Effect of sea sand in the behaviour of fresh concrete partially replaced with M-sand

Abstract

The research paper aims to address the environmental challenges caused by uncontrolled river sand mining in various regions of the country. Indiscriminate mining has led to multiple issues, necessitating restrictions on river sand extraction, but these restrictions have also affected the building industry's stability. As a solution, exploring cost-effective alternative materials for cement production becomes essential to promote resource utilization and efficiency in the construction sector. The study focuses on using excavated marine sand as a fine aggregate to develop enduring and resilient concrete. Partial replacement of river sand and manufactured sand (MS) with dredged sea sand (DSS) is conducted to understand the benefits of the proposed concrete in terms of strength and durability compared to traditional concrete made of river sand (RS). This investigation is significant in the current scenario to assess the potential of DSS as a building material. The methodology employed includes grading analysis, assessment of flexural and compressive strength, evaluation of water absorption, alkalinity testing, rapid chloride penetration test, bond strength examination, and sorptivity assessment. The research aims to determine the behavior of fresh concrete with sea sand as a partial replacement for traditional sands, ultimately contributing to more eco-friendly and resource-efficient construction practices. The gradation has been done in three different proportions say 10, 20, and 30%. The results indicate that for all the mixes the compressive strength of the cylinder shows an average value of 0.83 times the strength of the cubes, while the flexural strength value (K√fck) shows an average of 0.69 times the strength of the cubes for all the mixes. RCPT and Water Absorption results show an average value of 1775 and 3.96 respectively which is within the limit specified. The addition of MS improves the alkalinity of concrete and the result was in accordance with ASTM D 4262. The bond strength increases with an increase in the replacement of sea sand and sorptivity decreases with an increase in the replacement of sea sand. This is indeed a study of the strength of concrete and toughness using MS as a partial replacement for dredged sand. The analysis shows that a 30% replacement of dredged sea sand with MS does not impact the overall strength of concrete, ensuring satisfactory strength and durability.