tag:blogger.com,1999:blog-68911499952737834992024-03-05T17:21:02.310-08:0057derajat, calculator, unit converterCALCULATOR UNIT CONVERTER57derajathttp://www.blogger.com/profile/05826101404901224245noreply@blogger.comBlogger13125tag:blogger.com,1999:blog-6891149995273783499.post-88993320732112013842018-01-10T02:02:00.003-08:002018-01-10T02:02:33.902-08:00Concrete Uses Cement as a Binder<div style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px;">
<div style="text-align: justify;">
<span style="font-size: 12.8px;">When aggregate is mixed together with dry Portland cement and water, the mixture forms a fluid slurry that is easily poured and molded into shape. The cement reacts chemically with the water and other ingredients to form a hard matrix that binds the materials together into a durable stone-like material that has many uses.</span></div>
<div style="text-align: justify;">
<span style="font-size: 12.8px;">Often, additives (such as pozzolans or superplasticizers) are included in the mixture to improve the physical properties of the wet mix or the finished material. Most concrete is poured with reinforcing materials (such as rebar) embedded to provide tensile strength, yielding reinforced concrete.</span></div>
<div style="text-align: justify;">
<span style="font-size: 12.8px;">The size distribution of the aggregate determines how much binder is required.</span><span style="font-size: 12.8px;"> </span></div>
<div style="text-align: justify;">
<span style="font-size: 12.8px;">Aggregate with a very even size distribution has the biggest gaps whereas adding aggregate with smaller particles tends to fill these gaps. The binder must fill the gaps between the aggregate as well as pasting the surfaces of the aggregate together, and is typically the most expensive component.</span><span style="font-size: 12.8px;"> </span></div>
<div style="text-align: justify;">
<span style="font-size: 12.8px;">Workability of concrete is an important property of concrete while concrete is in its fresh state. Therefore slump test or compaction factor test should be performed to check workability of concrete.</span><span style="font-size: 12.8px;"> </span></div>
<div style="text-align: justify;">
<span style="font-size: 12.8px;">Concrete strength is normally to be ascertained from cubes or prisms samples tested at 28 days.</span></div>
<div style="text-align: justify;">
<span style="font-size: 12.8px;">The water permeability test, Rapid Chloride Ion Penetration test, water absorption test, and the initial surface absorption test are tests to determine the durability of concrete. To determine its ability to resist weathering action, chemical attack and any process of deterioration.</span></div>
</div>
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57derajathttp://www.blogger.com/profile/05826101404901224245noreply@blogger.comtag:blogger.com,1999:blog-6891149995273783499.post-49507297469260560202018-01-09T01:50:00.006-08:002018-01-09T01:50:56.323-08:00Admixture and Surfactant<div style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px;">
<div style="text-align: justify;">
<span style="font-size: 12.8px;">An admixture is defined as “a material other than water, aggregates, cement</span><span style="font-size: 12.8px;"> and fiber reinforcement that is used as an ingredient of a cement mixture to modify its freshly mixed, setting, or hardened properties and that is added to the batch before or during its</span><span style="font-size: 12.8px;"> </span><span style="font-size: 12.8px;">mixing,” and a chemical admixture is defined as “an admixture in the form of a liquid, suspension, or water-soluble solid”.</span></div>
<div style="text-align: justify;">
<span style="font-size: 12.8px;">Many chemical admixtures, such as air-entraining, water-reducing, and</span><span style="font-size: 12.8px;"> </span><span style="font-size: 12.8px;">shrinkage-reducing, belong to a class of chemicals called surfactants.</span><span style="font-size: 12.8px;"> </span></div>
<div style="text-align: justify;">
<span style="font-size: 12.8px;">Surfactants have an amphiphilic molecular structure. </span><span style="font-size: 12.8px;">An amphiphilic is a chemical compound possessing both hydrophilic (water-loving, polar) and hydrophobic (fat-loving) properties. The surfactant hydrophilic area of the molecule penetrates into the polar liquid and the surfactant hydrophobic part into the gas phase. Consequently, the surfactant lowers the surface tension and stabilize air in the form of foam.</span></div>
<div style="text-align: justify;">
<span style="font-size: 12.8px;">Surfactants are compounds that lower the surface tension (or interfacial tension) between two liquids, between a gas and a liquid, or between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents, and dispersants.</span></div>
<div style="text-align: justify;">
<span style="font-size: 12.8px;">Most commonly, surfactants are classified according to polar head group. A non-ionic surfactant has no charged groups in its head. The head of an ionic surfactant carries a net positive, or negative charge. If the charge is negative, the surfactant is more specifically called anionic; if the charge is positive, it is called cationic. If a surfactant contains a head with two oppositely charged groups, it is termed zwitterionic.</span></div>
</div>
<div style="text-align: justify;">
