The columns for a building in central Long Island are to be madeof concrete with the
following specifications:
• Design compressive strength: 4500 psi, based on 20 tests ofsamples having a
standard deviation of 600 psi
• Non-air entrained, and clear space between rebar: 1.5 inch
• Fine aggregate: G = 2.350, FM = 2.5
• Coarse aggregate: G = 2.65, bulk density = 3000 lb/cy
Determine the following:
i. w/c ratio, largest nominal max. coarse aggregate size, % coarseaggregate, % air
(2 pts.)
ii. weight of water, weight of cement, and weight of coarseaggregate to be used per
cubic yard of concrete (1 pt.)
iii. weights and volumes of water, cement, air, coarse aggregate,and fine aggregate
needed to mix a 15-yard batch of this mix (3 pts.)
Also:
• Specify two admixtures that might be used for this mix based onthe provided
information, and why to use it. (2 pts.)
• Why we might create a composite of this concrete poured into aPVC (polyvinyl
chloride) sleeve for these columns? (Give specific reasons based onthe
characteristics of the individual materials.) (2 pts.)
