The compound of Portland cement which reacts immediately with water and also sets first is
Tri-calcium silicate
Di-calcium silicate
Tri-calcium aluminate
Tetra calcium alumino ferrite
Correct Answer :
C. Tri-calcium aluminate
Related Questions
The cast iron when heated to red heat with powdered red haematite in an oven for increasing its toughness, is converted to
Grey cast iron
White cast iron
Mottled cast iron
Toughed cast iron
Assertion A : Pure lime takes a long time to develop adequate strength. Reason R : Pure lime has slow hardening characteristics. Select your answer according to the coding system given below:
Both A and R is true and R is correct explanation of A
Both A and R is true and R is not a correct explanation of A
A is true but R is false
A is false but R is true
The percentage of alumina in a good brick earth lies between
5 to 10 %
20 to 30 %
50 to 60 %
70 to 80 %
Chlorite, a green colour mineral is mainly derived from the decomposition of
Augite
Biotite
Hornblende
All of these
A bull nose brick is not used for
Rounding off sharp corners
Pillars
Decoration purpose
Arches
Assertion A : Normally turpentine oil is recommended as thinner for indoor painting. Reason R : Turpentine oil is costlier than other thinners. Select your answer according to the coding system given below:
Both A and R is true and R is the correct explanation of A
Both A and R is true but R is not the correct explanation of A
A is true but R is false
A is false but R is true
Brittleness of cold is due to an excess of
Sulphur
Carbon
Phosphorus
Silicon
Bitumen in
Solid state, is called asphalt
Semi fluid state, is called mineral tar
Fluid state, is called petroleum
All the above
The rocks which are formed due to cooling of magma at a relatively shallow depth from the earth's surface are called
Plutonic rocks
Hypabyssal rocks
Volcanic rocks
Igneous rocks
Ground glass
Is made by grinding its one side
Is made by melting powdered glass paints surface
Is used for getting light without transparency
All the above
Refractory bricks resist
High temperature
Chemical action
Dampness
All the above
A piece of timber whose thickness and width are respectively 5 cm and 10 cm is called
Slate
Plank
Board
Strip
For filling cracks in masonry structures, the type of bitumen used, is
Cut-back bitumen
Bitumen-emulsion
Blown bitumen
Plastic bitumen
For the manufacture of plywood, veneers are placed so that grains of adjacent veneers
Run at right angles
Parallel
Inclined at 45°
Inclined at 60°
PVC stands for
Plastic very compact
Polythene vinyl chloride
Polythene vinyl carbon
Polythene vanadium carbide
A prime coat is given to steel work with
An oxide of iron paint
A mixture of white lead and lead paint
A special paint
Cement paint
The steel used for rails under heavy traffic and on sharp curves, is
Nickel steel
Chrome steel
Manganese steel
Vanadium steel
Pick up the correct characteristic of Pyroxene from the following:
It forms octagonal crystals
It converts to chlorine by hydration
Its density is 2.3 to 3.6 g/cm2
All the above
Sewer pipes are made of
Earthen ware
Stone ware
Refractory clay
All the above
Mild steel is used for
Structural works in beams, joints and girders
Small sized water pipes
Columns and struts
None of these
The tendency of a stone is, to split along:
Texture
Fracture
Cleavage
Structure
Pick up the correct statement from the following:
The lime in excess makes the cement unsound and causes the cement to expand and disintegrate
The silica in excess makes the cement stronger but its setting time also increases
The excess amount of alumina weakens the cement
All the above
The coefficient of hardness of stones used in road work should be greater than
10
12
15
17
The proportions of lime and sand in the mortar normally used in brick construction are
1 : 2
1 : 4
1 : 6
1 : 8
The frog of the brick in a brick masonry is generally kept on
Bottom face
Top face
Shorter side
Longer side
Three basic raw materials which are needed in large quantities for production of steel are
Iron ore, coal and sulphur
Iron ore, carbon and sulphur
Iron ore, coal and lime stone
Iron ore, carbon and lime stone
Pick up the correct statement from the following:
The free quartz suddenly expands at a temperature lower than 600°C
The lime stone resists fire upto about 800°C and at higher temperature it splits into CaO and CO2
The sand stone with silicates resist a fire in a better way
All the above
Stones used for ornamental work must be
Soft
Hard
Light
Heavy
Pick up the correct statement from the following:
In basic Bessemer process, the steel heats the converter
In open-hearth process, the furnace heats the steel
In Siemens process, the impurities of pig iron are oxidised by the oxygen of the ore
All the above
The harmonious mixing of the clay ingredients, is known as
Weathering
Blending
Tempering
None of these