REPORT ON DRAIN CONSTRUCTION
Before starting construction we first have to check the building materials
whether they can be used or not it is done in the field itself and hence this
process is known as Field Tests of Building Materials. Field test of brick,
cement, sand and stone chips are very much essential as they are the most
common construction materials which are used in almost all of the civil
engineering construction from brickwork to floor finishing everywhere.. A
proper quality control is essential at all the stages, specially at the very start,
where we have to select right materials for a type of construction, as the
materials are the cell of each structure. A Civil Engineer may not always have
the facility of laboratory at the site for the testing of materials so as to
ascertain the quality of a material weather it is bad or good, suitable or not. So
a civil engineer should be able to judge the quality of the basic construction
materials such as Brick, Cement, Sand and Stone Chips by means of Visual
Inspection of those materials, which can be done by doing the Field Test on
those materials. Here are some of the different field tests for basic
construction materials which becomes necessary in day to day work.
How To Check If Cement Is Good?
The following field tests is be performed to determine if the cement is of good
quality: -
1. The cement should be of Greenish Gray colour for Ordinary Portland
Cement, and Blackish Gray colour for Portland Pozzolana Cement and Whitish
Gray colour for Portland Slag Cement.
2. There should not be any hard lumps on cement, the cement should be finely
powdered. If cement contains hard lumps, then it must be rejected.
3. The cement when rubbed between fingers should feel smooth, it should not
feel granular. If it is granular then it means adulteration with sand.
4. A cement paste should feel sticky in between fingers.
5. When hand is dipped into a heap or into a bag of cement, it should feel cool,
not warm.
1
,6. If a hand full of cement is thrown into a bucket of water, the cement should
sink, not float as the Specific Gravity of Cement is greater than that of Water.
7. If a thick cement paste made on a glass and immersed in water should set,
not crack.
How To Check If Sand Is Good?
The following tests should be performed to determine the quality of Sand: -
1. The Sand should be free from organic impurities and mineral salts, The
maximum permissible quantity of organic impurities should be restricted to
5%.
2. The Sand should be of Golden Yellow colour.
3. The Sand particles should be sharp and angular to increase the interlocking
property between the sand particles.
4. The sand should coarse for Concreting and medium sand may be allowed in
brickwork and is preferable for plastering works.
How To Check If Stone Chips Are Good?
The visual tests or field tests for Coarse aggregate, that is stone chips are very
limited though there are many laboratory tests are available. Mainly the
following things are observed as for Field Test: -
1. The Stone Chips are to be well graded to increase the mechanical
interlocking between them.
2. Stone Chips should be Angular as far as possible and be porous.
3. The Stone Chips should not be flaky and elongated.
4. The Stone Chips should not contain organic and other impurities, as only 5%
clay content in concrete can reduce the strength of the concrete as much as
20%.
1. TEST FOR ORGANIC IMPURITIES IN FINE AGGREGATE
The aggregate must be checked for organic impurities such as decayed
vegetations, humus, and coal dust, etc. Colour test is a reliable indicator of the
presence of harmful organic matter in aggregates except in areas where there
are deposits of lignite.
2
, Procedure:
a) Fill a 350 ml clear glass medicine bottle upto 75 ml mark with a 3% solution of
caustic soda or sodium hydroxide.
A 3% solution of caustic soda is made by dissolving 3 gm of sodium hydroxide
(which can be purchased from any local laboratory chemicals shop) in 100 ml of
clean water (preferably distilled water). The solution should be kept in glass
bottle tightly closed with a rubber stopper. Handling sodium hydroxide with
moist hands may result in serious burns. Care should be taken not to spill the
solution for it is highly injurious to clothing, leather and other materials.
b) The representative sands sample is next added gradually until the volume
measured by the sandy layer is 125 ml. The volume is then made up to 200 ml
by the addition of more of the solution. The bottle is then corked and shaken
vigorously and allowed to stand for 24 hours.
c)At the end of this period, the colour of the liquid will indicate whether the sand
contains a dangerous amount of matter or not. A colorless liquid indicates clean
sand free from organic matter. A straw-colored solution indicates some organic
matter but not enough to be seriously objectionable. Darker colour means that
the sand contains injurious, amounts and should not be used unless it is washed
and a retest then shows that it is satisfactory.
2. TEST FOR SILT CONTENT OF FINE AGGREGATE
It is important to use clean aggregate for concrete. If the aggregates are coated
with dirt, silt or clay, it will result in a poor concrete because the dirt will prevent
the cement from setting and also weaken the bond between the aggregates and
the cement paste.
Further owing to their fineness and therefore large surface area, increases the
amount of water necessary to wet all the particulars in the mix, this also resulted
more shrinkage of concrete. As determine with the given field test, the sand
shall not contain more than 8% of silt.
Procedure:
(a) Fill a measuring cylinder with a representative sand (fine aggregate) sample
up to 100 ml mark and add clean water up to 150 ml. To perform this test, more
correctly better dissolve a little salt in the water (1 tea spoonful to 250 ml is the
right proportion).
