Materials

For masonry works we usually use bricks or stone. Stone masonry was adopted before brick making was invented.  Brick tiles, concrete blocks or precast concrete blocks are also used for masonry.  Bricks and tiles are made by burning clay while stone is a natural material.  Concrete blocks are made of stone, cement and sand. Properly executed masonry shall have a fairly long life. 

Due to increased cost of bricks we now a days construct thinner walls utilising the intrinsic strength of the brick and masonry, supervision has therefore become more important.

Bricks

Common Burnt Clay Bricks 

They shall be free from modules of free lime, visible cracks, flaws, warpage and organic matter. They shall have a frog of size 100 mm x 40 mm x 10 to 20 mm deep in one face. Machine made bricks and brick tiles may not have frogs. 

Flyash Bricks 

It shall be sound, compact and uniform in shape and free from cracks etc. having a frog like common clay bricks. Flyash shall confirm to grade 1 or Grade 2 of IS: 3812-1981. 

Tile Bricks 

The bricks of 4 cm height are usually moulded without frogs. 

Brick Bats 

Brick bats shall be obtained from well burnt bricks. 

Sand 

Clay and silt in the sand shall preferably be less than 5%.

Lime

Lime is most commonly used material from olden days. There are afferent type of limes available for various uses. Lime shall confirm to class C hydrated lime of IS 712-1984. 

Quick Lime: It should be received in the form of lumps and not powders. All over burnt and under burnt lump and powders should be removed from the supply of lime. It should then be converted to lime putty and used. 

Hydrated Lime: It should be in the form of dry powder. It should be received in water proof bags or containers and used within 4 months of manufacture. 

Storage: Lime should be stored in water proof stores. 

Light weight aggregate may also be used. Coarse aggregate should not contain any deleterious material that could affect the strength or durability of concrete or affect the reinforcement. Aggregates which are chemically reactive with alkalies of cement should not be used. The percentage of deleterious material by weight should be less than 5.

Stone

The stone shall be of the type specified such as granite, trap, lime stone, sand stone, quartzite etc, and shall be obtained from approved quarries. 

Generally the length of stones.for stone masonry shall not exceed three times the height and the breadth or base shall not be greater than three fourth of the thickness of wall or not less than 15cm. The height of stone may be upto 30 cm. 

Each stone shall be hammer dressed on the face, the sides and the bed. This would enable stones to be laid closely. 

Hydrated lime should be stored like cement.

Coarse Aggregate

Aggregates most of which is retained on 4.75 mm IS Sieve is known as coarse aggregate. It can be stone, gravel or brick and should'be obtained from approved sources only. 

a) Stone Aggregate 

It should consist of broken, crushed or uncrushed stones. It should be hard, strong, dense, durable and clean. It should be hard, strong, dense, durable and clean. It should  be hard, strong, dense, durable and clean. It should be free from veins, adherent coatings, alkali, vegetable matter and other deleterious substances. It should be roughly cubical in shape. Flaky and elongated pieces should be avoided. It should conform to IS:383-1970. 

b) Gravel 

It should consist of naturally occurring river bed (shingle) or pit gravel-crushed, uncrushed or broken. It should be clean, sound and hard. It should be free from flat particles or shale powdered clay, silt, loam, adherent coatings and other deleterious substances. Pit gravels should be properly washed. These should conform to IS 138 3- 1970. 

c) Brick Aggregate 

Brick aggregate should be obtained by breaking well burnt or over burnt dense bricks. They should be homogeneous in texture, roughly cubical in shape, clean and free from unburnt clay, vegetable matters and other deleterious substances. Sulphale content should be less than one per cent. They should absorb less than 10% of their own mass of water when used in cement concrete and less than 20% when used in lime concrete. It should conform to IS 306-1986. 

d) Grading 

The aggregate should conform to the specified grading. At work site different aggregate may be mixed lo obtain the required grading. Nominal size of brick aggregate should be 40 mm and conform to specified grading.

Testing: Physical and chemical properties of lime should be tested as per IS 6932- 1973.

Fine Aggregate

Aggregate most of which passes through 4.75 mm  IS Sieve, known as fine aggregate,  is used in mortar. It can be sand, crushed stone, stone dust, fly ash or crushed brick or  cinder commonly known as sushi. It should be clean, chemically inert, hard, durable, tree from organic impurities etc. The silt content in sand should be less than 8%, otherwise it should be washed. The grading of fine aggregate should be determined and checked with the specified grading. By mixing fine aggregate of the same type but of different grading we may get the specified grading. 

Bulking 

Fine aggregates when fully saturated or dry has almost the same volume but presence of water increases the volume. This is known as bulkage. At the time of preparation of mortar or concrete the bulkage of most fine aggregate need be accounted for so that correct quantity is used. The moisture content of fine aggregate may be determined by any field method. For guidance the following relation can be considered. 

Broken Brick Fine Aggregate 

Fine aggregate from broken bricks, known as surkhl, should be made by grinding well burnt, not over or under burnt, broken bricks as specified in IS 3068-1986. It should not contain any harmful impurities like salts, coal, mica, shale etc. as to adversely affect hardening, strength, durability or appearance of the mortar.

Flyash

Flyash is produced during burning of pulverished coal in boilers. Flyash, used should conform to IS 38 12- 198 1. It should be free from impurities.  It is generally used as a part replacement of fine aggregate in mortar. 

Water 

It is importiant to ensure that water used for mixing and curing is free from harmful quantities of alkalies, acids, oils, organic materials, etc. Otherwise, the masonry may be affected in the long run. Generally potable water is considered satisfactory for mixing and curing. The value of water should be not less than 6. It is also important to ensure that sulphite and chloride contents are less than 500 and 2000 mg./litre respectively. It should also be checked that curing water does not produce any stain on the surface. 

Sea water should not be used for mixing or curing. 

Water from each source should be tested before commencement and subsequently after every three months till the completion of the work as the properties of the underground water gets changed. Test of treated water supplied by municipalities may be less frequent.