Need for different concrete compressive strength for a different purpose
Based on the structural importance /occupancy of a building or any constructions,different grades of concrete with specific compressive strength are needed. Compressive strength of concrete is important to determine the amount of load, a given structural member, such as a floor slab, beam, column or foundation can hold. The strength in concrete is expressed in PSI that signifies the amount of weight it can support.
Concrete grade with compressive strength of 2500 PSI is used for a less critical application like residential slabs or sidewalks. For midrise buildings, we usually use 3000-4000 PSI Strength. With the engineered design, mixes of over 6,000 PSI used in specialized applications. So there are many different types, strengths & compositions of concrete. Each with characteristics that makes them perform for different applications.