scholarly journals Influence on Durability of Concrete with Different Types of Cement, Pozzolonic Materials & Epoxy Coating on Concrete Exposed to Different Types of Acid Exposure.

2019 ◽  
Vol 9 (1) ◽  
pp. 7173-7180
Keyword(s):  
Fly Ash ◽  
Protective Coating ◽  
Storage Tank ◽  
Research Work ◽  
Epoxy Coating ◽  
Concrete Durability ◽  
Acid Attack ◽  
Different Types ◽  
Epoxy Paint ◽  
Durability Of Concrete

The concrete is a highly alkaline material and it is highly susceptible to acid attack. The concrete is one of the most useful materials for storage tank of different types of acids in Industries. Thus the durability of concrete against acid attack is one of the great concern in industries. In this paper the research work was carried out on influence of different types of cement, pozzolonic materials and Epoxy coating on concrete durability against different types of acid attack like H2SO4, HNO3 & H3PO4 . From the research work it has been observed that concrete with normal Portland cement shows more deterioration than concrete with Portland composite cement and also concrete with Pozzolonic materials like Fly ash & GGBS shows extensive resistance against acid attack in concrete due to consumption of Ca(OH)2 in concrete through Pozzolonic reaction. The research work also shows that concrete with GGBS in concrete & also concrete with external protective coating of Epoxy paint has high potential resistance against acid attack in concrete.

scholarly journals Influência de materiais de proteção na resistividade elétrica do concreto

2012 ◽  
Vol 2 (1) ◽  
pp. 46-56
Author(s):  
M. S. Santor ◽  
A. L. G. Gastaldini ◽  
C. Crauss ◽  
G. T. Dos Santos ◽  
F. C. Rossini
Keyword(s):  
Electrical Resistivity ◽  
Surface Treatment ◽  
Protective Action ◽  
Concrete Structures ◽  
Concrete Durability ◽  
Surface Protection ◽  
Different Types ◽  
Polymer Mortar ◽  
Durability Of Concrete

RESUMOA durabilidade das estruturas de concreto armado é resultado da ação protetora do concreto sobre a armadura. Quando a passivação do aço deixa de existir a estrutura torna-se vulnerável ao fenômeno da corrosão, cuja propagação, após iniciada é essencialmente controlada pela resistividade elétrica do concreto. O objetivo deste trabalho foi avaliar a alteração na resistividade elétrica de concretos produzidos com diferentes tipos de cimento, CP II F, CP IV e CP V, submetidos a tratamento superficial com produto obturador dos poros e argamassa polimérica. Para efeito de análise os resultados foram comparados com os mesmos concretos sem aplicação do produto. Esses tratamentos foram realizados em concretos confeccionados com resistências à compressão na idade de 28 dias de 21,6MPa, 26,6 MPa e 31,6 MPa. Para todos os tipos de cimento utilizados e níveis de resistência adotados o tratamento superficial com argamassa polimérica resultou em maiores valores de resistividade elétrica.Palavras chave: Concreto; durabilidade; material de proteção superficial; resistividade elétrica.ABSTRACTThe durability of concrete structures is a result of the protective action of concrete on the reinforcement. When there is no passivation of steel, the structure becomes vulnerable to corrosion, and once corrosion starts its propagation is essentially controlled by the electrical resistivity of concrete. The objective of this study was to evaluate the change in electrical resistivity of concretes produced with different types of cement: CP II F, CP IV and CP V that were surface-treated with pore filler and polymer mortar. For analysis purposes, the results were compared with those of the blanks that were not subjected to surface treatment. These treatments were performed in concretes with the following compressive strengths at the age of 28 days: 21.6 MPa, 26.6 MPa and 31.6 MPa. For all types of cement used and strengths adopted, surface treatment with polymer mortar led to higher electrical resistivity values.Key words: Concrete; durability; surface protection material; electrical resistivity.

scholarly journals Effects of Micro Silica & Flyash on Strength & Durability Parameters of High Strength Concrete

2021 ◽  
Vol 9 (VI) ◽  
pp. 4650-4653
Author(s):  
Hiral Karavadra
Keyword(s):  
Fly Ash ◽  
High Strength Concrete ◽  
High Strength ◽  
Engineering Properties ◽  
Original Form ◽  
Nano Silica ◽  
Acid Attack ◽  
Strength Concrete ◽  
Micro Silica ◽  
Durability Of Concrete

