scholarly journals Influence of Polyfunctional Additive on Hardening Process and Properties of Cement Concrete

2019 ◽  
Vol 18 (4) ◽  
pp. 330-338
Author(s):  
N. S. Gurinenko ◽  
E. I. Batyanovskiy
Keyword(s):  
Standardized Testing ◽  
Cement Stone ◽  
Energy Costs ◽  
Concrete Compressive Strength ◽  
Multifunctional Additive ◽  
Additive Structure ◽  
Hardening Process ◽  
Polyfunctional Additive ◽  
Ratio Of Components ◽  
Reducing Energy

The paper presents results of research aimed at developing a new semi-functional concrete additive that provides an increase in rate and level of its strength growth while reducing energy costs to accelerate hardening process, as a basis for reducing energy intensity in manufacturing of concrete and reinforced concrete products and structures. Experimentally a rational ratio of components for a polyfunctional additive has been found of mass cement: a superplasticizer based on polycarboxylate resins (for example, “Stachement 2000” or “Relamiks PC”) – 0.5 %, ultradispersed microsilica (SiO2) – 1.0 %, sodium sulfate (Na2SO4), hardening accelerator – 0.5 %, aluminum sulfate (Al2(SO4)3), sealing additive structure ‒ 0.25 %. The mentioned components ensure the largest increase in strength of cement stone and structural heavy concrete. Results of derivatographic and X-ray phase analyses have shown that strength growth is based on formation of a fine-crystalline form of low-base crystalline silicates of CSH-silicate group, which complements traditionally formed C2SH by the reaction of threeand two-calcium silicate cement with water, as well as it is based on an increase in the number of neoplasms due to the reaction of Ca(OH)2 with amorphous SiO2 and ettringite 3CaO × Al2O3 × 3CaSO4 × 32H2O, being formed due to reactions with cement aluminates these are accelerating-compacting additive components, that in total provides an increase in density and strength of cement stone. While having the case with concrete, the effect is complemented by hardening the zone of contact between aggregate surface and cement stone due to the reaction between Ca(OH)2 and SiO2. These effects have been confirmed by growth (up to 38 %) of water which is chemically bound with cement in presence of a multifunctional additive in samples of cement stone, which is characterized by the largest strength. While using standardized testing methods, effectiveness of a multifunctional additive has been experimentally confirmed and it has been expressed in growth of quality characteristics and properties of structural heavy concrete: compressive strength – up to 40–60 %, flexural strength – up to 15 %, reduction of shrinkage – up to 50 % and water absorption – by 1.5–2 times, increase in frost resistance from brand F250 to F500, water resistance – from W6–W8 to W20.

scholarly journals OPTIMIZATION OF THE COMPOSITION OF A COMPLEX POLYFUNCTIONAL ADDITIVE BY THE STRENGTH CRITERION OF CEMENT STONE AND CONCRETE

2020 ◽  
Author(s):  
Н.С. Гуриненко ◽  
Э.И. Батяновский
Keyword(s):  
Standardized Test ◽  
Experimental Studies ◽  
High Strength ◽  
Strength Criterion ◽  
Test Methods ◽  
Cement Stone ◽  
Structural Concrete ◽  
Multifunctional Additive ◽  
C 50 ◽  
Polyfunctional Additive

