Building Materials and Construction, Objective Type Question Part-I

Gypsum is a : Chemically Precipitated Sedimentary Rock

Sedimentary rocks which changes into quartzite by metamorphic action: Sand Stone

Quartzite is a:  Silicious Rock

Slate is formed by metamorphic action of: Shale

Sandstone is a:  aqueous, silicious & sedimentary rock

A heavy stone is suitable for: Retaining Walls

Stone suitable for rubble masonary should be: Tough

Which metamorphic rock has the most weather resisting characteristics: Quartzite

A good building stone should not absorb water more than: 5%

Jumper is a tool used for: Quarrying Of Stone

The important test to be conducted on a stone used in docks & harbours is: Weight Test

The predominant constituent which is responsible for strength in granite is: Quartz

Granite is not suitable for ordinary building purpose because: It is costly

Stone which is suitable for construction of piers & abutments of a railway bridge: Granite

The p[reparation of surface of stone to obtain plain edges or to obtain stones of required size & shape is known as: Dressing Of Stones

Crushing strength of good building stone should be more than: 100Mpa

Specific gravity for most of building stones lies between: 2.5 to 3.0

Spalling Hammer is used for: Breaking small projection of stones

Cross cut saw is used for: Cutting Hard Stones

Sapwood consists of : Portion of timber between heartwood and cambium layer

The radial splits which are wider on the outside of the log & narrower towards the pith are known as: Starshakes

Trees yielding soft wood: Chir & Deodar

A tree yielding hard wood: Shishum

The disease of dry rot in timber is caused by: Lack of ventilation

Plywood has the advantage of: Same tensile strength in all directions

In which of the following directions, the strength of timber is maximum: Parallel to grains

The moisture content in a well seasoned timber is : 10% to 12 %

The trunk of tree left after cutting all the branches: Log

The age of tree can be known by examining: Annual Rings

Plywood is made by bounding together thin layers of wood in such a way that the angle between grains of any layer to grains of adjacent layers is : 90 degree

The plywood has: greater impact resistance to blows than ordinary wood

The practical limit of moisture content achieved in air drying of timber is: 15%

First class timber has an average life of: More than 10 years

Crushing Strength of 1st Class brick should not be less than: 10.5 N/mm2

The main fuction of alumina in brick earth is : To impart plasticity

The % of alumina in good brick earth lies between: 20% – 30%

Excess of alumina in brick earth makes the brick: To crack & warp on drying

The nominal size of modular brick is: 200mm x 200mm x 100mm

Percentage of silica in good brick earth lies between: 50% to 60%

Excess of silica in brick earth results in:  Loss of cohesion

Which ingredient of brick earth enables the brick to retain it’s shape: Silica

Building Materials and Construction, Objective Type Question Part-II

The process of mixing clay, water & other ingredients to make brick is known as: Kneading

Advantage of a clamp compared to a kiln for burning bricks is: It has less initial cost

The internal size of mould used in brick preparation is: Greater than size of fully burnt brick

Pug mill is used for: Preparation Of Clay

Bricks used for lining of furnaces:  Refractory Bricks

The frog of brick in a brick masonry is generally kept on: Top Face

Number of bricks required for one cubic meter of brick masonry is: 500

Glazing is used to make earthenware: Impervious

Quick lime is: Calcium Oxide

Quick lime is: Slow in setting & Rapid in slacking

Hydraulic lime is obtained by: Burning of kankar

The main constituent which imparts hydraulicity to hydraulic lime is: Clay

The main ingredients of Portland Cement are: Lime & Silica

The constituent of cement which is responsible for initial setting of cement is: Tricalcium Aluminate

The initial setting time for ordinary Portland cement as per IS specifications should not be less than: 30 minutes

The final setting time for ordinary Portland cement as per IS specifications should not be less than: 10 hours

For testing compressive strength of cement, the size of cube used is: 50mm

The normal consistency of ordinary Portland cement is about: 30%

Early attainment of strength in rapid hardening cement is mainly due to: Finer Grinding

