Cements
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Portland cement is produced by heating limestone and clay in a kiln to form clinker, which is then ground with gypsum. It gets its strength from chemical reactions when mixed with water called hydration. The main compounds in cement are tricalcium silicate, dicalcium silicate, tricalcium aluminate, and tetracalcium aluminoferrite. When water is added, these compounds hydrate and harden to bind the cement over time. The grade of cement corresponds to its minimum compressive strength after specific time periods of curing.
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Cements
Portland cement is produced by heating limestone, clay, sand and iron ore in a kiln to form clinker, which is then ground with gypsum. It gains strength through hydration reactions with water. The main compounds in cement are tricalcium silicate, dicalcium silicate, tricalcium aluminate, and tetracalcium aluminoferrite. These compounds hydrate at different rates and contribute to cement's initial set, early strength gain, and long-term strength. Hydration forms calcium silicate hydrates, calcium hydroxide, and fills pores in hardened cement paste. Grades 43 and 53 cement correspond to average compressive strengths of 43 and 53 MPa after 28 days.
Hydration of Portland cement
The document discusses hydration of Portland cement, which is the chemical reaction between cement and water. Key points:
- Hydration involves irreversible exothermic reactions that produce heat and hydration products like calcium silicate hydrates and calcium hydroxide. These bind the cement paste and concrete.
- Understanding hydration is important for achieving optimal strength, durability, and preventing cracks from thermal stresses. Proper curing is also important.
- The main reactants (C3S, C2S, C3A, C4AF) hydrate by different mechanisms to form different products over time as the rate of hydration decreases. Temperature and presence of gypsum affect the reactions.
Hydration of cement
Hydration is the chemical reaction between cement and water that forms bonds and results in a solid mass. The main compounds in cement - C3S, C2S, C3A, and C4AF - hydrate to form calcium silicate hydrates (C-S-H gel), calcium hydroxide, and calcium aluminate hydrates. Hydration is affected by factors like composition, fineness, water-cement ratio, and curing temperature. Special cements include acid-resistant, blast furnace, expanding, colored, high alumina, hydrophobic, low heat, and oil well cements used for their properties.
CON 123 - Session 5 - Chemical Properties
The document discusses the chemical compounds found in Portland cement and how they react during hydration, including tricalcium silicate, dicalcium silicate, tricalcium aluminate, and tetracalcium aluminoferrite. It examines how the compounds influence properties like heat evolution, setting time, strength development and durability when reacted with water. The inclusion of supplementary cementitious materials like fly ash, slag, and silica fume can improve sulfate resistance, reduce permeability, and limit alkali-silica reaction.
cement
Cement is a binder that sets and hardens, binding other materials together. There are two main types: hydraulic cement, which sets in the presence of water, and non-hydraulic cement, which requires dry conditions to set. Portland cement is the most common type of hydraulic cement, produced by heating limestone, clay, and other materials in a kiln to form clinker, which is then ground with gypsum. The clinker is composed mainly of calcium silicates, aluminates, and aluminoferrites which give Portland cement its strength and properties.
Cement chemical
The document discusses the major compounds found in cement clinker and their abbreviations. The four major compounds are tricalcium silicate (C3S), dicalcium silicate (C2S), tricalcium aluminate (C3A), and tetracalcium aluminoferrite (C4AF). C3S contributes to early strength while C2S defines later strength. C3A reacts immediately with water but causes flash setting without gypsum. Hydration of the cement forms calcium silicate hydrate (C-S-H) and calcium hydroxide, which are the primary products that give cement its strength.
Hyd07
Dr. Kimberly Kurtis discusses Portland cement hydration and composition. Cement is made by heating limestone, clay, sand, and iron oxide at high temperatures, producing clinker which is then ground with gypsum. When water is added, the cement compounds hydrate through dissolution and precipitation reactions, forming hydration products like calcium silicate hydrates (C-S-H) and calcium hydroxide that provide strength over time as hydration continues. The hydration rates of the main cement phases influence properties such as setting time and hardening.
Hydration of cement
Hydration is the chemical reaction between cement and water that forms bonds and results in a solid mass. The main compounds in cement - C3S, C2S, C3A, and C4AF - hydrate to form calcium silicate hydrates (C-S-H gel), calcium hydroxide, and calcium aluminate hydrates. Hydration is affected by factors like composition, fineness, water-cement ratio, and curing temperature. Special cements include acid-resistant, blast furnace, expanding, colored, high alumina, hydrophobic, low heat, and oil well cements used for their properties.
Recommended
Cements
Portland cement is produced by heating limestone, clay, sand and iron ore in a kiln to form clinker, which is then ground with gypsum. It gains strength through hydration reactions with water. The main compounds in cement are tricalcium silicate, dicalcium silicate, tricalcium aluminate, and tetracalcium aluminoferrite. These compounds hydrate at different rates and contribute to cement's initial set, early strength gain, and long-term strength. Hydration forms calcium silicate hydrates, calcium hydroxide, and fills pores in hardened cement paste. Grades 43 and 53 cement correspond to average compressive strengths of 43 and 53 MPa after 28 days.
Hydration of Portland cement
The document discusses hydration of Portland cement, which is the chemical reaction between cement and water. Key points:
- Hydration involves irreversible exothermic reactions that produce heat and hydration products like calcium silicate hydrates and calcium hydroxide. These bind the cement paste and concrete.
- Understanding hydration is important for achieving optimal strength, durability, and preventing cracks from thermal stresses. Proper curing is also important.
- The main reactants (C3S, C2S, C3A, C4AF) hydrate by different mechanisms to form different products over time as the rate of hydration decreases. Temperature and presence of gypsum affect the reactions.
Hydration of cement
Hydration is the chemical reaction between cement and water that forms bonds and results in a solid mass. The main compounds in cement - C3S, C2S, C3A, and C4AF - hydrate to form calcium silicate hydrates (C-S-H gel), calcium hydroxide, and calcium aluminate hydrates. Hydration is affected by factors like composition, fineness, water-cement ratio, and curing temperature. Special cements include acid-resistant, blast furnace, expanding, colored, high alumina, hydrophobic, low heat, and oil well cements used for their properties.