High strength concrete is a term used to describe concrete with special properties not attributed to normal concrete. High-performance means that the concrete has one or more of the following properties: low shrinkage, low permeability, a high modulus of elasticity, or high strength. The application of nanotechnology in concrete has added a new dimension to the efforts to improve properties of High strength concrete. Nano materials, by virtue of their very small particle size can affect the concrete properties by altering the microstructure. Concrete can deteriorate for a variety of reasons, and concrete damage is often as result of combination of factors. This causes stresses in the concrete, which can eventually have resulted in cracking, delamination, and spalling. Concrete resists weathering action, chemical attack, and abrasion while maintaining its desired engineering properties throughout its lifespan. Different concretes require different degrees of durability depending on the exposure of environment and the properties desired. Durable concrete will retain its original form, quality and serviceability when exposed to its environment. The main characteristics influencing the durability of concrete is its permeability to the ingress of water, oxygen, carbon dioxide, chloride, sulphate and other deleterious substances. It became necessary to impart knowledge about durability of concrete and factors affecting durability to the society, as the wide use of concrete as a material in the constructions. This study concerns with the use of Nano silica of size 12 nm in M60 grade of concrete to improve the compressive strength of concrete and study on various durability parameters of High strength concrete. An experimental investigation is planned to carry out with different amount of Fly ash as 15% ,20%, 25%,30% and Micro silica as 5.5%,7%,8.5%,10% in concrete by weight of concrete. have been planned to carry out are workability, compressive test, flexural test, split tensile test. To study durability parameters of High strength concrete with nano silica Rapid chloride penetration test (RCPT), Water Sorptivity test, Acid attack test, Sulphate attack test are conduct. In this study it was observed that t the durability, strength and workability are increase as the percentage of fly ash & micro silica increses

scholarly journals Cements with calcareous fly ash as component of low clinker eco-self compacting concrete

2019 ◽  
Vol 9 (1) ◽  
pp. 196-201
Author(s):  
Jacek Gołaszewski ◽  
Grzegorz Cygan ◽  
Tomasz Ponikiewski ◽  
Małgorzata Gołaszewska
Keyword(s):  
Fly Ash ◽  
Hardened Concrete ◽  
Self Compacting Concrete ◽  
Basic Properties ◽  
Ecological Self ◽  
Different Types ◽  
Hardened State ◽  
Main Component ◽  
New Generation ◽  
Good Workability

AbstractThe main goal of the presented research was to verify the possibility of obtaining ecological self-compacting concrete of low hardening temperature, containing different types of cements with calcareous fly ash W as main component and the influence of these cements on basic properties of fresh and hardened concrete. Cements CEM II containing calcareous fly ash W make it possible to obtain self-compacting concrete (SCC) with similar initial flowability to analogous mixtures with reference cement CEM I and CEM III/B, and slightly higher, but still acceptable, flowability loss. Properties of hardened concretes with these cements are similar in comparison to CEM I and CEM III concretes. By using cement nonstandard, new generation multi-component cement CEM “X”/A (S-W), self-compacting concrete was obtained with good workability and properties in hardened state.

scholarly journals Modified Nanoclays/Straw Fillers as Functional Additives of Natural Rubber Biocomposites

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 799
Author(s):  
Justyna Miedzianowska ◽  
Marcin Masłowski ◽  
Przemysław Rybiński ◽  
Krzysztof Strzelec
Keyword(s):  
Natural Rubber ◽  
Raw Materials ◽  
Research Work ◽  
Damping Properties ◽  
Main Research ◽  
Functional Additives ◽  
Different Types ◽  
Elastomeric Materials ◽  
Research Goal ◽  
The Impact

Increasingly, raw materials of natural origin are used as fillers in polymer composites. Such biocomposites have satisfactory properties. To ensure above-average functional properties, modifications of biofillers with other materials are also used. The presented research work aimed to produce and characterize elastomeric materials with a straw-based filler and four different types of montmorillonite. The main research goal was to obtain improved functional parameters of vulcanizates based on natural rubber. A series of composites filled with straw and certain types of modified and unmodified nano-clays in various ratios and amounts were prepared. Then, they were subjected to a series of tests to assess the impact of the hybrids used on the final product. It has been shown that the addition of optimal amounts of biofillers can, inter alia, increase the tensile strength of the composite, improve damping properties, extend the burning time of the material and affect the course of vulcanization or cross-linking density.

