This chapter covers the importance of properly making and curing concrete test specimens in both the field and in the laboratory. This chapter was previously authored in ASTM STP 169B [1] by R. F. Adams and in ASTM STP 169A [2] by T. B. Kennedy. In ASTM STP 169 [3], the information was in a section of the chapter, Static and Fatigue Strength, authored by Clyde E. Kesler and Chester P. Siess.