CON 123 - Session 5 - Chemical Properties
The document discusses the chemical compounds found in Portland cement and how they react during hydration, including tricalcium silicate, dicalcium silicate, tricalcium aluminate, and tetracalcium aluminoferrite. It examines how the compounds influence properties like heat evolution, setting time, strength development and durability when reacted with water. The inclusion of supplementary cementitious materials like fly ash, slag, and silica fume can improve sulfate resistance, reduce permeability, and limit alkali-silica reaction.
cement
Cement is a binder that sets and hardens, binding other materials together. There are two main types: hydraulic cement, which sets in the presence of water, and non-hydraulic cement, which requires dry conditions to set. Portland cement is the most common type of hydraulic cement, produced by heating limestone, clay, and other materials in a kiln to form clinker, which is then ground with gypsum. The clinker is composed mainly of calcium silicates, aluminates, and aluminoferrites which give Portland cement its strength and properties.
Cement chemical
The document discusses the major compounds found in cement clinker and their abbreviations. The four major compounds are tricalcium silicate (C3S), dicalcium silicate (C2S), tricalcium aluminate (C3A), and tetracalcium aluminoferrite (C4AF). C3S contributes to early strength while C2S defines later strength. C3A reacts immediately with water but causes flash setting without gypsum. Hydration of the cement forms calcium silicate hydrate (C-S-H) and calcium hydroxide, which are the primary products that give cement its strength.
Hyd07
Dr. Kimberly Kurtis discusses Portland cement hydration and composition. Cement is made by heating limestone, clay, sand, and iron oxide at high temperatures, producing clinker which is then ground with gypsum. When water is added, the cement compounds hydrate through dissolution and precipitation reactions, forming hydration products like calcium silicate hydrates (C-S-H) and calcium hydroxide that provide strength over time as hydration continues. The hydration rates of the main cement phases influence properties such as setting time and hardening.
Hydration of cement
Hydration is the chemical reaction between cement and water that forms bonds and results in a solid mass. The main compounds in cement - C3S, C2S, C3A, and C4AF - hydrate to form calcium silicate hydrates (C-S-H gel), calcium hydroxide, and calcium aluminate hydrates. Hydration is affected by factors like composition, fineness, water-cement ratio, and curing temperature. Special cements include acid-resistant, blast furnace, expanding, colored, high alumina, hydrophobic, low heat, and oil well cements used for their properties.
Preparation of Glass-like Materials by Sol-Gel Method Using Alkoxide Precursor
This document summarizes the preparation of glass-like materials using the sol-gel method with tetraethoxysilane (TEOS) as the alkoxide precursor. TEOS was first synthesized from the reaction of tetrachlorosilane and ethanol. Gels were then formed by acid- or base-catalyzed hydrolysis of TEOS followed by condensation. The gels were dried and fired at 600°C to produce glass-like materials. Infrared spectroscopy (IR) and X-ray diffraction (XRD) analysis confirmed the formation of the gels and high purity glass-like products.
Power point presentation
This document discusses the composition and hydration process of ordinary Portland cement. It begins by outlining the major components of cement and the physical and chemical processes involved in hydration. The key points are:
- Cement is produced by burning limestone, clay, and other materials at high temperatures, forming clinker which is then ground with gypsum.
- The main compounds in cement are tricalcium silicate, dicalcium silicate, tricalcium aluminate, and tetracalcium aluminoferrite.
- Hydration involves physical and chemical changes as the cement sets and hardens over time. Hydration produces heat and results in a solid material.
- Gy
sol gel method
This document provides information about the sol-gel method process, which consists of several steps: 1) formation of a sol through hydrolysis and condensation reactions, 2) gel formation through further condensation and polycondensation, 3) drying to produce aerogels or xerogels, 4) calcination to remove organic species and densify the gel, and 5) heat treatment to shape the material. The sol-gel method allows production of monosized nanoparticles and synthesis of glasses and ceramics at lower temperatures but controlling particle growth and agglomeration can be challenging.
Deleterious material
Deleterious Material
clay lumps, shale, soft,or laminated particles, vegetable matter, or other objectionable material
Or
The harmful material in any construction is called Deleterious material.
Main reactions of deleterious material:
Alkali aggregates reaction
Alkali silica reaction
Alkali carbonates reaction
Alkali–aggregate reaction is a term mainly referring to a reaction which occurs over time in concrete between the highly alkaline cement paste and non-crystalline silicon dioxide, which is found in many common aggregates
The alkali–silica reaction (ASR), more commonly known as "concrete cancer", is a reaction which occurs over time in concrete between the highly alkaline cement paste and the reactive non-crystalline (amorphous) silica found in many common aggregates, given sufficient moisture
Mechanism of concrete deterioration:
The mechanism of ASR causing the deterioration of concrete can be described in four steps as follows:
The alkaline solution attacks the siliceous aggregate, converting it to viscous alkali silicate gel.
Consumption of alkali by the reaction induces the dissolution of Ca2+ ions into the cement pore water.
The penetrated alkaline solution converts the remaining siliceous minerals into bulky alkali silicate gel. The resultant expansive pressure is stored in the aggregate.
The accumulated pressure cracks the aggregate and the surrounding cement paste when the pressure exceeds the tolerance of the aggregate
Alkali carbonate reaction:
The alkali–carbonate reaction is a process suspected for the degradation of concrete containing dolomite aggregate.
Alkali from the cement might react with the dolomite crystals present in the aggregate inducing the production of brucite, (MgOH)2, and calcite (CaCO3). This mechanism was tentatively proposed by Swenson and Gillott (1950) and may be written as follows:
CaMg(CO3)2 + 2 NaOH → CaCO3 + Na2CO3 + Mg(OH)2
Brucite (Mg(OH)2), could be responsible for the volumetric expansion after de-dolomitisation of the aggregate, due to absorption of water.