NEURAL CLASSIFICATION OF MASS ABNORMALITIES WITH DIFFERENT TYPES OF FEATURES IN DIGITAL MAMMOGRAPHY

2006 ◽  
Vol 06 (01) ◽  
pp. 61-75 ◽  
Author(s):  
R. PANCHAL ◽  
B. VERMA
Keyword(s):  
Breast Cancer ◽  
Research Work ◽  
Breast Cancer Diagnosis ◽  
Classification Rate ◽  
Test Dataset ◽  
Benchmark Database ◽  
Different Types ◽  
Breast Tissues ◽  
Mass Type

Early detection of breast abnormalities remains the primary prevention against breast cancer despite the advances in breast cancer diagnosis and treatment. Presence of mass in breast tissues is highly indicative of breast cancer. The research work presented in this paper investigates the significance of different types of features using proposed neural network based classification technique to classify mass type of breast abnormalities in digital mammograms into malignant and benign. 14 gray level based features, four BI-RADS features, patient age feature and subtlety value feature have been explored using the proposed research methodology to attain maximum classification on test dataset. The proposed research technique attained a 91% testing classification rate with a 100% training classification rate on digital mammograms taken from the DDSM benchmark database.

Durability of Red Mud Based Geopolymer Paste in Acid Solutions

2016 ◽  
Vol 866 ◽  
pp. 99-105 ◽  
Author(s):  
Smita Singh ◽  
M.U. Aswath ◽  
R.V. Ranganath
Keyword(s):  
Mechanical Properties ◽  
Acetic Acid ◽  
Fly Ash ◽  
Red Mud ◽  
Acetic Acid Solution ◽  
Strength Loss ◽  
Acid Solutions ◽  
Test Results ◽  
Acid Attack ◽  
Geopolymer Paste

The present investigation is on the effect of red mud on the mechanical properties and durability of the geopolymer paste in sulphuric and acetic acid solution. Red mud and fly ash were used to form the geopolymer paste along with the alkalies. The variation of red mud in the paste composition was from 0% to 90%. Cylindrical shaped specimens of 1 inch diameter and 1 inch height were prepared. The specimens were immersed in 5% sulphuric acid and 5% acetic acid for 1, 7, 14, 28, 56 and 84 days and tested for weight loss, visual deformation, strength loss and colour of the solvent, based on the procedure specified by ASTM C 267 – 01. SEM/EDX Tests were performed on the geopolymer specimens. Test results show that initially, the strength of the geopolymer increased upon the addition of red mud. The strength was maximum when the percentage of red mud was 30%. The maximum strength obtained was 38 MPa for the paste containing 30% red mud using 10M alkali solution as against 31.69 MPa, when only fly ash was used. Geopolymer paste containing 30% and 50% red mud showed better resistance to acid attack. The strength loss was minimum for the samples containing 30% red mud in both inorganic and organic acid i.e. sulphuric and acetic acid.

Carbon Dioxide Sequestration Using Activated Carbon From Agro Waste-Waste Bamboo

2021 ◽  
Author(s):  
Emmanuel Ayodele ◽  
Victoria Ezeagwula ◽  
Precious Igbokwubiri
Keyword(s):  
Activated Carbon ◽  
Fly Ash ◽  
Greenhouse Gases ◽  
Surface Area ◽  
Carbon Capture ◽  
Agricultural Waste ◽  
High Surface ◽  
Research Work ◽  
High Surface Area ◽  
Bet Surface Area

Abstract Bamboo trees are one of the fastest growing trees in tropical rainforests around the world, they have various uses ranging from construction to fly ash generation used in oil and gas cementing, to development of activated carbon which is one of the latest uses of bamboo trees. This paper focuses on development of activated carbon from bamboo trees for carbon capture and sequestration. The need for improved air quality becomes imperative as the SDG Goal 12 and SDG Goal13 implies. One of the major greenhouse gases is CO2 which accounts for over 80% of greenhouse gases in the environment. Eliminating the greenhouse gases without adding another pollutant to the environment is highly sought after in the 21st century. Bamboo trees are mostly seen as agricultural waste with the advent of scaffolding and other support systems being in the construction industry. Instead of burning bamboo trees or using them for cooking in the local communities which in turn generates CO2 and fly ash, an alternative was considered in this research work, which is the usage of bamboo trees to generate activated, moderately porous and high surface area carbon for extracting CO2 from various CO2 discharge sources atmosphere and for water purification. This paper focuses on the quality testing of activated carbon that can effectively absorb CO2. The porosity, pore volume, bulk volume, and BET surface area were measured. The porosity of the activated carbon is 27%, BET surface area as 1260m²/g. Fixed carbon was 11.7%, Volatility 73%, ash content 1.7%.

