Bonding is the industry term that’s given to the pattern in which the bricks are laid. Whilst the primary purpose of a bond is to ensure the brickwork is strong and stable, it can also have a dramatic effect on the visual appearance of a wall. There are a number of ways in which the stretcher (the longer, rectangular face) and the header (the shorter, square face) can be laid, so deciding on a preferred style up front is crucial.
The direction in which a brick is laid can create interesting patterns and add value to virtually any wall. The most popular orientation is brick on bed, where the stretcher face is displayed. To create a feature detail, the brick can be placed on end in a soldier course orientation. The quoted compressive strength of the brick will reduce in this orientation.
The brick can be placed on edge to create details such as cappings (this is also known as Rowlock). The quoted compressive strength of the brick will reduce in this orientation.
- 1 What are the principles of bonding of brickwork?
- 2 What is the statement to obtain a good bonding in brick wall?
- 3 What is the main point of bonding?
- 4 Why do we need a bond?
- 5 Why is bond Value important?
- 6 What are the principles observed in the construction of stone masonry walls?
What are the principles of bonding of brickwork?
8 MUST FOLLOW RULES FOR GOOD BONDING IN BRICKWORK | July 7, 2015 |, | Bonds in brick work means method of arranging the bricks in courses so that individual brick units are tied together and the vertical joints of the successive courses do not lie in same vertical line. Types of Bonding
What are the types of brick bonds used in brick work?
Types of Bonds in Brick Masonry Wall Construction : – The most commonly used types of bonds in brick masonry are:
- Stretcher bond
- Header bond
- English bond and
- Flemish bond
Other Types of bonds are:
- Facing bond
- Dutch bond
- English cross bond
- Brick on edge bond
- Raking bond
- Zigzag bond
- Garden wall bond
What is the statement to obtain a good bonding in brick wall?
The following rules for getting a good brick bond should be adopted. The bricks should be uniform in size. The length of the brick should be twice the width plus one joint so that a uniform lap is obtained. A good bond is not possible if the lap is non-uniform.
What is the main point of bonding?
What is bonding? – Bonding is used to reduce the risk of electric shocks to anyone who may touch two separate metal parts when there is a fault somewhere in the supply of electrical installation. By connecting bonding conductors between particular parts, it reduces the voltage there might have been. The types of bonding generally used are main bonding and supplementary bonding.
What are the 4 types of bonding?
crystal – Types of bonds The properties of a can usually be predicted from the valence and bonding preferences of its atoms. Four main bonding types are discussed here: ionic, covalent, metallic, and molecular. Hydrogen-bonded solids, such as, make up another category that is important in a few crystals.
There are many examples of solids that have a single bonding type, while other solids have a mixture of types, such as covalent and metallic or covalent and ionic. exhibits ionic bonding. The has a single in its outermost shell, while needs one electron to fill its outer shell. donates one to chlorine, forming a sodium (Na + ) and a chlorine (Cl − ).
Each ion thus attains a closed outer shell of electrons and takes on a spherical shape. In addition to having filled shells and a spherical shape, the ions of an ionic solid have integer valence. An ion with positive valence is called a, In an ionic solid the cations are surrounded by ions with negative valence, called,
- Similarly, each anion is surrounded by cations.
- Since opposite charges attract, the preferred bonding occurs when each ion has as many neighbours as possible, consistent with the ion radii.
- Six or eight nearest neighbours are typical; the number depends on the size of the and not on the bond angles.
- The alkali halide crystals are binaries of the AH type, where A is an alkali ion (lithium, sodium, potassium, rubidium, or cesium) and H is a halide ion (fluorine, chlorine, bromine, or iodine).
The crystals have bonding, and each ion has six or eight neighbours. Metal ions in the (magnesium, calcium, barium, and strontium ) have two electrons in their outer shells and form divalent cations in ionic crystals. The (oxygen, sulfur, selenium, and tellurium) need two electrons to fill their outer p -shell.
