APPLICATION AND STORAGE OF LIME BASIC INFORMATION AND TUTORIALS

After being processed, quicklime can generate many varieties of lime, such as quicklime powder, hydrated lime powder, lime cream, and lime paste. And different varieties have different purposes.

1. Lime Powder
Lime powder can be made into silicate products mixed with materials containing silicon. With water, pulverized lime can be molded by being mixed with fiber materials (such as glass fiber) or lightweight aggregate. Then, it can be carbonized artificially with carbon dioxide for carbonized lime board.

Carbonized lime board has a good processing property, suitable for the non-load-bearing inner partition and ceiling. Mixed with a certain percentage of clay, pulverized lime can generate limestone soil.

Triple-combined soil can be generated by mixing lime powder with clay, gravel, and slag. Lime soil and triple-combined soil are mainly used for foundation, bedding cushion, and roadbed.

2. Lime Paste
The aged lime paste or hydrated lime can turns into lime milk, diluted with water, as paint of internal and external walls and ceilings; if mixed with a certain amount of sand or cement and sand, it can be prepared into lime mortar or compound mortar for masonry or finishing; it can be used to paint inner walls or ceilings by being mixed with paper pulp and hemp fiber.

3. Storage of Lime
Quicklime will absorb the water and carbon dioxide in the air, generate calcium carbonate powder and lose cohesive force. Thus, when stored on construction site, quicklime should not be exposed to moisture, not be more, and not stay for a long time.

Moreover, the aging of lime will release a great amount of heat, so quicklime and inflammable matter should be stored separately in order to avoid fire. Usually quicklime should be stabilized immediately and the storage period should be changed into aging period.

MECHANICAL PROPERTIES OF ALUMINIUM AND ALUMINIUM ALLOYS

The compositional specifications for wrought aluminium alloys are now internationally agreed throughout Europe, Australia, Japan and the USA. The system involves a four-digit description of the alloy and is now specified in the UK as BS EN 573, 1995.

Registration of wrought alloys is administered by the Aluminum Association in Washington, DC. International agreement on temper designations has been achieved, and the standards agreed for the European Union, the Euro-Norms, are replacing the former British Standards.

Thus BS EN 515. 1995 specifies in more detail the temper designations to be used for wrought alloys in the UK. At present, there is no Euro-Norm for cast alloys and the old temper designations are still used for cast alloys.

In the following tables the four-digit system is used, wherever possible, for wrought materials.

Alloy designation system for wrought aluminium

The first of the four digits in the designation indicates the alloy group according to the major alloying elements, as follow:

1XXX aluminium of 99.0% minimum purity and higher

2XXX copper

3XXX manganese

4XXX silicon

5XXX magnesium

6XXX magnesium and silicon

7XXX zinc

8XXX other element, incl. lithium

9XXX unused

1XXX Group:

In this group the last two digits indicate the minimum aluminium percentage.

Thus 1099 indicates aluminium with a minimum purity of 99.99%. The second digit indicates modifications in impurity or alloying element limits. 0 signifies unalloyed aluminium and integers 1 to 9 are allocated to specific additions.

2XXX-8XXX Groups:

In these groups the last two digits are simply used to identify the different alloys in the groups and have no special significance. The second digit indicates alloy modifications, zero being allotted to the original alloy.

National variations of existing compositions are indicated by a letter after the numerical designation, allotted in alphabetical sequence, starting with A for the first national variation registered.

ALUMINUM AND HEAT TREATMENT OF ALUMINUM BASIC INFORMATION AND TUTORIALS

Aluminum is an important commercial metal possessing some very unique properties. It is very light (density about 2.7) and some of its alloys are very strong, so its strength-weight ratio makes it very attractive for aeronautical uses and other applications in which weight saving is important.

Aluminum, especially in the pure form, has very high electrical and thermal conductivities and is used as an electrical conductor in heat exchangers, etc. Aluminum has good corrosion resistance, is nontoxic, and has a pleasing silvery-white color; these properties make it attractive for applications in the food and container industry, architectural, and general structural fields.

Aluminum is very ductile and easily formed by casting and mechanical forming methods. Aluminum owes its good resistance to atmospheric corrosion to the formation of a tough, tenacious, highly insulating, thin oxide film, in spite of the fact that the metal itself is very anodic to other metals.

