The invention relates to open-spandrel structural member. It includes open-spandrel form and bottom board. They are joined to entirety. The bottom board is set at least two cavity shuttering. The lateral surface of open-spandrel form is formed side formwork. Its feature is that the open-spandrel form is covered by at least two upper and lower bottom boards. It can be applied to hollow storey cover, room cover, wall body, foundation mat and hollow bridge of current cast reinforcement concrete or pre-stressed reinforcement concrete, especially for hollow mushroom floor. |