Construction method of concrete expanded head prestress anti-pulling anchor rod

The invention discloses a construction method of a concrete expanded head prestress uplift anchor rod. The construction method comprises the following steps of (1) movably pressing a steel sleeve on a pile end anchorage device, sinking the steel sleeve and the pile end anchorage device to a set depth, fixedly connecting a steel strand on the pile end anchorage device, and arranging a protective pipe fixed on an anchoring plate on the steel strand in a sleeve mode; (2) pouring fine aggregate concrete between the steel sleeve and the protective pipe; (3) repeatedly lifting upwards and inserting downwards the steel sleeve, enabling the fine aggregate concrete to flow out of the steel sleeve, and gradually forming a concrete expanded head, continuing pouring the fine aggregate concrete, and enabling a pile body with the set height to be formed in the steel sleeve; (4) pulling out the steel sleeve; and (5) excavating earthwork to a set depth, and tensioning and locking the steel strand after enabling the concrete