Form Ties Clause Samples
The 'Form Ties' clause defines the requirements and specifications for the devices used to hold concrete forms together during construction. It typically outlines the type, strength, spacing, and installation methods for form ties to ensure that concrete forms remain stable and properly aligned while concrete is poured and cured. For example, it may require the use of specific tie systems that can withstand certain pressures or mandate removal procedures to avoid damage to the finished concrete surface. The core function of this clause is to ensure structural integrity and safety during concrete placement, preventing formwork failure and ensuring the quality of the finished structure.
Form Ties. Embedded metal rods or sleeves used for holding forms shall remain embedded and shall terminate not less than 2½ cm from the face of the concrete. Embedded wire ties for holding forms will not be permitted in concrete walls which are to come into contact with liquids or where the concrete surfaces through which the ties would extend will be permanently exposed. Wire ties may be used for concrete walls to be plastered, stone faced or covered with earth. Wire ties shall be cut back at least 1.5 cm from the face of the concrete. The holes left in the concrete surfaces after cutting back of wire ties and removal of fasteners or holding rods or sleeves, and the insides of sleeves where sleeves are used, shall be completely filled with an approved non-shrinking mortar, and the mortar shall be finished flush with the concrete surfaces. This operation will be carefully carried out. The hole formed by the cutting process will be thoroughly cleaned and wetted before filling. Time mortar will be of damp, not wet, consistency. The patch will be properly towelled smooth to match the surrounding concrete surfaces and shall be thoroughly cured by keeping it moist continuously for at least three days. After the patch has hardened, the Engineer may require the patch and the adjacent concrete surface to be ground down smooth. Any patches that are loose or hollow on completion must be re-done. Water stop tie rods shall be used for liquid retaining structures. All costs for complying with the requirements of this Subsection shall be deemed to be included in the unit rates for formwork and shall not be paid for separately.
Form Ties. Factory-fabricated, removable or snap-off metal or glass-fiber-reinforced plastic form ties designed to resist lateral pressure of fresh concrete on forms and to prevent spalling of concrete on removal.
1. Furnish units that will leave no corrodible metal closer than 1 inch to the plane of exposed concrete surface.
Form Ties. Forms ties shall be of the removable or permanently embedded body type, and shall have sufficient strength and rigidity to support and maintain the form in proper position and alignment without the use of auxiliary spreaders. Cones, for the permanent embedded type shall be provided on the outer ends of each tie and the permanently embedded portion shall be at least 25mm back from adjacent outer concrete faces shall not be nearer the surface than the specified thickness of cover to the reinforcement. Form ties for indirect tutch with water walls, shall be provided with waterseal washers located on the permanently embedded portions of form ties, and approximately at the centre of the wall. Permanently embedded portions of form ties, which are not provided with threaded ends, shall be constructed so that the removable ends are readily broken off without damage to the concrete. The type of form ties used shall be acceptable to the Engineer. Form ties in exposed surface shall be uniformly spaced and aligned in horizontal and vertical rows.
Form Ties. Factory-fabricated, internally disconnecting ties designed to resist lateral pressure of fresh concrete on forms and to prevent spalling of concrete on removal.
2.1.12.1 Furnish ties with tapered tie cone spreaders that, when removed, will leave holes 25 mm (1 inch) diameter on concrete surface.
2.1.12.2 Furnish internally disconnecting ties that will leave no metal closer than 38 mm (1-1/2 inches) from the architectural concrete surface.
2.1.12.3 Furnish ties with integral water-barrier plates to walls indicated to receive dampproofing or waterproofing.