A group of 35 tests on a given type of concrete had a mean strength of 4750 psi and a standard deviation of 320 psi. Does this concrete satisfy the requirements of ACI 301 (formally Section 5.3.2 in ACI 318-11) for 4500 psi concrete?
Solution
yes this data satisfies the requirement of ACI 301
ACI 301 sectiion 5.3.2 specifeid that average required compressive strength is determined as
from given data the required compressive strength is calculated as 5178.8 psi
which is greater then 4500 psi
also code stated that the compressive strength computed from the number of tests should be greater or equal to the compressive strngth of the given concrete for the acceptence but not less than it. and here we have strength greater than 4500 psi.
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Ecosystem Interactions Class Discussion Presentation in Blue Green Lined Styl...
Does Concrete Meet ACI 301 Code
1. A group of 35 tests on a given type of concrete had a mean strength of 4750 psi and a standard
deviation of 320 psi. Does this concrete satisfy the requirements of ACI 301 (formally Section
5.3.2 in ACI 318-11) for 4500 psi concrete?
Solution
yes this data satisfies the requirement of ACI 301
ACI 301 sectiion 5.3.2 specifeid that average required compressive strength is determined as
from given data the required compressive strength is calculated as 5178.8 psi
which is greater then 4500 psi
also code stated that the compressive strength computed from the number of tests should be
greater or equal to the compressive strngth of the given concrete for the acceptence but not less
than it. and here we have strength greater than 4500 psi.
specifeid compressive strength required average compressive strength(whichever is larger)
fc<5000 psi Fcr= fc + 1.34 standard deviation
f Fcr=fc+2.33 std deviation-500