В материале статьи приведены результаты исследований влияния новой комплексной полифункциональной добавки, содержащей пластификатор, ультрадисперсный микрокремнезем (УДМК) и ускоряюще-уплотняющий компонент, на кинетику твердения (темп роста) и уровень прочности на сжатие тяжелого конструкционного бетона. С применением методов математической статистики оценено влияние на процесс твердения (рост прочности) цементного камня и цементного бетона, составляющих полифункциональную добавку компонентов (при разном их соотношении в комплексе в целом). На этом основании (включая результаты экспериментальной оценки прочности образцов цементного камня и бетона) разработаны и запатентованы составы полифункциональной добавки в бетон, характеризующиеся оптимальным диапазоном содержания в ее составе компонентов: суперпластификатора на основе поликарбоксилатных смол ‒ 0,25 %...0,5 % от массы цемента, ультрадисперсного микрокремнезема (SiO2) ‒ 0,25 %...1,0 % от МЦ, ускорителя твердения ‒ сульфата натрия (Na2SO4) ‒ 0,35 %...0,5 % от МЦ и уплотняющей структуру добавки ‒ сульфата алюминия (Al2(SO4)3) ‒ 0,15 %...0,25 % от МЦ, при меньших значениях для тяжелого конструкционного бетона класса ≤ С50/60 и бόльших значениях для высокопрочного, особо плотного бетона класса ≥ С70/85 (прочностью fcm.28 ≥ 100 МПа). В исследованиях прочностных характеристик и эксплуатационных свойств бетона применены стандартизованные методики испытаний. Результаты экспериментальных исследований подтверждены производственными испытаниями разработки, их данные заактированы и подтверждают возможность экономии цемента на 10 %…15 % без снижения прочностных и эксплуатационных свойств бетона, при снижении затрат тепловой энергии на обогрев изделий из бетона с добавкой в 1,5…2,0 раза (за счет сокращения времени подачи теплоносителя до 1,5…2,0 ч (с последующим твердением по методу термоса) и снижения температуры разогрева бетона до 45 °С…50 °С). The article presents the results of studies of the effect of a new complex multifunctional additive containing a plasticizer, ultradispersed microsilica (UDMS) and an accelerating-sealing component on the hardening kinetics (growth rate) and the level of compressive strength of heavy structural concrete. Using the methods of mathematical statistics, the influence on the hardening process (growth of strength) of cement stone and cement concrete of the components constituting a multifunctional additive (with their different ratios in the complex as a whole) was evaluated. On this basis (including the results of an experimental assessment of the strength of cement stone and concrete samples), compositions of a polyfunctional additive to concrete have been developed and patented, characterized by the optimal range of content in its composition of components: superplasticizer based on polycarboxylate resins – 0.25 %...0.5 % of the mass of cement, ultradispersed microsilica (SiO2) – 0.25 %...1.0 % of WC, hardening accelerator – sodium sulfate (Na2SO4) – 0.35 %...0.5 % from WC and the additives that seal the structure - aluminum sulfate (Al2(SO4)3) – 0.15 %...0.25 % of WC, at lower values for heavy structural concrete of class ≤ С50/60 and higher values for high-strength , especially dense concrete of class ≥ С70/85 (strength fcm.28 ≥ 100 MPa). In studies of the strength characteristics and operational properties of concrete, standardized test methods were used. The results of experimental studies are confirmed by production tests of the development, their data are recorded and confirm the possibility of saving cement by 10 %...15 % without reducing the strength and operational properties of concrete, while reducing the cost of heat energy for heating concrete products with an additive of 1.5...2.0 times (by reducing the time of supplying the coolant to 1.5...2.0 h (with subsequent hardening by the thermos method) and reducing the temperature of concrete heating to 45 °C...50 °C).

scholarly journals THE ESTIMATION METHODS OF MICROFILLERS INFLUENCE ON CEMENT STONE PROPERTIES/MIKROUŽPILDŲ ĮTAKOS CEMENTINIO AKMENS SAVYBĖMS ANALITINIO ĮVERTINIMO PRINCIPAI

1997 ◽  
Vol 3 (10) ◽  
pp. 69-75
Author(s):  
Juozas Deltuva ◽  
Žymantas Rudžionis
Keyword(s):  
Relative Density ◽  
Silica Fume ◽  
Cement Paste ◽  
Heterogeneous Material ◽  
Estimation Methods ◽  
Cement Stone ◽  
Structural Element ◽  
Regular Form ◽  
Amorphous Sio2 ◽  
Hardening Process

The concrete and cement microfillers are materials of different fineness, such as wastes of production or pulverized rocks. According to their influence on cement hardening process, they may be classified into inert microfillers or chemically active ones. The chemically active microfillers, such as silica fume, fly ashes and others, have more then 50% amorphous SiO2, that takes part in cement hardening process. Inert microfillers, such as granite, dolomite, sand dust and others, in most cases have no influence on the cement hydration. The usage of microfillers in concrete is common, but so far no clear dependence between the quantity of added microfillers and properties of concrete has been established. One of possible ways to estimate the microfillers influence on the products with cement binder is the structural element method. The structural element is the smallest cell, approximated to a spatial figure of regular form, that has all components with the same proportions, as in all the volume of heterogeneous material. The essence of this method is to divide the mix in to bigger particles, that are named “nuclei” of structural elements and take 50% of all mix volume, and smaller particles, that form cover layers of the nuclei and make up the rest of the volume of the mix. The dependence between the relative density of loose materials and relation (1) between the diameters of the bigger and smaller particles of the structural element has been estimated. This relation is changed when microfillers are added to the cement. There is a possibility to optimize relative density by (2), (3) and (4) relations, if the granulometric composition of the cement and microfillier is known. The experimental and calculated results of this optimization are shown in Table 1. The properties of pressed cement stone with inert microfillers admixture are presented in Table 2. Formulae for calculating the relative density (8) and compressive strength (11) of hardening cement have been estimated. The chemically active microfillers, such as silica fume, interact with Ca(OH)2 and form new CSH. The density and strength of cement stone increased after this interaction. The influence of chemically active microfillers on the relative density of the cement stone is given in (12). The density of cement stone increases to 4.5% and strength increases to 40.2%, if the quantity of inert microfillers in the cement paste reaches 10%. The density of cement stone increases to 7.4% and strength increases to 54.7%, if the quantity of chemically active microfillers in the cement paste reaches 10%.

