In this paper, removal time of side form from concrete using OPC(ordinary Portland cement) and FAC(fly ash cement) are proposed by appling logistic model, which evaluates the strength development of concrete with maturity. W/B, types of cement and curing temperatures are adapted as test parameters. The estimation of strength development by logistic model has a good agreement between calculated values and measured ones. As for the removal times of form works suggested in this paper, as W/8 increases, curing temperature decreases and fly ash is used, removal time of side form is prolonged. Removal time of form from concrete using OPC suggested in this paper is shorter $2.5~3.5$ days than those of KASS-5 (Korean Architectural Standard Specifications-5) in the range of over $20^{circ}C$. And in the range of $10~20^{circ}C$ removal time of form is shorter than that of KASS-5 by as much as $4~4.5$ days. The use of FAC results in an increase in removal time of form compared to that of OPC by about 1 day.