GSB Compaction test by sand replacement method

 Field dry density test by sand replacement method of GSB



why field dry density test ?

    GSB Compaction test by sand replacement method method  as per Indian standard code 2720 -part 28 :1974  give the result  compaction of GSB in natural and artificial . we known berry well bearing capacity and stabile capacity of GSB 

Testing Equipment  

  1. Weight  machine 
  2. dry density test cylinder  
  3. dry sand (sieve of sand passing in 600 micron and retained 300 micron)
  4. four peg for fixing the tray
  5. 200mm hole tray 
  6. oven
  7. GSB compaction field 
  8. knife 
Testing with example   
  • Maximum dry density =2.18gm/cc
  • optimum moisture content percentage =7.75%
  • Bulk density of sand Ys (gamma s) =1.35
  • Location-Road and Hard standing and bell mouth 

SL no

Observation and calculation

 

Determination

 

 

 

(1)

(2)

(3)

1

Depth of hole (mm)

200

200

200

2

Weight of wet material (Wm)

8968

8963

8970

3

Weight of sand + cylinder before pouring (W1)

15370

15372

15372

4

Weight of sand + cylinder after pouring (W2)

9098

9091

9089

5

Weight of sand in cone (W3)

1012

1012

1012

6

Weight of sand in hole (W4=W1-W2-W3)

5260

5269

5277

7

Volume of sand in hole V=(W4/γs)

3896.29

3902.96

3908.88

8

Wet density of material γw=(Wm/v)

2.30

2.29

2.29

9

Moisture content Mc =

6.21

6.15

6.13

10

Field dry density γd =

2.16

2.15

2.15

11

Percentage of compaction

99.08

98.62

98.62

12

Average percentage of compaction

 

98.77

 

Note: W1=Wet of weight material 
          W2=Weight of dry material 
          W3=Weight of empty container

Result 
   For road and hard standing minimum 98% compaction .it will be depend on type of structure.

  •  Field dry density test of sand replacement method not only for GSB it also  test for WMM and Soil etc
  • Field dry density test also called as cone test 
  • Before another layer laying on the material field dry density test is compulsory 
  • every week compulsory maintain resister and signature by the our department 
  • if compaction is not proper then water spray and mechanical roller rolling on the material 
  • after rolling field dry density test or cone test for last satisfying   

  



Comments

Post a Comment

Popular posts from this blog

Number of cubes for concrete as per is code

Image
 Number of cubes for concrete as per is code The minimum frequency of sampling of concrete of the each grade shall be in accordance with the following Quantity of concrete in the work in m 3 Number of sample 1-5 1 6-15 2 16-30 3 31-50 4 51 and above 4 plus one additional sample for each additional 50m 3      Characteristic Compressive Strength Compliance Requirement : Specified grade Mean of the group of 4 non-overlapping consecutive test results in N/mm 2 Individual test results in N/mm 2 M-15 >= fck + 0.825 x established standard deviation (rounded off to nearest 0.5 N/mm 2 ) or fck + 3 N/mm 2 whichever is greater >=fck – 3 N/mm 2 M-20 or above >= fck + 0.825 x established standard deviation (rounded off to nearest 0.5 N/mm 2 ) or fck + 4 N/mm 2 whichever is greater >= fck – 4 N/mm 2 Note : at least one sample taken
Read more

Silt Content Test as per IS Code

Image
Silt Content Test as per IS Code   Take a little sand and rub the same in hand, if palm remain clean it can be assumed that sand is free of silt that called is silt content test . It is hand test. Frequency of testing  Every 20cum or more frequency as decided by engineer in charge  Permissible limit   Acceptance standard -maximum permissible limit silt content shall not be " more than 8%"  as per is code 383 and as per CPWD specification  Note: (i) If silt content is more, corrective action taken should be noted in column 10 and silt content referred after such action  and recorded in the register.             (i) Fine aggregate contenting more silt than allowable percentage shall be washed so that the silt contents are with in prescribed limit for which nothing shall be paid  Test for silt content  The method for determining silt contents is as follows:     A sample of sand to be tested shall be placed with out drying in a 200 ml measuring cylinder the volume of sample shal
Read more

1:2:4 concrete mix calculator

Image
 1:2:4 concrete mix calculator concrete mix1:2:4 mins one is cement and two is sand(fine aggregate) and 4 is stone chip (coarse aggregate) coarse aggregate is two type 10mm and 20mm , 10mm will be 40 percentage and 20mm will be 60 percentage (for batter mixing) 1 cum wet volume =1.53cum dry volume Ratio is 1:2:4=1+2+4=7 cement :  1/7x1.53=0.22/0.035=6.24 Bag =313 kg (cement unit volume 1450=50/1450=0.035) Sand (fine aggregate): 1/7x1.53x2=0.44 cum=15.43cft Coarse aggregate: 1/7x4x1.53=0.87 cum = 30.87 cft 10mm :  0.87x0.40=0.35cum = 12.28cft 20mm : 0.87x 0.60=0.522 cum =18.43cft Water : water cement ratio as per IS 456 0.45 to 0.6 . we  assume 0.5 if plasticizer is not provided=313x0.5=156.5liter (slump maintain for 100mm , if water cement ratio is more and give strength is less so maintain minimum water cement ratio) if plasticizer is used then it will be 0.8 percent of cement =0.008x313 =2.54 liter Note: it is nominal mix M20 grade , its not design mix This type of nominal mix are u
Read more