This section deals with potentially deleterious materials, including:
asbestos;
calcium silicate brickwork;
chlorides;
composite panels;
formaldehyde;
high alumina cement concrete;
Sol gel chemistry
The sol-gel technique involves creating a sol by dispersing colloidal particles in a liquid. This sol is then used to deposit coatings on substrates via spraying, dipping, or spinning. The particles in the sol are polymerized to form a continuous gel network. Finally, heat treatment forms an amorphous or crystalline coating. This technique allows for highly pure and uniform products to be formed at low temperatures and is used to create materials for applications like capacitors, transparent semiconductors, glasses, lenses, and nanopowder for dental and biomedical uses.
.Cement.
This presentation discusses cement industries and the process of cement manufacturing. It begins by defining Portland cement as a powdered material that hardens when mixed with water. There are various types of Portland cement depending on setting rate and strength. The manufacturing process involves mining limestone and clay as raw materials, grinding them, heating the mixture in a kiln to form clinker, and grinding the clinker with gypsum. The reactions that occur in the kiln form the key compounds that provide strength. Cement is an important building material used in construction of structures like roads, buildings and bridges.
Chemical attack
This document discusses different types of chemical attacks on concrete, including sulfate attack, sea water attack, and acid attack. Sulfate attack occurs when sulfates react with hydrated lime and calcium aluminate in concrete, forming ettringite and gypsum that cause cracking. Sea water attack involves corrosion of steel reinforcement due to chlorides as well as chemical and physical deterioration. Acid attack, which can be caused by acid rain, sewage, or industrial sources, dissolves calcium compounds in concrete and weakens its structure over time. Proper concrete mix design and coatings can improve resistance to chemical deterioration.
SAMS tutorial
Self Assembled Monolayers (SAMs) are 2-D molecular assemblies that form spontaneously when molecules with a head group chemisorb to a substrate. The head group binds strongly to the substrate while the tail groups interact weakly via van der Waals forces. SAMs can be formed using silanes on oxide surfaces or thiols on metal surfaces. They have applications as permeation coatings, for functionalizing nanostructures, and in organic thin film transistors. The document provides examples of forming hydrophobic and hydrophilic SAM coatings on various materials like aluminum oxide, nylon, and metals.
Nanotechnology Alumina Nano particles
The document discusses different methods for producing alumina nanoparticles, including sol-gel, spray pyrolysis, and emulsion combustion methods. Sol-gel produces nanoparticles below 30 nm and allows control of particle properties. Spray pyrolysis controls particle size below 400 nm using an ultrasonic spray of precursor solutions decomposed at 700°C. Emulsion combustion combines emulsion and combustion processes to continuously produce hollow spherical alumina nanoparticles 200-800 nm in size with 10 nm shells.
Lecture water 2016
1. Water sources include surface water (oceans, rivers, lakes) and groundwater located beneath the Earth's surface.
2. Water can contain up to 90 possible contaminants including inorganic compounds, organic compounds, solids, gases, and microorganisms. Treatment depends on the water's chemistry and contaminants.
3. Hardness in water is caused by calcium and magnesium ions which prevents soap from lathering. It is classified as temporary (removable by boiling) or permanent (not removable by boiling) and is measured in units like ppm, mg/L, degrees, and meq/L. Hard water causes issues for domestic and industrial uses.
Type of cement
This document discusses types of cement. It begins by defining cement as a mixture used as a binding material. It then lists 15 common types of cement including ordinary Portland cement, rapid hardening cement, and white cement. The document focuses on ordinary Portland cement, describing its chemical composition and key constituents like lime, silica, alumina. It explains that lime provides strength, silica must be in sufficient quantity to form other compounds, and alumina supports quick setting. The role of other components like iron oxide, magnesia, and gypsum are also summarized.
Aluminosilicate polymers influence of elevated temperatures, efflorescence
1) The document discusses the properties of aluminosilicate polymers (ASPs) made from fly ash activated with an alkaline solution.
2) It finds that ASPs have maximum strength when fired at 200°C but strength declines at higher temperatures. Firing above 600°C significantly reduces sodium leaching and efflorescence formation.
3) Sodium is weakly bonded in the ASP structure as Na(H2O)n+ rather than Na+, explaining the material's tendency to efflorescence in humid environments. Firing transforms the sodium bond and greatly reduces leaching.
Engineering Materials
Very Useful for B.Tech, B.Sc. and B.E. students. This ppt explains about Cement manufacturing process by Rotary Kiln, Tank furnace for Glass production and Lubrication Mechanism
Thin film deposition using spray pyrolysis
Spray pyrolysis is a simple and low-cost thin film deposition technique that involves spraying a metal salt solution onto a heated substrate. As the droplets impact and spread on the substrate, thermal decomposition occurs, leaving a film of metal oxides. The substrate temperature is the main parameter that determines the film properties, as it influences processes like precursor decomposition and solvent evaporation. Varying the deposition temperature can control the film morphology and optical/electrical characteristics. The precursor solution composition also affects the film structure, as additives can modify the solution chemistry and change the resulting film morphology.
An Experimental Enquiry into The Growth of Mordenite Nanocrystals Sans Seed A...
The importance of porous materials with very small crystal diameter is immensely increased because of their large range of applications in our daily life. Mordenite falls in the category which is a microporous, synthetic zeolite with an ideal unit cell composition of Na8. (AlO2)8. (SiO2)40. nH2O or Na8Al8Si40O96.nH2O and a lot of work is going on its synthesis according to its application.
But we have mainly focused on Mordenite synthesis in nanosize without adding seed and incorporating its effect on Mordenite morphology by comparing with standard Mordenite.
Synthesis of Mordenite nanocrystals was mainly divided into three steps. The first step covered the procedure for preparation of gel without adding seed. The gel is then converted into raw Mordenite under hydrothermal conditions in the second step. Finally, in third step raw Mordenite product is recovered into pure Mordenite crystals by applying washing with distilled water and drying techniques. The effect of sans adding seed and distilled water in the sample is then studied with the help of X-ray diffraction (XRD) and scanning electron microscopy (SEM).
Vast range of laboratorial and industrial applications of Mordenite are summarized into three major uses. These includes the use of Mordenite as a catalyst, as an adsorbent and as an ion exchanging sieve. Other uses of Mordenite are also discussed.
