scholarly journals Functional Method of Designing Self-Compacting Concrete

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 267
Author(s):  
Tomasz Rudnicki
Keyword(s):  
Coarse Aggregate ◽  
Cement Mortar ◽  
Experimental Studies ◽  
Functional Method ◽  
Structural Viscosity ◽  
Self Compacting Concrete ◽  
Theoretical Assumptions ◽  
Concrete Mix ◽  
Selection Of ◽  
Double Coating

The article presents a new functional method of designing self-compacting concrete (SCC). The assumptions of the functional method of designing self-compacting concrete were based on the double coating assumption (i.e., it was assumed that the grains of coarse aggregate were coated with a layer of cement mortar, whereas the grains of sand with cement paste). The proposed method is composed of four stages, each of which is responsible for the selection of a different component of the concrete mix. The proposed designing procedure takes into consideration such a selection of the mineral skeleton in terms of the volumetric saturation of the mineral skeleton, which prevents the blocking of aggregate grains, and the designed liquid phase demonstrated high structural viscosity and low yield stress. The performed experimental studies, the simulation of the elaborated mathematical model fully allowed for the verification of the theoretical assumptions that are the basis for the development of the method of designing self-compacting concrete.

Effect of some Key Factors on the Strength of Recycled Concrete

2012 ◽  
Vol 503-504 ◽  
pp. 576-581
Author(s):  
Xue Bing Zhang ◽  
Zhi Fang
Keyword(s):  
Coarse Aggregate ◽  
Cement Mortar ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Key Factors ◽  
Ordinary Concrete ◽  
Concrete Mix ◽  
Rate Maximum ◽  
Cement Strength ◽  
Granule Diameter

Because there exists a used cement mortar layer outside the recycled aggregate, there are more interfaces inside recycled concrete, which would result in recycled concrete has different properties from ordinary concrete. In this paper, the effect of such key factors for recycled concrete mix ratio as water-cement ratio, cement strength, sand rate, maximum granule diameter and gradation on the properties of concrete with recycled coarse aggregate was studied by experiment, and the some useful suggestion for mix ratio of recycled concrete was provided.

Experimental Studies on Basic Performance and Application of Self-Compacting Concrete Using Waste Brick Recycled Coarse Aggregate

2014 ◽  
Vol 955-959 ◽  
pp. 2658-2662
Author(s):  
Ying Li Liu ◽  
Han Qing Liu ◽  
Lin Gao
Keyword(s):  
Rural Areas ◽  
Coarse Aggregate ◽  
Experimental Studies ◽  
Green Building ◽  
Recycled Concrete ◽  
Clay Brick ◽  
Self Compacting Concrete ◽  
Aggregate Gradation ◽  
Construction Waste ◽  
Recycled Coarse Aggregate

With rapid economic development in China, the frequency of that new buildings replace old buildings increases gradually in rural areas, which inevitably results in the emergence of a large amount of waste clay brick. The processing of construction waste takes up a lot of land resources and worsen the existing rural environmental pollution situation. using waste clay brick to prepare recycled coarse aggregate concrete not only can effectively eliminate construction waste and reduce the consumption of original coarse aggregate and thus the cost of buildings, but also solves a series of environmental problems—it conforms to the concept of "green building" and stands in line with the strategic objectives of sustainable development. This paper researched on the influence of recycled coarse aggregate gradation and water cement ratio to the strength of recycled concrete at first, then experimentally verified the application feasibility of recycled coarse aggregate self-compacting concrete.

Correlation Research of Concrete Mix Proportion on Cement Dosage in Coarse Aggregate

2014 ◽  
Vol 556-562 ◽  
pp. 692-695
Author(s):  
Zhang Bo
Keyword(s):  
Cost Reduction ◽  
High Speed ◽  
Coarse Aggregate ◽  
Social Economy ◽  
Project Design ◽  
Mixing Ratio ◽  
Project Cost ◽  
Mix Proportion ◽  
Concrete Mix ◽  
Selection Of

Along with the high-speed development of social economy in our country, the country invests more in infrastructure construction. The ratio of concrete in coarse aggregate has great impact on engineering quality. If there are any proportion problems, a certain degree of engineering accidents and sometimes even devastating accidents can be caused. This article studies the correlation between concrete proportioning and cement dosage in coarse aggregate through practices, discovers the importance of reasonable selection of coarse aggregate in economic cement mixing ratio configuration process, and realizes the implementation of project cost reduction in project design.

