The environmental impact of making conventional Portland cement (OPC) is now making it more important to find sustainable ways of turning industrial by-products, such as fly ash, from waste into materials that can be used to make concrete that can withstand the elements while supporting building structures. This research project examined the feasibility of using fly ash as a substitute for OPC in combination with olive waste ash (OWA) for producing concrete made from ternary (mixed) products of OPC, OWA, and fly ash. Concrete was prepared with different combinations of binders: one consisting of only OPC (control), one consisting of a binary mixture of OPC and fly ash, and one consisting of a combined mixture of OPC with olive waste ash and fly ash as replacements for conventional concrete binders. The mechanical qualities were tested using compressive strength development and hardness (evaluated by rebound hammer tests) measures; the transport-related durability characteristics used for evaluations were absorbency and apparent porosity values from the tested mixtures. Results are presented at curing ages of 3, 7, 21, 28, and 56 days. The ternary blended system exhibits synergy, realizing improved later-age strength and increased surface hardness, as well as reduced absorption and porosity, compared to OPC-only and binary mixtures. Such improvements are in accordance with the combined filler, pozzolanic, and microstructural refinement effects of FA and finely processed biomass ash. The results affirm that recycling olive oil waste ash, a pressing environmental concern in Jordan and many Mediterranean countries, along with industrial fly ash, can yield low-carbon concrete with satisfactory durability for structural and infrastructure uses.