CMS-9532061 The failure of systems composed of brittle materials such as concrete and rock is controlled by the development and accumulation of microdefects referred to as damage. Macroscopically, damage reduces the elastic stiffness, causes anisotropy, and reduces the load-carrying capacity of the material. The objective of this research is to identify damage through the acoustic emission (AE) technique and to use this measurement of damage to assess the onset of failure in systems composed of rock-like materials. The accumulation of damage has a fundamental importance for defining the behavior of brittle materials in terms of their strength. In addition, the importance of detecting brittle failure of structures is brought on by the use of high-strength concrete, by the urgency in preserving classical monuments, and by the need to evaluate aggregate durability. It is claimed that a quantitative analysis of damage can be applied to components of full-scale structures by simplifying the deconvolution process for determining source mechanisms and orientations. The impact of this research on the infrastructure will be the real-time monitoring of systems to evaluate damage in the form of cracks, voids, loss of bond, and other detrimental processes leading to failure. ***