Field test of cement |test of cement in field | testing of cement in construction
Field test of cement |test of cement in field | testing of cement in construction
Field test of cement
Cement is one of the most important building materials which is used as a Binder to hold all ingredients of concrete materials
Field tests for cement performed
- To determine the physical properties of cement,
- To determine the strength of cement.
- To determine the Quality of cement.
Field tests on cement at a construction -
1. Colour of cement
2. Manufacturing date of cement
3. Adulteration test
4. Presence of lumps
5. Float test
6. Temperature test
7. Set test
8. Strength test
(a) compressive strength test,
(b) tensile strength test
1. Colour of cement
The Colour of cement should be uniform, grey colour or greenish shade, In fact, grey colour of cement is an indication of the pure variety of cement & the colour of cement also indicates the presence of an excess of clay or lime & burning of degree.
2. The manufacturing date of cement
The manufacturing date of cement should be used within 3 months ( 90 days) from its production date for construction structures, we should check the manufacturing date of cement because the strength of cement reduces with respect to an increase in the manufacturing date of packing,
- After 3 months its strength is reduced by 20-30 percent,
- after 6 months strength is reduced by 30-40 percent
- after 1-year cement is unsuitable for use in construction structures.
3. Adulteration test
It means adding non-cement materials or addition of other components to the cement that changes their standard chemical composition in contrast to changes like colour, and texture, this test is done by touching the cement with fingers.
if a small quantity of cement is pinched feel rub between the fingers, it should feel smooth, feel cool, if it feels rough,
4. Presence of lumps
Presence of lumps is formed due to high moisture content or high humidity in the Storage area of cement
Cement Samples should be free from the presence of air-set lumps & should always be stored in a cool or dry area.
5. Float test
Float test, this test is the physical properties of cement, Take a small quantity of cement sample and it is thrown in a bucket of water, it should sink & should not float on the surface.
6. Temperature test
This test is an important & necessary test to use in a short period of time in a construction site to decide the cement is good quality. When we insert a hand into bag of cement, then it should give the cool feeling that must be cold from the inside of the sample.
if we are feeling hot from the inside of the sample that is indicate the process of hydration of cement is taking place.
7. Set Test
Set Test, take a thick paste of cement with water is made on a glass plate & kept in water for 24 hours, then it should be set & not shows crack, too much of set indicates the good quality of cement.
8. Strength test
Strength test, this test is an important Field test on cement which is involved a block or briquette of size 25mm x 25mm x 200mm from a given sample of cement and prepared by cement: sand /1:6 ratio, this block is immersed it in water for 7 days, then remove the block from water, this should not break easily and should not be converted into powdered form, place over supports having spacing of 150mm and apply 340N central point load of specimen, the sample should not show any sign of failure under the loading. If the block will show no failure, the cement is of good quality.
Compressive Strength Test
Compressive strength test is the the must important test for hardened cement because cement is best in compression handling, take cement and standard sand in the proportion of 1:3 for prepare motar and water is added in the proportion of ( p/4)+3 percent. Then fill the mortar in 5000 mm2 area. Mould is immersed in water for sufficient duration for curing.
Temperature and humidity condition should be 27 degree Celsius and 90 percent respectively, strength should be tested for 3 days,7 days and 28 days.
Sample is tested in UTM (universal testing machine) and apply a gradual load of 35 N/mm2/minute, An average of 3 results for each age is taken as Compressive strength of cement for that age .
Compressive strength of 33 grade of OPC is following-
1. Days 3, Compressive strength 16 MPa
2. Days 7, Compressive strength 22 MPa
3. Days 28, Compressive strength 33 MPa
Tensile Strength Test
Regarding this, Tensile strength test, this test is repeating by the same process for preparing motar in compressive strength test , this test is the only difference is the water added is (p/5)+2.5 percent and spacimen is subjected to any form having tensile stress of 3.5 N/mm2/minute till failure, we have take an average of 12 result in this case as tensile strength of cement.
Tensile strength and compressive strength is related to generally having the value of tensile strength is 10-15 percent of compressive strength.
1. Days 3, tensile strength 2 MPa
2. Days 7, Tensile strength 2.5 MPa
How do you find the field test of cement?
how do you find the field of cement, field tests on cement easy to perform the test on construction site, performs to determine the physical properties of cement,to regulate the various stages in manufacturing process as a slight difference in the process of manufacture of cement may cause a great difference in the property of cement and very useful to understand the behaviour of cement after its use on the works and also this test is carried out to determine the strength of cements.
This test is find the field test for cement following –
1.The colour of cement should be grey , greenish and uniform within sample cement or a bag cement which is gives an indication of excess lime or clay and the degree of burning
2. Hand inserting into the cement bag ,then it is gives the smooth feeling.
3. It should be free from presence of lumps
4. a small quantity of cement sample is thrown in a bucket of water,it should sink and should not float on the surface.
5. we insert hand in bag of of cement or sample of cement ,then it should give cool feeling that must be cold from the inside of sample.
6. take a thick paste of cement with water is made on a glass plate and kept in water for 24 hours ,then it should be set and not shows crack
7. Strength of cement, the block having size 25mm x 25mm x 200mm will show no failure of test, the cement is of good quality.Compressive strength of cement increased for that increase age .
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