This document discusses several concepts related to the behavior of materials under load including: 1. Modules of rupture describes the ability of a material to resist deformation due to an applied load using an equation involving stress and bending moment. 2. Fatigue is deformation due to cyclic loading such as repeatedly bending a steel rod. 3. Creep is slow deformation over time under a sustained load due to mechanical stress. 4. Shrinkage is the reduction in size of a material like concrete due to drying or loss of water over time with no external loads.