In moist atmospheres, this protective oxide may not form, and some caution must be taken to maintain this film protection. Although aluminum can be joined by all welding processes, this same oxide film can interfere with the formation of good bonds during both fusion and resistance welding, and\ special fluxing and cleaning must accompany welding operations.

Commercially pure aluminum (99+%) is very weak and ductile: tensile strength of 90 Mpa (13,000 lb/in2), yield strength of 34.5 MPa (5000 lb/in2), and shearing strength of 62 MPa (9500 lb/in2). Extrapure grades (electrical conductor grade) are 99.7+% pure, and are even weaker, but have better conductivity.

Heat Treatment of Aluminum Alloys.

Alloys of the 1000, 3000, and 5000 series cannot be hardened by heat treatment. They can be hardened by cold working and are available in annealed (recrystallized) and cold-worked tempers.

The 5000 series alloys are the strongest non-heat-treatable alloys and are frequently used where welding is to be employed, since welding will generally destroy the effects of hardening heat treatment. The remaining wrought alloys can be hardened by controlled precipitation of alloy phases.

The precipitation is accomplished by first heating the alloy to dissolve the alloying elements, followed by quenching to retain the alloy in supersaturation. The alloys are then “aged” to develop a controlled size and distribution of precipitate that produces the desired level of hardening. Some alloys naturally age at room temperature; others must be artificially aged at elevated temperatures.

TITANIUM AND TITANIUM ALLOYS BASIC INFORMATION AND TUTORIALS

Titanium alloys are important industrially because of their high strength-weight ratio, particularly at temperatures up to 427°C. The density of the commercial titanium alloys ranges from 4.50 to 4.85 g/cm3, or approximately 70% greater than aluminum alloy and 40% less than steel.

The purest titanium currently produced (99.9% Ti) is a soft, white metal. The mechanical strength increases rapidly, however, with an increase of the impurities present, particularly carbon, nitrogen, and oxygen.

The commercially important titanium alloys, in addition to these impurities, contain small percentages (1% to 7%) of (1) chromium and iron, (2) manganese, and (3) combinations of aluminum, chromium, iron, manganese, molybdenum, tin, or vanadium.

The thermal conductivity of the titanium alloys is low, about 15 W/m ⋅ K at 25°C, and the electrical resistivity is high, ranging from 54 mΩ ⋅ cm for the purest titanium to approximately 150 mΩ ⋅ cm for some of the alloys.

The coefficient of thermal expansion of the titanium alloys varies from 2.8 to 3.6 x 10–6 per degree Celsius, and the melting-point range is from 1371 to 1704°C for the purest titanium. The tensile modulus of elasticity varies between 100 to 120 GPa (15 to 17 # 106 lb/in2).

The mechanical properties, at room temperature, for annealed commercial alloys range approximately as follows: yield strength 760 to 965 MPa (110,000 to 140,000 lb/in2); ultimate strength 800 to 1100 MPa (116,000 to 160,000 lb/in2); elongation 5% to 18%; hardness 300 to 370 Brinell.

On the basis of the strength-weight ratio many of the titanium alloys exhibit superior short-time tensile properties as compared with many of the stainless and heat-resistant alloys up to approximately 427°C.

However, at the same stress and elevated temperature, the creep rate of the titanium alloys is generally higher than that of the heat-resistant alloys. Above about 482°C, the strength properties of titanium alloys decrease rapidly. The corrosion resistance of the titanium alloys in many media is excellent; for most purposes, it is the equivalent or superior to stainless steel.

BRONZE, OR COPPER-TIN, ALLOYS BASIC INFORMATION AND TUTORIALS

Bronze is an alloy consisting principally of copper and tin and sometimes small proportions of zinc, phosphorus, lead, manganese, silicon, aluminum, magnesium, etc. The useful range of composition is from 3% to 25% tin and 95% to 75% copper.

Bronze castings have a tensile strength of 195 to 345 MPa (28,000 to 50,000 lb/in2), with a maximum at about 18% of tin content. The crushing strength ranges from about 290 MPa (42,000 lb/in2) for pure copper to 1035 MPa (150,000 lb/in2) with 25% tin content.

Cast bronzes containing about 4% to 5% tin are the most ductile, elongating about 14% in 5 in. Gunmetal contains about 10% tin and is one of the strongest bronzes.

