English Abstract
This research investigates the development and application of one-part alkali activated concrete (OPAAC) as a sustainable alternative to Portland cement concrete. The study encompasses three primary areas: material characterization, mechanical properties, and structural performance in a novel application.
Firstly, a comprehensive methodology for designing AAC mixtures was established using the ACI method as a foundation. The influence of key parameters, such as water-to-binder ratio, aggregate size, and activator dosage, on workability, setting time, and compressive strength was systematically evaluated. The results led to the development of predictive models for AAC strength and a step-by-step design procedure.
Secondly, the engineering properties of OPAAC were explored. The research focused on long-term strength development, workability, tensile strength, modulus of elasticity, and stress-strain behavior. The findings demonstrated the superior performance of OPAAC compared to conventional concrete, with improved mechanical properties. Predictive equations for tensile strength and modulus of elasticity were proposed.
Finally, to extend the practical application of OPAAC, the thesis also examined the performance of demountable steel-concrete composite beam-to-column joints incorporating precast geopolymer concrete slabs. Four full-scale joints were subjected to cyclic loading tests and different performance and characteristics such as crack patterns, failure modes, moment-rotation responses, force-displacement curves, strain distributions, shear connector slippage, and energy dissipation were evaluated. The influence of bolted shear connector diameter and slab reinforcement ratio on the structural behavior was assessed, revealing enhancements in joint rotation, stiffness, bearing capacity, and energy dissipation. The joints met the deformability and rotational capacity requirements of Eurocodes 3 and 4, and qualified as special moment-resisting connections per AISC341, demonstrating their suitability for seismic applications. ABAQUS software is used to develop finite element models of the composite joints investigated, and is shown to accurately simulate their observed structural behaviour.
Overall, this research provides a comprehensive understanding of the properties and potential applications of one-part slag-based geopolymer concrete (SBGC), paving the way for its effective implementation in sustainable construction practices.