Influence of water contamination in gear lubricants on wear and micro-pitting performance of case carburized gears

2017 ◽  
Vol 69 (4) ◽  
pp. 612-619 ◽  
Author(s):  
Christian Engelhardt ◽  
Jochen Witzig ◽  
Thomas Tobie ◽  
Karsten Stahl
Keyword(s):  
Carrying Capacity ◽  
Research Work ◽  
Load Carrying Capacity ◽  
Wear Performance ◽  
Content Type ◽  
Effect Of Water ◽  
Base Oils ◽  
Load Carrying ◽  
Different Types ◽  
Influence Of Water

Purpose Water can alter the performance of modern gear lubricants by influencing the flank load carrying capacity of gears significantly. The purpose of this paper is to investigate the influence of water contaminations in different kinds of base oils on the micro-pitting and wear performance of case carburized gears. Design/methodology/approach Concerning micro-pitting and wear, tests, based mostly on the following standardized tests, are performed on a Forschungsstelle fuer zahnraeder und getriebebau (FZG)-back-to-back gear test rig: micro-pitting short test Graufleckenkurztest (GFKT) according to DGMK 575 (screening test), micro-pitting test Graufleckentest (GT) according to FVA 54/7 (load stage test and endurance test) and Slow-speed wear test according to DGMK 377. To investigate the effect of water on the gear load carrying capacity dependent on different types of base oils, two polyglycol oils (PG1 and PG2), a polyalphaolefin oil, a mineral oil and an ester oil E are used. Each of these oils are common wind turbine gear oils with a viscosity ISO VG-220. Additionally, a manual transmission fluid with a viscosity of society of automotive engineers (SAE) 75W-85 is tested. Findings Considering the micro-pitting and wear performance, a significant decrease caused by water contaminations could not be detected. Regarding pitting damages, a generally negative influence was observed. This influence was differently distinctive for different base oil types. Especially non-polar lubricants seem to be affected negatively. The documented damages of the tooth flanks confirm this observation. While typical pitting damages appeared in test runs with polar lubricants, the disruption in test runs with non-polar lubricants was more extensive. Based on the experimental investigations, a general model of the damaging mechanisms of water contaminations in lubricants was derived. It is split into three partitions: interaction lubricant–water (effect of water on the molecular structure of base oils and additives), chemical-material-technological (especially corrosive reactions) and tribological influence (effect of water droplets in the contact zone). It has to be considered that the additive package of lubricants affects the influence of water contaminations on the flank load carrying capacity distinctively. An influence of water on the micro-pitting and wear performance in other than the given lubricants cannot be excluded. Originality/value While former research work was focused more on the effects of water in mineral oils, investigations concerning different types of base oils as well as different types of damages were carried out within this research project.

Incorporating Thermal Storage Into a SEGS Plant Using TRNSYS: A Status Report

Solar Energy ◽  
2004 ◽  
Author(s):  
Jade D. Braithwaite ◽  
Robert Boehm
Keyword(s):  
Power Generation ◽  
Storage Tank ◽  
Plug Flow ◽  
Transient Simulation ◽  
Status Report ◽  
Tank Model ◽  
Component Type ◽  
Different Types ◽  
Fluid Properties ◽  
Generating System

Two new preliminary component types were developed for the transient simulation program TRNSYS with IISiBat that models three different types of sensible thermal storages for analysis with use in a solar electric generating system (SEGS) simulation. One component containing a fully mixed, a stratified and a plug flow tank model options has been developed such that the input and parameter specifications are similar so that all three models could be easily placed into one component type. A single, cylindrical direct storage tank with one inlet and one outlet that evaluates fluid properties as a function of temperature is representative for all three models. The second component is a storage controller that passes along pertinent charging, dwell or discharging information to the storage and integrates the storage into a given SEGS model. Results were generated for each storage tank integrated into a SEGS VI simulation model for temperature distribution and power generation.

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