After Storage, the strength of cement: Decreases

According to IS specifications, the compressive strength of ordinary Portland cement after three days should not be less than: 16 MPa

Addition of pozzolana to ordinary Portland cement increases: Shrinkage

Gypsum consists of: CaSO4 & H2O

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

The slump recommended for mass concrete is about: 25 mm to 50 mm

With increase in moisture content, the bulking of sand: first increases to a certain maximum value and then decreases

Which cement is suitable for use in massive concrete structures such as large dams: Low Heat Cement

Proper amount of entrained air in concrete results in: Better Workability & Better resistance to freezing & thawing

The most common admixture which is used to accelerate the initial set of cement is: Calcium Chloride

The maximum quantity of calcium chloride used as an accelerator in cement in percentage by weight of cement is: 2

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

Cement which contains maximum percentage of dicalcium silicate: Low Heat Cement

Most commonly used retarder in cement is: Gypsum

Three basic raw materials which are needed in large quantities for production of steel are: iron ore, coal & lime stone

Compared to mild steel, cast iron has: High Compressive Strength & Low tensile Strength

Which gradient exerts maximum influence on properties of steel: Carbon

Measurement of Settleable Solids

Measurement of Settleable Solids

Object: Measurement of Settleable Solids in Sewage

THEORY: Sewage contains 99.9% water and 0.1% solids. The solids are either
in dissolved form or in suspension. When sewage is passed through a filter the filtrate is not clear and looks turbid (turbidity is the obstruction in the passage of light). The turbidity is because of the filterable solids. This fraction consists of colloidal solids as well as dissolved solids. The colloidal fraction consists of the particulate matter of diameter ranging from 1 milimicron to 1 micron. The colloidal fraction consists of finely divided particles of gels, emulsions, grease, oil causing foams. The colloidal particles are also the fine clay particles with same charge repulsing each other. Because of their size and charge they can not settle by gravitational force. They have to be removed either by biological oxidation or chemical coagulation.
But a major portion of the suspended solids consists of larger, heavier particles that can settle in calm and quiescent conditions. They are known as settleable solids. In sewage treatment, after screening the first treatment unit is a sedimentation chamber known as the grit chamber. It is intended that particles of size 0.15mm to 0.2 mm with a specific gravity of 2.4 to 2.65 are settled in the grit chamber. These particles are generally inorganic particles and they are not degradable. The deposited particles, known as grit can be easily disposed of without any treatment. Even they can be used for filling purposes or low grade concrete.
The significance of this test is in finding the settelable portion of the suspended solids to design the grit chambers and to estimate the amount of deposited material daily in the grit chambers that is to be removed and disposed or used.

Apparatus
Imhoff Cone: It is a long glass cone specially designed with a mark on the top indicating its capacity as one litre; mounted on a stand.

Procedure

Pour the well mixed sample in the Imhoff cone upto 1 litre mark. Allow the sample to settle for 45 minutes. Gently stir sides of the cone with a knife so that the material sticking to the sides may also get settled. Allow it to settle for further 15 minutes. Thus the total settling time is 1 hour. The bottom of the cone is graduated in milliliters. Read from the graduated scale in terms of milliliters per litre.

CALCULATION AND RESULTS

Direct reading on the graduated bottom of the cone gives the amount of settleable solids in
milliliters per litre of sewage.
The settleable solid in the given sample of sewage are ……………milliliters /L

