THE HISTORY OF CONCRETE

Concrete is a building material looks like a stone that is man made. Combining cement and aggregates with sufficient of water to make concrete. The function of water is allow them to bind it together. Concrete can be reinforced by adding some steel mesh or rods before it poured into mould. In Serbia, remains of a hut dating from 5600 BC have been found, with a floor made of red lime, sand, and gravel. The pyramids of Shaanxi in China, built thousands of years ago, contain a mixture of lime and volcanic ash or clay. The Assyrians and Babylonians used clay as cement in their concrete. The Egyptians used lime and gypsum cement.

The first recorded fact points to the year 1756 when John Smeaton, an engineer made the present day concrete by mixing coarse aggregate (pebbles) and powered brick and mixed it with cement. He built the Eddystone Lighthouse in Cornwall, England with the use of hydraulic cement in 1973. Joseph Aspdin is an investor, invented Portland cement. By burning grounded chalk and finely crushed clay in a limekiln till the carbon dioxide evaporated to made concrete, resulting in strong cement.


The first systematic testing of concrete took place in Germany in 1836. The test measure the compressive strength and tensile of concrete   Another main ingredients are concrete, sand, clay, gravel and so on.  Concrete that uses imbedded metal is called reinforced concrete. Joseph Monier  was a Gardner who made flowerpots and tubs of reinforced concrete with the use of iron mesh. The reinforced concrete combined the tensile power of metal and the compression strength of concrete to support heavy loads.


The first rotary kiln is introduced that made constant production in England.  In 1891, George Bartholomew made the first concrete street in Ohio, USA. Concrete found major usage in construction of roads and buildings of that industry. The first concrete dams were built by  Hoover and Grand Cooley.
More concrete is used than any other man-made material in the world. Concrete, known a strongest building material has found major uses in dams, highways, buildings and many different kinds of building and construction.

PICTURE OF CONCRETE BUILDING

Brick Bonding

Brickwork is masonry produced by a bricklayer, using bricks and mortar to build up brick structures as walls. A Bond is the pattern how bricks are laid. Where the bricks are to remain fully exposed, as opposed to being covered up by plaster, this is known as face-work or facing brickwork. As a Quantity surveyor, we have to recognize and understand the pattern in order to calculate the the quantity accurately.

( Click on the Pictures below to get a clearer view ! )

Brickwork Bond

English Bond
1. A traditional bond.
2.  Very strong bond and usually used in factories, stations & retaining walls or is always likely to be found in the wall of bridges.
3. Easy to recognize because it consists of a course of headers followed by a course of of stretchers.
4. One header is placed centrally above each stretcher.

Flemish Bond
1. Also known as dutch bond.
2. Consists of alternate headers & stretchers in every single course.
3. Not as strong as the English bond but is more decorative pattern than English bond especially if the header use a differently coloured brick.
4. Requires fewer than English bond.

English Garden Wall Bond

1. An alternative version of English bond with header courses being inserted at every fourth or sixth courses.

2. There is also a Scottish bond or American bond featuring 5 courses of stretchers between courses of headers.

3. Not as strong as true English bond but was quicker and cheaper to lay because stretchers are easier to lay than headers.

Flemish Garden Wall Bond
1. The number of stretchers is increased.
2. The header bricks are separated by 3 stretchers.
3. The headers of even numbered courses are set to the centre on the middle stretchers of the underlying odd numbered courses.

Header Bond
1. Using only the header (end) of the brick as the facing wall.
2. Not used as often as Stretcher bond, but is equally simple.
3. It is popular for diaper work. When bricks of different colours are used to make a regukar pattern, it is called Diapering.
4. Sometimes used to make a building looks bigger.
5. Not preferable to use for load bearing wall.

Stretcher Bond
1. Easiest bond to lay, minimizes the amount of cutting required.
2. Most common.
3. Consists of all stretchers in every course.
4. Used in half-brick walls.
5. Only possible in case of walls with less thickness.

Evolution of Stone Construction Form

Dry Stone Stacking

Dry stone stacking the earliest form of stone construction. These are free standing structures such as long distance field walls and bridges. Stones with irregular shapes are carefully selected and placed so that they hold each others closely and tightly together without slipping.  Furthermore, as height increases structures which possess wider base are needed. Plus, the support of structure is originated from the weight of the stone which tends to push inwards, and  settling makes the structure lock tightly together and become more stable and stronger. Dry stone structures have high durability. Moreover, dry stone structures do not need frequent maintenance as they allow water to drain through them, without causing damage to the stones. In addition, this form of stone construction do not require any special equipments, only the skill and technique of the craftsman in selecting and placing the stones.