Portland cement and its manufacturing
Portland cement is a finely ground powder that is produced by burning and grinding a mixture of limestone and clay or limestone and shale. It was invented in 1824 by Joseph Aspdin and is composed mainly of calcium silicates. The manufacturing process involves mixing raw materials, burning them at high temperatures to produce clinker, and then grinding the clinker into a powder. There are two main processes - wet and dry - with dry being more common today. The cement is then stored and packaged for use in construction.
Rusting of iron expt and prevention
The document describes an experiment to determine the conditions required for iron rusting. Tubes containing iron samples were exposed to different combinations of air, water, and salt. Results showed rust only formed when samples had both air and water, and salt made rusting worse. Common ways to prevent rusting include coating metals with oil, paint, zinc, or alloys, electroplating with other metals, using sacrificial protection, or coating with plastic.
Casting
This document provides an overview of casting processes and patterns. It discusses three main casting methods - sand casting, investment casting, and die casting. Sand casting involves pouring molten metal into a sand mold, investment casting uses the lost-wax process, and die casting injects metal into steel dies under pressure. It also describes the different types of patterns used to form molds, including single-piece, split, gated, and segmented patterns. Patterns are made larger than required to allow for shrinkage, draft, distortion, and machining allowances during the casting and finishing processes.
Basic concept of cement and boguh's compound
1. Cement is made from calcining limestone and clay, and is a powder that can be mixed with water or sand and gravel to make mortar or concrete.
2. There are different types of cement classified based on their composition and properties, including rapid hardening, heat resistant, sulfate resisting, and white cement.
3. The typical composition of ordinary Portland cement includes calcium oxide, silica, alumina, iron oxide, and alkalies. The specific composition determines the cement's physical, mechanical, and chemical properties as well as its cost and applications.
SALT POTS JK 2015
Molten salts corrode heat resistant alloys by dissolving the protective chromium oxide scale. Good performance of salt pots depends more on maintenance than alloy selection. Higher nickel alloys like 600 generally perform better than 309 or 330 in molten salt, but alloy choice is less important than proper maintenance to prevent salt contamination, oxygen buildup, and sludge accumulation.
Cement .pptx
The document discusses different types of cement. It defines cement and describes its composition and manufacturing process. The main types discussed are ordinary Portland cement (OPC), Portland pozzolana cement (PPC), Portland blast furnace slag cement (PBSF), rapid hardening cement, low heat cement, sulfate resisting cement, and white cement. It provides details on the characteristics and common applications of each cement type.
Chemistry of cement
1) Cement is a substance used to bind together sand and aggregates like stone. Hydraulic cement forms water resistant products when mixed with water.
2) The main chemical compounds in Portland cement are tri-calcium silicate (C3S), di-calcium silicate (C2S), tri-calcium aluminate (C3A), and tetra-calcium aluminoferrite (C4AF).
3) When mixed with water, cement undergoes hydration reactions where the compounds react to form products like calcium silicate hydrates and calcium hydroxide that harden and bind the materials together.
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Preparation of Glass-like Materials by Sol-Gel Method Using Alkoxide Precursor
This document summarizes the preparation of glass-like materials using the sol-gel method with tetraethoxysilane (TEOS) as the alkoxide precursor. TEOS was first synthesized from the reaction of tetrachlorosilane and ethanol. Gels were then formed by acid- or base-catalyzed hydrolysis of TEOS followed by condensation. The gels were dried and fired at 600°C to produce glass-like materials. Infrared spectroscopy (IR) and X-ray diffraction (XRD) analysis confirmed the formation of the gels and high purity glass-like products.
Power point presentation
This document discusses the composition and hydration process of ordinary Portland cement. It begins by outlining the major components of cement and the physical and chemical processes involved in hydration. The key points are:
- Cement is produced by burning limestone, clay, and other materials at high temperatures, forming clinker which is then ground with gypsum.
- The main compounds in cement are tricalcium silicate, dicalcium silicate, tricalcium aluminate, and tetracalcium aluminoferrite.
- Hydration involves physical and chemical changes as the cement sets and hardens over time. Hydration produces heat and results in a solid material.
- Gy
sol gel method
This document provides information about the sol-gel method process, which consists of several steps: 1) formation of a sol through hydrolysis and condensation reactions, 2) gel formation through further condensation and polycondensation, 3) drying to produce aerogels or xerogels, 4) calcination to remove organic species and densify the gel, and 5) heat treatment to shape the material. The sol-gel method allows production of monosized nanoparticles and synthesis of glasses and ceramics at lower temperatures but controlling particle growth and agglomeration can be challenging.
Deleterious material
Deleterious Material
clay lumps, shale, soft,or laminated particles, vegetable matter, or other objectionable material
Or
The harmful material in any construction is called Deleterious material.
Main reactions of deleterious material:
Alkali aggregates reaction
Alkali silica reaction
Alkali carbonates reaction
Alkali–aggregate reaction is a term mainly referring to a reaction which occurs over time in concrete between the highly alkaline cement paste and non-crystalline silicon dioxide, which is found in many common aggregates
The alkali–silica reaction (ASR), more commonly known as "concrete cancer", is a reaction which occurs over time in concrete between the highly alkaline cement paste and the reactive non-crystalline (amorphous) silica found in many common aggregates, given sufficient moisture
Mechanism of concrete deterioration:
The mechanism of ASR causing the deterioration of concrete can be described in four steps as follows:
The alkaline solution attacks the siliceous aggregate, converting it to viscous alkali silicate gel.
Consumption of alkali by the reaction induces the dissolution of Ca2+ ions into the cement pore water.
The penetrated alkaline solution converts the remaining siliceous minerals into bulky alkali silicate gel. The resultant expansive pressure is stored in the aggregate.
The accumulated pressure cracks the aggregate and the surrounding cement paste when the pressure exceeds the tolerance of the aggregate
Alkali carbonate reaction:
The alkali–carbonate reaction is a process suspected for the degradation of concrete containing dolomite aggregate.
