BUILDING, CONSTRUCTION & MATERIAL

•  Gypsum is a mechanically formed sedimentary rock.
•  Quartzite is a silicious rock.
•  Slate is formed by metamorphic action on shale.
•  Heavy stone is suitable for retaining wall.
•  Hard stone is suitable for rubble masonry.
•  Soft stones is suitable for ornamental work.
•  Quartzite has most weather resisting characteristics.
•  A good building stone should not absorb water more than 5%.
•  Compact sand stone has more fire resisting characteristics.
•  Weight test is conducted on a stone used in docks and harbours.
•  Granite stone is best suited for construction of piers and abutments.
•  Crushing strength of good building stone should be more than 100mpa.
•  Specific gravity of most of the building stone lies between 2.5 to 3.
•  Pith-annular rings-heartwood-sapwood-cambium layer-inner and outer bark.
•  Shisham is hard wood and offer maximum resistance to the white ants.
•  Star shakes-the radial splits which are wider on the outside of the log and narrow towards the pith.
•  Chir and deodar yields soft wood.
•  Mulberry tree used for making of sports goods.
•  Dry rot caused due to lack of ventilation.
•  Foxiness caused due to over maturity.
•  Honey combing caused due to-seasoning.
•  Strength of the timber is maximum in the parallel direction.
•  10% to 12% is the moisture content of well seasoned timber.
•  The age of the tree can be known by annular rings.
•  1st class timber has an average life of more than 10 years.
•  1st class brick should not absorb water more than 20% when immersed in water for about 24 hours, 22% for 2nd class bricks and 25% for 3rd class bricks.
•  Crushing strength of 1st class bricks not less than 10.5N/mm^2, 7.5N/mm^2 for 2nd class bricks.
•  The main function of alumina in brick earth is to impart plasticity.
•  The percentage of alumina in good brick earth is 20 to 30%.
•  Excess of alumina in brick earth cause crack and warp on drying.
•  Excess of silica cause brittleness.
•  20*10*10 cm is the nominal size of the brick.
•  19*9*9cm is the standard size of brick.
•  50 to 60 % silica in good brick earth.
•  Silica makes the brick to retain the shape.
•  Kneading –the process of mixing the clay water and other ingredients called.
•  60 to 70% turn over in clamp burning where as 80 to 90% turn over in kiln burning.
•  Pug mill used for preparation of clay.
•  Refractory bricks used in combustion chambers.
•  The frog of the brick generally kept on the top face of masonry.
•  500 bricks required for one cubic metre of brick masonry.
•  Quick lime is calcium oxide.
•  Hydraulic lime is obtained from burning of kankar.
•  Lime and silica are the main ingredients of the Portland cement.
•  C3A is responsible for all undesirable properties of cement.
•  Le chate lier apparatus is used for testing the soundness of cement.
•  Vicat apparatus used for testing setting time of cement.
•  C3A is responsible for intial setting time of cement.
•  The intial setting time for ordinary Portland cement not less than 30minute.
•  The final setting time should be 10 hour.
•  The normal consistency of ordinary Portland cement is 30%.
•  Early attainment of strength of cement in rapid hardening of cement is due to finer grinding.
•  After storage the strength of the cement is decreases.
•  Addition of pozzolana to ordinary Portland 
• cement cause shrinkage.
•  Gypsum consists of caso4 and H2O.
•  25mm to 50mm is the slump recommended for mass concrete.
•  Low heat cement is used in massive concrete structures.
•  Calcium chloride is the common admixture to accelerate the intial setting time.
•  The basic purpose of retarder in concrete is to increase the intial setting time of concrete.
•  Gypsum is most commonly used retarder.
•  Carbon influences the maximum properties in steel.
•  Wrought iron is the purest form of iron.
•  The ultimate tensile strength of steel is 420N/mm^2.
•  0.25% of carbon in mild steel.
•  Yield stress is used for identifying the quality of structural steel.
•  Flemish bond –alternate courses of header and stretcher.
•  English bond-alternate header and stretcher.
•  The pressure acting on the stones in stone masonry should be perpendicular to the direction of bedding planes.
•  Queen closer-the brick is cut into 2 equal parts in length wise.
•  English bond is provided in masonry for carrying heavy loads.
•  Slenderness ratio-effective length to least radius of gyration, for masonry walls not more than 20.
•  The differential settlement in case of sandy soil not more than 25mm.
•  In case of foundation on black cotton soil the most suitable method is to replace the poor soil.
•  Grillage foundation is the most economical foundation to transmit the heavy load.
•  Batter pile is used to resist the horizontal and vertical forces.
•  0.9m is the minimum depth of the foundation on clay soil.
•  The bearing capacity of a water logged soil can be improved by draining the soil.
•  Depth or height of arch-is the perpendicular distance between the intrados and extrados.
•  Flat roof is constructed where the rainfall is less and temperature is high.
•  Pitched and sloping roofs are suitable for coastal region.
•  The maximum number of steps generally restricted is 12.
•  Sum of tread and rise must between 400 to 450mm.
•  Minimum width of landing should be equal to width of stairs.
•  In any good stair case the maximum and minimum pitch is 40’ and 25’.
•  Doglegged stairs are half turn stairs.
•  Horizontal projection at head and sill called horns.
•  Revolving door is suitable for entrance in an air conditioned building.
•  Attrition test determines the rate of wear of stones.
•  Efflorescence-formation of white patches on the brick surface due to presence of alkalies.
•  Vanadium steel used in the manufacture of axles and springs.
•  Neoprene is suitable for bearing of bridges.
•  To produce low heat cement it is necessary to reduce the C3A.
•  Timber can be made more fire resistant by sir abel’s process.
•  Creosote is derived from wood or coal.
•  Excess of sulphur in steel results in red shortness.
•  Distemper is used to coat interior surface not exposed to weather.
•  Putty is made up of powdered chalk and raw linseed oil.
•  The limit of proportionality is applied more in the case of mild steel.
•  The compacting factor test determines the workability.
•  The split tensile strength is 10% to 15%.
•  The approximate ratio between the strength of cement concrete 7 to that of 28 days is 2/3.
•  The moisture content of timber is 12%.
•  0.85P times amount of water is used ofr intial setting time, 0.72P for soundness cement.
•  Lime mortar is generally made with hydraulic lime.
•  The texture of sand stone is granular crystalline.
•  Seasoning of timber is required to remove sap from timber.
•  The ratio of youngs modulus of high tensile steel to that of mild steel is about 1.
•  Poly vinyl chloride is thermoplastic material.
•  King closer is related to brick masonry.
•  High alumina cement is produced by limestone and bauxite.
•  The optimum number of revolutions required for concrete mix is 20.
•  Manganese steel used in the manufacture of rails.
•  Gauged mortar is obtained by adding sand and lime.
•  1300’to 1500’ is the temperature range of cement in kiln.
•  Before testing setting time of cement one should be test for consistency.
•  The super plasticizer in a cement paste is disperse the particles, remove air bubbles and to retard setting.
•  Surkhi is added to lime mortar to impart hydraulicity.
•  Increase in fineness of cement results in increase in development of strength and leads to higher shrinkage.
•  The purpose of frog is to form key joint between brick and mortar.
•  Bricks are burnt at a temperature of 900-1200 degree Celsius.