Aci Concrete Mix Design Example 4j4r4u

CE 60 Thu ursday Lab 2012 Seyoon Y Yoon

ACI Mix M Design Ex xample - Condiitions Targeted d 28-day com mpressive strrength: 4000 psi (lb/in2) Targeted d slump: 3 in Maximum m size aggreegate (MSA)): 3/8 in Cement: Type I, BSG G (Bulk Speccific Gravity y) = 3.15 Fine Agg gregate (FA)): BSG = 2.6 67, moisture = +2.37 % ((over-saturatted), finenesss modulus = 2.9 Coarse Aggregate A (C CA): BSG = 2.68, 2 moistu ure = -0.81% % (dry) dry-rod dded unit weeight (DRUW W) = 103 pcff

- Steps Step 1. Estimation E of o mixing water w and airr content baased on you ur targeted sslump and M MSA.

Therefore, the water requirementt is 385 lb/yd d3 and the reecommendedd air contentt is 3 %

Step 2. Selection S of water/cemeent ratio.

Thus, thee estimate fo or required w/c w ratio to give a 28-dayy strength off 4000 psi is 0.57

Step 5. Calculation C of cement content. c weight of cement =

385 lb/yd 3  675.44 lb//yd 3 0.57

Step 6. Estimation E of o coarse ag ggregate con ntent.

2.9 0.45

The volu ume fraction of dry-roddeed CA is 0.4 45 CA will occupy: o 0.45 5  27ft 3 /yd 3  12.15 ft 3 / yd 3 CA weig ght = 12.15 ft3/yd3 × 103 lb/ft3(DRUW W) = 1251 lb lb/yd3

Step 7. Estimation of Fine Aggregate Content Water = 385 lb / 62.4 lb/ft3

= 6.17 ft3

Cement = 675.44 lb / (3.15 × 62.4 lb/ft3) = 3.44 ft3 CA = 1251 lb / (2.68 × 62.4 lb/ft3)

= 7.483 ft3

Air = 3 % × 27 ft3

= 0.81 ft3 Total

= 17.90 ft3

Thus, FA = 27 – 17.90 = 9.1 ft3 FA weight = 9.1 ft3 × (2.67 × 62.4 lb/ft3) = 1516 lb/yd3

SSD lbs (0.01 yd3) Water = 3.85 lb

Cement = 6.75 lb

FA = 15.16 lb

Step 8. Moisture Correction FA: 15.16 + (2.37/100) × 15.16 = 15.52 lb CA: 12.51 + (-0.81/100) × 12.51 = 12.41 lb Water: 3.85 - (2.37/100)×15.16 - (-0.81/100)×12.51 = 3.58 lb Cement: 6.57 lb

CA = 12.51 lb