Answer / viki

the 28 days cube strength for M-25 grade
concrete should be 25N/mm2.
acceptance criteria are some conditions defined by IS 456
regarding characteristic strength of concrete when the mix
is prepared on site.strength tests are performed on 4
blocks of concrete.avg strength is calculated.
then fck+3 means that the avg strength of the concrete mix
at the site should be 3N/mm2 greater than fck of mix.
i.e. mean strength= (fck+3)N/mm2
(refer IS456 CLAUSE 16)

Answer / p c debnath

fck +3 is the average/mean strength of four consecutive set
of cube

Answer / ashwani kumar

AFTER 28 DAY M-25 GRADE CUBE STRENGTH IS 25 N/MM2 , ITS
ACCEPTANCE CRITERIA IN THE IS-456, FCK+3 IS AVG
CHARACTERSRICK SRENGTH OF CONCRETE.

Answer / n pandian

The quality of concrete is acceptable only if both 1) and 2) are satisfied:
1) As per column 2 in Table 11 of IS 456 – 2000, mean of the group of 4 
non-overlapping consecutive test results shall be greater than or equal to
a) (fck + 0.825s)   N/mm2

where fck is the characteristic compressive strength of concrete;
s is the established standard deviation which is to be arrived for  
atleast 30 samples as early as possible at site. 


Note: In the absence of established standard deviation value assumed standard deviation values given in Table 8 of IS: 456-2000 may be used.

b) (fck + 3)  N/mm2 for M15 or (fck + 4)for N20 and above
a) or b) whichever is greater








2) As per column 3 in Table 11 of IS: 456 – 2000, Individual test Results (ITR) shall be greater than or equal to (fck - 3)  N/mm2.

what does gabion mattress means in stone pitching works

0 Answers  

---

satart to end steps by step process of building construction...? i want to planning theme accuretly

0 Answers  

---

where the corner reinforcement be placed in the rigid road pavement? can it be placed below the bottom main bar of double netting pavement?

1 Answers  

---

how to tie 10 legged stirrups

0 Answers   Khan,

---

weight of 32mm rod/m

8 Answers  

---

---

draw the sfd and bmd of catilever beam subjected to point load and udl. plot graphically the difference in deflection pattern of simply supported and cantilever beam subjected to point load.

2 Answers   Microsoft, TCS,

---

cinder filling or Brick Aggregate filling in sunken portion.which one is better

1 Answers   Chenab Valley Power Projects,

---

what we do if excavation is more than actual requirement

6 Answers   Airtel,

---

How do we calculate the weight of aggregates, sand and cement M 25 design mixfor 1 cum

1 Answers  

---

what will be the grade of concrete for PCC having ratio 1:4:8?

8 Answers   L&T, UIPL,

---

kindly mail me by attaching files , formats for quality checks of common building materials like cement , concrete , bricks , sand and aggregates plz send my email id- VMANDAL91@gmail.com

0 Answers   CPWD,

---

what is the meaning of 40/20 src

0 Answers  

---