Precast

Precast concrete elements have been an important part of the construction industry for a long time providing structural, non-structural, fire resistance, weatherproofing and architectural solutions to buildings. There are unique elements of precas...

For the purposes of this topic ‘Precast Concrete - Vertical Structures’ the information is limited to walls and columns as a part of the building structure. It doesn’t cover precast concrete pipes/culverts, precast floors and beams or the like which...

Precast elements may serve numerous objectives including:

Tilt-up and pre-cast panels must be designed for both erection loads and for loadings experienced when they make up part of the completed building or structure (i.e. ‘in-service loads’). The loads applied to the panel during lifting off the castin...

A key aspect of precast works is the grouting as this performs one, multiple or all of the following functions; • Structural (loadbearing) • Fire resistance • Weatherproofing It’s important to determine which aspect you are trying to achieve a...

Precast panels are connected to other structural elements including other precast panels using an array of connections in two categories as below; Type 1 – Precast to other structures other structures as built • Structural steel plates/brackets...

Detailed drawings should be provided that includes information on the following areas: • Marking plan of panel locations • Marking plan of cast in connections • Design of the panel itself for the in-situ application as part of the final structur...

Drawings for the erection of the panels should include details on how the panels are to be placed and secured into position. Information to be shown on these drawings include: • project location • date and issue number of the drawing • position ...

The following should apply to the design and installation of lifting and bracing inserts: • a factor of safety of not less than 2.5 against failure • compliance with the manufacturer’s specifications for minimum edge distances, depth, concrete st...

Tilt-up panels should only be lifted when the concrete has cured long enough for the panel to be safely lifted and the 2.5 factor of safety can be maintained on the lifting inserts. The minimum concrete strength at which this can be achieved, for mo...

Its critical the correct finishes are achieved when casting the panels. Some of the more common finishes includes; • off form finish with concrete or flat painted finish • off form finish with light texture paint finish through to heavy texture f...

The manufacture process for precast construction should be monitored in a similar manner that ensures the panels is correctly constructed just as you do for an in-situ concrete slab onsite. We need to ensure precast elements are cast in accordance w...

Consideration to transport route and limitations on precast delivery should be considered early to review maximum height of loaded truck, - Pre-cast concrete panels and elements should be transported to site in a safe manner and loaded on trucks so ...

Please see below items that should be discussed/followed for the installation of concrete panels. HB-SUPP-ITP 015 is to be read in conjunction with the below, as it contains a complete step by step process to be followed for installation: • High...

Reference to the below methodology and manufacturers requirements. The critical part of web bed is ensuring there is a form of some description to push the wet bed against, and for the installers to ensure once the panel is propped to ram the grou...

Where drypack (particularly where voids are rectified), the method of grout packing must include the use of appropriate tools (not just using hands) to create a solid form surface to ram the grouting at to ensure adequate compaction is achieved

To verify the grout has been installed full depth the following methodology is adopted. Check with the engineer but typically waiting 7 days for the grout to harden before completing this work We initially drilled test holes using a 12mm drill b...

As noted in the manufacturer’s literature, compressive grout strength is affected by the amount of water added. To ensure the require strength is achieved, the grout requires testing. Grout testing is completed as below - the Australian Stan...

Typical detailing of precast elements that require a sealant as a façade are as below – its important to consider the vertical to horizontal interface and with other structures

In respect to sealants – closed cell backing rods should be used – this requires the correct selection of rod given limitation of compressibility of the rod itself (talk to the quality team if subcontractors raise concerns with this including claims...

ITP-015 is a generic document to be modified for each job (copy at rear of this document) – this has been created as a document in Aconex Purpose is to record the various steps of the precast install and maintain adequate photographic records of t...

In summary Precast Concrete works are a HIGH RISK activity and requires considerable planning from start to finish - from design phase to signoff/certification • Preplan the design carefully • Check the shop drawings thoroughly • Supervise all a...

NCC Part B Structural provisions Part C Fire resistance Part F Health and amenity (weatherproofing) Australian Standards 1170 Structural Design actions (part 1-4) 3600 Concrete Structures 3610 Formwork for Concrete (Surface Finishe...