
R. Khanbilvardi ◽  
S. Afshari
Keyword(s):  
Fine Aggregate ◽  
Concrete Mix ◽  
Sludge Ash

Measure and Analyze the Problems of Concrete Mixture Production via Six Sigma DMAIC Tools: Central Concrete Mix Plant as a Case Study

2012 ◽  
Vol 622-623 ◽  
pp. 472-477
Author(s):  
Ali A. Karakhan ◽  
Angham E. Alsaffar
Keyword(s):  
Six Sigma ◽  
Business Strategy ◽  
Concrete Mixture ◽  
Statistical Tools ◽  
Sigma Level ◽  
Defect Rate ◽  
Concrete Production ◽  
Concrete Mix ◽  
Six Sigma Methodology

The aims of this study are to measure the defect rate and analyze the problems of production of ready concrete mixture plant by using Six Sigma methodology which is a business strategy for operations improvement depending basically on the application of its sub-methodology DMAIC improvement cycle and the basic statistical tools where the process sigma level of concrete production in the case study was 2.41 σ.

scholarly journals THE INFLUENCE OF GRANITE SIFTINGS ON THE PROPERTIES OF CLEAVED SURFACE EXTERIOR CONCRETE BRICKS

2010 ◽  
Vol 2 (6) ◽  
pp. 43-49 ◽  
Author(s):  
Mindaugas Tumosa ◽  
Mindaugas Daukšys ◽  
Ernestas Ivanauskas
Keyword(s):  
Mechanical Properties ◽  
Concrete Mixture ◽  
Fine Aggregate ◽  
Technological Properties ◽  
Product Durability

Research deals with granite siftings as fine aggregate possibilities to be used for manufacturing cleaved surface exterior concrete bricks. The article describes the influence of granite siftings on the technological properties of concrete mixture and on the physical mechanical properties of cleaved surface exterior concrete bricks formed using these mixtures and forecasts product durability. The following several compositions of concrete mixture for producing exterior concrete bricks are composed: using only 0/4 fraction sand (B1) as a fine aggregate, using only 0/2 fraction granite siftings (B2), and 50% of 0/4 fraction sand replacing with 0/2 fraction granite siftings (B3) depending on the volume. The products were formed in metal moulds; at a later stage, they were cleaved in half. The technological properties of concrete mixture and the physical mechanical properties of cleaved surface exterior concrete bricks formed using the above introduced mixtures were tested forecasting product durability. The results of the conducted research reveal that due to the properly selected ratio between sand and granite siftings in the fine aggregate, granite siftings may be used for manufacturing cleaved surface exterior concrete bricks.

scholarly journals Analysis of influencing factors of flow state concrete mixture performance

2021 ◽  
Vol 2076 (1) ◽  
pp. 012073
Author(s):  
Dandan Shi ◽  
Xing Qin ◽  
Hao Qu
Keyword(s):  
Measurement Method ◽  
Engineering Application ◽  
Performance Testing ◽  
Reducing Agent ◽  
Mineral Admixture ◽  
Raw Material ◽  
Concrete Mixture ◽  
Flow State ◽  
Test Results ◽  
Concrete Mix

Abstract Based on the principle of benefiting the durability of concrete, machined sand is used to configure C40 flow concrete, and the engineering application environment and economy are considered. In this paper, the author through the flow state concrete mix ratio design, give the raw material dosage, concrete mixing, finally combined with the workability measurement method, five groups of concrete mix performance testing. According to the test results, the influence of mineral admixture and water reducing agent on the workability of concrete mixture is studied and analyzed, and the reasonable admixture dosage and water reducing rate of water reducing agent and its admixture dosage are finally given.

Durability and Mechanical Properties of Self-Compacting Concrete Incorporating Recovered Filler from Hot Mix Asphalt Plants and Recycled Fine Aggregate

2021 ◽  
Vol 894 ◽  
pp. 95-101
Author(s):  
Sepehr Ghafari ◽  
Fereidoon Moghadas Nejad ◽  
Ofelia Corbu
Keyword(s):  
Compressive Strength ◽  
Hot Mix Asphalt ◽  
Mechanical Performance ◽  
Fine Fraction ◽  
Production Plant ◽  
Fine Aggregate ◽  
Self Compacting Concrete ◽  
Limestone Filler ◽  
Recycled Fine Aggregate ◽  
Maximum Particle

In this research, a sustainable approach is followed to develop efficient mixtures incorporating recycled fine aggregate (RFA) remained from structure demolition as well as limestone filler (LF) from production of hot mix asphalt (HMA). The LF is a byproduct of the drying process in HMA production plant which is not entirely consumed in the production of the HMA and must be hauled and disposed in landfills. The maximum particle size of the LF is approximately 40 µm. Self-Compacting Concrete (SCC) mixtures were designed replacing 5% and 10% of the cement with LF. Incorporation of 50%, and 100% RFA with the fines in the mixtures were considered with and without addition of the LF. Due to the formwork and prefabrication restrictions, the paste volume and the high range water reducer content were tuned in such a way that the slump flow of the mixtures remained between 660 mm to 700 mm without segregation. Durability and mechanical performance of the mixtures were evaluated by resistance against freeze-thaw scaling exposed to deicing agents and compressive strength. It was observed that the SCC mixtures containing 10% LF outperformed those without the use of LF while 5% SCC mixtures did not exhibit tangible superiority. Incorporation of RFA as the fine fraction degraded the durability of all the mixtures. While replacing all the fine fraction with RFA significantly impaired durability and compressive strength, 50% RF mixtures could be designed containing 10% LF that remained in the allowable limits.

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