Building Materials Construction| Important Points |

Building Materials Important points:

1. High alumina cement is produced by mixture of limestone & bauxite.
2. Blast furnace slag cement consist of 40% Calcium Oxide(Cao) & 25% Silica.
3. Temperature range in cement kiln is about 1300-1500 Degree Celsius.
4. Specific gravity of Ordinary Portland Cement (OPC) is 3.15
5. Fineness of cement is measured in Area/Mass.
6. 1 bag Portland cement is 50 kg in weight = 35 litre bulk volume.
7. Approximate ratio between Strength of cement concrete at 7days & 28 days is 2/3
8. The Approximate ratio of strength of 15 cm x 30 cm concrete cyclinder to that of 15 cm of Cube of same concrete is 0.85
9. The carbon of structural steel is is 0.1 to 0.25 %
10. Ratio of direct tensile strength to that ofmodulus of ruptureof concrete is 0.5
11. Concrete most suitable in extreme cold climate is Air entrained concrete.
12. Cubical Aggregate gives maximum strength in concrete.
13. Range of fineness modulusof sand least suitable for making good concreteis 3.5-4.5
14. Mix design for pavement concrete is based on Flexure strength.
15. If fineness modulus is equal to 3 then representative geometric mean size of agregate is equal to 600 Micron.
16. Ratio of Flexural strength(Fck) to Characteristic compressive strength of concrete for M25 is 0.14
17. Good brick should not absorb 20% water by weight.
18. Window sills in residential house = 80-90 cm from floor level.
19. Crushing strength of good building stone = 100 Mpa (Atleast) & 200 Mpa (Generally).
20. Slenderness ratio for masonry wall is not more than 30
21. Bricks are burnt at temperature about 900-1200 Degree Celsius.
22. When corner of brick is removed along line joining midpoints of adjoining sides is known as King closer.
23. According to IS Code weight of timber is to be reckoned at moisture content of 12%
24. Strength of timber is maximum when load applied is Parallel to Grain.
25. Nail Diameter should not more than thickness (t)/6
26. Seasoning of timber is done to remove Sap from timber.
27. Timber is made fire resistant by soaking it in Ammonium Sulphate.
28. Dry rot in timber is caused by Lack of Ventilation.
29. Teakwood is used for high quality & durable furniture.
30. Timber as natural material is An-isotropic.
31. Treatment for making timber fire resistant is known as Abel's Process.
32. In paints linseed oil is used as a Vehicle.
33. Specific Gravity of stones = 1.0-1.5
34. Terracotta in building is used for Ornamental work.
35. Asbestos paints most resistant to fire.
36. Slate & Marble are Metamorphic rock.
37. Quartzite is Siliceous rock.
38. Whitewashing or Distempering on corrugated iron sheet is 14%
39. Soundness test of cement is used to identify Free lime.
40. 50 kg cement bag = 22.5 liters water required.
41. For manufacturing of plywood veneers are placed at 90 degree.
42. Shingle is disintegrated laterite.
43. Main composition of granite = mica, feldspar, quartz.
44. Crushing strength of stone depends on Workability.
45. Process of mixing clay, water, other ingredient to make brick is known as Kneading.
46. Granite is obtain from Igneous rock.
47. Pugmill is used for tempering brick earth.
48. Diameter of Vicat plunger = 10 mm, length  = 40-50 mm.
49. Curing period is minimum for using OPC.
50. Segregation is responsible for Honeycomb in concrete.
51. Cyclopean aggregate is an aggregate having size more than 75 mm.
52. Datum temperature for maturity by plowman is -11.7 Degree Celsius.
53. Strength of concrete shows an increase with increase in rate of loading.
54. In case of hand mixing of concrete extra cement to be added is 10%.
55. Maximum shrinkage takes place in concrete after drying for 28 days.
56. Steam Curing is not used with Rapid Hardening Cement.