Ordinary Concrete Grade

 Ordinary Concrete Grade

Ordinary grade concrete is not used for M40 & M25, as it includes only M10, M15 and M20.

As per  IS 456:2000



                                        Type of Grades concrete

 

 

        Group

 

         Grade         Designation

Specified characteristic compressive strength of 150mm cube

At 28 days (N/mm2)

     1

2

3

Ordinary concrete

M10

M15

M20

10

15

20

Standard concrete

M25

M30

M35

M40

M45

M50

M55

M60

25

30

35

40

45

50

55

60

High strength concrete

M65

M70

M75

M80

M85

M90

M95

M100

65

70

75

80

85

90

95

100

  •               In the designation of concrete mix M refers to the mix & the number specifies characteristic compressive strength of 150mm size cube at 28 days, expressed in N/mm2.

  •                         For concrete of grades above M60, design parameters given in the standard may not applicable & the values may be obtained from specialized literatures & experimental results.


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