ACI Tilt-Up Technician flashcards

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

Panel weight formula

Panel weight equals panel volume multiplied by concrete unit weight; normal-weight concrete is about 150 pounds per cubic foot.

Control point layout

Control points are fixed survey references used to locate panel edges, openings, and embeds; all layout dimensions are measured from them to avoid cumulative error.

Square corner check

A 3-4-5 triangle or equal diagonal measurements confirm a form corner is square; unequal diagonals indicate the rectangle is skewed and must be adjusted.

Casting surface preparation

The casting surface is cleaned, checked for level, and kept free of standing water; surface defects can transfer to the panel face or change panel thickness.

Crane access planning

Crane access planning fixes the crane position, pick radius, outrigger footprint, and travel path before casting so panel orientation and lift inserts match the lift plan.

Panel identification mark

A panel identification mark is a unique label placed on the casting surface or form that links each panel to its erection drawing, orientation, and location.

Opening blockout layout

Opening and blockout layout uses the same control lines as the panel perimeter; consistent layout prevents openings from shifting relative to edges and inserts.

Form release agent

Form release agent is a coating applied in a thin uniform film to forms and the casting surface to prevent concrete adhesion; puddling or overspray can contaminate reinforcement or inserts.

Form joint sealing

Form joints and corners are sealed to stop grout loss; escaping mortar creates voids, honeycomb, and dimensional variation at panel edges and openings.

Chamfer strip function

A chamfer strip forms a beveled edge on the panel; the bevel reduces chipping and spalling when the panel is lifted, handled, and erected.

Blockout anchoring

Blockouts and reveals are anchored to forms or the casting surface so fresh concrete cannot float or shift them during placement.

Form line and grade

Form line and grade are the horizontal position and elevation of the formwork; they are checked before concrete placement because movement changes panel geometry.

Fresh concrete pressure

Fresh concrete exerts lateral pressure on forms; pressure increases with placement rate, concrete temperature, and depth of the concrete lift.

Form removal strength

Forms are removed only after concrete has gained enough strength to resist damage from form removal and to carry handling stresses.

Lift insert placement

Lift inserts are placed at the lift points shown on panel drawings and oriented to accept the rigging hardware without eccentric loading.

Reinforcement cover

Reinforcement cover is the distance from the concrete surface to the nearest bar or wire; chairs and spacers maintain cover during concrete placement.

Embed plate alignment

Embed plates are fixed to forms or supporting steel so their face, elevation, and alignment match the erection drawings and connecting steel.

Rebar chair function

Rebar chairs support reinforcement at the specified elevation; displaced or missing chairs reduce cover and can change panel strength.

Insert capacity check

Lift insert capacity must exceed the load from panel weight, rigging angle, and dynamic lift effects; the controlling load is the highest insert demand.

Sleeve coordination

Sleeves and blockouts are coordinated with reinforcement so bars are not cut and inserts are not moved from their design locations.

Concrete consolidation

Internal vibration consolidates concrete around reinforcement and inserts; over-vibration causes segregation and can displace embeds or blockouts.

Bleed water finishing

Bleed water is water that rises to the concrete surface after placement; finishing while bleed water is present can cause weak, blistered surfaces.

Curing compound coverage

Curing compound is sprayed or rolled over exposed concrete to slow moisture loss; coverage must be continuous at the rate specified for the product.

Screed panel thickness

Screeding levels and compacts fresh concrete to the form height; screed rails and grade stakes control panel thickness and surface elevation.

Cold joint prevention

A cold joint forms when fresh concrete is placed against concrete that has already set; continuous placement between planned joints prevents unintended cold joints.

Test cylinder sampling

Concrete test cylinders are sampled from the delivered concrete and cured under controlled conditions; they estimate strength for form removal, lifting, and acceptance.

Sling tension formula

For two symmetric slings, tension per sling equals panel weight divided by two times the cosine of the sling angle from vertical.

Center of gravity lift

The panel center of gravity is the point where its weight balances; lift inserts are arranged so the panel hangs level and does not rotate unexpectedly.

Pre-lift inspection

A pre-lift inspection verifies lift inserts, rigging hardware, crane setup, panel condition, and bracing before the panel is raised.

Exclusion zone

The exclusion zone is the area under and around a suspended panel where personnel are kept clear during lifting and erection.

Temporary bracing

Temporary bracing supports an erected panel until permanent connections carry design loads; bracing is installed immediately after the panel is set.

Rigging hardware rating

Rigging hardware is selected by rated capacity; slings, shackles, and hooks are inspected for damage before each lift.