In recent years, ultra-high-strength concrete of 300 N/mm² has been used for precast members. The authors developed the ultra-high-strength grout that can reach the strength of 300N/mm² with heat curing at 90℃. In this paper, we report the experimental results of proposed heating methods for the precast member joints using heating sheets externally surrounding. With the target surface temperature of the heating sheets at 140〜180℃, the temperature at the center of the joint achieved more than 90℃, enough to obtain the designed strength.