A master's thesis by researcher Batool Abdul-Abbas Mahdi was defended at the Department of Materials Engineering, College of Engineering, University of Basrah. The research was conducted under the supervision of Prof. Dr. Safaa Abdul-Qadir Saleh and Dr. Safaa Khairi Jazza, and was titled: SUSTAINABLE FABRICATING OF BRICKS FROM RECYCLED THE CONSTRUCTION DEBRIS USING ACOUSTIC EMISSION TECHNIQUE

    Construction waste and debris resulting from ongoing construction and demolition operations pose a real environmental threat and deplete natural resources. Given the global trend towards sustainability and finding solutions to dispose of this waste through recycling, this study aims to manufacture sustainable bricks from wall waste containing both brick and cement mortar waste, along with a polymer binder (epoxy resin and polyester resin) as an alternative to using cement. A mixture of bricks and cement mortar waste-containing compounds with an epoxy-content (BM-EC) and polyester (BM-PC) binder was produced at a waste/binder ratio of 15 to 40 by weight. BM-EC showed a peak compressive strength of 41.7 MPa at 30% epoxy, while BM-PC achieved 91–94 MPa at 30–40% polyester, indicating that a polyester-based formulation can better bear loads than an epoxy-based option. The compressive strain of BM-EC increased from 7.5% to 40.5% with higher epoxy content, suggesting a ductile behavior as compared to the strains for BM-PC, which only varied by 10–13%, indicating brittle behavior. For both systems, with the increased binder content, thermal conductivity is decreased. Hardness increased with increasing polymer content (Shore D) from 79 for BM-EC and 88 for the BM-PC at a loading of 40%.
Acoustic emission analysis revealed improved properties of the manufactured bricks with increasing polymer binder content, leading to clear patterns of damage development. Low resin content produced few acoustic emission signals and low-frequency signals, indicating a sudden and brittle collapse dominated by interfacial separation and aggregate friction. Optimal and high resin content generated a large number of acoustic emission signals and higher peak frequencies, reflecting gradual micro-cracking in the base material and distributed damage prior to collapse. The displacement-acoustic emission curves confirmed the transition from catastrophic collapse at low resin content to controlled and damage-resistant behavior at high resin content. This is attributed to the polymer binders improving material homogeneity and reducing voids, thus enhancing the material's ductility.
The study highlights the potential for converting wall waste into high-performance polymer composites for sustainable building applications and shows that the type and content of resin critically control the strength, durability, and breakdown mechanisms of recycled polymer composites, with acoustic emission monitoring providing valuable real-time insight into the development of internal damage