- Electron shells are divided into subshells, designated as s, p, d, f, g, and so forth.
- Each subshell is divided further into orbitals.) Two electrons are transferred from the cations to the anions, leaving each with a closed shell.
- The earth chalcogenides form crystals such as (BaO), (CaS), barium selenide (BaSe), or strontium oxide (SrO).
They have the same structure as sodium chloride, with each atom having six neighbours. can be combined with various cations to form a large number of ionically bonded solids.,,, and a few other elements form covalently bonded solids. In these elements there are four electrons in the outer -shell, which is half filled.
The s p -shell is a hybrid formed from one s and one p subshell.) In the an atom shares one (outer-shell) electron with each of its four nearest neighbour atoms. The bonds are highly directional and prefer a tetrahedral arrangement. A covalent bond is formed by two —one from each atom—located in orbitals between the ions.
Insulators, in contrast, have all their electrons within shells inside the atoms. The perpetual spin of an electron is an important aspect of the covalent bond. From a vantage point above the spinning particle, counterclockwise rotation is designated spin-up, while clockwise rotation is spin-down.
- A fundamental law of is the, which states that no two electrons can occupy the same point in space at the same time with the same direction of spin.
- In a covalent bond two electrons occupy the same small volume of space ( i.e., the same orbital) at all times, so they must have opposite spin: one up and one down.
The exclusion principle is then satisfied, and the resulting bond is strong. In the carbon atoms are arranged in parallel sheets, and each atom has only three near neighbours. The covalent bonds between carbons within each layer are quite strong and are called bonds.
- The fourth in carbon has its orbital perpendicular to the plane.
- This orbital bonds weakly with the similar orbitals on all three neighbours, forming bonds.
- The four bonds for each carbon atom in the graphite structure are not arranged in a tetrahedron; three are in a plane.
- The planar arrangement results in strong bonding, although not as strong as the bonding in the configuration.
The bonding between layers is quite weak and arises from the ; there is much slippage parallel to the layers. Diamond and graphite form an interesting contrast: diamond is the hardest material in nature and is used as an, while graphite is used as a lubricant.
Besides the elemental semiconductors, such as silicon and germanium, some binary crystals are covalently bonded. has three electrons in the outer shell, while lacks three. (GaAs) could be formed as an insulator by transferring three electrons from gallium to arsenic; however, this does not occur. Instead, the bonding is more covalent, and gallium arsenide is a covalent,
The outer shells of the gallium atoms contribute three electrons, and those of the arsenic atoms contribute five, providing the eight electrons needed for four covalent bonds. The centres of the bonds are not at the midpoint between the ions but are shifted slightly toward the arsenic.
Such bonding is typical of the — i.e., those consisting of one element from the third column of the and one from the, Elements from the third column (boron, aluminum, gallium, and indium) contribute three electrons, while the fifth-column elements (nitrogen, phosphorus, arsenic, and antimony) contribute five electrons.
All III–V semiconductors are covalently bonded and typically have the structure with four neighbours per atom. Most common favour this arrangement. The factor that determines whether a binary crystal will act as an or a semiconductor is the valence of its constituent atoms.
- That donate or accept one or two valence electrons form insulators.
- Those that have three to five valence electrons tend to have covalent bonds and form semiconductors.
- There are exceptions to these rules, however, as is the case with the IV–VI semiconductors such as lead sulfide.
- Heavier elements from the fourth column of the periodic table (germanium, tin, and lead) with the chalcogenides from the sixth row to form good binary semiconductors such as germanium telluride (GeTe) or tin sulfide (SnS).
They have the sodium chloride structure, where each atom has six neighbours. Although not tetrahedrally bonded, they are good semiconductors. Filled atomic shells with -orbitals have an important role in covalent bonding. Electrons in atomic orbits have ( L ), which is quantized in integer ( n ) multiples of h : L = n h,
Electron orbitals with n = 0 are called -states, with n = 1 are -states, and with n = 2 are d -states. and ions have one valence electron outside their closed shells. The outermost filled shell is a d -state and affects the bonding. Eight crystals are formed from the copper and, Three (AgF, AgCl, AgBr) have the sodium chloride structure with six neighbours.