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57derajathttp://www.blogger.com/profile/05826101404901224245noreply@blogger.comtag:blogger.com,1999:blog-6891149995273783499.post-83765275846861970722018-01-08T02:34:00.002-08:002018-01-08T02:34:40.320-08:00Efflorescence in Cementitious Materials<br />
<div style="text-align: justify;">
<span style="background-color: white; color: #222222; font-family: "arial" , sans-serif; font-size: 12.8px;">Efflorescences can occur in natural and built environments. On porous construction materials it may present a cosmetic outer problem only (primary efflorescence causing staining), but can sometimes indicate internal structural weakness (migration/degradation of component materials). </span><span style="background-color: white; color: #222222; font-family: "arial" , sans-serif; font-size: 12.8px;">Efflorescence occurs when dissolved salts migrate within a porous material to its surface, where the water evaporates and salt precipitate, leaving white spots. Typical efflorescence in materials based on Portland cement (OPC) is caused by calcium carbonate.</span></div>
<span style="background-color: white; color: #222222; font-family: "arial" , sans-serif; font-size: 12.8px;"></span><br />
<div style="text-align: justify;">
<span style="background-color: white; color: #222222; font-family: "arial" , sans-serif; font-size: 12.8px;"><span style="font-size: 12.8px;"><br /></span></span></div>
<span style="background-color: white; color: #222222; font-family: "arial" , sans-serif; font-size: 12.8px;">
<div style="text-align: justify;">
<span style="font-size: 12.8px;">Primary efflorescence</span></div>
</span><span style="background-color: white; color: #222222; font-family: "arial" , sans-serif; font-size: 12.8px;"><div style="text-align: justify;">
<span style="font-size: 12.8px;">This occurs days or weeks after application, during the setting and curing process. Either excess water from the mortar matrix or severe climatic conditions (low temperature, high humidity) extend the setting time and increase the amount of moisture at the surface. The moisture at the surface then reacts with the free lime in the mortar.</span></div>
</span><span style="background-color: white; color: #222222; font-family: "arial" , sans-serif; font-size: 12.8px;"><div style="text-align: justify;">
<span style="font-size: 12.8px;">For controlling primary efflorescence, formulations containing liquid fatty acid mixtures (e.g., oleic acid and linoleic acid) have been commonly used.</span></div>
</span><span style="background-color: white; color: #222222; font-family: "arial" , sans-serif; font-size: 12.8px;"><div style="text-align: justify;">
<span style="font-size: 12.8px;"><br /></span></div>
<div style="text-align: justify;">
<span style="font-size: 12.8px;">Secondary efflorescence</span></div>
</span><span style="background-color: white; color: #222222; font-family: "arial" , sans-serif; font-size: 12.8px;"><div style="text-align: justify;">
<span style="font-size: 12.8px;">This can occur years after application due to contact with moisture or when a substrate is subjected to cycles of re-wetting and drying. Moisture penetrates into the matrix and/or leaches substances from it. Calcium hydroxide (a by-product of portland cement) can partly dissolve, or salts (from the substrate) can migrate to the surface.</span></div>
</span><span style="background-color: white; color: #222222; font-family: "arial" , sans-serif; font-size: 12.8px;"><div style="text-align: justify;">
<span style="font-size: 12.8px;">For controlling secondary efflorescence, admixtures containing aqueous-based calcium stearatedispersion (CSD) are often added at a later stage of the batching process with the mix water.</span></div>
</span><span style="background-color: white; color: #222222; font-family: "arial" , sans-serif; font-size: 12.8px;"><div style="text-align: justify;">
<span style="font-size: 12.8px;"><br /></span></div>
<div style="text-align: justify;">
<span style="font-size: 12.8px;">To prevent (both primary and secondary) efflorescence in cementitious materials is by using special admixtures that chemically react with and bind the salt-based impurities in the concrete.</span></div>
</span>57derajathttp://www.blogger.com/profile/05826101404901224245noreply@blogger.comtag:blogger.com,1999:blog-6891149995273783499.post-18093138282826108812018-01-07T01:57:00.002-08:002018-01-07T01:58:41.588-08:00Ceramic Stain Resistance<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="font-family: "Arial",sans-serif; font-size: 10.0pt; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: IN;">Ceramic
tiles offer a combination of durability, versatility and convenience and are
available in hundreds of different styles, shapes and colors.</span><span style="font-family: "Arial",sans-serif; font-size: 10.0pt;"><o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="font-family: "Arial",sans-serif; font-size: 10.0pt;">Tile is a
ceramic surfacing unit, usually relatively thin in relation to facial area,
made from clay or a mixture of clay and other ceramic materials, called the
body of the tile, having either a “glazed” or “unglazed” face and fired above
red heat in the course of manufacture to a temperature sufficiently high to
produce specific physical properties and characteristics.<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="font-family: "Arial",sans-serif; font-size: 10.0pt;">special-purpose
tile is a tile, either glazed or unglazed, made to meet or to have specific
physical design or appearance characteristics such as size, thickness, shape,