Bell metal contains about 20% tin. Copper-tin-zinc alloy castings containing 75% to 85% copper, 17% to 5% zinc, and 8% to 10% tin have a tensile strength of 240 to 275 Mpa (35,000 to 40,000 lb/in2), with 20% to 30% elongation.

Government bronze contains 88% copper, 10% tin, and 2% zinc; it has a tensile strength of 205 to 240 MPa (30,000 to 35,000 lb/in2), yield strength of about 50% of the ultimate, and about 14% to 16% elongation in 2 in; the ductility is much increased by annealing for ½ h at 700 to 800°C, but the tensile strength is not materially affected.

Phosphor bronze is made with phosphorus as a deoxidizer; for malleable products such as wire, the tin should not exceed 4% or 5%, and the phosphorus should not exceed 0.1%. United States Navy bronze contains 85% to 90% copper, 6% to 11% tin, and less than 4% zinc, 0.06% iron, 0.2% lead, and 0.5% phosphorus; the minimum tensile strength is 310 MPa (45,000 lb/in2), and elongation at least 20% in 2 in.

Lead bronzes are used for bearing metals for heavy duty; an ordinary composition is 80% copper, 10% tin, and 10% lead, with less than 1% phosphorus. Steam or valve bronze contains approximately 85% copper, 6.5% tin, 1.5% lead, and 4% zinc; the tensile strength is 235 Mpa (34,000 lb/in2), minimum, and elongation 22% minimum in 2 in (ASTM Specification B61). The bronzes have a great many industrial applications where their combination of tensile properties and corrosion resistance is especially useful.

CLASSIFICATION OF FERROUS MATERIALS BASIC INFORMATION AND TUTORIALS

Iron and steel may be classified on the basis of composition, use, shape, method of manufacture, etc. Some of the more important ferrous alloys are described in the sections below.

Ingot iron is commercially pure iron and contains a maximum of 0.15% total impurities. It is very soft and ductile and can undergo severe cold-forming operations. It has a wide variety of applications based on its formability.

Its purity results in good corrosion resistance and electrical properties, and many applications are based on these features. The average tensile properties of Armco ingot iron plates are tensile strength 320 MPa (46,000 lb/in2); yield point 220 MPa (32,000 lb/in2); elongation in 8 in, 30%; Young’s modulus 200 GPa (29 # 106 lb/in2).

Plain carbon steels are alloys of iron and carbon containing small amounts of manganese (up to 1.65%) and silicon (up to 0.50%) in addition to impurities of phosphorus and sulfur. Additions up to 0.30% copper may be made in order to improve corrosion resistance.

The carbon content may range from 0.05% to 2%, although few alloys contain more than 1.0%, and the great bulk of steel tonnage contains from 0.08% to 0.20% and is used for structural applications.

Medium-carbon steels contain around 0.40% carbon and are used for constructional purposes—tools, machine parts, etc. High-carbon steels have 0.75% carbon or more and may be used for wear and abrasion-resistance applications such as tools, dies, and rails.

Strength and hardness increase in proportion to the carbon content while ductility decreases. Phosphorus has a significant hardening effect in low-carbon steels, while the other components have relatively minor effects within the limits they are found.

It is difficult to generalize the properties of steels, however, since they can be greatly modified by cold working or heat treatment.

High-strength low-alloy steels are low-carbon steels (0.10% to 0.15%) to which alloying elements such as phosphorus, nickel, chromium, vanadium, and niobium have been added to obtain higher strength.

This class of steel was developed primarily by the transportation industry to decrease vehicle weight, but the steels are widely used. Since thinner sections are used, corrosion resistance is more important, and copper is added for this purpose.

ELASTIC STRENGTH OF STRUCTURAL MATERIALS BASIC INFORMATION

What is Elastic Strength?

To the user and the designer of machines or structures, one significant value to be determined is a limiting stress below which the permanent distortion of the material is so small that the structural damage is negligible and above which it is not negligible. The amount of plastic distortion which may be regarded as negligible varies widely for different materials and for different structural or machine parts.

In connection with this limiting stress for elastic action, a number of technical terms are in use; some of them are

1. Elastic Limit. The greatest stress which a material is capable of withstanding without a permanent deformation remaining on release of stress. Determination of the elastic limit involves repeated application and release of a series of increasing loads until a set is observed upon release of load.

Since the elastic limit of many materials is fairly close to the proportional limit, the latter is sometimes accepted as equivalent to the elastic limit for certain materials. There is, however, no fundamental relation between elastic limit and proportional limit. Obviously, the value of the elastic limit determined will be affected by the sensitivity of apparatus used.

