FLYASH IN CONCRETE

•C’+ F=1.1 C•= RATIO

EXAMPLE OF IS CODE METHOD

DURABLITY REQUIREMENT TABLE

CAN BE FROM EXPERIENCE ALSO

STEP II : w/c*=0.45

W/C RATIO = 0.45

IF WE USE A P/SP THEN WATER CAN BE REDUCED TO 75%W= 126 KG AND CEMENT = 126/0.45= 280 KG

IF WE USE A P/SP THEN WATER CAN BE REDUCED TO 75%W= 126 KG AND CEMENT = 126/0.45= 280 KG FIND OUT Fagg and Cagg

Find out the constituents if we use 25% Fly AshFROM IS CODE

CORRECTIONS FOR ABSORPTION OF WATER IN THE AGGREGATES

•To be included in the calculations as per IS code. •This is a home work. •Will be discussed in next class by Student Offrs.

DOE METHOD

VALID FOR BRITISH CONDITIONS

Cast a trial mix with w/c=0.50 and test it after 28 daysFor selection of curve

After selection of curve locate Tgt Mean Str and find out w/C ratio

IN CASE CA IS CRUSHED AND FA IS NOT CRUSHED (NATURAL)

If Our Wet Density is 2450 kg/m3

W= 195 kg/m3

C=440 kg/m3

Aggregate content 2450-635= 1835 kg/m3

FA=540 kg/m3

35% of total aggregate

k factor : efficiency of pulverised fly ash k=0.30

Cylinder str=0.8 times cube strengthM25 STR WILL BE M20

Fc+ 10.9

DRY-RODDED WEIGHTTHE WEIGHT PER UNIT VOLUME OF AN AGGREGATE WHEN COMPACTED DRY UNDER STANDARDIZED CONDITIONS.

Not a correct statement