Device and method for performing construction by taking marine sand as concrete fine aggregates

The invention discloses a device and a method for performing construction by taking marine sand as concrete fine aggregates. The device comprises a direct-current power supply and a template (1), wherein a sliding groove is formed in the inner surface of the template (1); a stainless steel plate (3) is arranged at the bottom of the sliding groove; a drawer plate is arranged in the sliding groove in a sliding-fit manner; a conductive net (11) is embedded in the inner side of a steel reinforcement cage (8) of a concrete structure (6); a positive electrode of the direct-current power supply is connected with the stainless steel plate (3) through a lead wire; and a negative electrode of the direct-current power supply is connected with the conductive net (11). The method comprises the following key steps: pouring and tamping the concrete aggregates; in 2-4 days, pulling out the drawer plate and sealing an opening of the sliding groove with a seal strip (5), so that the surface of the concrete structure (6), the seal strip (5) and the sliding groove form a sealed chamber; and filling the chamber with an electrolyte solution (7), so that chlorine ions in the concrete structure (6) are migrated to the electrolyte solution (7). According to the device and method, the chlorine ion concentration of the marine sand can be effectively reduced.