English Bond and Flemish Bond – Features & Difference

English Bond and Flemish Bond – Features & Difference

The English bond and the Flemish bond are the two most common types of brick masonry used in wall construction. An English bond is formed by a brick construction pattern with alternate brick courses laid as stretchers and headers. A flemish bond is a design of brick building consisting of alternate stretchers and headers for each course.

English Bond

For almost all wall thicknesses, an English bond can be built Among all other bonds, this bond is the strongest. This bond is made up of alternate header and stretcher courses. The vertical joints overlap one another. This is also followed by the stretcher course's vertical joints. The vertical joints are broken by using a queen closer to prevent the joints from forming inline. The queen closer is placed for each heading course after the quoin header.

Features of English Bond

The basic features of English Bond are:

1. No continuous vertical joints are formed.
2. In the elevation, the alternate course either shows headers or stretchers.
3. Every header in an alternative course comes centrally over the joint formed by two stretchers below it.
4. The stretchers have a minimum lap of one-fourth their length over the headers. This is the case for the stretcher course.
5. Those walls with even multiple half bricks show the same appearance on both the faces. Hence a course that shows stretchers on the front face would show stretchers on the back face.
6. Those walls with odd multiple half bricks show stretchers on one face and the headers on the other dace.
7. The middle portion of the thicker walls consists of headers.
8. Queen closer is not required for a stretcher course. It is used for the header course placed just after the quoin header. No header course should start with the queen closer.
9. The joints formed in the header course are greater (twice) than the stretcher course. Hence the joint in the header course is made thinner compared to the joints in the stretcher course.

Flemish Bond

A Flemish bond pattern consists of each course of alternate headers and stretchers. Every alternate course starts with a quoin header at the corner. To the next of quoin header, quoin closer is placed in alternate courses to develop face lap. The patterns arrange such that every header is centrally supported over the stretcher below it.

Flemish bonds can be either:

1. Double Flemish Bond
2. Single Flemish Bond

1. Double Flemish Bond

In each course, a double flemish bond with alternating headers and stretchers. The feature of the double flemish bond is that it has the same color on both the front and back sides. This feature, therefore, gives a better appearance for all wall thickness compared to the English bond.

Features of Double Flemish Bond

The basic features of Double Flemish Bond are:

1. Each Course has headers and stretchers placed alternately.
2. The facing and backing of the wall have the same appearance.
3. In alternate courses, quoin closers are placed next to quoin headers.
4. The walls with odd multiple of half brick employ half bats and three-quarter bats.
5. The walls with even multiple of half bricks, do not require bats.

2. Single Flemish Bond

In each case, a single flemish bond consists of the double flemish bond on its face and the English bond as heartfelt support. The bond, therefore, makes use of both English and Flemish bond power. This bond can be used to build walls of not less than one and a half brick with a thickness. The double flemish bond facing is used with costly bricks of good quality.

Also Read  Types Of Masonry Construction Based On Material

Difference between English and Flemish Bond

ENGLISH BOND	FLEMISH BOND
Bond pattern with alternate header and stretcher course	Bond Pattern with each course having alternate header and stretcher
More strength given for bricks with thickness greater than one & half brick	Less strong and compact compared to English bond
Less pleasing appearance	Appearance is more attractive and pleasing
Expensive	Economical
No strict supervision and skill is demanded	Requires good workmanship and careful supervision.

Types of Foundation

Classification of Foundation

On the basis of depth, foundations are broadly classified into two categories.

1. Shallow foundation
2. Deep foundation

Shallow foundation :

"The foundation is known as the shallow foundation that immediately beneath the lowest part of the structure, near to the ground level."

OR

“A shallow foundation is a type of building foundation that transfers building loads to the earth very near to the surface, rather than to a subsurface layer or a range of depths as does a deep foundation.” 

Such foundations are mostly placed below ground level on the first hard strata. Shallow foundations are those that at shallow depth transmit the loads to the soil. 

When the soil at shallow depth is strong enough to withstand the load, a shallow foundation is provided The ratio of foundation depth D to foundation width, B is equal to or less than 1 for shallow foundations.

