Preparing bonded anchors for a steel building foundation

The design should specify the correct system, rods, depth and installation conditions. It must be checked whether the solution covers cracked or uncracked concrete, as required. Substituting the mortar with another of similar description is not automatically permissible.

Check the concrete class and condition, the element thickness and the actual dimensions. The position of the reinforcement and any existing damage are important. Do not drill randomly through structural rods. Any collision must be resolved with the person responsible for the design.

The edge distance affects the behaviour of the anchorage. Shifting the hole by a few centimetres can change the conditions relative to the calculations. If the foundation was constructed with a deviation, the problem should not be concealed by arbitrarily reaming the column base. An assessment of the connection is required.

It is advisable to relate the measurement of the column axes to a common reference point. Measuring each base separately from an uneven concrete edge can transfer its deviations to the entire frame.

The hole dimensions depend on the mortar, the rod and the substrate. There is no single rule allowing any arbitrary allowance to be added to the rod diameter. A hole that is too large or too shallow may not correspond to the intended arrangement. The requirements must be read for the specific system.

Also check the permitted drilling method and moisture conditions. A dry, wet and water-filled hole need not be treated the same. Not every product covers all situations. Selection should account for the actual condition, not the assumption of a perfectly dry foundation.

Dust can weaken the bond between mortar and substrate. Cleaning is therefore carried out in accordance with the procedure of the given system. The right tools and the sequence of operations matter. One number of blows and brushings should not be taken as the rule for every anchor.

Before application, check the condition of the brush and equipment. A brush that is too small may not clean the walls of the hole as required. If a specific method of extraction during drilling is specified, its conditions must be maintained. Shortening the work without confirmation is not an equivalent method.

Check the expiry date, storage conditions and proper mixing of the components. Application and insertion of the rod must take place within the specified working time. The method of filling the hole should limit voids, in accordance with the kit instructions.

The curing time before loading is specified separately. It depends, among other things, on the substrate temperature and the type of mortar. The time from a warm day must not be transferred to cold concrete. Until curing is complete, the rod should not be moved or loaded contrary to the system requirements.

The base must have provision for bearing and a method of transferring forces. If the design includes grouting, its material and execution conditions must be maintained. Nuts and washers are selected to suit the solution. Tightening should correspond to the required values and sequence.

A large unevenness should not be compensated for with a random stack of washers. The organisation of the frame assembly and its temporary stability are also important. An anchor that has not reached the specified parameters must not be treated as a finished point of load transfer.

Document the system used, the installation conditions and the actual position of the anchors. Check compliance with the design and the time before loading. In the event of discrepancies, an assessment is needed, not just painting over the connection. Inspection should take place before the next stage that will impede access.

Acceptance tests are carried out when they arise from the design or the adopted procedure. They do not replace the correct selection of the entire foundation. Well-prepared anchoring allows the calculations to be linked to the actual execution. This is important especially for a hall whose envelope will later transfer wind loads to the frame.