Measurement of Fluoride in Water

Measurement of Fluoride in Water

Object: Measurement of Fluoride in Water
THEORY: Fluoride is essential for human beings to fight against dental caries. The desirable concentration is 1 mg/l, if it is more than this it proves to be harmful. Fluoride concentration of more than 3 ppm is not allowed in potable water in any case. As per W.H.O the fluorides should not be more than 1.5 ppm. Actually the higher concentration of fluoride leads to the discoloration of teeth known as dental fluorosis. The more dangerous is the deformation of the Skelton. In Rajasthan about 25 districts are fluoride affected and some of them are severely affected. The fluoride in the ground water of Nagaur District is so high (5-10 ppm) that above 50% of the people in one particular area (known as ‘Banka Patti’ ) are with distorted Skelton. The name Banka itself means distorted or bent bones. The skeletal fluorosis affects the bones, tendons and ligaments followed by pain and ultimately leads to the seizer of neck and other limbs movement. So it is very important to check the fluoride concentration in drinking water.
The actual laboratory determination is done by spectrophotometer but it can be done at student’s primary level by visual comparison also. In this test we use the combination of zirconium and either alizarin dye or SPADNS dye. This combination gives a reddish colour and the colour produced is commonly referred as a ‘lake’. The intensity of colour produced is reduced if the amount of zirconium present is decreased.

Equipment and Reagents

(i) Nessler tubes
(ii) Standard Sodium fluoride solution
Dissolve 0.0221 gm of dry sodium fluoride in distilled water and make upto 1000 ml. One
ml of this solution contains 0.01 mg of fluoride as F.
(iii) Acid zirconium alizarin reagent
Dissolve 0.3 gm of zirconium oxychloride or 0.25 gm of zirconium oxynitrate in 50 ml of distilled water. Dissolve 0.07 gm of alizarin sodium monosulphonate in another 50 ml of distilled water and add the later solution to the zirconium solution calmly with continuous stirring.
(iv) Sodium thiosulphate solution (0.1N)
Dissolve 25 gm of Na2S2O3 . 5H2O in distilled water and make upto 1 litre.

Procedure
(i) The sample should be free from chlorine, it should be dechlorinated with sodium thiosulphate solution before use.
(ii) Take 1, 2, 3, 5, 7, 9, 11 ml of standard sodium fluoride solution in six Nessler Tubes.
(iii) Add 5 ml of acid zirconium reagent in each Nessler tube.
(iv) Add 5 ml of acid zirconium reagent in each Nessler tube containing 100 ml of sample.
(v) Mix thoroughly and compare the colour developed after one hour with the six tubes.

Measurement of Nitrates in Water

Measurement of Nitrates in Water

Aim: Measurement of Nitrates in Water

THEORY: Generally the ground water has high nitrate concentration because of the percolating
sewage, industrial waste, chemical fertilizers, leaches from solid waste landfills, septic tank effluents etc. Whatever may be the reason the high concentration of nitrate is harmful to human beings, particularly for infants. The low acidity in the infants’intestine permits the growth of nitrate reducing bacteria that converts the nitrate to nitrite that is then absorbed in the blood stream. The nitrite has a great affinity for hemoglobin than the oxygen and it replaces oxygen in the blood. The deficiency of oxygen causes suffocation. The colour of the skin of the infants becomes blue so it is termed as blue baby disease. The medical name is ‘mathemoglobinemia’. This disease is a fatal disease and it takes place when the concentration of nitrates is more than 45 ppm. So it is important to find the amount of
nitrate in drinking water though it is a difficult task and requires spectrophotometer also.

Apparatus
(i) Spectrophotometer with a range of 300 – 700 nm.
(ii) Nessler tubes capacity 100 ml

Reagents
(i) Standard silver sulphate
(ii) Phenol disulphonic acid
(iii) Ammonium hydroxide
(iv) Stock nitrate solution: Dry potassium nitrate (KNO3) in an oven at 105°C for 24 hours. Dissolve 0.1631 g in water and dilute to 1000 ml. 1.0 ml = 100 micro gram NO3- N. Preserve with 2 ml CHCl3/l
(v) Standard nitrate solution