Stone Masonry

Traditional stone masonry is the evolution form of stone construction of dry stone stacking. Stone blocks are placed in rows evenly (courses) or unevenly (uncoursed) height, and hold together tightly with the addition of mortar, a cement or lime mixture between the stones. The building stones are conventionally extracted by surface quarrying, drilled and split using diamond saws or iron wedges, and then shaped and polished according to their requirements. The basic hand equipments used to shape stones are chisels, mallet and a metal straight edge, but modern power tools such as angle grinders and compressed air-chisels are often used to save time and money. Plus, stones are either shaped into a block, known as ashlar masonry, or left rough and cut irregularly, known as rubble masonry. However, mortared stone structures have lower durability than dry stone         structures, because water can easily get trapped between the stones and push them apart.

Stone Cladding

Nowadays, traditional stone masonry is rarely used because stone is rather expensive to quarry, cut and transport, and the building process is labour and skill-intensive. Instead, most modern stonework utilises a veneer of stone (thin, flat pieces) glued against a wall of concrete blocks. This is known as veneered stone or stone cladding.

Slip Form Stone Structure

Slip form stone structures are a combination between veneered masonry and traditional masonry. Short forms (around 2 feet tall) are placed on either side of the wall, to act as a guide for the structure. Stones are placed inside the forms with the flat face out, and concrete is then poured behind the rocks to hold it together. Stone buildings can be constructed swiftly and easily with this method.

via Sustainablebuild~

Stone

Stone has been used as a building material for thousands of years. It is a beautiful natural material that can be used for floors, walls, arches and roofs. Besides, it has also recognised as a material of great durable, low maintenance and with high thermal mass. It is a generic available in many shapes, sizes, colours and textures, and Stone blends well with the natural landscape, and can easily be recycled for other building purposes. Therefore, it can provide environmental friendly.

Type of stone

Sandstone

Sandstone is the most common types of stone used for build houses. Sandstone consists of several types of small grains of minerals including quartz, calcite and feldspar. The stones are usually in gray, brown, red, green or cream colour. The sandstone layer may contain natural gas and petroleum, and are common aquifers. Sandstone is quarry for building, and crushed for aggregate.

Limestone

Humans have been building with limestone for thousands of years. The use of lime is in steel manufacturing. Where the lime is used as a flux  to remove impurities such as phosphorus and sulphur. To remove sulphur from the emissions, lime is used in power plant smokestacks . It is used in road construction and traditional building construction. Besides, Limestone is a porous rock that carves easily, making it ideal for building. The stone colour is often gray, off-white or cream, and it is almost every colour of the stone exists.

Slate

·        Slate can be made into roofing slates. It consists of small grains of mica and quartz. Slate is an ideal stone for building houses because it is weatherproof and last longer. Slate has a dull appearance in a dark gray colour, but it can range from brown to green depending on the stone's origin. Furthermore, a very small amount of slate is crushed and used for road construction, concrete mixes and other construction purposes. It is more expensive to import other crushed stone products such as limestone or granite. Therefore, it is used locally. For centuries it has been used for roofing and for pavement stones around homes, buildings and gardens. The same feature made slate a most suitable material for making pool table tops.

Granite

·          Granite is an intrusive igneous rock. Intrusions are bodies of igneous rock that result from crystallisation of magma deep underground. Slow cooling at depth in the Earth produces larger crystals that can easily be seen by the naked eye.Granite is commonly used on kitchen counter tops as the stone is both scratch and heat resistant. However, granite is also ideal for building homes as well. Granite is one of the toughest and durable stones available. It consists of quartz, alkali feldspar and plagioclase feldspar. Granite  is generally light coloured in shades of white, grey, or pink. But the addition of other minerals can add more colour dimensions, so that it can making each piece of granite unique.

Eco-Bricks

Bricks made with wool. 
(Credit: Galán-Marín et al.)

Today, the researchers in Europe have created a new brick that is stronger and more environmentally friendly. According to the study published in the year 2010 in the journal Construction and Building Materials, Spanish and Scottish researchers have added wool fibers to the clay material used to make bricks and combine these with a natural polymer which is extracted from seaweed called alginate.


"The objective was to produce bricks reinforced with wool and to obtain a composite that was more sustainable, non-toxic, using abundant local materials, and that would mechanically improve the brick strength," Carmen Galán and Carlos Rivera, authors of the study and researchers at the Schools of Architecture at the University of Seville in Spain and the University of Strathclyde in Glasgow, UK said about their invention.

