In the unloading, handling, and storage of structures, care should be exercised so as not to damage the surface or surface coating, or deform the members. Bare wire rope or steel chains should not be used for handling without adequate protection of the surface. Structural members should not be dumped, dragged, rolled, dropped, nor used as loading or unloading skids or blocking.
Heavy members should not be stacked on top of lighter members. The maximum weight of material bundles should not exceed a specified weight, typically 1600–1800 kg (3500–4000 lb), to facilitate handling and unloading. Components with dissimilar finishes should not be stored over one another to minimize discoloration of the lower members.
Care should be taken to ensure proper blocking, stacking, and handling of concrete members. Refer to the structure drawings and instructions to verify correct lifting methods, replacement of support blocking, and stacking limitations.
It is very common for concrete poles to require a two-point pickup due to the weight and possible long lengths. Identifying the correct blocking locations is important to eliminate the potential of overstressing the member. The constructor should verify correct blocking and number of possible layers for stacking to avoid damage to concrete members lower in the stack.
All members should be placed on wood blocking or other suitable material to ensure that the material to be stored is not in contact with the ground. Blocking should also be used to separate layers of stacked material.
It should be noted that oak wood blocking or oil-treated timbers can bleed and stain a structure finish. Members should be supported in such a manner as to prevent bending and distortion as well as to allow water to drain from the material.

Failure to provide for proper drainage of stacked, galvanized steel components could result in the formation of “white rust.” White rust (zinc oxide) forms when two galvanized surfaces are closely nested for an extended time without adequate ventilation. Ingress of water between the surfaces forms an electrolytic cell which may, in time, erode some of the zinc layer.
The white rusting action will stop after exposure to air. When extended transport or storage is anticipated, either of the following two methods can be used to prevent oxide formation:
a) Spacers may be placed between the nested pieces to ensure adequate ventilation.
b) Galvanized members may be treated with a solution which will inhibit oxide formation for six months to one year.

Weathering steel fasteners, though rarely used on concrete poles, and other materials subject to deterioration should be protected from the elements during storage.

During the course of the project, the material yard should be kept relatively neat and clean and the growth of vegetation kept to a minimum. Good housekeeping minimizes damage and loss of material in the yard, facilitates material handling and periodic physical inventories, and complies with environmental considerations.

If delivery of material is made initially to the structure site for storage, care should be taken to avoid interference with foundation construction, access roads, or drainage. Truck delivery of complete structures from the manufacturer directly to the structure site can be advantageous since it eliminates at least one unloading and loading cycle.
However, security of material stored at a structure site is minimal and the subsequent loss of time due to missing items can result in significant construction cost increases.

Related post

No comments:

free counters