**1. Introduction**

In recent years, due to high demand of construction materials, some actions have been developed such as extraction of large amounts of raw materials, development of new materials, use of recycled and demolition waste; all of them generating higher costs and environmental problems. Special attention on the development of economic and ecological materials through the use of waste materials has generated a novel research area. Moreover, in order to reduce the ecological impact, many efforts have been made for reducing the consumption of nonrenewable resources in the production of construction materials, one of these is the production or addition of waste or recycled materials into the mixture in substitution of the common mineral aggregates, taking care of the final quality that includes parameters such as resistance, modulus of elasticity, and durability, among others.

Although some advantages are obtained when adding waste or recycled materials for improvement of the toughness of construction materials, they present some disadvantages such as lower values on the compressive strength, which should be attended. One alternative is the use of gamma radiation. Recent works have studied the effects of gamma radiation on compressive properties; in one of them, the results show more resistance to crack propagation; moreover, compressive strain and the elasticity modulus depend on the combination of the particle sizes and the radiation dose. This chapter attempts to use gamma irradiation as modifier of the physicochemical properties of waste and recycled materials, and use them as reinforcements of construction composites and as a consequence improve their mechanical properties. This chapter promotes the use of waste and recycled materials in the construction industry, as one alternative for reducing environmental pollution.