color, or decoration; keys or lugs on backs or sides; special resistance to
staining, frost, alkalies, acids, thermal shock, physical impact, high
coefficient of friction, or electrical properties.<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="font-family: "Arial",sans-serif; font-size: 10.0pt;">(According
to ISO 10545-2) Method applicable to all working surfaces of ceramic tiles to
determine their resistance to stains. Each staining agent (Green staining in light oil/red staining for
green tiles, Iodine alcohol solution,
Olive oil) must remain on at least 5 testing samples (whose proper surface has first
been cleaned and dried) use of different cleaning agents, for at least 24
hours, whose working surfaces has been cleaned and dried beforehand. Removal of
the staining agents takes place in subsequent steps using various cleaning
agents and cleaning procedures.<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="font-family: "Arial",sans-serif; font-size: 10.0pt;">Classification
of the results follows visual inspection: class 1 tiles are the easiest from
which to remove a given stain, while with class 5 tiles, such stains cannot be
removed and the proper surface has been damaged irreversibly.<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<br /></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="font-family: "Arial",sans-serif; font-size: 10.0pt;">Cleaning
agents<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="font-family: "Arial",sans-serif; font-size: 10.0pt;">1) Hot
water.<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="font-family: "Arial",sans-serif; font-size: 10.0pt;">2) Weak
commercial cleaning agent.<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="font-family: "Arial",sans-serif; font-size: 10.0pt;">3) Strong
commercial cleaning agent.<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="font-family: "Arial",sans-serif; font-size: 10.0pt;">4)
Solvents (hydrochloric acid, potassium hydroxide, acetone, others to be
specified)<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<br /></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="font-family: "Arial",sans-serif; font-size: 10.0pt;">Cleaning
procedures<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="font-family: "Arial",sans-serif; font-size: 10.0pt;">A)
Running hot water.<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="font-family: "Arial",sans-serif; font-size: 10.0pt;">B) Manual
cleaning with weak commercial cleaning agent.<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="font-family: "Arial",sans-serif; font-size: 10.0pt;">C)
Mechanical cleaning with strong commercial cleaning agent.<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="font-family: "Arial",sans-serif; font-size: 10.0pt;">D)
Immersion in suitable solvent (hydrochloric acid, potassium hydroxide, acetone,
others to be specified).<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<br /></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<br /></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="font-family: "Arial",sans-serif; font-size: 10.0pt;">Class 1 -
the stain is removed using hot water<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="font-family: "Arial",sans-serif; font-size: 10.0pt;">Class 2 -
the stain is removed using a weak commercial cleaning agent<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="font-family: "Arial",sans-serif; font-size: 10.0pt;">Class 3 -
the stain is removed using a strong commercial cleaning agent<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="font-family: "Arial",sans-serif; font-size: 10.0pt;">Class 4 -
the stain is removed using solvent, such as acetone for example<o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="font-family: "Arial",sans-serif; font-size: 10.0pt;">Class 5 -
such stains cannot be removed and the proper surface has been damaged
irreversibly.<o:p></o:p></span></div>
<br />
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<br /></div>
</div>
57derajathttp://www.blogger.com/profile/05826101404901224245noreply@blogger.comtag:blogger.com,1999:blog-6891149995273783499.post-71484034935658286992018-01-06T02:57:00.003-08:002018-01-06T02:58:46.213-08:00Chemical Admixtures for Concrete<div class="MsoNormal" style="background: white; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="color: #222222; font-family: "arial" , sans-serif; font-size: 10.0pt;">Chemical admixtures are used to improve workability and quality of concrete
during mixing, transporting, application, placement, curing and setting
time. <o:p></o:p></span></div>
<div class="MsoNormal" style="background: white; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="color: #444444; font-family: "arial" , sans-serif; font-size: 10pt;">Chemical admixtures are the admixtures that are
added to concrete in a very small amount for a specific function to concrete.
If chemical admixtures are added more than the defined than it has a very wide
range of negative effects on the properties of fresh as well as hardened
concrete. </span><o:p></o:p></div>
<br />
<div class="MsoNormal" style="background: white; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm;">
<span style="color: #444444; font-family: "arial" , sans-serif; font-size: 10pt;">chemical admixtures are the extra ingredients
other than water, cement, and aggregates. These are added to the concrete batch
plant during batch mixing or at the start when other quantities are added.