Prediction of self compacted rubberized concrete properties using Taguch methods

2018 ◽  
Vol 9 (2) ◽  
pp. 52
Author(s):  
Mohamed Safaan ◽  
Fatma Mohamed Eid ◽  
Amal A. Nasser ◽  
Mohamed Emara
Keyword(s):  
Coarse Aggregate ◽  
Impact Resistance ◽  
Rubberized Concrete ◽  
Signal To Noise ◽  
Rubber Content ◽  
Self Compacting Concrete ◽  
Coarse Aggregates ◽  
Concrete Properties ◽  
Concrete Mix ◽  
Four Levels

The effect and optimization of using self-compacting rubberized concrete was investigated by using Taguchi method. Design of experiment was performed via orthogonal array to accommodate four factors with four levels. These factors were the percentage of fine rubber, coarse rubber, fly ash and viscocrete in the concrete mix. The signal-to-noise (S/N) ratio and the analysis of variance (ANOVA) were employed to study the performance characteristics of self-compacting rubberized concrete (SCRC). Rubberized concrete can be improved using the concrete proportioned as self-compacting concrete. The results indicate that there was a reduction in the strength with increasing rubber content but there was an increase in impact resistance. However, the replacement of 10% of coarse aggregate with coarse rubber gave more strength than that of zero rubber mix by 124% at 90 days. Replacement of 20% of both fine and coarse aggregates with fine and coarse rubber respectively, increased impact resistance by 453% compared to the corresponding SCRC control mix.

scholarly journals Studi Mengenai Perlakuan Agregat Berukuran 2,38 mm ­ 4,75 mm sebagai Agregat Kasar dalam Campuran Beton (Hal. 22-31)

2018 ◽  
Vol 4 (4) ◽  
pp. 22
Author(s):  
Ahmad Ramdani ◽  
Priyanto Saelan
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Aggregate Size ◽  
Self Compacting Concrete ◽  
Cylinder Diameter ◽  
Strength Tests ◽  
Concrete Mix ◽  
Crushed Aggregate

ABSTRAKBatu pecah berukuran 2,38 mm – 4,75 mm tidak digunakan dalam campuran beton. Jika campuran beton dirancang menggunakan batu pecah ini sebagai agregat kasar, maka campuran beton yang dihasilkan diduga tidak akan mengalami segregasi untuk semua kelecakan, lebih homogen, dan jika diberi bahan tambahan superplasticizer diduga dapat dengan mudah berperilaku sebagai campuran beton memadat mandiri. Penelitian ini dilakukan untuk membuktikan dugaan tersebut. Penelitian dilakukan dengan kuat tekan rencana 30 MPa, slump 40 mm dan 100 mm, tanpa dan dengan bahan tambahan superplasticizer dengan dosis 1% dan 1,5%. Perancangan campuran beton dengan cara Dreux menggunakan faktor granular 0,40; 0,45; 0,50; dan 0,55. Pengujian kuat tekan pada benda uji silinder diameter 10 cm dan tinggi 20 cm membuktikan bahwa dugaan tersebut adalah benar, dan perancangan campuran beton dengan memperlakukan batu pecah berukuran 2,38 mm – 4,75 mm sebagai agregat kasar dapat dilakukan untuk faktor granular 0,40 – 0,50.Kata kunci: batu pecah berukuran 2,38 mm – 4,75 mm,agregat kasar,superplasticizer ABSTRACT2.38 mm – 4.75 mm crushed aggregate size is not used in concrete mix. If this crushed aggregate is used as coarse aggregate, the resulting concrete mix is assumed will not segregate in all workability, more homogeneous, and it will behave easily as self-compacting concrete by adding superplasticizer. This research was conducted to prove these assumption. Concrete mix with compressive strength of 30 MPa, 40 mm and 100 mm slump is made using Dreux method with granular factor 0.40; 0.45; 0.50; and 0.55. The doses of superplasticizer is 1% and 1.5% by cement weight. Compressive strength tests of 10 cm diameter and 20 cm height cylinder diameter showed these assumption is true, and concrete mix can be designed using granular factor 0.40 – 0.50.Keywords: 2,38 mm – 4,75 mm crushed aggregate size, coarse aggregate, superplasticizer

