Abstract: This study explores the relationship between the water-cement ratio compressive strength, water absorption and flexural strength in M35 grade concrete, a widely utilized high-strength mix in the construction industry. The research investigates how the compressive and flexural strength of M35 grade concrete changes when the water - cement ratio ranges from 0.35 to 0.50 after 7,14 and 28 days curing period. In this experiment, fabricated 150 mm cubes of M35 grade concrete following the guidelines outlined in IS 10262:2009 (Guidance on mix design). The results revealed a decrease in compressive and flexural strength with an increase in the water-cement ratio. The highest compressive strength and flexural strength recorded after 28 days were 39.55 N/mm² and 3.35 N/mm² respectively at a water-cement ratio of 0.40. Water absorption test was also carried on a set of cubes at 28 days. But, the highest water absorption was recorded 0.83% at a water cement ratio of 0.45. This indicates the significant role of water-cement ratio in concrete production. By selecting an appropriate water-cement ratio, one can achieve an effective, cost-efficient, and suitably strong concrete mix. These findings are valuable for engineers in making informed decisions when using M35 concrete in construction projects, contributing to more resilient and environmentally-conscious building practices.

Keywords: Water cement ratio, Compressive strength, Flexural strength, Water absorption, M35, Design mix

| DOI: 10.17148/IARJSET.2023.10938