Admixtures offer very favorable effects to the properties of fresh or hardened
concrete only if proper use of admixtures is made possible.</span><span style="color: #222222; font-family: "arial" , sans-serif; font-size: 10.0pt;"><br />
<br />
ASTM C494 specifies the requirements for chemical admixture types.<br />
<br />
Type A: Water-reducing admixtures<br />
Type B: Retarding admixtures<br />
Type C: Accelerating admixtures<br />
Type D: Water-reducing and retarding admixtures<br />
Type E: Water-reducing and accelerating admixtures<br />
Type F: Water-reducing, high range admixtures<br />
Type G: Water-reducing, high range, and retarding admixtures<br />
Type S: Specific performance ( corrosion inhibitors, shrinkage control,
alkali-silica reactivity inhibitors, and coloring ) admixtures.<br /><br />
The materials used in the concrete mixtures shall include Type I or Type II
cement, pozzolan, fine and coarse aggregates, and air-entraining admixture.<br />
Types F and G admixtures may exhibit much higher water reduction in concrete
mixtures having higher cement factors.<br />
Mixtures having a high range water reduction generally display a higher rate of
slump loss.<br />
Admixtures that contain relatively large amounts of chloride may accelerate
corrosion of prestressing steel.<o:p></o:p></span></div>
57derajathttp://www.blogger.com/profile/05826101404901224245noreply@blogger.comtag:blogger.com,1999:blog-6891149995273783499.post-47501247847144041622018-01-06T02:45:00.001-08:002018-01-06T02:49:06.395-08:00Nanotechnology<div style="text-align: justify;">
<div class="MsoNormal" style="background: white; line-height: normal; margin-bottom: 0.0001pt;">
<span style="font-family: "arial" , sans-serif; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: IN;">Nanotechnology
deals with the fact that properties of materials can change drastically when
the size falls below approximately 100 nanometers ( 1 nanometers = 0.000000001
meter ) in at least one dimension. Nano materials have already found
applications in several areas in industry and they are also very promising for
construction industry. Nano sized particles can be produced in a
"top-down" process from larger particles or in a
"bottom-up" process from smaller particles. <o:p></o:p></span></div>
<div class="MsoNormal" style="background: white; line-height: normal; margin-bottom: 0.0001pt;">
<span style="font-family: "arial" , sans-serif; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: IN;">Nanoparticles
are characterized by their chemical composition, size, shape, structure,
surface chemistry. And it should be noted, that different methods of synthesis
can lead to marked differences in the structure and properties of the
nanoparticles. <o:p></o:p></span></div>
<div class="MsoNormal" style="background: white; line-height: normal; margin-bottom: 0.0001pt;">
<span style="font-family: "arial" , sans-serif; mso-fareast-font-family: "Times New Roman"; mso-fareast-language: IN;">Materials
reduced to the nanoscale can show different properties compared to what they
exhibit on a macroscale, enabling unique applications. For instance, opaque
substances can become transparent (copper); stable materials can turn
combustible (aluminium); insoluble materials may become soluble (gold). <o:p></o:p></span></div>
<div class="MsoNormal" style="background: white; line-height: normal; margin-bottom: 0.0001pt;">
<span style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; font-family: "arial" , sans-serif;">Nanotechnology is the engineering of functional systems at
the molecular scale. This covers both current work and concepts that are more
advanced. In its original sense, anotechnology refers to the projected ability
to construct items from the bottom up, using techniques and tools being
developed today to make complete, high performance products.</span> <span style="font-family: "arial" , "helvetica" , sans-serif;">One nanometer (nm)
is one billionth, or 10<sup style="text-align: start;">−9</sup><span style="text-align: start;">, of a meter. </span></span><span style="background-color: white; font-family: "arial" , "helvetica" , sans-serif;">By comparison, typical carbon-carbon </span><span style="background-color: white; font-family: "arial" , "helvetica" , sans-serif;">bond lengths,
or the spacing between these atoms in a molecule,
are in the range </span><span class="nowrap" style="background-color: white; font-family: "arial" , "helvetica" , sans-serif;"><span style="text-align: start;">0.12–0.15 nm</span></span><span style="background-color: white; font-family: "arial" , "helvetica" , sans-serif;">. By convention, nanotechnology is taken as the scale range </span><span class="nowrap" style="background-color: white; font-family: "arial" , "helvetica" , sans-serif;"><span style="text-align: start;">1 to 100 nm</span></span><span style="background-color: white; font-family: "arial" , "helvetica" , sans-serif;"> following the definition used by the National
Nanotechnology Initiative in the US. The lower limit is set by the size of
atoms (hydrogen has the smallest atoms, which are approximately a quarter of a
nm diameter) since nanotechnology must build its devices from atoms and
molecules.</span></div>
</div>
57derajathttp://www.blogger.com/profile/05826101404901224245noreply@blogger.comtag:blogger.com,1999:blog-6891149995273783499.post-61486473530454539912018-01-06T02:28:00.002-08:002018-01-06T02:28:39.066-08:00High Alumina Cement<div class="MsoNormal">
<span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 9.5pt; line-height: 107%;">High alumina cement is a
hydraulic binder based on calcium aluminates, rather than calcium silicates
which are the basis of Portland cement. These high alumina cement provide
specific properties which are ideally suited to certain applied building products.
