Cert III Steelfixing flashcards

34 cards. Read the term and the definition here. The deck at the top of this page is optional.

Nominal bar diameter

The designated size of a reinforcing bar in millimetres, used to calculate mass, lap length and bend dimensions. It is a nominal value, not a measured average, and identifies the bar on drawings and bar schedules.

Concrete cover

The distance from the outer concrete surface to the nearest surface of the reinforcement. It protects steel from corrosion and fire, and must never be reduced below the minimum shown on the drawings.

Bar mass formula

Mass per metre in kilograms equals 0.006165 multiplied by the square of the nominal diameter in millimetres. A 12 mm bar therefore has a mass of about 0.89 kg per metre.

Lap length

The length over which two bars overlap so that force transfers from one to the other. The designer sets it from concrete strength, bar size, bar type and stress condition, and laps are staggered.

Staggering laps

Arranging lapped bars so that laps in adjacent bars do not occur at the same cross-section. This avoids a weak plane in the member and spreads the load transfer along the reinforcement.

Standard hook

A bar end bent through a specified angle and extension, formed around a mandrel of specified diameter. The geometry is fixed by the detailing standard because tighter bends can fracture the bar.

Tying wire

Soft annealed wire used to hold bars in position until concrete is placed. It is not counted as structural reinforcement, and wire tails are turned into the concrete rather than left exposed.

Bar chair

A support placed under the reinforcement to hold the cage at the correct height and maintain the top and bottom cover. Chairs must be strong enough to resist the weight of the cage and workers.

Spacer block

A small block fixed to the outside of the cage to hold the specified side cover against the formwork. It must be of a material and density that prevents the bars moving during concreting.

Safe work method statement

A document setting out the high-risk construction work, the hazards, and the controls to be applied. Workers must follow it, and work stops if the controls cannot be met.

Person conducting a business

The legal duty holder under work health and safety law, responsible for managing risks so far as is reasonably practicable. Steelfixers must comply with controls and report hazards.

Reinforcement placing drawing

The drawing that shows bar marks, sizes, spacings, laps and cover for a specific member. The fixed cage is checked against it before the concrete pour is approved.

Bar schedule

A table listing each bar mark with its size, shape, bend dimensions, number required and total length. It is used for cutting and bending, and to check delivered steel against the order.

Cutting and bending

Preparing bars to the shape and length on the bar schedule, using shears or benders. Bends are formed to the specified mandrel diameter and hook geometry so the bar is not damaged.

Position tolerance

The permitted deviation of a fixed bar from its drawn location. Cover must never fall below the specified minimum, and spacers are adjusted if the cage moves during fixing.

Housekeeping on site

Keeping access ways clear, stacking off-cuts and tie wire in bins, and removing trip and penetration hazards. Good housekeeping is a required control, not an optional extra.

Precast panel cage

Reinforcement assembled in a jig so the panel dimensions and cover are accurate. Lifting inserts and cast-in plates are fixed to the placing drawing before the cage is closed.

Lifting insert

A cast-in fitting that provides an attachment point for lifting a precast element. Its position and embedment are set by the placing drawing and it is checked before concrete is placed.

Post-tensioning duct

A tube that forms the void for a post-tensioning tendon. It is fixed to the profile shown on the drawings and supported at close centres so it cannot move during concreting.

Anchorage zone

The region where a post-tensioning tendon transfers force into the concrete. It is heavily reinforced, and exclusion zones apply during stressing because stored energy is released there.

Welded wire mesh pitch

The spacing of wires in a mesh sheet, given as a pair of dimensions such as 500 by 500 millimetres. Pitch and wire diameter together define the mesh designation on the drawings.

Mesh sheet lap

The overlap between adjacent mesh sheets, commonly one full pitch plus 50 millimetres or as detailed. Laps are tied at regular centres so the sheets cannot separate during placing.

Welding reinforcement

Joining or attaching bars by arc welding, permitted only with designer approval. Welding alters the bar's metallurgy and can cause brittle failure, so it is never done as a casual fix.

Mechanical coupler

A sleeve that joins two bars end to end by threads, grout or swaging instead of lapping. It is installed to the manufacturer's torque or engagement specification and inspected before concreting.

Threaded splice

A joint formed by screwing a bar with a rolled or cut thread into a coupler or anchor. Thread engagement and tightening torque are checked against the supplier's published requirements.

Stressing exclusion zone

A marked area kept clear of people while a tendon is stressed. Nobody stands in line with the tendon or anchorage, because a failure releases stored energy along that axis.

Cast-in plate

A steel plate embedded in concrete to receive a later connection. Its position, level and orientation are set from the placing drawing and verified before the pour.

Formwork interface

The boundary between the reinforcement cage and the form face. Cover is checked there, and tie wire tails are bent into the concrete rather than left against the formwork.

Cover meter

A non-destructive instrument that measures the depth of reinforcement below a concrete surface. It is used to verify cover and bar position on completed work and on precast elements.

Pre-pour inspection

The check of the fixed reinforcement against the placing drawing before concrete is placed. Cover, laps, spacings, bar marks and embedded items are confirmed and the result recorded.

Embedded items

Components such as ducts, plates, sleeves and inserts cast into the concrete. Their position is fixed and checked before the pour, because they cannot easily be moved afterwards.

Falsework interface

The relationship between the support structure and the reinforcement cage. The steelfixer checks that the cage sits at the correct level and cover against the formwork before the pour.

Tendon profile

The path a post-tensioning tendon follows through a member, usually curved. It is set from the drawings and held by supports at close centres so it stays on profile during concreting.

Reinforcement inspection record

A signed record confirming that fixed steel matches the placing drawing and that cover, laps and spacings are correct. It is completed before the concrete pour is authorised.