The other five (AgI, CuF, CuCl, CuBr, CuI) have the zinc blende structure with four neighbours. The bonding in this group of solids is on the borderline between covalent and ionic, since the crystals prefer both types of bonds. The halides exhibit somewhat different behaviour.
The alkali metals are also monovalent cations, but their halides are strictly ionic. The difference in bonding between the alkali metals on the one hand and silver and copper on the other hand is that silver and copper have filled d -shells while the alkalis have filled p -shells. Since the d -shells are filled, they do not covalently bond.
This group of electrons is, however, highly polarizable, which influences the bonding of the valence electrons. Similar behaviour is found for and, which have two valence electrons outside a filled d -shell. They form binary crystals with the chalcogenides, which have tetrahedral bonding.
In this case the covalent bonding seems to be preferred over the, In contrast, the alkaline earth chalcogenides, which are also divalent, have outer p -shells and are ionic. The zinc and cadmium chalcogenides are covalent, as the outer d -shell electrons of the two cations favour covalent bonding. Metallic bonds fall into two categories.
The first is the case in which the are from the -shells of the metal ions; this bonding is quite weak. In the second category the valence electrons are from partially filled d -shells, and this bonding is quite strong. The d -bonds dominate when both types of bonding are present.
The are bonded with s p -electrons. The electrons of these metal atoms are in filled atomic shells except for a few electrons that are in unfilled s p -shells. The electrons from the unfilled shells are detached from the metal ion and are free to wander throughout the crystal. They are called, since they are responsible for the electrical conductivity of metals.
Although the conduction electrons may roam anywhere in the crystal, they are distributed uniformly throughout the entire solid. Any large imbalance of charge is prevented by the strong electrical attraction between the negative electrons and the positive ions, plus the strong repulsion between electrons.
The phrase electron correlation describes the correlated movements of the electrons; the motion of each electron depends on the positions of neighbouring electrons. Electrons have strong short-range order with one another. Correlation ensures that each unit cell in the crystal has, on the average, the number of electrons needed to cancel the positive charge of the cation so that the unit cell is electrically neutral.
is the energy gained by arranging the atoms in a crystalline state, as compared with the state. Insulators and semiconductors have large energies; these solids are bound together strongly and have good mechanical strength. Metals with electrons in s p -bonds have very small cohesive energies.
This type of is weak; the crystals are barely held together. Single crystals of simple metals such as are mechanically weak. At room the crystals have the mechanical consistency of warm butter. Special care must be used in handling these crystals, because they are easily distorted. Metals such as magnesium or aluminum must be alloyed or polycrystalline to have any mechanical strength.
Although the simple metals are found in a variety of structures, most are in one of the three closest-packed structures: fcc, bcc, and hcp. calculations show that the cohesive energy of a given metal is almost the same in each of the different crystal arrangements; therefore, crystal arrangements are unimportant in metals bound with electrons from s p -shells.
A different type of metallic bonding is found in, which are metals whose atoms are characterized by unfilled d -shells. The d -orbitals are more tightly bound to an ion than the s p -orbitals. Electrons in d -shells do not wander away from the ion. The d -orbitals form a covalent bond with the d -orbitals on the neighbouring atoms.
The bonding of d -orbitals does not occur in a tetrahedral arrangement but has a different directional preference. In metals the bonds from d -orbitals are not completely filled with electrons. This situation is different from the tetrahedral bonds in semiconductors, which are filled with eight electrons.
- In metals the covalent bonds formed with the d -electrons are much stronger than the weak bonds made with the s p -electrons of simple metals.
- The cohesive energy is much larger in transition metals.