These include self-levelling, rapid hardening, fast setting and high strength mortars.</span><span style="color: #222222; font-family: "Arial",sans-serif; font-size: 9.5pt; line-height: 107%;"><br />
<span style="background: white;">High Alumina Cement is used in applied products either as a
hydraulic binder in its own right or as an accelerator of portland cement
depending on the final performance required. Although the setting time is
similar to that of portland cement, it offers rapid strength development.</span><br />
<span style="background: white;">Unlike portland cement, high alumina cement does not release
free lime during hydration. In concretes with a low porosity, this property
gives a good chemical resistance and eliminates the major cause of
efflorescence.</span><br />
<span style="background: white;">High alumina cement may be used as a hydraulic cement on its
own or in association with other mineral products such as Portland cement,
calcium sulphates and filler or organics such as polymers in liquid or
redispersible powder.</span><br />
<span style="background: white;">The main active constituent of calcium aluminate
cements is monocalcium aluminate (CaAl<sub>2</sub>O<sub>4</sub>, CaO · Al<sub>2</sub>O<sub>3</sub>,
or CA in the cement chemist notation). It usually contains other calcium
aluminates as well as a number of less reactive phases deriving from impurities
in the raw materials. Rather a wide range of compositions is encountered,
depending on the application and the purity of aluminium source used.</span><o:p></o:p></span></div>
57derajathttp://www.blogger.com/profile/05826101404901224245noreply@blogger.comtag:blogger.com,1999:blog-6891149995273783499.post-6633073151492217192018-01-05T06:51:00.000-08:002018-01-05T06:51:07.271-08:00Ordinary Portland Cement (OPC)<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm; text-align: justify;">
<span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 10.5pt;">Portland cement is by far the most common type
of cement in general use around the world. This cement is made by heating </span><span style="background: white; font-family: "Arial",sans-serif; font-size: 10.5pt;">limestone<span style="color: #222222;"> (calcium carbonate) with other materials (such as </span></span>clay<span style="color: #222222;">) to 1450 °C in a </span>kiln<span style="color: #222222;">, in a process known as </span>calcination<span style="color: #222222;">, whereby a molecule of </span>carbon dioxide<span style="color: #222222;"> is liberated from the calcium carbonate to form </span>calcium
oxide<span style="color: #222222;">, or quicklime, which then chemically combines
with the other materials that have been included in the mix to form calcium
silicates and other cementitious compounds. The resulting hard substance,
called 'clinker', is then ground with a small amount of </span>gypsum<span style="color: #222222;"> into a powder to make 'ordinary Portland cement',
the most commonly used type of cement (often referred to as OPC). Portland
cement is a basic ingredient of </span>concrete<span style="color: #222222;">, </span>mortar<span style="color: #222222;"> and
most non-specialty </span>grout<span style="color: #222222;">. The
most common use for Portland cement is in the production of concrete. Concrete
is a composite material consisting of </span>aggregate<span style="color: #222222;"> (</span>gravel<span style="color: #222222;"> and </span>sand<span style="color: #222222;">), cement, and </span>water<span style="color: #222222;">. As a construction material, concrete can be cast in
almost any shape desired, and once hardened, can become a structural (load
bearing) element. Portland cement may be grey or white.</span><o:p></o:p></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm; text-align: justify;">
<span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 10.5pt;">When water is mixed with Portland cement, the
product sets in a few hours, and hardens over a period of weeks. These
processes can vary widely, depending upon the mix used and the conditions of </span><span style="background: white; font-family: "Arial",sans-serif; font-size: 10.5pt;">curing<span style="color: #222222;"> of the product, but a typical concrete sets in
about 6 hours and develops a </span></span>compressive strength<span style="color: #222222;"> of 8 MPa in 24 hours. The strength rises
to 15 MPa at 3 days, 23 MPa at 1 week, 35 MPa at
4 weeks, and 41 MPa at 3 months. In principle, the strength
continues to rise slowly as long as water is available for continued hydration,
but concrete is usually allowed to dry out after a few weeks and this causes
strength growth to stop.</span><o:p></o:p></div>
<br />
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm; text-align: justify;">
<span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 10.5pt;">White Portland cement or white ordinary
Portland cement (WOPC) is similar to ordinary, grey, Portland cement in all
respects, except for its high degree of whiteness. Obtaining this colour
requires high purity raw materials (low Fe</span><sub style="text-align: start;"><span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 8.5pt;">2</span></sub><span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 10.5pt;"><span style="text-align: start;">O</span></span><sub style="text-align: start;"><span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 8.5pt;">3</span></sub><span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 10.5pt;"><span style="text-align: start;"> content), and some modification to the method of