Wool and an alginate conglomerate from the cell walls of seaweed were mixed with clay to create the bricks. The mixture seemed to be less easy to crack and less likely to wrap. For your information, these kinds of bricks can be manufactured without firing, which directly contributes to energy conservation. According to the authors; "This is a more sustainable and healthy alternative to conventional building materials such as baked earth bricks and concrete blocks."

Via Science Daily
   

          

Bricks

Bricks are hard rectangular blocks typically made of clay and water, they are arranged or laid in rows and columns to construct building structures. There are various types of bricks depending on their properties or special features in the construction process.

How Bricks are made

3 Common Shape of Bricks

Frogged Brick

Brick with this shape possess an small and indented rectangular pit on top of the brick. This kind of bricks usually be laid with the pit at the top so that the load is spread equally across the width of the brick, not just across the edges.

Perforated Brick

Perforated brick possess a holes through top to bottom. The objective of the holes is to decrease the weight of the brick and provide air gap for insulation purpose. 

Solid Brick

As shown in the figure above, solid brick is flat in all six sides,hence it is a perfect rectangular block.

Bricks With Different Functions

Building Bricks

Building bricks are mainly used to provide support or act as filler for construction structure instead of provide aesthetic look.

Engineering Bricks

Engineering bricks are tough, strong and long-lasting. They possess damp or water resistance, this property makes them suitable for tough construction such as sewers and retaining walls. Unfortunately, this type of brick is not a good looker.

Common Bricks

This type of bricks is cheap, filler bricks that are used where are unseen, thus their profile is not important. However, they can be used as facing bricks if you do not worried about looks as they have lower cost than facing bricks.

Facing Bricks

Facing bricks have aesthetic view and they are usually used externally. The most visible part of the building is cover by them.

Stock Bricks

Stock Bricks have a slightly irregular shape made by using a mechanised moulding process which is called soft mud moulding. A variety of colours are available. In terms of price, as well as style, stock bricks fall between the wirecut bricks and the handmade bricks. 

Wirecut Bricks

Wirecut Facing Bricks are made by extrusion of a continuous column of clay which is cut by the wire but not before the column has been textured. They are to adapt in almost every type of application and are available in a variety of colours and textures. Besides, the highly automated production process makes wirecuts bricks is relatively inexpensive compared to some other types of brick.

Handmade Bricks

Handmade Bricks are made manually by skilled craftsmen pouring clay into moulds. Every single brick is unique and they have a nice and attractive appearance with a creased face as well as longstanding durability.

Standard Special Bricks

Standard special bricks are made for specific uses in unique form of brickwork. They are made of fine clays to control and decrease the shrinkage deformation during firing. 

Bullnose Bricks

This type of brick has one, some or all of its corners rounded off. Those curves is used to create a soft and attractive curve for a structure such as round steps of staircase.

Radial Bricks

Radial bricks are special bricks used to create curved walls. Radial bricks were created in Europe in the 19th century and were used to build chimneys. Nowadays, radial bricks can be used to create a feature such as giant round pillars or round entrance.

Types of bricks

In the construction industry, there are many types of bricks. But, today we will mainly focus on 3 bricks which are CLAY BRICKS, CALCIUM SILICATE BRICKS and CONCRETE BRICKS. Each of them have different physical properties. The different physical properties of bricks will influence the choice of bricks used for low or high rise building.

Clay bricks

Properties: Have high compressive strength, and fired to sufficiently high temperature can withstand compressive strength.Porosity helps to regulate the temperature of the inside building by release and reabsorb moisture by capillary effect.

The durability of clay bricks is depend on the amount of soluble salts, present in the bricks and the firing temperature.

 Calcium silicate bricks

Properties: Strength of calcium silicate bricks is comparable to to clay bricks. However, they can't achieve the extremely high strength of engineering clay bricks.

The water absorption of calcium silicate bricks is generally higher than clay bricks.

Calcium silicate bricks have satisfactory durability and they cant contact with sewage and exposed to strong acids.

                                                      

Concrete bricks

Properties: Concrete bricks are harder, more difficult to cut than clay or calcium silicate bricks

How to prevent cracks in brickwork ???
Bricks are  the most material used on construction and housing industry. But, sometimes the bricks will crack with the mortar due to the weather influence or the material problem. So, how to prevent it occur?

