ABSTRACT
This chapter describes the most common test methods used to assess the strength of concrete and then discuss the factors influencing the results obtained from them. It discusses a more detailed consideration of the cracking and fracture processes taking place within concrete. The chapter explores strength under multiaxial loading conditions. Strength is probably the most important single property of concrete, since the first consideration in structural design is that the structural elements must be capable of carrying the imposed loads. The simplest compressive strength test uses a concrete cube, and this is the standard test in the UK and many other countries. A concrete cylinder, of the type used for compression testing, is placed on its side in a compression-testing machine and loaded across its vertical diameter. However, at these high values the paste itself is extremely fluid, and it is very difficult to achieve a homogeneous, cohesive concrete without significant segregation.
