1) Inexpensive filler 2) Improved workablility 3) Dimensional stability 4) Increased wear resistance 5) All of the Above
All of the above is the correct choice. Basic concrete consists of the paste (Portland cement & water), fine aggregate (sand) and coarse aggregate (crused stone or gravel). Aggregates can account for up to 75% of the volume of concrete and are considerably less expensive than the Portland cement. They also play a substantial role in determining workability, strength, dimensional stability, and durablity of the concrete.