For shallow foundation:

D / B  <  1

Deep foundation :

The foundation built sufficiently below ground level is called the deep foundation at its base with some artificial arrangements such as piles, wells, etc.

Deep foundations are those transiting the load into deeper soil. Deep foundations are required when a structure can not be supported by the soil at shallow depth and a hard stratum is available at larger depth.

For deep foundations, the ratio of the depth of the foundation to the width of the foundation is greater than 1. 

D / B > 1

Types of shallow foundation:

• Spread footing or open trench foundation. 
• Raft or Mate foundation.
• Stepped footing.
• Inverted arch footing. 

Spread footing or open trench foundation:

The spread foundation is the shallow foundation type. It is defined as the structural components used to support the column and wall as well as to transmit and distribute the load on the structure to the soil.

In plan, the shape can be circular, square and rectangular.

In such foundation, the spread is given under the base of a wall or a column by providing offsets. This spread is known as footing and the foundation itself is called spread footing.

Wall footing, Masonry pillar footing, and Concrete column footings. ( isolated and combined) are the types of spread footing.

Wall footing:

This is a typical and simplest form of spread footing. It consists of the number of brick courses, the lowest being usually twice the above wall thickness.

By having 50 mm offsets on either side of the wall, the base width of the wall is increased.

 Each course usually has a depth of 100 mm.

The course at the bottom is 200 mm deep.

The size of offsets is slightly more in the case of stone walls.

Used for ordinary building walls.

Masonry wall footing:

The isolated footing is used to support the individual pillars and columns constructed in brick or stone masonry.

Concrete column footing:

These are either stepped type, type of slate or type of slope with projections in the concrete base. Reinforcement is also provided at the base to support heavy loads.

Raft or Mate foundation:

The foundation that consists of a thick R.C.C slab that covers the entire area in the form of a mat is known as a raft or mat foundation.

The entire area is excavated to the specified depth in the construction of the Raft Foundation.

The bed is compacted and water-sprinkled.

A layer of lime concrete or lean concrete (1:8:16) is then laid to an appropriate thickness to act as a base cover.

The reinforcement is laid after that. The reinforcement consists of closely spaced bars placed between them at right angles.

Then the cement concrete (1:2:4) is laid and compacted to the thickness required.

This type of foundation is useful for public buildings, office buildings, school buildings, residential quarters, etc, where the ground conditions are very poor and bearing power of the soil is so low that individual spread footing cannot be provided.

STEPPED FOUNDATION :

Another type of foundation is stepped foundation, For Stepped Foundation Construction, excavation is performed in steps with the short length and uniform thickness and the masonry work is performed on the horizontal concrete bed thus prepared.

If the structure can be slipped body-wise, R.C.C piles can be driven on the sloping side along with its base concrete.

Strap footing :

A strap footing is a component of a building's foundation. It is a type of combined footing, consisting of two or more column footings connected by a concrete beam. 

This is the most common type of foundation used where you have a solid soil base and a logged area of nan-water.

With this type of foundation, most small buildings of just one floor are constructed.

Depending on the recommendations of the structural engineer, the size of your foundation for the small building could be 600 mm to 1200 mm.

 Types of deep foundation:

1. pile foundation
2. well foundation 

Pile foundation :

A pile is basically a long cylinder of a strong material like concrete that is pushed into the ground to act as permanent support for structures built on top of it.

The foundations of the pile are deep foundations. These are composed of long, slender, columnar structures that are usually made of steel or reinforced concrete, or sometimes wood. When its depth is more than three times its width, a foundation is described as' piled.

Pile foundations are used when the surface has a layer of weak soil. This surface can not bear the building's weight, therefore the building's loads must bypass this layer and be moved to the layer of stronger soil or rock below the weak layer.

it is also when there are heavy concentrated loads in a house, such as a high-rise tower, bridge, or water tank.