2. Proportional Limit. The greatest stress which a material is capable of withstanding without a deviation from proportionality of stress to strain. The statement that the stresses are proportional to strains below the proportional limit is known as Hooke’s Law. The numerical values of the proportional limit are influenced by methods and instruments used in testing and the scales used for plotting diagrams.

3. Yield Point. The lowest stress at which marked increase in strain of the material occurs without increase in load. If the stress-strain curve shows no abrupt or sudden yielding of this nature, then there is no yield point. Iron and low-carbon steels have yield points, but most metals do not, including iron and low-carbon steels immediately after they have been plastically deformed at ordinary temperatures.

4. Yield Strength. The stress at which a material exhibits a specified limiting permanent set. Its determination involves the selection of an amount of permanent set that is considered the maximum amount of plastic yielding which the material can exhibit, in the particular service condition for which the material is intended, without appreciable structural damage.

A set of 0.2% has been used for several ductile metals, and values of yield strength for various metals are for 0.2% set unless otherwise stated. The yield strength is generally used to determine the elastic strength for materials whose stress-strain curve in the region pr is a smooth curve of gradual curvature.

AUTOMATED MATERIAL IDENTIFICATION SYSTEMS BASIC AND TUTORIALS

When construction materials arrive at CIC job sites, they are identified at the unloading area, and the job site inventory database in the central computer is updated. CIC requires tight control on inventory and integrated operation of automated equipment.

Further, all construction materials must be tracked from the time of their arrival at the job site to their final position in the finished facility. Such tracking of construction materials may be done by employing automated identification systems.

There are two means of tracking construction materials: direct and indirect. Direct tracking involves identifying a construction material by a unique code on its surface. This method of tracking can be employed with the use of large prefabricated components.

Indirect tracking involves identifying construction material by a unique code on the material handling equipment. This method of tracking can be employed for tracking bulk materials such as paints [Rembold et al., 1985]. Select automatic identification systems for construction materials are described below.

Bar Coding

The U.S. Department of Defense (DOD) was the first organization to implement bar coding technology. The Joint Steering Group for Logistics Applications of Automated Marking and Reading Symbols (LOGMARS) spearheaded the DOD’s effort in the implementation of bar coding technology. The symbology of bar codes conveys information through the placement of wide or narrow dark bars that create narrow or wide white bars.

With the rise of the LOGMARS project, code 39 (also called “3 of 9” coding) has become a standard for bar coding. To date, most construction bar code applications have used the code 39 symbology [Teicholz and Orr, 1987; Bell and McCullough, 1988].

Laser beams and magnetic foil code readers are two basic technologies available for reading bar codes. Lasers offer the ability to read bar codes that move rapidly. Magnetic code readers are among the most reliable identification systems. It is possible to transmit the code without direct contact between the code reader and the write head on the code carrier. When the workpiece passes the read head, the code is identified by the code reader [Teicholz and Orr, 1987; Rembold et al., 1985].

Voice Recognition

Voice recognition provides computers the capability of recognizing spoken words, translating them into character strings, and sending these strings to the central processing unit (CPU) of a computer. The objective of voice recognition is to obtain an input pattern of voice waveforms and classify it as one of a set of words, phrases, or sentences.

This requires two steps: (1) analyze the voice signal to extract certain features and characteristics sequentially in time and (2) compare the sequence of features with the machine knowledge of a voice, and apply a decision rule to arrive at a transcription of the spoken command [Stukhart and Berry, 1992].

Vision Systems

A vision system takes a two-dimensional picture by either the vector or the matrix method. The picture is divided into individual grid elements called pixels. From the varying gray levels of these pixels, the binary information needed for determining the picture parameters is extracted. This information allows the system, in essence, to see and recognize objects.

The vector method is the only method that yields a high picture resolution with currently available cameras. The vector method involves taking picture vectors of the scanned object and storing them at constant time intervals. After the entire cycle is completed, a preprocessor evaluates the recomposed picture information and extracts the parameters of interest [Rembold et al., 1985].

DEEP SEA CLAY BASICS AND TUTORIALS

DEEP SEA CLAY BASIC INFORMATION
What Are Deep Sea Clay? Deep Sea Clay Information

The clay materials formed in large parts of the deep sea and oceanic basins are, generally, quite distinct from terrigenous clays. This is because many such areas are so far removed from land that detrital terrigenous material becomes a minor, even insignificant, source of sediment.


