Application of photonics in determining the strength characteristics of composite concretes

For the sustainable developments of the construction industry, there is a growing need for reducing the usage of the rapidly depleting natural resources in building concrete structures. Re-utilisation of conventional wastes such as different grades of polymeric particulates derived from municipal wastes is being explored as a partial replacement of natural aggregates in making concretes. This poses new challenges to researchers as methods to evaluate the effects of new host particles on the mechanical strength characteristics of composite concretes at microscale and their subsequent effects on their bulk strength are not yet well established. In this research work, municipal polymeric wastes in various forms and fly ash from incineration of municipal solid wastes are used together as secondary raw materials for the preparation of concrete mixtures. The influence of various forms of polyethylene (PE) substitution on the local and global shear stress distribution are sensed whole-field on the cylindrical and notched concrete beams using the principles of photonics. The generic methodology reported here would be of great interest in measuring the strength of concretes and other cementitious composite materials under different loading environments in future. Furthermore, an improved understanding on both microscale stress (/strain) evolution and macro strength characteristics could form a basis to develop new strength theories of composite concretes.