Types of Pile Foundation  

01. Based on Material:

 Timber pile

 Steel pile

 Concrete pile

 Composite pile 

02. Based on Shape: 

Cylindrical pile

Tapered pile 

Under-reamed pile 

03. Based on Load Transfer Mode:

 End bearing pile

 Friction pile 

04. Based on Construction Method:

 Cast-in-site reinforced concrete 

Precast reinforced concrete 

05. Based on the Installation Method: 

Bored pile 

Driven pile 

Vibrated pile 

Well foundation:

Well foundation is a type of deep foundation that is usually provided for bridges below the water level. Cassions or well have been in use since the Roman and Mughal periods for bridge foundations and other structures.

How to calculate cement sand and aggregate quantity in concrete

Quantities of materials for concrete such as cement, sand, and aggregates for production of required quantity of concrete of given mix proportions such as 1:2:4 (M15), 1:1.5: 3 (M20), 1:1:2 (M25).

We assume that we have 30 cft volume of concrete and the mixing ratio is 1:2:4 (M15).
So we know that the unit weight of concrete is 150 lbs per cubic foot.  so, first of all, we need to find the weight of 30 cft concrete.

Weight of 30 cft concrete 

30 x 150 = 4500 lbs

We know that this is the weight of wet concrete so now we will find the dry weight of concrete.

for converting wet concrete weight to dry concrete weight the weight of wet concrete multiply with 1.54.

(If you want to know why we multiplied it with 1.54 then Read this : 

      Quantity Of Cement And Sand Calculation In Mortar CFT )

Dry weight of concrete 

4500 x 1.54 = 6930 lbs

Now we will calculate the quantity of cement, sand, coarse aggregate and water.

Calculation

First of all, we will find the sum of ratio

Sum of ratio = 1+2+4 = 7

Sum of ratio = 7

Now

Quantity of cement = 

( 1 ÷ 7 ) x 6930 = 990 lbs

We know that 1 Kg = 2.204 lb so

990 ÷ 2.204 = 449.18 kg  say 150 kg

We also know that  the weight of1 bag of cement is 50 Kg so

150 ÷ 50 = 3 bags

Quantity of cement = 3 Bags

Quantity of sand = 

( 2 ÷ 7 ) x 6930 = 1980 lbs

Quantity of sand in kg = 

1980 ÷ 2.204 = 898.36 kg say 900 kg

Quantity of sand = 900kg

Quantity of coarse aggregate = 

( 3 ÷ 7 ) x 6930 = 2970 lbs

Quantity of coarse aggregate in kg = 

2970 ÷ 2.204 = 1347.54 say 1348 kg

Quantity of coarse aggregate= 1348 kg

(Note = 0.4 to 0.6 water-cement ratio used in M15 concrete. we will take o.5 w/c ratio)

Quantity of water = 

0.5 x 150 = 75 liter 

(150 is the weight of cement)

Quantity of water = 75 liters 

Quantity of material in 30 cft:

Cement = 3 bags

Sand = 900 kg

Coarse aggregate = 1348 kg

Water = 75 liters

What is foundation ? purposes of Foundation and factor effects on Foundation

Many structures like dams, bridges, buildings, roads, etc are created by civil engineers to serve our numerous necessities. Structures apply load on soil on which they rest.
This part of the structure is called sub-structure. Sub-structure is usually called foundation. Thus structural elements that connect, bridges, buildings etc. to the ground are called foundations.
Foundation of any structure is incredibly necessary as a result of the safety and reliability of structure depends upon foundation.

“The lowest part of a structure which transfers a load of superstructure along with its own weight into the soil underneath without carrying shear failure or bearing capacity failure and excessive settlement is called foundation.”

The following are the main functions of the foundation:

• To distribute the load of the structure over a large bearing area to bring the intensity of loading within the safe bearing capacity.
• To load the bearing surface at a uniform rate ( prevent unequal settlement)
• To prevent the lateral movement ( caused by wind, water or earth quick)
• To increase the stability of the building as a whole.

Also Read Types Of Masonry Construction Based On Material

The requirement of a good foundation:

• Foundation should be located that it is able to resist any unexpected future influence which may adversely affect its performance.
• The foundation should be stale against any possible failure.
• The foundation should not settle or deflect.

Factor affecting the selection of foundation:

• Importance of the Building
• Life of the Structure
• Loads from superstructure
• Type of construction materials to be used.
• Water table level.
• Type of adjoining structure.
• Soil condition.
• Location of building