Procedure
(i) Take 50 ml of filtered sample in a flask.
(ii) Add an equivalent amount of silver sulphate to remove chlorides. So chloride determination is done prior to the nitrates. 1 mg/lCl = 1 ml Ag2SO4 solution.
(iii) Slightly warm and filter the precipitated AgCl.
(iv) Evaporate the filtrate in a porcelain dish to dryness.
(v) Cool and dissolve the residue in 2 ml phenoldisulphonic acid and dilute to 50 ml.
(vi) Add 10 ml of liquid ammonia to develop a yellow colour. Actually nitrate reacts with disulphonic acid and produces a nitro- derivative that in alkaline medium produces a yellow colour..
(vii) Observe the colour developed at 410 nm with a light path of 1 cm.
(viii) Calculate the concentration of nitrate from the standard curve.
(ix) Prepare the standard curve using suitable aliquots of standard nitrate solution in
the range of 5 to 500 mg NO3 by following the above procedure.

TESTS ON FRESH CONCRETE

TESTS ON FRESH CONCRETE

1. WORKABILITY

AIM: To determine the workability of fresh concrete by slump test as per IS: 1199 - 1959.

APPARATUS
i) Slump cone
ii) Tamping rod

PROCEDURE

i) The internal surface of the mould is thoroughly cleaned and applied with a light coat of oil.
ii) The mould is placed on a smooth, horizontal, rigid and nonabsorbent surface.
iii) The mould is then filled in four layers with freshly mixed concrete, each approximately to one-fourth of the height of the mould.
iv) Each layer is tamped 25 times by the rounded end of the tamping rod (strokes are distributed evenly over the crosssection).
v) After the top layer is rodded, the concrete is struck off the level with a trowel.
vi) The mould is removed from the concrete immediately by raising it slowly in the vertical direction.
vii) The difference in level between the height of the mould and that of the highest point of the subsided concrete is measured.
viii) This difference in height in mm is the slump of the concrete.

REPORTING OF RESULTS
The slump measured should be recorded in mm of subsidence of the specimen during the test. Any slump specimen, which collapses or shears off laterally gives incorrect result and if this occurs, the test should be repeated with another sample. If, in the repeat test also, the specimen shears, the slump should be measured and the fact that the specimen sheared, should be
recorded.

2. COMPACTING FACTOR

AIM: To determine the workability of fresh concrete by compacting factor test as per IS: 1199 - 1959.

APPARATUS
i) Compacting factor apparatus

PROCEDURE
i) The sample of concrete is placed in the upper hopper upto the brim.
ii) The trap-door is opened so that the concrete falls into the lower hopper.
iii) The trap-door of the lower hopper is opened and the concrete is allowed to fall into the cylinder.
iv) The excess concrete remaining above the top level of the cylinder is then cut off with the help of plane blades.
v) The concrete in the cylinder is weighed. This is known as weight of partially compacted concrete.
vi) The cylinder is filled with a fresh sample of concrete and vibrated to obtain full compaction. The concrete in the cylinder is weighed again. This weight is known as the weight of fully compacted concrete.

REPORTING OF RESULTS
Compacting factor =
Weight of partially compacted concrete
Weight of fully compacted concrete
It should normally be stated to the nearest second decimal
place.


3.VEE-BEE

AIM: To determine the workability of fresh concrete by using a Vee-Bee consistometer as per IS: 1199 - 1959.

APPARATUS
i) Vee-Bee consistometer

PROCEDURE
i) A conventional slump test is performed, placing the slump cone inside the cylindrical part of the consistometer.
ii) The glass disc attached to the swivel arm is turned and placed on the top of the concrete in the pot.
iii) The electrical vibrator is switched on and a stop-watch is started, simultaneously.
iv) Vibration is continued till the conical shape of the concrete disappears and the concrete assumes a cylindrical shape.
v) When the concrete fully assumes a cylindrical shape, the stop-watch is switched off immediately. The time is noted.

REPORTING OF RESULTS
The consistency of the concrete should be expressed in VB-degrees, which is equal to the time in seconds, recorded above.

TESTS ON AGGREGATES

TESTS ON AGGREGATES

1. SIEVE ANALYSIS

AIM:To determine the particle size distribution of fine and coarse aggregates by sieving as per IS: 2386 (Part I) - 1963.

