Evaluation of surface and durability characteristics of ready-mixed concrete under various curing conditions

Specific durability problems are often due to inadequate drying, resulting in poor hydration, increased permeability and reduced durability. This study examines the effects of two field-representative curing methods on the mechanical properties and durability of concrete grade G25, G30 and G35 ready mixed. Site Curing 1 (SC1), exposed to ambient conditions and Site Curing 2 (SC2) covered with plastic sheets for the first seven days. Significant durability metrics, including compressive strength, water absorption, volume of permeable voids (VPV), and sorptivity, were evaluated experimentally at 7, 28, and 56 days in different specimen zones. According to the results, the compressive strength of the concrete specimen, SC2 found to be improved values at 56 days. Grade G25 increased from 29.76 MPa (SC1) to 30.37 MPa, G30 from 38.88 MPa to 39.71 MPa, and G35 from 40.26 to 40.74 MPa. Water absorption decreased under SC2, G25 7–6.45%, G30 5.80–5%, and G35 4.51–4%. Volume of permeable voids also reduced, indicating a denser microstructure: G25 14.98–13.48%, G30 11.76–11.60%, and G35 10.31–8.25%. In addition, Sorptivity, reflecting capillary suction, decreased with SC2, G25 from 0.0097 to 0.0096 gm/cm², G30 from 0.0083 to 0.0085 gm/cm², and G35 from 0.0074 to 0.0062 gm/cm². These results emphasize that even under field conditions where traditional water treatment is difficult, simple on-the-spot treatment. Covering concrete with plastic sheets during the early treatment period can substantially enhance its strength and durability.