3
Before starting construction we first have to check the building materials
whether they can be used or not it is done in the field itself and hence this
process is known as Field Tests of Building Materials. Field test of brick,
cement, sand and stone chips are very much essential as they are the most
common construction materials which are used in almost all of the civil
engineering construction from brickwork to floor finishing everywhere.. A
proper quality control is essential at all the stages, specially at the very start,
where we have to select right materials for a type of construction, as the
materials are the cell of each structure. A Civil Engineer may not always have
the facility of laboratory at the site for the testing of materials so as to
ascertain the quality of a material weather it is bad or good, suitable or not. So
a civil engineer should be able to judge the quality of the basic construction
materials such as Brick, Cement, Sand and Stone Chips by means of Visual
Inspection of those materials, which can be done by doing the Field Test on
those materials. Here are some of the different field tests for basic
construction materials which becomes necessary in day to day work.
How To Check If Cement Is Good?
The following field tests is be performed to determine if the cement is of good
quality: -
1. The cement should be of Greenish Gray colour for Ordinary Portland
Cement, and Blackish Gray colour for Portland Pozzolana Cement and Whitish
Gray colour for Portland Slag Cement.
2. There should not be any hard lumps on cement, the cement should be finely
powdered. If cement contains hard lumps, then it must be rejected.
3. The cement when rubbed between fingers should feel smooth, it should not
feel granular. If it is granular then it means adulteration with sand.
4. A cement paste should feel sticky in between fingers.
5. When hand is dipped into a heap or into a bag of cement, it should feel cool,
not warm.
1
,6. If a hand full of cement is thrown into a bucket of water, the cement should
sink, not float as the Specific Gravity of Cement is greater than that of Water.
7. If a thick cement paste made on a glass and immersed in water should set,
not crack.
How To Check If Sand Is Good?
The following tests should be performed to determine the quality of Sand: -
1. The Sand should be free from organic impurities and mineral salts, The
maximum permissible quantity of organic impurities should be restricted to
5%.
2. The Sand should be of Golden Yellow colour.
3. The Sand particles should be sharp and angular to increase the interlocking
property between the sand particles.
4. The sand should coarse for Concreting and medium sand may be allowed in
brickwork and is preferable for plastering works.
How To Check If Stone Chips Are Good?
The visual tests or field tests for Coarse aggregate, that is stone chips are very
limited though there are many laboratory tests are available. Mainly the
following things are observed as for Field Test: -
1. The Stone Chips are to be well graded to increase the mechanical
interlocking between them.
2. Stone Chips should be Angular as far as possible and be porous.
3. The Stone Chips should not be flaky and elongated.
4. The Stone Chips should not contain organic and other impurities, as only 5%
clay content in concrete can reduce the strength of the concrete as much as
20%.
1. TEST FOR ORGANIC IMPURITIES IN FINE AGGREGATE
The aggregate must be checked for organic impurities such as decayed
vegetations, humus, and coal dust, etc. Colour test is a reliable indicator of the
presence of harmful organic matter in aggregates except in areas where there
are deposits of lignite.
2
, Procedure:
a) Fill a 350 ml clear glass medicine bottle upto 75 ml mark with a 3% solution of
caustic soda or sodium hydroxide.
A 3% solution of caustic soda is made by dissolving 3 gm of sodium hydroxide
(which can be purchased from any local laboratory chemicals shop) in 100 ml of
clean water (preferably distilled water). The solution should be kept in glass
bottle tightly closed with a rubber stopper. Handling sodium hydroxide with
moist hands may result in serious burns. Care should be taken not to spill the
solution for it is highly injurious to clothing, leather and other materials.
b) The representative sands sample is next added gradually until the volume
measured by the sandy layer is 125 ml. The volume is then made up to 200 ml
by the addition of more of the solution. The bottle is then corked and shaken
vigorously and allowed to stand for 24 hours.
c)At the end of this period, the colour of the liquid will indicate whether the sand
contains a dangerous amount of matter or not. A colorless liquid indicates clean
sand free from organic matter. A straw-colored solution indicates some organic
matter but not enough to be seriously objectionable. Darker colour means that
the sand contains injurious, amounts and should not be used unless it is washed
and a retest then shows that it is satisfactory.
2. TEST FOR SILT CONTENT OF FINE AGGREGATE
It is important to use clean aggregate for concrete. If the aggregates are coated
with dirt, silt or clay, it will result in a poor concrete because the dirt will prevent
the cement from setting and also weaken the bond between the aggregates and
the cement paste.
Further owing to their fineness and therefore large surface area, increases the
amount of water necessary to wet all the particulars in the mix, this also resulted
more shrinkage of concrete. As determine with the given field test, the sand
shall not contain more than 8% of silt.
Procedure:
(a) Fill a measuring cylinder with a representative sand (fine aggregate) sample
up to 100 ml mark and add clean water up to 150 ml. To perform this test, more
correctly better dissolve a little salt in the water (1 tea spoonful to 250 ml is the
right proportion).
3