PRINCIPLE
By passing the sample downward through a series of standard sieves, each of decreasing size openings, the aggregates are separated into several groups, each of which contains aggregates in a particular size range.

APPARATUS
A SET OF IS SIEVES
i) A set of IS Sieves of sizes - 80mm, 63mm, 50mm, 40mm,31.5mm, 25mm, 20mm, 16mm, 12.5mm, 10mm, 6.3mm, 4.75mm, 3.35mm, 2.36mm, 1.18mm, 600μm, 300μm, 150μm
and 75μm

ii) Balance or scale with an accuracy to measure 0.1 percent of the weight of the test sample

PROCEDURE
i) The test sample is dried to a constant weight at a temperature of 110 + 5oC and weighed.
ii) The sample is sieved by using a set of IS Sieves.
iii) On completion of sieving, the material on each sieve is weighed.
iv) Cumulative weight passing through each sieve is calculated as a percentage of the total sample weight.
v) Fineness modulus is obtained by adding cumulative percentage of aggregates retained on each sieve and dividing the sum by 100.

REPORTING OF RESULTS
The results should be calculated and reported as:
i) the cumulative percentage by weight of the total sample
ii) the percentage by weight of the total sample passing through one sieve and retained on the next smaller sieve, to the nearest 0.1 percent.
The results of the sieve analysis may be recorded graphically on a semi-log graph with particle size as abscissa (log scale) and the percentage smaller than the specified diameter as ordinate.

2. WATER ABSORPTION

AIM: To determine the water absorption of coarse aggregates as per IS: 2386 (Part III) - 1963.

APPARATUS
i) Wire basket - perforated, electroplated or plastic coated with wire hangers for suspending it from the balance.
ii) Water-tight container for suspending the basket
iii) Dry soft absorbent cloth - 75cm x 45cm (2 nos.)
iv) Shallow tray of minimum 650 sq.cm area
v) Air-tight container of a capacity similar to the basket
vi) Oven
SAMPLE
A sample not less than 2000g should be used.

PROCEDURE
i) The sample should be thoroughly washed to remove finer particles and dust, drained and then placed in the wire basket and immersed in distilled water at a temperaturebetween 22 and 32 degree C.
ii) After immersion, the entrapped air should be removed by lifting the basket and allowing it to drop 25 times in 25 seconds. The basket and sample should remain immersed for a period of 24 + - ½ hrs. afterwards.
iii) The basket and aggregates should then be removed from the
water, allowed to drain for a few minutes, after which the aggregates should be gently emptied from the basket on to one of the dry clothes and gently surface-dried with the cloth, transferring it to a second dry cloth when the first would remove no further moisture. The aggregates should be spread on the second cloth and exposed to the atmosphere away from direct sunlight till it appears to be completely surface-dry. The aggregates should be weighed (Weight 'A').
iv) The aggregates should then be placed in an oven at a temperature of 100 to 110oC for 24hrs. It should then be removed from the oven, cooled and weighed (Weight 'B').

REPORTING OF RESULTS

Water absorption =[(A - B)/B]x 100%

Two such tests should be done and the individual and mean results should be reported.
A sample proforma for the record of the test results is given in

3. AGGREGATE ABRASION VALUE
AIM: To determine the abrasion value of coarse aggregates as per IS: 2386 (Part IV) - 1963.

APPARATUS
i) Los Angles abrasion testing machine
ii) IS Sieve of size - 1.7mm
iii) Abrasive charge - 12 nos. cast iron or steel spheres approximately 48mm dia. and each weighing between 390 and 445g ensuring that the total weight of charge is 5000 + - 25g
iv) Oven

PREPARATION OF SAMPLE

The test sample should consist of clean aggregates which has been dried in an oven at 105 to 110oC to a substantially constant weight.