Analyzing the Performance of Ceramic Kiln by Using Thermal Image Technique for Reducing Energy Costs

2018 ◽  
Vol 766 ◽  
pp. 7-12
Author(s):  
Siwat Lawanwadeekul ◽  
Mattika Bunma
Keyword(s):  
Thermal Efficiency ◽  
Research Area ◽  
Thermal Image ◽  
Energy Costs ◽  
Thermal Camera ◽  
Depth Interview ◽  
Liquid Petroleum Gas ◽  
Image Technique ◽  
Reducing Energy

The aim of this research was to find a way to reduce energy costs by using thermal image techniques for investigating the thermal efficiency of ceramic furnaces. The case study was “Ban Nam Jo Ceramic”. The researchers collected the information by performing an in-depth interview at the research area, collecting preliminary data and using the thermal camera in the technical analysis part. The researchers also measured the temperature and volume of gas in the furnace. After that, those data were used to calculate the energy balance and the thermal efficiency of ceramic kilns. The data showed that the first measured furnace had calculated thermal efficiency of 9.99%. After the maintenance, the thermal efficiency increased to 16.64%. Furthermore, the volume of liquid petroleum gas decreased by 40%, and the damage in products after firing decreased by 3 %.

scholarly journals The principles of justification of an object construction duration

2019 ◽  
Vol 110 ◽  
pp. 02126
Author(s):  
Pavel Oleinik ◽  
Nadezhda Cherednichenko ◽  
Stefan Shvedov ◽  
Vitaliy Melnichuk
Keyword(s):  
Final Stage ◽  
Energy Costs ◽  
Construction Technology ◽  
Construction Stage ◽  
Object Construction ◽  
Reducing Energy

The duration of an object construction is considered as a parameter expressing the concentrated influence of all stages of its formation, including design, preconstruction, construction, etc. It is shown that the construction stage, as the final stage, is the most flexible and its components that include organization of construction, technology and mechanization of construction and installation works promptly implement solutions from all previous stages, consisting of a large number of various methods and ways of influencing the construction duration. These activities allow reducing energy costs and making production less energy intensive. The decisions on combining the work of the preconstruction and the main periods of construction are given as an example.

scholarly journals The Connected Life

2015 ◽  
Vol 137 (09) ◽  
pp. 36-41 ◽  
Author(s):  
Ahmed K. Noor
Keyword(s):  
Deep Learning ◽  
Real Estate ◽  
Creative Thinking ◽  
Heterogeneous Data ◽  
Energy Costs ◽  
Smart Systems ◽  
Cognitive Work ◽  
Practical Information ◽  
Real Estate Assets ◽  
Reducing Energy

The article presents an overview of how connected or smart systems can help improve day-to-day lives and be beneficial for businesses as well. Connectivity opens a world of possibilities for improving occupant experience, reducing energy costs, and managing building equipment—three areas that can increase returns on real estate assets. Smart systems are expected to improve the efficiency of heat, light, sanitation, security, safety, and a host of services. The savings of energy alone could be significant. Connections between things and people, supported by networked processes, will enable everyone to turn vast amounts of heterogeneous data into practical information that can be used to do things that weren’t possible before, or to do familiar tasks better. Cognitive work and service assistants with deep learning and reasoning capabilities will support various human activities. The unprecedented communication can inspire creative thinking and collaborations among businesses and organizations.

Effects of Container Geometry on Energy Consumption During Hardening in Ice Cream Manufacturing

2010 ◽  
Author(s):  
W. C. Cromer ◽  
Mark J. Miller ◽  
X. J. Xin ◽  
Z. J. Pei ◽  
Karen A. Schmidt
Keyword(s):  
Energy Consumption ◽  
Food Industry ◽  
Energy Savings ◽  
Ice Cream ◽  
The United States ◽  
Dairy Food ◽  
Hardening Process ◽  
Container Shape ◽  
The U.S ◽  
Reducing Energy

Energy consumption by the dairy food industry in the United States constitutes 10% of all energy consumed by the U.S. food industry. Reducing energy consumption in cooling and refrigeration of foods plays an important role in meeting the challenge of the energy crisis. Hardening is an important and energy-intensive step in ice cream manufacturing. This work presents Finite Element Method (FEM) investigation of the ice cream hardening process, aiming to provide insight and guidance for energy savings in ice cream manufacturing. Effects of container shape and dimensions, container layers, and heat transfer boundary conditions on energy consumption for hardening of ice cream were investigated.

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