Question

7) You are working on a concrete mix design that requires each cubic yard of concrete to have a 0.45 water–cement ratio,2100 lb/yd3 of dry gravel, 250 lb/yd3 of water, and 5% air content. The available gravel (NMS = ¾”) has a specific gravity of 2.6 , moisture content of 2.5% and absorption of 4.5%.The available sand has a specific gravity of 2.4, a moisture content of 2.5% and absorption of 2%. Air entrainer is to be included using the manufacturers specification of 0.1 fl.oz / 1% air / 100 lb cement. For each cubic yard of concrete needed on the job, calculate the weight of cement, moist gravel, moist sand, and water that should be added to the batch. Summarize and total the mix design when finished.

Answer 1