scholarly journals Adaptive Control Structure with Neural Data Processing Applied for Electrical Drive with Elastic Shaft

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3389
Author(s):  
Marcin Kamiński ◽  
Krzysztof Szabat
Keyword(s):  
Neural Network ◽  
Adaptive Control ◽  
Dynamic Properties ◽  
Experimental Studies ◽  
Drive System ◽  
Particle Swarm Optimizer ◽  
The Neural Network ◽  
Control Concept ◽  
Constant Coefficients ◽  
Selection Of

This paper presents issues related to the adaptive control of the drive system with an elastic clutch connecting the main motor and the load machine. Firstly, the problems and the main algorithms often implemented for the mentioned object are analyzed. Then, the control concept based on the RNN (recurrent neural network) for the drive system with the flexible coupling is thoroughly described. For this purpose, an adaptive model inspired by the Elman model is selected, which is related to internal feedback in the neural network. The indicated feature improves the processing of dynamic signals. During the design process, for the selection of constant coefficients of the controller, the PSO (particle swarm optimizer) is applied. Moreover, in order to obtain better dynamic properties and improve work in real conditions, one model based on the ADALINE (adaptive linear neuron) is introduced into the structure. Details of the algorithm used for the weights’ adaptation are presented (including stability analysis) to perform the shaft torque signal filtering. The effectiveness of the proposed approach is examined through simulation and experimental studies.

Constraints on the accuracy of messenger RNA movement

1985 ◽  
Vol 18 (4) ◽  
pp. 423-450 ◽  
Author(s):  
C. G. Kurland ◽  
Måns Ehrenberg
Keyword(s):  
Messenger Rna ◽  
Experimental Studies ◽  
Physical Problem ◽  
Translational Accuracy ◽  
Trna Species ◽  
Selection Of

SUMMARYTheoretical as well as experimental studies of translational accuracy have most often been concerned with the selection of aminoacyl-tRNA by codon-programmed ribosomes. The selection of the successive codons on the mRNA has received much less attention, probably because it represents both conceptually and experimentally, a much more demanding physical problem. Nevertheless, it would seem that errors in the selection of the codon are potentially much more destructive than errors in selection of aminoacyl-tRNA species. This can be appreciated from the following.

scholarly journals Collective Losses of Low Power Cage Induction Motors—A New Approach

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1749
Author(s):  
Elzbieta Szychta ◽  
Leszek Szychta
Keyword(s):  
Control System ◽  
Experimental Studies ◽  
Complex Problem ◽  
Accurate Estimation ◽  
New Approach ◽  
Water Pumping ◽  
Efficiency Control ◽  
Interacting Systems ◽  
Cage Induction Motor ◽  
Selection Of

Energy efficiency of systems of water pumping is a complex problem since efficiency of two distinct interacting systems needs to be combined: water and power supply. This paper introduces a non-intrusive method of calculating the so-called “collective losses” of a cage induction motor. The term “collective losses”, which the authors define, allows for accurate estimation of motor efficiency. Control system of a pump determines operating point of a pumping station, and thus its efficiency. General estimated performance characteristics of a motor, components of a control system, are assumed to serve selection of a range of pumping speed variations. Rotational speed has a direct effect on motor load torque, pump power and head, and thus on motor performance. Hellwig’s statistical method was used to specify characteristics of estimated collective losses on the basis of experimental studies of 21 motors rated at up to 2.2 kW. The results of simulations and experiments are used to verify validity and efficiency of the suggested method. The method is non-intrusive, simple to use, and requires minimum data.

