Comparative Analysis of Rainwater use over Potable Water in the Production of Retarded Concrete

This study investigates the use of rainwater as an economical and environmentally sustainable alternative to potable water in the production of retarded concrete, utilizing sugar as a retarder. Two concrete mixes were prepared: a standard mix of cement, fine and coarse aggregates, and water, and a retarded mix incorporating 0.05% sugar by cement weight. Rainwater quality parameters, including pH (7.26), TDS (135 mg/L), and TSS (25 mg/L), were within WHO standards, confirming its suitability for concrete production. Workability tests using slump measurements showed consistent results for rainwater and potable water mixes, both achieving a slump of approximately 25 mm. Compressive strength tests at 28 days indicated an average strength of 23.72 MPa for potable water mixes and 22.67 MPa for rainwater mixes, with statistical analysis (t-value = 0.234, p-value = 0.823) confirming no significant difference between the two concrete mix. Setting time tests revealed a marginal 10% delay in initial setting for rainwater-mixed concrete when compared with the concrete mixed with potable water, attributed to its lower pH and specific mineral composition. These results demonstrate that rainwater can replace potable water in retarded concrete production without significant impacts on workability or compressive strength, offering an environmentally sustainable solution for construction, particularly in regions with limited access to potable water.