Alkali from the cement might react with the dolomite crystals present in the aggregate inducing the production of brucite, (MgOH)2, and calcite (CaCO3). This mechanism was tentatively proposed by Swenson and Gillott (1950) and may be written as follows:
CaMg(CO3)2 + 2 NaOH → CaCO3 + Na2CO3 + Mg(OH)2
Brucite (Mg(OH)2), could be responsible for the volumetric expansion after de-dolomitisation of the aggregate, due to absorption of water.
This section deals with potentially deleterious materials, including:
asbestos;
calcium silicate brickwork;
chlorides;
composite panels;
formaldehyde;
high alumina cement concrete;
Sol gel chemistry
The sol-gel technique involves creating a sol by dispersing colloidal particles in a liquid. This sol is then used to deposit coatings on substrates via spraying, dipping, or spinning. The particles in the sol are polymerized to form a continuous gel network. Finally, heat treatment forms an amorphous or crystalline coating. This technique allows for highly pure and uniform products to be formed at low temperatures and is used to create materials for applications like capacitors, transparent semiconductors, glasses, lenses, and nanopowder for dental and biomedical uses.
.Cement.
This presentation discusses cement industries and the process of cement manufacturing. It begins by defining Portland cement as a powdered material that hardens when mixed with water. There are various types of Portland cement depending on setting rate and strength. The manufacturing process involves mining limestone and clay as raw materials, grinding them, heating the mixture in a kiln to form clinker, and grinding the clinker with gypsum. The reactions that occur in the kiln form the key compounds that provide strength. Cement is an important building material used in construction of structures like roads, buildings and bridges.
Chemical attack
This document discusses different types of chemical attacks on concrete, including sulfate attack, sea water attack, and acid attack. Sulfate attack occurs when sulfates react with hydrated lime and calcium aluminate in concrete, forming ettringite and gypsum that cause cracking. Sea water attack involves corrosion of steel reinforcement due to chlorides as well as chemical and physical deterioration. Acid attack, which can be caused by acid rain, sewage, or industrial sources, dissolves calcium compounds in concrete and weakens its structure over time. Proper concrete mix design and coatings can improve resistance to chemical deterioration.
SAMS tutorial
Self Assembled Monolayers (SAMs) are 2-D molecular assemblies that form spontaneously when molecules with a head group chemisorb to a substrate. The head group binds strongly to the substrate while the tail groups interact weakly via van der Waals forces. SAMs can be formed using silanes on oxide surfaces or thiols on metal surfaces. They have applications as permeation coatings, for functionalizing nanostructures, and in organic thin film transistors. The document provides examples of forming hydrophobic and hydrophilic SAM coatings on various materials like aluminum oxide, nylon, and metals.
Nanotechnology Alumina Nano particles
The document discusses different methods for producing alumina nanoparticles, including sol-gel, spray pyrolysis, and emulsion combustion methods. Sol-gel produces nanoparticles below 30 nm and allows control of particle properties. Spray pyrolysis controls particle size below 400 nm using an ultrasonic spray of precursor solutions decomposed at 700°C. Emulsion combustion combines emulsion and combustion processes to continuously produce hollow spherical alumina nanoparticles 200-800 nm in size with 10 nm shells.
Lecture water 2016
1. Water sources include surface water (oceans, rivers, lakes) and groundwater located beneath the Earth's surface.
2. Water can contain up to 90 possible contaminants including inorganic compounds, organic compounds, solids, gases, and microorganisms. Treatment depends on the water's chemistry and contaminants.
3. Hardness in water is caused by calcium and magnesium ions which prevents soap from lathering. It is classified as temporary (removable by boiling) or permanent (not removable by boiling) and is measured in units like ppm, mg/L, degrees, and meq/L. Hard water causes issues for domestic and industrial uses.
Type of cement
This document discusses types of cement. It begins by defining cement as a mixture used as a binding material. It then lists 15 common types of cement including ordinary Portland cement, rapid hardening cement, and white cement. The document focuses on ordinary Portland cement, describing its chemical composition and key constituents like lime, silica, alumina. It explains that lime provides strength, silica must be in sufficient quantity to form other compounds, and alumina supports quick setting. The role of other components like iron oxide, magnesia, and gypsum are also summarized.
Aluminosilicate polymers influence of elevated temperatures, efflorescence
1) The document discusses the properties of aluminosilicate polymers (ASPs) made from fly ash activated with an alkaline solution.
2) It finds that ASPs have maximum strength when fired at 200°C but strength declines at higher temperatures. Firing above 600°C significantly reduces sodium leaching and efflorescence formation.
3) Sodium is weakly bonded in the ASP structure as Na(H2O)n+ rather than Na+, explaining the material's tendency to efflorescence in humid environments. Firing transforms the sodium bond and greatly reduces leaching.
Engineering Materials
Very Useful for B.Tech, B.Sc. and B.E. students. This ppt explains about Cement manufacturing process by Rotary Kiln, Tank furnace for Glass production and Lubrication Mechanism
Thin film deposition using spray pyrolysis
Spray pyrolysis is a simple and low-cost thin film deposition technique that involves spraying a metal salt solution onto a heated substrate. As the droplets impact and spread on the substrate, thermal decomposition occurs, leaving a film of metal oxides. The substrate temperature is the main parameter that determines the film properties, as it influences processes like precursor decomposition and solvent evaporation. Varying the deposition temperature can control the film morphology and optical/electrical characteristics. The precursor solution composition also affects the film structure, as additives can modify the solution chemistry and change the resulting film morphology.
An Experimental Enquiry into The Growth of Mordenite Nanocrystals Sans Seed A...
The importance of porous materials with very small crystal diameter is immensely increased because of their large range of applications in our daily life. Mordenite falls in the category which is a microporous, synthetic zeolite with an ideal unit cell composition of Na8. (AlO2)8. (SiO2)40. nH2O or Na8Al8Si40O96.nH2O and a lot of work is going on its synthesis according to its application.
But we have mainly focused on Mordenite synthesis in nanosize without adding seed and incorporating its effect on Mordenite morphology by comparing with standard Mordenite.
