Dear Readers, Welcome to Building Materials and Construction Interview Questions and Answers have been designed specially to get you acquainted with the nature of questions you may encounter during your Job interview for the subject of Building Materials and Construction. These Building Materials and Construction Questions are very important for campus placement test and job interviews. As per my experience good interviewers hardly plan to ask any particular questions during your Job interview and these model questions are asked in the online technical test and interview of many IT & Non IT Industries.
(a)What are the qualities of good building stones?Discuss them.
(b)What is the texture of rock.Enumerate its various types.
(a)Discuss the varieties of terra-cotta?
(b)Write the advantages, disadvantages and uses of terra-cotta.
(a)Describe the chemical composition of cement.
(b)What are the good characteristics of aggregate used in cement concrete?
(a)Draw a neat cross-section of an exogenous tree and show various components of it and explain.
(b)Distinguish between mild steel and hard steel.
(a)What is a raft foundation ?When and where is it preferred to other shallow foundations.Explain with a neat sketch.
6.(a)Discuss the advantages of modular bricks .
(b)Discuss the advantages of brick masonry over stone masonry.
(a)State briefly the requirements of a good staircase.
(b)How are treads & risers proportioned.
(c)Where do you use the following types of stairs
i. Dog-leggedstair. ii.Open newel stair. iii.Geometrical stair.
SDBC- Semi Dense Bituminous Concrete
KVLY-TV is the best man made construction in the world. Its height is 2063 feet.
And The another one is Burl Dubai. Its height is 800 meter.
Cubic Feet, Cubic Yard and Cubic Meter are the three method which are used to measure the concrete size.
The period elasping between the time when water is added to the cement and the time at which the needle failes to pierce the test block by (+,- 5) mm is taken as initial setting times
A. Le chatelier’s methods (it measures expansion due to lime) shall not more have an expansion of more than 10 mm.
B. Autoclave test (it measures expansions due to magnisa) shall not have expansion moe than 0.8%.
suitable materials known as admixtures may be added by conc.mix just before or during the mixture to modify one or more properties of the conc. in the plastics or hardened state as desired.
1. Mineral Admixtures
a. Fly ash
b. silica fume
c. Ground granulated blast furnace slag
d. Rice husk ash
2. Chemical Admixtures
a. Accelerating Admixtures
b. Retarding Admixtures
c. Water-Reducing Admixtures
d. super plasticizing Admixtures
Building mortar is defined of a mixture of cement, sand, and water.
mortar is similar to conc. but these not contain coarse aggregate.
mortar we used for filling joints as a binder in stone and brick masonary.
Mortars are classified on the basis of following :
Kind of binding materials
nature of application
According to the bulk density of mortars in dry state there are two types of mortars:
1. Heavy Mortars:- The mortars having bulk density of 15 KN/M^3 or more are known as the heavy mortars and they are prepared from heavy quarts or other sands.
2. Light weight Mortars:- The mortars having bulk density less than 15 KN/M^3 are known as the light mortars and they are prepared from light porous sands from pumice and other fine aggregate.
The kind of binding material for a mortar is selected by keeping in mind several factors such as expected working conditions, hardening temperature, moisture conditions, etc. According to the kind of binding material, the mortars are classified into the following five categories:
i. Lime mortar
ii. Surkhi mortar
iii. Cement mortar
iv. Gauged mortar
v. Gypsum mortar.
i. Lime mortar:
In this type of mortar, the lime is used as binding material. The lime may be fat lime or hydraulic lime. The fat lime shrinks to a great extent and hence it requires about 2 to 3 times its volume of sand. The lime should be slaked before use. This mortar is unsuitable for water-logged areas or in damp situations. It possesses good cohesiveness with other surfaces and shrinks very little. It is sufficiently
durable, but it hardens slowly. It is generally used for lightly loaded above-ground parts of buildings.
ii. Surkhi mortar:
This type of mortar is prepared by using fully surkhi instead of sand or by replacing half of sand in case of fat lime mortar. The powder of surkhi should be fine enough to pass BIS No. 9 sieve and the residue should not be more than 10% by weight. The surkhi mortar is used for ordinary masonry work of all kinds in foundation and superstructure. But it cannot be used for plastering or pointing since surkhi is likely to disintegrate after some time”.
iii. Cement mortar:
In this type of mortar, the cement is used as binding material. Depending upon the strength required and importance of work, the proportion of cement to sand by volume varies from 1:2 to 1:6 or more. It should be noted that surkhi and cinder are not chemically inert substances and hence they cannot be used as adulterants with matrix as cement. Thus the sand only can be used to form cement
mortar. The proportion of cement with respect to sand should be determined with due regard to the specified durability and working conditions. The cement mortar is used where a mortar of high strength and water-resisting properties is required such as underground constructions, water saturated soils, etc.
iv. Gauged mortar:
To improve the quality of lime mortar and to achieve early strength, the cement is sometimes added to it. This process is known as the gauging. It makes lime mortar economical, strong and dense. The usual proportion of cement to lime by volume is about 1:6 to 1 :8. It is also known as the composite mortar or lime-cement mortar and it can also be formed by the combination of cement and clay. This mortar may be used for bedding and for thick brick walls.
v. Gypsum mortar:
These mortars are prepared from gypsum binding materials such as building gypsum and anhydrite binding materials.
The important properties of a good mortar mix are mobility placeability and water retention.
1. it is used to indicate the consistency of mortar mix which may range frome stiff to fuild.
2. The mobility of mortar mix depends on the composition of mortar and the mortar mixes to be masonary work are made suffciently mobile.
1. it is the ease which the mortar mix can be placed with minimum coast in a thin and a uniform layer over the surface depends on the mobility of the mortar.
2. The placeability of mortar mix should be such that a strong bond is developed with the surface of the bed .
3. A good mortar mix should poses the ability of retaining adequate umidity durig transportain and laying over the porous bed.
Workability is the amount of work to produce full compaction
The important facts in connection with workability are:-
if more water is added to attain the required degree of workamship,it results into concrete of low strgenth and poor durability
if stregnth of concrete is not to be affected the degree of workability can be obtained:
a. by slightly changing the proportion of line and coarse aggregate, in case the concrete mixture is too dry
b. by adding a small quantity of water cement paste in the propertion of original mix, in case the concrete mixture is too dry
3. The workability of concrete is also affected by the maximum size of the coarse aggregates to be used in the mixtures.