Formwork for Concrete Beams
Formwork for beams consists of a bottom and two sides in addition to their supporting elements. The bottom is typically made of ply-
wood or lumber sheathing with thickness of 0.75 in. (19.0 mm) or 1 in. (25.4 mm). The bottom is supported by and fastened to horizontal joists. Beam sides are also made of plywood or lumber sheathing.
Once the bottom of the beam form is constructed and leveled, one side of the beam is erected first with holes drilled into it for installing the tie rods. Tie rods are steel rods that hold the two sides of the beam together. After the first side of the beam form is erected, the reinforcement is placed inside the beam and then the other side of the beam is erected. Tie rods are then inserted into all holes and the walers on both sides of the beam. The tie rods’ function is to resist the horizontal pressure resulting from the freshly placed concrete and thus keep the sides of the beams in their proper location. Tie rods are fastened to the sides of the beam and also to vertical walers and clamps. To further support the two sides of the beam and hold them together, additional temporary spreaders are fastened at the top of the beam sides at regu-
lar distances. Temporary spreaders may be made from wood or steel.