manufacture, a.o. a higher kiln temperature required to sinter the clinker in
the absence of ferric oxides acting as a flux in normal clinker. As Fe</span></span><sub style="text-align: start;"><span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 8.5pt;">2</span></sub><span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 10.5pt;"><span style="text-align: start;">O</span></span><sub style="text-align: start;"><span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 8.5pt;">3</span></sub><span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 10.5pt;"><span style="text-align: start;"> contributes to decrease the melting point of the
clinker (normally 1450 °C), the white cement requires a higher sintering
temperature (around 1600 °C). Because of this, it is somewhat more
expensive than the grey product. The main requirement is to have a low iron
content which should be less than 0.5 wt.% expressed as Fe</span></span><sub style="text-align: start;"><span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 8.5pt;">2</span></sub><span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 10.5pt;"><span style="text-align: start;">O</span></span><sub style="text-align: start;"><span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 8.5pt;">3</span></sub><span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 10.5pt;"><span style="text-align: start;"> for white cement, and less than 0.9 wt.% for
off-white cement. It also helps to have the iron oxide as ferrous oxide (FeO)
which is obtained via slightly reducing conditions in the kiln, i.e., operating
with zero excess oxygen at the kiln exit. This gives the clinker and cement a
green tinge. Other metallic oxides such as Cr</span></span><sub style="text-align: start;"><span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 8.5pt;">2</span></sub><span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 10.5pt;"><span style="text-align: start;">O</span></span><sub style="text-align: start;"><span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 8.5pt;">3</span></sub><span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 10.5pt;"><span style="text-align: start;"> (green), MnO (pink), TiO</span></span><sub style="text-align: start;"><span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 8.5pt;">2</span></sub><span style="background: white; color: #222222; font-family: "Arial",sans-serif; font-size: 10.5pt;"><span style="text-align: start;"> (white), etc., in trace content, can also give colour
tinges, so for a given project it is best to use cement from a single batch.</span><o:p></o:p></span></div>
57derajathttp://www.blogger.com/profile/05826101404901224245noreply@blogger.comtag:blogger.com,1999:blog-6891149995273783499.post-83734828071484839492018-01-05T06:23:00.003-08:002018-01-05T06:27:25.902-08:00Cement as a Binder<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm; text-align: justify;">
<span style="background: white; font-family: "arial" , sans-serif; font-size: 10.5pt;">A </span>cement<span style="text-align: start;"> is a </span><span style="background: white; font-family: "arial" , sans-serif; font-size: 10.5pt;">binder</span><span style="background: white; font-family: "arial" , sans-serif; font-size: 10.5pt;"><span style="text-align: start;">, a substance used
for construction that </span></span><span style="background: white; font-family: "arial" , sans-serif; font-size: 10.5pt;">sets</span><span style="background: white; font-family: "arial" , sans-serif; font-size: 10.5pt;"><span style="text-align: start;">, hardens and
adheres to other </span></span><span style="background: white; font-family: "arial" , sans-serif; font-size: 10.5pt;">materials</span><span style="background: white; font-family: "arial" , sans-serif; font-size: 10.5pt;"><span style="text-align: start;">, binding them
together. Cement is seldom used on its own, but rather to bind sand and gravel (</span></span><span style="background: white; font-family: "arial" , sans-serif; font-size: 10.5pt;">aggregate</span><span style="background: white; font-family: "arial" , sans-serif; font-size: 10.5pt;"><span style="text-align: start;">) together. Cement
is used with fine aggregate to produce </span></span><span style="background: white; font-family: "arial" , sans-serif; font-size: 10.5pt;">mortar</span><span style="background: white; font-family: "arial" , sans-serif; font-size: 10.5pt;"><span style="text-align: start;"> for masonry,
or with sand and gravel aggregates to produce </span></span><span style="background: white; font-family: "arial" , sans-serif; font-size: 10.5pt;">concrete</span><span style="background: white; font-family: "arial" , sans-serif; font-size: 10.5pt;"><span style="text-align: start;">.</span><o:p></o:p></span></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm; text-align: justify;">
<span style="background-color: white; font-family: arial, sans-serif; font-size: 10.5pt;">Cement starts to set when mixed with water which causes a
series of hydration chemical reactions. The constituents slowly hydrate and the
mineral hydrates solidify; the interlocking of the hydrates gives cement its
strength. Contrary to popular perceptions, hydraulic cements do not set by
drying out; proper curing requires maintaining the appropriate moisture content
