Onliner Question Answer of Building Materials And Construction Part-1

1.The rock has more fire resisting characteristics-Compact sand stone

2.The rocks which are formed due to cooling of magma at a considerable depth from earth's surface are called- Plutonic rocks

3.Plywood has the advantage of-Same tensile strength in all directions

4.Due to attack of dry rot, the timber -Reduces to powder

5.Excess of alumina in brick earth makes the brick-To crack and warp on drying

6-The constituent of cement which is responsible for all the undesirable properties of cement is-Tri-calcium aluminate

7.Inner part of a timber log surrounding the pitch, is called -Heart wood

8.For testing compressive and tensile strength of cement, the cement mortar is made by mixing cement and standard sand in the proportions of- 1 : 3

9.If ‘P’ is the percentage of water required for normal consistency, water to be added for determination of initial setting time, is-0.85 P

10.The basic purpose of a retarder in concrete is -To increase the initial setting time of cement paste in concrete

11.Clay and silt content in a good brick earth must be at least-50 %

12. The purest form of iron-Wrought iron

13.If the iron ore contains clay as an impurity, the flux added during calcination, is-Lime stone

14.The stretcher bond in brick masonry can be used only when the thickness of wall is- 90 mm

15.The plywood-Has greater impact resistance to blows than ordinary wood

16.Early attainment of strength in rapid hardening cement is mainly due to-Finer grinding

17.Cements contains maximum percentage of dicalcium silicate-Low heat cement

18.Stresses is used for identifying the quality of structural steel-Yield stress

19.Quick lime-(A) Generates heat when added to water, (B) Reacts with carbon dioxide, (C) May be used for white-washing

20.A mortar joint in masonry which is normal to the face of wall is known as - Cross joint