PROCEDURE
The test sample and the abrasive charge should be placed in the Los Angles abrasion testing machine and the machine rotated at a speed of 20 to 33 revolutions/minute for 1000 revolutions. At the completion of the test, the material should be discharged and sieved through 1.70mm IS Sieve.

REPORTING OF RESULTS
i) The material coarser than 1.70mm IS Sieve should be washed, dried in an oven at a temperature of 100 to 110oC to a constant weight and weighed (Weight 'B').
ii) The proportion of loss between weight 'A' and weight 'B' of the test sample should be expressed as a percentage of the original weight of the test sample. This value should be reported as,
Aggregate abrasion value = [(A-B)/A] x 100%

4. AGGREGATE IMPACT VALUE

AIM:To determine the aggregate impact value of coarse aggregates as per IS: 2386 (Part IV) - 1963.

APPARATUS
i) Impact testing machine conforming to IS: 2386 (Part IV)- 1963
ii) IS Sieves of sizes - 12.5mm, 10mm and 2.36mm
iii) A cylindrical metal measure of 75mm dia. and 50mm depth
iv) A tamping rod of 10mm circular cross section and 230mm length, rounded at one end
v) Oven

PREPARATION OF SAMPLE
i) The test sample should conform to the following grading:
- Passing through 12.5mm IS Sieve 100%
- Retention on 10mm IS Sieve 100%

ii) The sample should be oven-dried for 4hrs. at a temperature
of 100 to 110oC and cooled.

iii) The measure should be about one-third full with the prepared aggregates and tamped with 25 strokes of the tamping rod.
A further similar quantity of aggregates should be added and a further tamping of 25 strokes given. The measure should finally be filled to overflow, tamped 25 times and the surplus aggregates struck off, using a tamping rod as a straight edge. The net weight of the aggregates in the measure
should be determined to the nearest gram (Weight 'A').

PROCEDURE
i) The cup of the impact testing machine should be fixed firmly in position on the base of the machine and the whole of the test sample placed in it and compacted by 25 strokes of the
tamping rod.
ii) The hammer should be raised to 380mm above the upper surface of the aggregates in the cup and allowed to fall freely onto the aggregates. The test sample should be subjected to a total of 15 such blows, each being delivered at an interval of not less than one second.

REPORTING OF RESULTS
i) The sample should be removed and sieved through a 2.36mm IS Sieve. The fraction passing through should be weighed (Weight 'B'). The fraction retained on the sieve should also be weighed (Weight 'C') and if the total weight (B+C) is less than the initial weight (A) by more than one gram, the result should be discarded and a fresh test done.
ii) The ratio of the weight of the fines formed to the total sample weight should be expressed as a percentage.
Aggregate impact value = (B/A) x 100%
iii) Two such tests should be carried out and the mean of the results should be reported.

5. AGGREGATE CRUSHING VALUE

AIM:To determine the aggregate crushing value of coarse aggregates as per IS: 2386 (Part IV) - 1963.

APPARATUS:
i) Cylindrical measure and plunger
ii) Compression testing machine
iii) IS Sieves of sizes - 12.5mm, 10mm and 2.36mm

PROCEDURE
i) The aggregates passing through 12.5mm and retained on 10mm IS Sieve are oven-dried at a temperature of 100 to 110oC for 3 to 4hrs.
ii) The cylinder of the apparatus is filled in 3 layers, each layer tamped with 25 strokes of a tamping rod.
iii) The weight of aggregates is measured (Weight 'A').
iv) The surface of the aggregates is then levelled and the plunger inserted. The apparatus is then placed in the compression testing machine and loaded at a uniform rate so as to achieve 40t load in 10 minutes. After this, the load is released.
v) The sample is then sieved through a 2.36mm IS Sieve and the fraction passing through the sieve is weighed (Weight 'B').
vi) Two tests should be conducted.

REPORTING OF RESULTS

Aggregate crushing value = (B/A) x 100%
The result should be recorded to the first decimal place and the
mean of the two results reported.