Concrete Mix Calculation

1. The concrete mix proportions for the batch were calculated before the beginning of the lab by a select few group members. Calculations were done with goal of the having the greatest early strength as reasonably possible. To accomplish this, the accelerator agent of calcium chloride was added at a proportion of 2 Ib. of calcium chloride to every 100 Ib. of cementitious material. This ended up being 0.483 Ib. of accelerator. The physical properties, like specific gravity and percent absorption, of the course and fine aggregates were provided. At first the amounts were calculated for a cubic yard of concrete, and then they were adjusted for the amount needed for the lab. Two additives were added to increase ductility. These two additives were ¾” wire segments from 18 gauge copper audio cable and 1 1/2” segments of braded fishing line. The amounts were not calculated be merely added based on the availability of each material. A total of 71.5g of copper wire and 8.7g fishing line …show more content…
A slight amount of water was added and then the mixer was turned on. With the mixer on, the cement powder and water were added in small, alternating amounts. This was to prevent the powder from flying out of the mixer. Once all of the water and cement was added, the copper fibers and fishing line segments were added. They were added by sprinkling them in small amounts to prevent clumping. Once the fiber was added, the water reduce WRDA®82 was added at the group’s discretion until a reasonable workability was reached. A total of 5 fl. oz. was added by the group.
Once the mixing was complete the fresh properties test begun. The first test that was complete was a temperature check of the concrete. With the concrete still in the mixer, a thermostat was inserted into the mix. The thermostat remained in the fresh concrete until it came to a steady temperature ready. The batch was found to have a temperature of 75 degrees