Synthesis of Mordenite nanocrystals was mainly divided into three steps. The first step covered the procedure for preparation of gel without adding seed. The gel is then converted into raw Mordenite under hydrothermal conditions in the second step. Finally, in third step raw Mordenite product is recovered into pure Mordenite crystals by applying washing with distilled water and drying techniques. The effect of sans adding seed and distilled water in the sample is then studied with the help of X-ray diffraction (XRD) and scanning electron microscopy (SEM).
Vast range of laboratorial and industrial applications of Mordenite are summarized into three major uses. These includes the use of Mordenite as a catalyst, as an adsorbent and as an ion exchanging sieve. Other uses of Mordenite are also discussed.
Portland cement and its manufacturing
Portland cement is a finely ground powder that is produced by burning and grinding a mixture of limestone and clay or limestone and shale. It was invented in 1824 by Joseph Aspdin and is composed mainly of calcium silicates. The manufacturing process involves mixing raw materials, burning them at high temperatures to produce clinker, and then grinding the clinker into a powder. There are two main processes - wet and dry - with dry being more common today. The cement is then stored and packaged for use in construction.
Rusting of iron expt and prevention
The document describes an experiment to determine the conditions required for iron rusting. Tubes containing iron samples were exposed to different combinations of air, water, and salt. Results showed rust only formed when samples had both air and water, and salt made rusting worse. Common ways to prevent rusting include coating metals with oil, paint, zinc, or alloys, electroplating with other metals, using sacrificial protection, or coating with plastic.
Casting
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Basic concept of cement and boguh's compound
1. Cement is made from calcining limestone and clay, and is a powder that can be mixed with water or sand and gravel to make mortar or concrete.
2. There are different types of cement classified based on their composition and properties, including rapid hardening, heat resistant, sulfate resisting, and white cement.
3. The typical composition of ordinary Portland cement includes calcium oxide, silica, alumina, iron oxide, and alkalies. The specific composition determines the cement's physical, mechanical, and chemical properties as well as its cost and applications.
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Molten salts corrode heat resistant alloys by dissolving the protective chromium oxide scale. Good performance of salt pots depends more on maintenance than alloy selection. Higher nickel alloys like 600 generally perform better than 309 or 330 in molten salt, but alloy choice is less important than proper maintenance to prevent salt contamination, oxygen buildup, and sludge accumulation.
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Cement .pptx
The document discusses different types of cement. It defines cement and describes its composition and manufacturing process. The main types discussed are ordinary Portland cement (OPC), Portland pozzolana cement (PPC), Portland blast furnace slag cement (PBSF), rapid hardening cement, low heat cement, sulfate resisting cement, and white cement. It provides details on the characteristics and common applications of each cement type.
Chemistry of cement
1) Cement is a substance used to bind together sand and aggregates like stone. Hydraulic cement forms water resistant products when mixed with water.
2) The main chemical compounds in Portland cement are tri-calcium silicate (C3S), di-calcium silicate (C2S), tri-calcium aluminate (C3A), and tetra-calcium aluminoferrite (C4AF).
3) When mixed with water, cement undergoes hydration reactions where the compounds react to form products like calcium silicate hydrates and calcium hydroxide that harden and bind the materials together.
chemical composition of cement.pdf
Cement is manufactured by heating raw materials consisting of lime, silica, alumina, and iron oxide in a kiln. These oxides form complex compounds including tricalcium silicate, dicalcium silicate, tricalcium aluminate, and tetracalcium aluminoferrite. The proportions of these compounds influence cement properties and are calculated using Bogue's equations. Gypsum is added during grinding to control the hydration of tricalcium aluminate. The chemical composition and compounds present determine cement properties such as setting time, strength development, and resistance to cracking from expansion.
ABOUT CEMENT MANUFACTURING.ppt
The document discusses the manufacture and properties of cement. There are two main processes for cement production - the dry process and wet process. In the dry process, raw materials are ground, dried, blended and fed into a kiln to form clinker. This process uses less water and energy than the wet process. The major chemical compounds in cement are tricalcium silicate, dicalcium silicate, tricalcium aluminate and tetracalcium aluminoferrite. Hydration reactions of these compounds produce strength-giving calcium silicate hydrates and calcium hydroxide. The type and proportions of compounds affect properties like strength development and heat evolution.
5. important engineering material
Infomatica, as it stands today, is a manifestation of our values, toil, and dedication towards imparting knowledge to the pupils of the society. Visit us: http://www.infomaticaacademy.com/
Behaviour of fresh and hardened concrete
This PPT discusses the structure and properties of concrete making materials. This is followed by hydration of cement, porosity of cement pastes and a study of selected topics regarding fresh and hardened concrete behaviour.
1. To understand the different complex compounds in cement.
2. Study the behavior of concrete with the fundamental interactions between ingredients
3. Fundamental understanding of the mechanism governing concrete performance.
4. Demonstrating the porosity of cement paste and elastic modulus.
5. Dramatize the rheology of concrete in terms of Bingham’s parameter.
Concrete
Concrete Construction: Batching of mixes; casting process, compaction and curing;
requirement of mix design and casting of test cubes – removing cubes from moulds and
curing for strength tests; bar-bending equipments and preparation of reinforcement for
R C C works
Chapter 5_Portland Cement_Lecture 3.pdf
Portland cement is produced by heating limestone and clay at high temperatures. This produces clinker which is then ground with gypsum. The main compounds in Portland cement are tricalcium silicate, dicalcium silicate, tricalcium aluminate, and tetracalcium aluminoferrite. When mixed with water, these compounds undergo hydration reactions producing heat and forming hydrates that harden the cement over time. Gypsum is added to retard the initial setting of the cement caused by the rapid reaction of tricalcium aluminate. The proportions of compounds in the cement affect properties like strength, heat generation, and durability.
Manufacture of cement - Classification and hydration
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Grinding and Packaging - Setting and hardening - Flow chart
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Engineering Materials
Cement
This document provides an overview of cement, including its classification, raw materials, manufacturing process, chemical reactions during burning and hardening, and special types of cement. The main points are:
- Cement is a binder that sets and hardens, binding other materials together. The principal constituents are calcium and aluminum/silicon compounds.
