scholarly journals Development of Concrete Mixture Design Process Using MCDM Approach for Sustainable Concrete Quality Management

2020 ◽  
Vol 12 (19) ◽  
pp. 8110
Author(s):  
Mohd. Ahmed ◽  
Javed Mallick ◽  
Saeed AlQadhi ◽  
Nabil Ben Kahla
Keyword(s):  
Quality Management ◽  
Design Process ◽  
Design Procedure ◽  
Mixture Design ◽  
Design Methods ◽  
Concrete Mixture ◽  
Sustainable Concrete ◽  
Concrete Production ◽  
Concrete Mix ◽  
Concrete Quality

The development of a concrete mixture design process for high-quality concrete production with sustainable values is a complex process because of the multiple required properties at the green/hardened state of concrete and the interdependency of concrete mixture parameters. A new multicriteria decision making (MCDM) technique based on Technique of Order Preference Similarity to the Ideal Solution (TOPSIS) methodology is applied to a fuzzy setting for the selection of concrete mix factors and concrete mixture design methods with the aim towards sustainable concrete quality management. Three objective properties for sustainable quality concrete are adopted as criteria in the proposed MCDM model. The seven most dominant concrete mixture parameters with consideration to sustainable concrete quality issues, i.e., environmental (density, durability) and socioeconomic criteria (cost, optimum mixture ingredients ratios), are proposed as sub-criteria. Three mixture design techniques that have potentiality to include sustainable aspects in their design procedure, two advanced and one conventional concrete mixture design method, are taken as alternatives in the MCDM model. The proposed selection support framework may be utilized in updating concrete design methods for sustainability and in deciding the most dominant concrete mix factors that can provide sustainable quality management in concrete production as well as in concrete construction. The concrete mix factors found to be most influential to produce sustainable concrete quality include the water/cement ratio and density. The outcomes of the proposed MCDM model of fuzzy TOPSIS are consistent with the published literature and theory. The DOE method was found to be more suitable in sustainable concrete quality management considering its applicable objective quality properties and concrete mix factors.

scholarly journals Life-Cycle Assessment of the Substitution of Sand with Coal Bottom Ash in Concrete: Two Concrete Design Methods

2019 ◽  
Vol 9 (17) ◽  
pp. 3620 ◽  
Author(s):  
Svetlana Pushkar
Keyword(s):  
Life Cycle ◽  
Design Method ◽  
Bottom Ash ◽  
Mixture Design ◽  
Design Methods ◽  
Concrete Mixture ◽  
Electricity Production ◽  
Environmental Damage ◽  
Coal Bottom Ash ◽  
Concrete Production

Life-cycle assessments (LCAs) were conducted to evaluate the replacement of sand with coal bottom ash (CBA) in concrete. CBA is a byproduct of coal-fueled electricity production. Sand was replaced with CBA at proportions of 0, 25, 50, 75, and 100 wt.%, and the resultant concretes were denoted as CBA0, CBA25, CBA50, CBA75, and CBA100, respectively. Two concrete mixture design methods (that resulted in different component qualities of concrete mixtures) were used: (i) Mixture with a fixed slump (MIX-fixed-SLUMP) and (ii) mixture with a fixed water/cement ratio (MIX-fixed-W/C). The ReCiPe2016 midpoint and single score (six methodological options) methods were followed to compare the environmental damage caused by the CBA-based concretes. The ReCiPe2016 results showed that replacing sand with CBA was environmentally (i) beneficial with the MIX-fixed-SLUMP design and (ii) harmful with the MIX-fixed-W/C design. Therefore, using CBA as a partial sand replacement in concrete production is a controversial issue as it highly depends on the concrete mixture design method.

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.

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

2013 ◽  
Vol 313-314 ◽  
pp. 771-776
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.

