Concrete is one of the most widely used construction materials worldwide. Its conventional production relies on the consumption of large quantities of cement, natural aggregates, and water, leading to the depletion of natural resources and increased environmental impacts associated with the construction materials industry. With the growing emphasis on achieving sustainability in the construction sector, the use of recycled materials in concrete production has become an important approach to reducing waste and improving resource efficiency while maintaining the required engineering properties. This study aims to improve concrete mix design using recycled materials by investigating the possibility of replacing some conventional concrete components with alternative materials obtained from waste recycling, such as recycled concrete aggregate, glass powder, recycled rubber, and agricultural ash. Several concrete mixtures can be prepared using different replacement percentages, along with a reference mixture containing conventional materials, to compare the results and determine the effects of recycled materials on concrete performance. The study focuses on developing concrete mix designs by selecting appropriate proportions of cement, water, aggregates, and recycled materials, while considering the water-to-cement ratio, aggregate gradation, and workability. Chemical admixtures, such as superplasticizers, can also be used to improve workability and reduce the required water content without negatively affecting concrete strength. The evaluation process includes conducting several laboratory tests to determine the fresh and hardened properties of concrete, such as the slump test for assessing workability, compressive strength, splitting tensile strength, flexural strength, density, and water absorption. These tests can be performed at different curing ages, such as 7, 28, and 56 days, to investigate the effects of recycled materials on concrete strength development and durability over time. The effectiveness of concrete mixtures containing recycled materials depends on the physical and chemical properties of these materials, their replacement percentages, and their compatibility with other mixture components. For example, using recycled concrete aggregate may increase water absorption due to the presence of adhered old cement mortar, while finely ground glass powder may contribute to improving the microstructure of concrete because of its pozzolanic properties. Recycled rubber may also affect concrete strength and its behavior under loading, making it necessary to determine suitable replacement percentages to achieve the desired performance. It is expected that improving concrete mix design using recycled materials will contribute to producing concrete with acceptable mechanical properties and better environmental performance, provided that suitable materials are selected and optimum replacement percentages are determined. Furthermore, optimizing aggregate gradation, reducing internal voids, and using appropriate admixtures may help compensate for some of the negative effects associated with incorporating recycled materials. The significance of this study lies in developing a scientific approach for producing sustainable concrete mixtures based on the reuse of industrial, construction, and agricultural waste. This can contribute to reducing the consumption of natural raw materials, minimizing waste quantities, decreasing dependence on conventional cement, and supporting circular economy principles and environmentally friendly construction practices. In conclusion, improving concrete mix design using recycled materials represents an important approach toward developing sustainable construction technologies. Achieving this requires investigating the effects of different types of recycled materials and their replacement percentages on the mechanical and physical properties of concrete, as well as determining the optimum mix design that achieves a balance between strength, durability, workability, cost, and environmental impact.