Cascade control of «smart home» heating

2022 ◽  
Vol 14 (4) ◽  
pp. 82-89
Author(s):  
Sergey Polyakov ◽  
V. Akimov ◽  
A. Polukazakov
Keyword(s):  
Structural Changes ◽  
Experimental Studies ◽  
Residential Building ◽  
Heating System ◽  
Cascade Control ◽  
Virtual Object ◽  
Coolant Temperature ◽  
Home Heating ◽  
Input Signals ◽  
Selection Of

The article discusses the issues of implementing the conversion of input signals of «smart» sensors for automation of the heating system, an algorithm for calculating the parameters of measuring circuits with a nonlinear element and an operational amplifier is developed. The issues of modeling cascade control of residential building heating systems are investigated. The results of the analysis and selection of parameters of the cascade control system are presented. An algorithm implementing the operation of a virtual object is given. The structures of management of residential building objects are proposed. The method of calculating the adjustment of the controller for cascade control is given. For the heating system stand, the procedure for setting the parameters of the process of PID control of the coolant temperature is considered. The results confirming the achievability of the proposed structural changes are obtained. The results of experimental studies are presented.

scholarly journals Kajian Karakteristik Beton Memadat Sendiri yang Menggunakan Serat Ijuk (Hal. 54-65)

2018 ◽  
Vol 4 (4) ◽  
pp. 54
Author(s):  
Iis Nurjamilah ◽  
Abinhot Sihotang
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Coarse Aggregate ◽  
Fresh Concrete ◽  
High Strength ◽  
Self Compacting Concrete ◽  
Palm Fiber ◽  
Fiber Concrete ◽  
Dilute Mixture

ABSTRAKKajian karakteristik beton memadat sendiri yang menggunakan serat ijuk merupakan sebuah kajian yang dilakukan untuk mengetahui pengaruh penambahan serat ijuk terhadap karakteristik beton memadat sendiri (SCC). Beton memadat sendiri yang menggunakan serat ijuk (PFSCC) didesain memiliki campuran yang encer, bermutu tinggi (= 40 MPa) dan memiliki persentase kekuatan lentur yang lebih baik. PFSCC  didapatkan dari hasil pencampuran antara semen sebanyak 85%, fly ash 15%, superplastizicer 1,5%, serat ijuk 0%, 0,5%; 1%; 1,5%; 2% dan 3% dari berat binder (semen + fly ash), kadar air 190 kg/m3, agregat kasar 552,47 kg/m3 dan pasir 1.063 kg/m3. Semakin banyak persentase penambahan serat ijuk ke dalam campuran berdampak terhadap menurunnya workability beton segar. Penambahan serat ijuk yang paling baik adalah sebanyak 1%, penambahan tersebut dapat meningkatkan kekuatan tekan beton sebesar 13% dan lentur sebesar 1,8%.Kata kunci: beton memadat sendiri (SCC), beton berserat, beton memadat sendiri yang menggunakan serat ijuk (PFSCC), serat ijuk ABSTRACTThe study of characteristics self compacting concrete using palm fibers is a study conducted to determine the effect of adding palm fibers to characteristics of self compacting concrete (SCC). palm fibers self compacting concrete (PFSCC) is designed to have a dilute mixture, high strength (= 40 MPa), and have better precentage flexural strength. PFSCC was obtained from mixing of 85% cement, 15% fly ash, 1.5% superplastizicer, 0%, 0.5%, 1%, 1.5%, 2% and 3% palm fibers from the weight of binder  (cement + fly ash), water content 190 kg/m3, coarse aggregate 552.47 kg/m3 and sand 1,063 kg/m3. The more persentage palm fibers content added to the mixture makes workability of fresh concrete decreases. The best addition of palm fiber is 1%, this addition can increases the compressive strength 13% and flexural strength 1.8%.Keywords: self compacting concrete (SCC), fiber concrete, Palm fiber self compacting concrete (PFSCC), palm fiber

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