Grant: Collaborative Research and Development Grants

Unreinforced masonry (URM) is used in a number of structures including buildings, bridges, driveways, parking areas, manufacturing plants, blast furnaces, mining appurtenances and fencing. Unfortunately, due to missed maintenance and lack of durability in materials themselves, many masonry structures are rapidly deteriorating and are rendered unsafe. To worsen the situation, recent earthquakes have demonstrated that URM structures perform poorly under seismic conditions. The existing repair and strengthening technique are unfortunately neither cost-effective nor sustainable and perform unsatisfactorily. Much further research is required in this area. The proposed project aims to develop Sprayable, ECO-FRIENDLY DUCTILE CEMENTITIOUS COMPOSITES (EDCC) for repair and strengthening of masonry structures. Sustainable binders based on ordinary Portland cement, geopolymers and MgO cements and recycled sand will be investigated. Fiber reinforcement will be optimized to obtain EDCC with a minimum strain capacity of 3% in tension. EDCC will be optimized for spray rheology, setting and hardening characteristics, in-situ mechanical response, fatigue and impact endurance, durability and bond with old masonry. The effectiveness of scrim reinforcement in EDCC will be assessed. The performance of Sprayable EDCC will be investigated in both mid-scale and full- scale masonry structures and involve both stone wall masonry representing heritage construction and concrete and clay brick masonry representing modern construction. Appropriate design guidelines for rehabilitation will be developed. Finally, two fully monitored strengthening demonstration projects - one a school and another a heritage structure - will be carried out. The team will strive to promote higher learning in masonry design and retrofit technologies in collaboration with the industry through courses, workshops and seminars.