Design of rural water systems using dynamic models

1999 ◽  
Vol 39 (4) ◽  
pp. 221-231
Author(s):  
A. H. Lobbrecht
Keyword(s):  
Dynamic Models ◽  
Water System ◽  
Design Procedure ◽  
Real Data ◽  
Water Systems ◽  
Design Methods ◽  
Water Quality Criteria ◽  
Rural Water ◽  
Rural Water Systems ◽  
The Way

The properties of main water ways and infrastructure of rural water systems are often determined by very general design methods. These methods are based on standards that use only little information of the actual water system. Most design methods applied in the Netherlands are based on land use and soil texture. Standards have been developed on the basis of generalized properties of water systems. Details of the actual layout of the water system and the way in which that system is controlled, are usually not incorporated. Present-day dynamic simulation programs and the computer power currently available enable more detailed modeling and incorporation of location-specific data into models. Such models can be used to design the water system and can include real data. A model-based design method is introduced, in which the actual situation of the water system is taken into consideration as well as the way in which the water system is controlled. Stochastics concerning the operation and availability of controlling infrastructure are included in the method. Models can be evaluated by including real data. In this way the actual safety of the water system, for example during floods, can be determined. Water-quantity design criteria can be incorporated as well as water-quality criteria. Application of the method makes it possible to design safe water systems in which excess capacities are avoided and in which all requirements of interest are met. The method, called the ‘dynamic design procedure’, can result in considerable savings for water authorities when new systems have to be designed or existing designs have to be reconsidered.

scholarly journals A review on sustainable concrete mix proportions

2021 ◽  
Vol 1025 ◽  
pp. 012019
Author(s):  
Kanta Naga Rajesh ◽  
Ponnada Markandeya Raju ◽  
Kapileswar Mishra ◽  
Pavan Kumar Madisetti
Keyword(s):  
Sustainable Concrete ◽  
Concrete Mix

Impact of Secondary Flow on the Accuracy of Simplified Design Methods for Steam Turbine Stages

2012 ◽  
Author(s):  
Jan Schumann ◽  
Ulrich Harbecke ◽  
Daniel Sahnen ◽  
Thomas Polklas ◽  
Peter Jeschke ◽  
...  
Keyword(s):  
Secondary Flow ◽  
Steam Turbine ◽  
Design Process ◽  
Design Method ◽  
Computing Time ◽  
Leading Edge ◽  
Design Methods ◽  
Preliminary Design ◽  
Line Design ◽  
Radial Equilibrium

The subject of the presented paper is the validation of a design method for HP and IP steam turbine stages. Common design processes have been operating with simplified design methods in order to quickly obtain feasible stage designs. Therefore, inaccuracies due to assumptions in the underlying methods have to be accepted. The focus of this work is to quantify the inaccuracy of a simplified design method compared to 3D Computational Fluid Dynamics (CFD) simulations. Short computing time is very convenient in preliminary design; therefore, common design methods work with a large degree of simplification. The origin of the presented analysis is a mean line design process, dealing with repeating stage conditions. Two features of the preliminary design are the stage efficiency, based on loss correlations, and the mechanical strength, obtained by using the beam theory. Due to these simplifications, only a few input parameters are necessary to define the primal stage geometry and hence, the optimal design can easily be found. In addition, by using an implemented law to take the radial equilibrium into account, the appropriate twist of the blading can be defined. However, in comparison to the real radial distribution of flow angles, this method implies inaccuracies, especially in regions of secondary flow. In these regions, twisted blades, developed by using the simplified radial equilibrium, will be exposed to a three-dimensional flow, which is not considered in the design process. The analyzed design cases show that discrepancies at the hub and shroud section do exist, but have minor effects. Even the shroud section, with its thinner leading-edge, is not vulnerable to these unanticipated flow angles.