- Portland cement is the most common type of artificial cement, produced by burning limestone and clay at high temperatures.
- The manufacturing process involves mixing and crushing raw materials, burning in a rotary kiln, grinding the clinkers, and adding gypsum before storage and packaging.
lecture 3 Manufacture of Portland cement.ppt
Portland cement is the most widely used construction material and is made through a process of grinding and burning raw materials like limestone and clay in a kiln. There are different types of Portland cement used for various purposes depending on their chemical composition and properties. The major compounds in cement are tricalcium silicate, dicalcium silicate, tricalcium aluminate, and tetracalcium aluminoferrite which influence the rate of hardening, strength development and other characteristics.
Portland Cement
Portland cement was first patented in 1824 by Joseph Aspdin. It is made by heating limestone and clay at high temperatures in a kiln, which produces cement clinker. The clinker is then ground into a fine powder that sets and hardens when mixed with water. The hydration process involves chemical reactions between the cement compounds (C3S, C2S, C3A, C4AF) and water that produce heat and calcium silicate hydrates and calcium hydroxide, binding the concrete mixture. Cement is tested for fineness, setting time, soundness, and strength to ensure quality control.
Chapter 5 plain and reinforced cement concrete construction
This document discusses the key ingredients and properties of reinforced cement concrete (RCC). It describes cement, aggregates, water, and steel reinforcement bars as the main ingredients. Cement acts as the binding agent. Fine and coarse aggregates provide structure and strength. Water enables the chemical reactions during curing. Steel reinforcement bars provide tensile strength to counteract the low tensile strength of concrete. The document also discusses different types of cement used for RCC, including their compositions and purposes. Testing methods for cement such as fineness, setting time, strength, and soundness are also summarized.
Cement
Portland cement is manufactured by heating limestone and clay at high temperatures. It is composed mainly of calcium silicates and is used widely in construction materials like concrete and mortar. Cement production involves mixing raw materials, burning them in a kiln to form clinker, grinding the clinker, and adding gypsum. When cement powder is mixed with water, it undergoes hydration and hardens into a strong building material. Reinforced cement concrete combines cement with aggregates and steel reinforcement to make structures able to resist both compressive and tensile stresses.
Rak 82 3131-power_point_material_of_lectures_2
This document discusses the chemical composition and mineralogical composition of Portland cement. It describes the main components of cement as calcium oxide, silicon dioxide, aluminum oxide, iron oxide, and sulfur trioxide. The main mineral phases are tricalcium silicate, dicalcium silicate, tricalcium aluminate, and tetracalcium aluminate ferrite. It also discusses the hydration process and hydration products of cement, including the formation of calcium-silicate-hydrate gel and calcium hydroxide.
Cement
This document provides an overview of building materials and cement construction. It begins with an introduction to cement, including its history and composition. It then discusses the raw materials used to make cement, the manufacturing process, and the properties of cement compounds. Key points covered include the hydration, heat of hydration, setting and hardening of cement. It also outlines different types of cement such as ordinary Portland cement, rapid hardening cement, and sulphate resisting cement. The document provides detailed information on the production and characteristics of cement.
b.Tech.Unit-4.pdf chemiestry.pdf
This document discusses various aspects of hard water including types of hardness, degree of hardness, boiler troubles caused by hard water, and techniques for water softening. It covers the following key points:
1. There are two types of hardness - temporary hardness caused by calcium and magnesium bicarbonates which can be removed by boiling, and permanent hardness caused by other salts which requires treatment.
2. Hard water causes scale and sludge formation in boilers, increasing fuel costs and risk of explosions.
3. Common water softening techniques discussed are lime soda process, ion exchange, zeolite process, and reverse osmosis. Each method uses different chemical reactions to remove calcium and magnesium ions from water.
6982.engineering materials modified
Engineering materials include cementing materials, lime, cement, gypsum plasters, ceramics, glass, clay products, refractories, abrasives, composites, adhesives, lubricants, rocket fuels, and insulators. Their properties and applications depend on their chemical, electrical, mechanical, optical, physical, thermal, and technological characteristics. Common engineering materials are discussed, including their composition, manufacturing processes, properties, and uses.
Cement
This document discusses cement, including its manufacture and composition. It notes that cement is made by heating limestone and clay at high temperatures which forms calcium silicates and other compounds. The raw materials are finely ground and mixed with water to form a slurry, then heated in a kiln at 1400-1500°C. This process forms cement clinker which is then cooled, ground into a powder, and mixed with gypsum. When cement is mixed with water, it undergoes hydration and hardening reactions that cause it to set and strengthen over time. The main uses of cement are in construction applications like buildings, bridges, and concrete.
CONCRETE-TECHNOLOGY.pdf
This document provides information on the chemical composition and microstructure of cement and fly ash through SEM and XRD analysis. It discusses the hydration process of cement and the different types of cement including rapid hardening cement, low heat cement, and white cement. The hydration process involves dissolution and precipitation reactions that form calcium silicate hydrates and calcium hydroxide. Cement hydration occurs in four stages with different rates of reaction over time.
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Concrete admixtures are added ingredients beyond cement, water, and aggregates that are used to modify the properties of fresh and hardened concrete. The main types of admixtures are air entrainers, water reducers, set retarders, set accelerators, and plasticizers. Air entrainers add microscopic air bubbles that increase durability in freezing environments. Water reducers allow a reduction in water while maintaining workability, increasing strength. Set retarders delay setting for hot weather, while set accelerators increase early strength for cold weather. Plasticizers make low-slump concrete flowable. Admixtures are selected and dosed to achieve specific concrete properties for construction needs.
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Cements
- 2. It is a fine powder produced by heating materials in a kiln to form what is called clinker, grinding the clinker, and adding small amounts of other materials. Several types of Portland cement are available, with the most common being called ordinary Portland cement (OPC) which is grey in color, but a white Portland cement is also available.
