Load support device of cardboard material. The load support device includes at least one block element having a polygonal shape, at least two vertical walls, a horizontal base, an upper load receiving surface, and at least one locking fold arranged in at least one corner of the block element. The locking fold is formed by at least two lateral vertical contact sections of the block element such that the block element, in an area of the locking fold, provides load support and the locking fold functions as reinforcement. A reinforcing locking wedge element made of a same material as said at least one block element is utilized and includes a base and four portions. At least one of the four portions is structured and arranged to strengthen and lock a position of the at least one locking fold.