during the curing process. If hydraulic cements dry out during curing, the
resulting product can be significantly weakened.</span></div>
<div class="MsoNormal" style="line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm; text-align: justify;">
<o:p></o:p></div>
<div class="MsoNormal" style="background: white; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm; text-align: justify;">
<span style="font-family: "arial" , sans-serif; font-size: 10.5pt;">Cements used in construction are usually <span style="color: windowtext; text-decoration-line: none;">inorganic</span>,
often <span style="color: windowtext; text-decoration-line: none;">lime</span> or <span style="color: windowtext; text-decoration-line: none;">calcium
silicate</span> based, and can be characterized as being either hydraulic or non-hydraulic, depending upon the
ability of the cement to set in the presence of water.<o:p></o:p></span></div>
<div class="MsoNormal" style="background: white; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm; text-align: justify;">
<span style="font-family: "arial" , sans-serif; font-size: 10.5pt;">Non-hydraulic cement</span><span style="font-family: "arial" , sans-serif; font-size: 10.5pt;"> will not set in wet conditions
or underwater; rather, it sets as it dries and reacts with <span style="color: windowtext; text-decoration-line: none;">carbon
dioxide</span> in the air. It is resistant to attack by chemicals
after setting.</span></div>
<div class="MsoNormal" style="background: white; line-height: normal; margin-bottom: .0001pt; margin-bottom: 0cm; text-align: justify;">
<span style="font-family: "arial" , sans-serif; font-size: 10.5pt;">Hydraulic cements</span><span style="font-family: "arial" , sans-serif; font-size: 10.5pt;"> (e.g., <span style="color: windowtext; text-decoration-line: none;">Portland
cement</span>) set and become <span style="color: windowtext; text-decoration-line: none;">adhesive</span> due
to a <span style="color: windowtext; text-decoration-line: none;">chemical reaction</span> between the dry
ingredients and water. The chemical reaction results in mineral <span style="color: windowtext; text-decoration-line: none;">hydrates</span> that
are not very water-soluble and so are quite durable in water and safe from
chemical attack. This allows setting in wet condition or underwater and further
protects the hardened material from chemical attack. The chemical process for
hydraulic cement found by ancient Romans used <span style="color: windowtext; text-decoration-line: none;">volcanic ash</span> (<span style="color: windowtext; text-decoration-line: none;">pozzolana</span>)
with added lime (calcium oxide).</span></div>
57derajathttp://www.blogger.com/profile/05826101404901224245noreply@blogger.comtag:blogger.com,1999:blog-6891149995273783499.post-980568429175595332018-01-05T04:17:00.000-08:002018-01-05T06:32:50.838-08:00Structural Engineering<div style="background-color: white; color: #222222; font-family: arial, sans-serif; font-size: 12.8px; text-align: justify;">
<div class="MsoNormal">
<span style="font-family: "arial" , sans-serif; font-size: 12pt; line-height: 107%;">Structural engineering involves the
analysis and design of the built environment (buildings, bridges, equipment
supports, towers and walls). Those concentrating on buildings are sometimes
informally referred to as "building engineers". Structural engineers
require expertise in strength of materials, structural analysis, and in
predicting structural load such as from weight of the building, occupants and
contents, and extreme events such as wind, rain, ice, and seismic design of
structures which is referred to as earthquake engineering. Architectural
Engineers sometimes incorporate structural as one aspect of their designs; the
structural discipline when practiced as a specialty works closely with
architects and other engineering specialists.</span><o:p></o:p></div>
<br />
<div class="MsoNormal">
<span style="font-family: "arial" , sans-serif; font-size: 12pt; line-height: 107%;">Structural
engineering</span><span style="font-family: "arial" , sans-serif; font-size: 12pt; line-height: 107%;"><span style="text-align: start;"> is concerned with the </span></span><span style="font-family: "arial" , sans-serif; font-size: 12.0pt; line-height: 107%;"><a href="https://en.wikipedia.org/wiki/Structural_design" style="text-align: start;" title="Structural design"><span style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: windowtext; text-decoration-line: none;">structural design</span></a><span style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial;"><span style="text-align: start;"> and </span></span><a href="https://en.wikipedia.org/wiki/Structural_analysis" style="text-align: start;" title="Structural analysis"><span style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: windowtext; text-decoration-line: none;">structural analysis</span></a><span style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial;"><span style="text-align: start;"> of buildings, bridges, </span></span><a href="https://en.wikipedia.org/wiki/Tower" style="text-align: start;" title="Tower"><span style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: windowtext; text-decoration-line: none;">towers</span></a><span style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial;"><span style="text-align: start;">, </span></span><a href="https://en.wikipedia.org/wiki/Overpass" style="text-align: start;" title="Overpass"><span style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: windowtext; text-decoration-line: none;">flyovers</span></a><span style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial;"><span style="text-align: start;"> (overpasses),
