Low Cement Concrete (LCC), characterized by a cement content below 300 kg/m3, is emerging as a sustainable alternative in concrete production, addressing both environmental and economic concerns. This study investigates LCC with a cement content of 250 kg/m3, significantly lower than conventional concrete, by optimizing aggregate volume fractions using an experimental particle-packing method. Aggregates were separated based on sieve sizes, and their specific gravity and absorption were measured. Through compaction data analysis, an optimal aggregate volume ratio of 84% was identified. This ratio was then used in the volumetric mix design of LCC to minimize paste content while ensuring workability. To further enhance the paste content, CaCO₃ powder was added, along with superplasticizers and viscosity-modifying admixtures, resulting in improved workability and mechanical properties. Fresh concrete produced had a slump of 3–13 cm, with a paste volume of 16-18% of the total mixture. At 28 days, LCC with 10%, 15%, and 20% CaCO₃ exhibited higher compressive and flexural strengths compared to control concrete, indicating its potential as a viable material for sustainable construction. These findings demonstrate LCC's capacity to offer enhanced mechanical properties with a lower environmental footprint.