- Titanium, iron, and tungsten, for example, have exceptional mechanical strength.
- Crystal arrangements are important in the behaviour of the transition metals and occur in the close-packed fcc, bcc, or hcp arrangements.
: crystal – Types of bonds
Which brick bond is best for construction?
English Bond – This is another common type of bond that you see used on a lot of British buildings and is easy to spot since it’s such a distinctive pattern. The English brick bond alternates rows of headers with rows of stretchers. This type of wall-building uses more bricks than a stretcher bond, so is rarely used for largescale residential developments, but it is often considered one of the best and strongest brick bond designs around.
Which kind of brick bond is used in planning?
Types of Brick Bonds | The Construction Civil Some of the different bonds are, 1., 2.,
3. Stretching bond, 4. Heading bond, 5. Garden wall bond, 6. Facing bond, 7. Raking bond, 8. Dutch bond, 9. English cross-bond, 10. Zig-Zag bond,
11. Silverlock’s bond. For English and Flemish bond refer in our website.3. Stretching bond: In this arrangement of bonding, all the bricks are laid as stretchers. The overlap, which is usually of half brick, is obtained by commencing each alternate course with a half brick bat.
Stretching bond is used for half brick wall only. This bond is also termed as running bond and is commonly adopted in the of half brick thick leaves of cavity walls, partition walls, etc. Since there are no headers, suitable reinforcement should be used for structural bond.4. Heading bond : In this type of bonding all the bricks are laid as headers on the faces.
The overlap, which is usually-of half the width of the brick is obtained by introducing a three-quarter bat in each alternate course at quoins. This bond permits better alignment and as such it is used for walls curved on plan. This bond is chiefly used for footings in foundations for better transverse distribution of load.5.Garden wall bond: This type of bond is suitably adopted for one brick thick wall which may act as a garden wall or a boundary wall.
- In garden wall bond, it is possible to build uniform faces for a wall without much labour or expense.
- This type of bond is not so strong as English bond and its use is restricted to the construction of dwarf walls or other similar types of walls which are not subjected to large stresses.
- On accounts of its good appearance, this bond is sometimes used for the construction of the outer leaves of cavity walls.
There are two types of garden wall bond, (a) English garden wall bond (b) Flemish garden wall bond (a) English garden wall bond. The general arrangement of bricks in this type of bonding is similar to that of English bond except that the heading courses are only inserted at every fourth or sixth course.
Usually the arrangement consists of one course of headers to three courses of stretchers. A queen closer is placed next to the quoin header of the heading course to give the necessary lap. (b) Flemish garden wall bond. This consists of alternate course composed of one header to three or sometimes even five stretchers in series throughout the length of the courses.
Each alternate course contains a three quarter bat placed next to the quoin header and a header is laid over the middle of each central stretcher.6.Facing bond: This arrangement of bricks is adopted for thick walls, where the facing and backing are desired to be constructed with bricks of different thickness.
- This bond consists of heading and stretching courses so arranged that one heading course comes after several stretching courses.
- Since the number of joints in the backing and the facing differ greatly, the load distribution is not uniform.
- This may sometimes lead to unequal settlement of the two thickness of the wall.7.Raking bond: This is a bond in brick work in which the bonding bricks are laid at any angle other than zero or ninety degrees.
This arrangement helps to increase the longitudinal stability of thick walls built in English bond. In this arrangement of bonding, the space between the external stretchers of a wall is filled with bricks inclined to the face of the wall. This bond is introduced at certain intervals along the height of a wall.
- There arc two common forms of raking bond ; (a) Herring hone bond (b) Diagonal bond.
- A) Herring-bone bond.
- This type of bond is best suited for very thick walls usually not less than four bricks thick.
- In this arrangement of brick work, bricks are laid in course inclined at 45° in two directions from the centre.