tunnels, off shore structures like oil and gas fields in the sea, </span></span><a href="https://en.wikipedia.org/wiki/Aerostructure" style="text-align: start;" title="Aerostructure"><span style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: windowtext; text-decoration-line: none;">aerostructure</span></a><span style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial;"><span style="text-align: start;"> and other
structures. This involves identifying the loads which act upon a structure and
the forces and stresses which arise within that structure due to those loads,
and then designing the structure to successfully support and resist those
loads. The loads can be self weight of the structures, other dead load, live
loads, moving (wheel) load, wind load, earthquake load, load from temperature
change etc. The structural engineer must design structures to be safe for their
users and to successfully fulfill the function they are designed for (to be </span><i style="text-align: start;">serviceable</i><span style="text-align: start;">). Due to the
nature of some loading conditions, sub-disciplines within structural
engineering have emerged, including </span></span><a href="https://en.wikipedia.org/wiki/Wind_engineering" style="text-align: start;" title="Wind engineering"><span style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial; color: windowtext; text-decoration-line: none;">wind engineering</span></a><span style="background-attachment: initial; background-clip: initial; background-image: initial; background-origin: initial; background-position: initial; background-repeat: initial; background-size: initial;"><span style="text-align: start;"> and
earthquake engineering.</span><o:p></o:p></span></span></div>
</div>
57derajathttp://www.blogger.com/profile/05826101404901224245noreply@blogger.comtag:blogger.com,1999:blog-6891149995273783499.post-39847843327417609962018-01-04T02:39:00.001-08:002018-01-05T06:33:11.446-08:00Materials Engineering<div style="text-align: justify;">
Materials science is closely related to civil engineering. It studies fundamental characteristics of materials, and deals with ceramics such as concrete and mix asphalt concrete, strong metals such as aluminum and steel, and thermosetting polymers including polymethylmethacrylate (PMMA) and carbon fibers.
Materials engineering involves protection and prevention (paints and finishes).</div>
<div style="text-align: justify;">
Alloying combines two types of metals to produce another metal with desired properties. It incorporates elements of applied physics and chemistry. With recent media attention on nanoscience and nanotechnology, materials engineering has been at the forefront of academic research.</div>
57derajathttp://www.blogger.com/profile/05826101404901224245noreply@blogger.comtag:blogger.com,1999:blog-6891149995273783499.post-88559999650671079262018-01-03T03:19:00.001-08:002018-01-05T06:33:24.697-08:00Civil Engineering <div style="margin-bottom: .0001pt; margin: 0cm; text-align: justify;">
<span style="font-family: "arial" , sans-serif;">Civil engineering is the application of
physical and scientific principles for solving the problem. It is linked
to advances in understanding of physics and mathematics. Civil engineering is a
wide-ranging profession, including several specialized sub-disciplines, it is
linked to knowledge of structures, materials science, geography, geology,
soils, hydrology, environment, mechanics and other fields. </span><o:p></o:p></div>
<div style="margin: 0cm 0cm 0.0001pt; text-align: justify;">
<span style="font-family: "arial" , sans-serif;">Civil engineers apply the
principles of geotechnical engineering, structural engineering, environmental engineering,
transportation engineering and construction engineering to residential,
commercial, industrial and public works projects of all sizes and levels of
construction. Civil engineering is a professional engineering discipline that
deals with the design, construction, and maintenance of the physical and
naturally built environment, including works like roads, bridges, canals, dams,
and buildings.</span><o:p></o:p></div>
<span style="background-color: white; font-family: "arial" , sans-serif; text-align: justify;">Civil engineering takes place in the public sector from
municipal through to national governments, and in the private sector from
individual homeowners through to international companies.</span><br />
<div style="margin: 0cm 0cm 0.0001pt; text-align: justify;">
<o:p></o:p></div>
57derajathttp://www.blogger.com/profile/05826101404901224245noreply@blogger.comtag:blogger.com,1999:blog-6891149995273783499.post-9069530069392292402014-07-24T21:14:00.001-07:002018-01-05T04:15:36.491-08:00HOME<br />
Calculator, Unit Converter
<br />
<br />
This blog contains formulas and equations calculator civil engineers need for a wide variety of project applications. This way to save time handling routine and non routine calculations in the design, construction, rehabilitation, and maintenance.<br />
<br />57derajathttp://www.blogger.com/profile/05826101404901224245noreply@blogger.com