- 3. Portland cement gets its strength from chemical reactions between the cement and water. The process is known as hydration. This is a complex process that is best understood by first understanding the chemical composition of cement. Portland cement is manufactured by crushing, milling and proportioning the following materials: Lime or calcium oxide, CaO: from limestone, chalk, shells, shale or calcareous rock Silica, SiO2: from sand, old bottles, clay or argillaceous rock Alumina, Al2O3: from bauxite, recycled aluminum, clay Iron, Fe2O3: from clay, iron ore, scrap iron and fly ash Gypsum, CaSO4.2H20: found together with limestone
- 4. Compound Formula Shorthand form Calcium oxide (lime) Ca0 C Silicon dioxide (silica) SiO2 S Aluminum oxide (alumina) Al2O3 A Iron oxide Fe2O3 F Water H2O H Sulfate SO3 S
- 5. Approximate Oxide Composition Limits of Ordinary Portland Cement Oxide Per cent content CaO 60–67 SiO2 17–25 Al2O3 3.0–8.0 Fe2O3 0.5–6.0 MgO 0.1–4.0 Alkalies ( K2O, Na2O) 0.4–1.3 SO3 1.3–3.0
- 6. Name of Compound Formula Abbreviated Formula Tricalcium silicate 3CaO.SiO2 C3S Dicalcium silicate 2 CaO.SiO2 C2S Tricalcium aluminate 3 CaO.Al2O3 C3A Tetracalcium aluminoferrite 4CaO.Al2O3.Fe2O3 C4AF
- 7. These compounds contribute to the properties of cement in different ways Tricalciumaluminate,C3A:- It liberates a lot of heat during the early stages of hydration, but has little strength contribution. Gypsum slows down the hydration rate of C3A. Cement low in C3A is sulfate resistant. Tricalciumsilicate,C3S:- This compound hydrates and hardens rapidly. It is largely responsible for portland cement’s initial set and early strength gain. Dicalciumsilicate,C2S: C2S hydrates and hardens slowly. It is largely responsible for strength gain after one week. Ferrite,C4AF: This is a fluxing agent which reduces the melting temperature of the raw materials in the kiln (from 3,000o F to 2,600o F). It hydrates rapidly, but does not contribute much to strength of the cement paste. By mixing these compounds appropriately, manufacturers can produce different types of cement to suit several construction environments.
- 8. C3S = 4.07 (CaO) – 7.60 (SiO2) – 6.72 (Al2O3) – 1.43 (Fe2O3) – 2.85 (SO3) C2S = 2.87 (SiO2) – 0.754 (3CaO.SiO2) C3A = 2.65 (Al2O3) – 1.69 (Fe2O3) C4AF= 3.04 (Fe2O3) The identification of the major compounds of cement is largely based on Bogue’s equations and hence it is called “Bogue’s Compounds”
- 9. It is the reaction (series of chemical reactions) of cement with water to form the binding material. In other words, in the presence of water, the silicates (C3S and C2S) and aluminates (C3A and C4AF) form products of hydration which in time produce a firm and hard mass - the hydrated cement paste. There are two ways in which compounds of the type present in cement can react with water: In the first, a direct addition of some molecules of water takes place, this being a true reaction of hydration. The second type of reaction with water is hydrolysis,
- 10. When water is mixed with cement to form a paste, reaction starts. In its pure form, the finely ground cement is extremely sensitive to water. Out of the three main compounds, viz. C3A, C3S and C2S, reacts quickly with water to produce a jelly-like compound which starts solidifying . The action of changing from a fluid state to a solid state is called ‘setting’ and should not be confused with ‘hardening’. During the next stage of hydration, cement paste starts hardening owing to the reaction of C3S and C2S with water and the paste gains strength. The first few minutes, the setting action is more predominant and later on the hardening action becomes dominant.
- 11. At any stage of hydration, the hardened paste consists of: 1. crystallized hydrates of the various compounds (calcium silicates hydrate,tricalcium aluminates hydrate and calcium ferrite) , referred to collectively as gel. 2. crystals of Ca(OH)2 produced from the hydration of the silicates. 3.some minor components. 4.unhydrated cement. 5.Voids Capillary pores
- 12. a- Capillary pores: the capillary pores at any stage of hydration represent that part of the gross volume which has not been filled by the products of hydration. The volume of the capillary system is reduced with the progress of hydration. Thus the capillary porosity of the paste depends on: ? The water/cement ratio of the mix. When w/c ratio > 0.38 – The gel volume is not enough to fill all the available voids. ? The degree of hydration, which influence by the type of cement. b- Gel pores: The gel pores are interconnected interstitial spaces between the gel particles. The gel pores are much smaller than the capillary pores. It could be contain large amount of evaporable water.
- 13. Water held in hydrated cement paste We can see that water in hydrated cement is held with varying degrees of firmness and can be classified as: 1. Free water: present in the capillary pores – with weak firmness, and evaporate quickly leaving the paste. 2. Chemically combined water: form a definite part of the hydrated compounds. 3. Gel water: which found a) Gel pores b) Part of it is held by the surface force of the gel particles - It is known as the adsorbed water.
- 14. Fineness. Fineness, or particle size of portland cement affects rate of hydration, which is responsible for the rate of strength gain. ... Soundness. ... Consistency. ... Setting Time. ... Compressive Strength. ... Heat of hydration. ... Loss on Ignition. ... Specific gravity (relative density)
- 15. The grade 43 and 53 in cement mainly corresponds to the average compressive strength attained after 28 days ( 6724 hours) in mega pascals (Mpa) of at least three mortar cubes ( area of face 50 cm squared) composed of one part cement, 3 parts of standard s and ( conforming to IS 650:1966) by mass and P/4 ( P is the percentage of water required to produce a paste of standard consistency as per IS standard) + 3 percentage ( of combined mass of cement plus sand) of water , prepared, stored and tested in the manner described in methods of physical test for hydraulic cement. 721 hr not less than 23 MPa for 43 grade, 27 MPa for 53 grade 1682 hrs not less than 33MPa for 43 grade, 37MPa for 53 grade 6724 hrs not less than 43MPa for 43 grade, 53 MPa for 53grade.