Study on Techniques for Rapidly Testing the Composition of Concrete Mixture

2013 ◽  
Vol 838-841 ◽  
pp. 30-35
Author(s):  
Xiao Bin Sun ◽  
Tian Ling Du ◽  
Bo Tian
Keyword(s):  
Quality Control ◽  
Laboratory Test ◽  
Rapid Detection ◽  
Measurement Accuracy ◽  
Fresh Concrete ◽  
Concrete Mixture ◽  
Quality Problem ◽  
Detection Techniques ◽  
Concrete Quality ◽  
Practical Engineering

With regards to the quality problem of concrete that cant be found out earlier in the quality control, this paper discussed the principle to rapidly detect composition of concrete mixture and analyzed the measurement accuracy of water checker for fresh concrete through laboratory test. Experiments showed that the error in unit cement and unit water measured by instruments is relatively small and able to meet the accuracy requirements. And, the application of rapid detection techniques to the concrete quality control in practical engineering has achieved good results.

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.

scholarly journals MAIN PROBLEMS OF MANUFACTURING ASPHALT CONCRETE MIXTURES IN LITHUANIA/ASFALTBETONIO MIŠINIŲ GAMYBOS SVARBIAUSIOS PROBLEMOS LIETUVOJE

2000 ◽  
Vol 6 (1) ◽  
pp. 39-45
Author(s):  
Donatas Čygas
Keyword(s):  
Asphalt Concrete ◽  
High Speed ◽  
Statistical Data ◽  
Concrete Mixture ◽  
Cement Material ◽  
Asphalt Cement ◽  
Concrete Mixtures ◽  
Concrete Quality ◽  
Regressive Analysis ◽  
Speed Gradient

The article describes the main problems of manufacturing asphalt concrete mixtures at the factories under Ministry of Communication in the Republic of Lithuania. The Lithuanian Road Network is up to 21.122 km of state roads. 1.455 km of them are motorways, 3.415 km—national roads and 16.251 km—regional roads. Half of the state roads in Lithuania are paved with asphalt concrete. 98% of the motorways and 36% of the regional roads have asphalt pavement. Asphalt concrete pavement resistance to corrosion can be increased by improving asphalt concrete mixture production technology: ie by updating technological equipment, changing technological conditions and developing new methods of asphalt concrete mixture production. Therefore, the updating of asphalt concrete mixture production technologies is a very important factor for improving road operating properties and ensuring proper duration of asphalt concrete pavements. Here is the essence of the new separate successive technology: crushed stone and sand are mixed with bitumen in the main asphalt concrete mixer, the amount of bitumen being calculated according to the bitumen absorption in the materials. Then the asphalt cement material produced in a separate high-speed mixer is passed, and the whole mixture is remixed in the main mixer and supplied to the customer. Both separate consequent technologies differ from each other in the order of supplying asphalt cement material into the main mixing unit. Separate successive technology was theoretically grounded by the correlation between the technological thickness of bituminous film and the chemical-mineralogical composition and size of constituents, by the correlation between the particle size and their capability to compose aggregates, by the emergence of the oriented binding material coating on the technological bituminous film encoating mineral particles. Special attention is given to the manufacturing of asphalt cement material in a separate high-speed mixer (3 Table). It was theoretically grounded that mineral filler passing through the intensive shift zone between the paddle ends of the high-speed mixer and the walls of mixing chamber disintegrate and new active surfaces become visible. The molecular structure changes and free radicals appear. This intensive mixing guarantees high bitumen adsorption on the surface of mineral filler, which increases asphalt concrete resistance to corrosion and its durability, improves ecological environment in the asphalt concrete plant. In order to confirm the reliability of research results and explain correlative and regressive regularity, statistical data were processed applying statistical data processing programming system “STATGRAPHICS”. The linear regressive analysis for determining close relations of separate asphalt concrete quality indicators with speed gradient of asphalt cement material shift in a high-speed mixer was performed. Therefore, the possibility to change shift speed gradient from 3000 to 5000 1/s is provided in terms of reference for manufacturing asphalt concrete mixing plant. Correlation between separate asphalt concrete quality indicators and asphalt cement material shift speed gradient as well as bitumen amount in the asphalt cement material was determined by multi-dimensional regressive analysis of experimental data. The calculated correlation factor squared (R2) and F criteria indicate the adequacy and reliability of the multidimensional regression model.

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