Age strength of concrete

Strength of concrete on perticular required day can be find out by following formula as per SP 24 :-

t/(a+bxt) x fck

Where,

t, is the age in days
a, is value = 4.7
b, is value = 0.833
fck, is compressive strength of the concrete

Example:

To find compressive strength of concrete on 3rd day , fck is 35 N/mm2

Implementing above formula

t/(a+bxt) x fck

3/(4.7+0.833x3) x 35

= 14.59 N/mm2

Which is 15/35x100= 41.67% of fck

Comments

Post a Comment

Popular posts from this blog

Softening point IS 1205 1978

Hot the bitumen in oven or on hot plate at 75oc – 110oc above softening point say at 90oc + softening point of bitumen and pour it in the rings Balls weights 3.5 gms and dia of Ball is 9.5 mm After 30 min in air place it in beaker 600 ml and keep it in apparatus the temp of Distilled water should be 0oc and heat it at the rate of 5oc /min place the thermometer and note down the temp when balls touched the lower plate. For CRMB 55 the Softening point is 55oc For CRMB 50 the softening point is 50oc And For CRMB 60 the Softening point is 60oc For Bitumen having the Softening point above 80oc use Glysrine in place of water and the starting temp should be 35oc In IS 1205 1978 the water bath is written to perfotm the test first keep the beaker with sample in water bath for 15 min at 5oc and then allow to rise the temp at 5oc per min.
Read more

Shear Strength of concrete

Concrete subjected to bending and and shear stress is accopanied by tensile and compressive stress. The shear failure are due to resulting diagonal tension. The shear strength is generally 12 to 13 percent of compressive strength.
Read more