As a result, the products of other processes make a more important contribution to the fine grained sediments that accumulate in these environments (Berger 1974). Globally, the most important of these are the minute skeletal components of microfossils which form a continuous pelagic rain from surface to deeper waters.

Their contribution to the fine grained sediment accumulating at the ocean floor depends upon the dynamic balance between the processes of their production in surface waters and their destruction by dissolution on their journey down through the water column following death of the organisms. The two most important biogenic components are calcareous and siliceous microfossils.

The calcareous microfossils include foraminifera and coccoliths composed of calcium carbonate (CaCO3) mainly in the form of calcite, whilst the silceous microfossils include diatoms and radiolaria composed of opaline amorphous silica (SiO2), in the form known as opal-A. The rate of production of these organisms in surface ocean waters depends on biological fertility.

Diatoms dominate in more fertile nutrient rich water whereas coccoliths dominate in less fertile regions. Since seawater is universally under saturated with respect to amorphous silica, most silica is dissolved and recycled
as the skeletons of opaline microfossils descend through the water column.

A further fraction arrives at the sediment water interface where more is dissolved but in regions of high productivity some is preserved and may accumulate. Thus the distribution of siliceous pelagic sediments mirrors the patterns of the most highly productive ocean waters such as in regions of oceanic divergence and upwelling where nutrient-rich deep ocean waters rise to the surface.

The fate of calcareous pelagic sediment is similar except that the degree of undersaturation of seawater with respect to carbonates increases with depth. This gives rise to a depth in the oceans, known as the Calcite Compensation Depth (CCD), below which calcite does not accumulate.

In the deepest parts of the Ocean basins (> 3500 m) below the CCD, sedimentation rates may be extremely slow and hydrogenous processes involving iron and manganese oxides take on an important role. Such areas accumulate deposits know as deep sea red clays (Glasby 1991).

Red clays are extremely fine grained with often more than 80% < 2 um in size. They cover about 30% of the ocean basins and are most prevalent in the Pacific Ocean. Most of the components of Pacific red clays are allogenic, the most important being aeolian dust.

Red clays accumulate very slowly with the highest rates of sedimentation coeval with Pleistocene glacial periods when aeolian dust production was at a maximum (Glasby 1991). Because of their fine grain-size and long term stability serious consideration has been given to using red clays as sites for radioactive waste disposal (Burkett et al. 1991).

WOOD CHEMICAL COMPOSITION BASICS AND TUTORIALS

CHEMICAL COMPOSITION OF WOOD BASIC INFORMATION
What Are The Chemical Composition Of Wood?

Wood is composed of cellulose, lignin, hemicellulose, extractives, and ash-producing minerals. Cellulose accounts for approximately 50 percent of the wood substance by weight (USDA-FS, 1999).

The exact percent is species dependent. It is a linear polymer (aliphatic carbon compound) having a high molecular weight. The main building block of cellulose is sugar: glucose.

As the tree grows, linear cellulose molecules arrange themselves into highly ordered strands, called fibrils.

These ordered strands form the large structural elements that compose the cell walls of wood fibers. Lignin accounts for 23% to 33% of softwood and 16% to 25% of hardwood by weight.

Lignin is mostly an intercellular material. Chemically, lignin is an intractable, insoluble, material that is loosely bonded to the cellulose. Lignin is basically the glue that holds the tubular cells together.

The longitudinal shear strength of wood is limited by the strength of the lignin bounds.


Hemicelluloses are polymeric units made from sugar molecules. Hemicellulose is different from cellulose in that it has several sugars tied up in its cellular structure.

Hardwood contains 20% to 30% hemicellulose and softwood averages 15% to 20%. The main sugar units in hardwood and softwood are xylose and monnose, respectively.

The extractives compose 5% to 30% of the wood substance. Included in this group are tannins and other polyphenolics, coloring matters, essential oils, fats, resins, waxes, gums, starches, and simple metabolic intermediates.

These materials can be removed with simple inert neutral solvents, such as water, alcohol, acetone, and benzene. The amount contained in an individual tree depends on the species, growth conditions, and time of year the tree is harvested.

The ash-forming materials account for 0.1% to 3.0% of the wood material and include calcium, potassium, phosphate, and silica.