This bond is also commonly used for brick pavings. (b) Diagonal bond. This bond is best suited for walls which are 2 to 4 brick thick. This bond is usually introduced at every fifth or seventh course along the height of the wall. In this bond, the bricks arc placed end to end in such a way that extreme corners of the series remain in contact with the stretchers.8.Dutch bond: This bond is a modification of the old English cross bond and consists of alternate courses of headers and stretchers.
In this arrangement of brick work, each stretching course starts at the quoin with a three-quarter bat and every alternate stretching course has a header placed next to the three-quarter brick bat provided at the quoin.9. English cross-bond: This is similar to English bond and consists of alternate course of headers and stretchers.
However, in this bond, queen closer are introduced next to quoin headers and each alternate stretching course has header placed next to quoin stretcher. This bond is sufficiently strong and bears a good elevation.10. Zig-Zag bond: This is similar to herring-bone bond with the only difference that in this case the bricks are laid in a zig-zag fashion.
- This is commonly adopted in brick paved flooring.11.
- Silverlock’s bond: This is a form of bonding brick-work in which bricks are laid on edge.
- It is economical but weak in strength and hence it is only recommended for garden walls or partition walls.
- In this bond, the bricks are laid as headers and stretchers in alternate courses in such a way that headers are laid on bed aid the stretchers are laid on edge forming a continuous cavity.
: Types of Brick Bonds | The Construction Civil
Which bond is stronger in brick masonry?
For a one brick wall, header brick bond is the strongest bond because of the alternate stretcher and header course used. the loads are equally distributed and the bricks are completely placed over each other which transfers the upcoming load on adjacent bricks.
Why do we need a bond?
What are the benefits and risks of bonds? – Bonds can provide a means of preserving capital and earning a predictable return. Bond investments provide steady streams of income from interest payments prior to maturity. The interest from municipal bonds generally is exempt from federal income tax and also may be exempt from state and local taxes for residents in the states where the bond is issued.
- As with any investment, bonds have risks.
- These riskes include: Credit risk.
- The issuer may fail to timely make interest or principal payments and thus default on its bonds.
- Interest rate risk,
- Interest rate changes can affect a bond’s value.
- If bonds are held to maturity the investor will receive the face value, plus interest.
If sold before maturity, the bond may be worth more or less than the face value. Rising interest rates will make newly issued bonds more appealing to investors because the newer bonds will have a higher rate of interest than older ones. To sell an older bond with a lower interest rate, you might have to sell it at a discount.
Inflation risk. Inflation is a general upward movement in prices. Inflation reduces purchasing power, which is a risk for investors receiving a fixed rate of interest. Liquidity risk. This refers to the risk that investors won’t find a market for the bond, potentially preventing them from buying or selling when they want.
Call risk. The possibility that a bond issuer retires a bond before its maturity date, something an issuer might do if interest rates decline, much like a homeowner might refinance a mortgage to benefit from lower interest rates.
Why is bond Value important?
Key Takeaways –
- Bond valuation is a way to determine the theoretical fair value (or par value) of a particular bond.
- It involves calculating the present value of a bond’s expected future coupon payments, or cash flow, and the bond’s value upon maturity, or face value.
- As a bond’s par value and interest payments are set, bond valuation helps investors figure out what rate of return would make a bond investment worth the cost.
Which bond is the strongest?
In chemistry, a covalent bond is the strongest bond, In such bonding, each of two atoms shares electrons that bind them together. For example – water molecules are bonded together where both hydrogen atoms and oxygen atoms share electrons to form a covalent bond.
What is the principal constituent of brick?
|Nirupam Sinha said: (Mar 11, 2016)
|Silica may be higher in percentage. But alumina gives bond strength so it is consider main constituent.
What are the principles observed in the construction of stone masonry walls?
Basic Principles of Stone Masonry –
- No stone should be laid taller than it is long, except at corners.
- Avoid block or running joints only one stone on at least one side of a vertical joint.
- Avoid setting more than three stones against a riser.
- Risers should be evenly distributed throughout the wall.