Brick expansion joint
Brick is a construction material, it will change the volume with the change of the temperature. It will expand due to the moisture and the absorption of water. Using expansion joint in your brickwork, will separate your bricks into small segments, and will behave separate from other segments. The expansion joints will reduce brick cracking by changes in temperature, moisture, and so on.

Bricks vertical joint
Every joint in brickwork is different. There are different condition from one scene to another. So, dun treat all joints in the same ways. Good rule of thumb for the vertical joint in the brickworks are placed 25 every 25 feet. Vertical joints should be located at corners, offsets, setbacks, opening, wall intersection, and long walls.

Bricks horizontal joint
During construction process, remove the temporary shims to hold the angle in position while horizontal joint be located at underneath the shelf-angle.

How to repair the brick crack repair???
Brick crack is very serious things, it will affected the stability of the building even the building will collapse. With a few simple steps you can repair the crack, avoiding the expense of replacing the entire wall

1. Safety first
   Wear a pair of googles to protect your eyes.and the mask to protect ur face to avoid inhaling bits of brick or mortar, then remove the pieces of broken brick with a sledgehammer and chisel.  Slightly expand the crack in the brick with the chisel. Clean all the debris with a wire brush. Ready to fill the part of the crack,
2. Mix the mortar 
   Following the instruction of the package to mix the mortar, spread a little mortar on a scrap of corrugated cardboard and allow it to dry to test the colour. you can take some colouring mix with the mortar to match the previous mortar's colour.
3. Get the prefect shade
   When you have achieved the desired mortar shade, wet the crack down throughly with a garden hose. This should remove any lingering debris and moisten the repair site 
4. Fill the crack
   Fill the crack with mortar by a small trowel. Pack the mortar in firmly, tapping it down into the depth of the break and ensure the surface as even as possible.
5. Finish it
   Once the gap is solidly filled with mortar,  Mortar jointer will finish the surface of the mortar. The jointer should be used to make the joints, the area between the bricks.
6. Left to cure
   When finished the surface, allow the repaired area to cure.
7. Moisten each day
   During the curing process, you will need use water to lightly moisten at patched area in several times of day.
8. Finishing touch
   Optionally, you may finish the mortar-filled cracks by painting the repaired area to match the surrounding wall.  

Specification of Aggregate Concrete Block
Special Blocks Blocks produced to form an extensive 'kit-of-parts' which gives the designer-specifier great flexibility	Block Specification Block description Block types are available in various ranges produced by CBA manufactures, which may be generally described as follows Standard common blocks  Blocks suitable for general building work, offering excellent all round performance and normally available in 440 x 215mm face size, in addition to their loadbearing capabilities, they provide an excellent background for plastering and rendering as wall as for fixings. Paint grade common blocks Blocks manufactured with a close texture and suitable for direct painting. Standard facing blocks Blocks manufactured for applications where shape and texture consistency are of prime importance. Slight variations in color may be discernible .   Architectural masonry facing block Blocks manufactured to high standards of dimensional accuracy and consistency of color and texture. The block are inteded for use in situation where the visual apperance of the wall is of primary concern. The blocks are available in a range of color, textures finishes and shapes.   Dimensions Face sizes Aggregate concrete blocks are typically available in two standard face sizes (length x height)of 440 x 215mm and 390 x 190mm. Other face sizes are available of aid manual handling. To obtain the coordinating dimensions add the specified joint thickness (normally 10mm) to the height and length of the block.  Dimensions tolerances Tolerances permitted by BS EN 771-3 are:   Limiting deviation in millimetres.  Blocks will generally be supplied to D1 tolerance category unless otherwise specified. Block Strengths Block are available in compressive strengths from 2.9N/mm² to 40n/mm² (Solid) and 2.9N/mm² to 22.5N/mm² (cellular and hollow). Common strengths are 3.6N/mm² and 7.3N/mm² Density Aggregate concrete blocks are available in the net dry density range of 650 - 2400kg/m³ with tolerance of ± 10%. The full range of densities will not necessarily be available from all manufacturers. Gross dry densities are typically used for cellular and hollow units and for the same products will be lover than net dry densities. Configuration Units to BS EN 771-3: Aggregate concrete masonry units will fall within one of the 4 groups specified in BS EN 1996-1-1: Eurocode 6 – Design of masonry structures. Group 1 < 25% formed voids Group 2 > 25% < 60% formed vertical voids Group 3 > 25% < 70% formed vertical voids Group 4 > 25% < 50% formed horizontal voids Generally units will fall within Group 1 and Group 2 configurations.
Source From:� The Concrete Block Accosiation buildingmaterial1213.blogspot