However, there are well-known challenges of working with precast that worksite managers and project officers constantly deal with. This concerns the lifting and placement phases of finished precast elements.
Precast is incredibly heavy and often has complex shapes and sizes. There is certainly no room for error during the lifting and placement of these elements. Even a slight deviation from industry’s best practices, such as using incorrect rigging materials, can lead to massive errors and safety risks.
Understanding safe lifting protocols for precast concrete is essential to promoting safety on any worksite and ensuring precast elements are handled correctly. This guide provides an overview of proven industry best practices to help site managers and engineers execute flawless, safe lifts every time.
Understanding the Baseline: AS 3850 Compliance
AS 3850 (Prefabricated concrete elements) is the Australian Standard for the design, manufacture, handling, and installation of prefabricated concrete elements in construction [1]. It guides managers, engineers, and workers, ensuring safety and preventing worksite hazards.
Following AS 3850 ensures the following:
- Improved safety through proper design, lifting, transport, and installation.
- Compliance with Australian construction and workplace safety regulations.
- Higher construction quality with more consistent manufacturing and installation outcomes.
- Reduced risks and avoided costly rework.
Following industry guidelines ensures that all lifting inserts, clutches, and rigging gear are appropriately rated and tested for the specific loads that they will bear.
Essential Hardware: Anchors, Clutches, and Rigging
A safe lift requires knowledge of existing industry regulations and the right hardware. Here are the physical hardware requirements.
Lifting Anchors/Inserts
Lifting anchors are made of high-strength steel and designed to provide a durable, load-bearing attachment point for easy, safe lifting. These are cast directly into the concrete element, and AS 3850 requires that all lifting anchors must be permanently marked with the manufacturer’s identification, WLL, and must be compatible with the anchor used to lift the element [2]. It is critical that anchors be inspected for damage, corrosion, or any alteration before the lift.
Lifting Clutches
A concrete lifting clutch is typically made from high-strength alloy steel to withstand substantial loads. The correct clutch must match the cast-in anchor, as mismatched hardware can lead to rigging and lifting failure. There are various types of lifting clutches, including face-type and edge lifters, all of which must be designed, manufactured, and tested in accordance AS 3850 requirements. Lifting clutches without a valid certification must not be used at all [2].
Working Load Limits (WLL)
All types of slings, chains, and shackles must have a certified WLL that exceeds the total calculated weight of the precast concrete element. The rating must include a safety margin to account for dynamic forces, including wind loads, suction during ground lifting, and any sudden movement during lifting.
It is important to confirm that the clutch’s WLL matches the anchor’s. These components may be from the same manufacturer or approved for compatibility by the manufacturers of each component [2].
The Crucial Phase: Pre-Lift Planning and Preparation
Aside from the equipment, successful safe lifting of precast concrete elements requires intensive pre-lift planning and preparation.
Lift Plans & SWMS
Everyone involved in construction work has health and safety duties when lifting; therefore, the activity must be governed by a detailed lift plan and a Safe Work Method Statement. A detailed plan generally considers the following:
- Where the manufacture of the precast will take place
- How the elements will be lifted for transport
- Movement of materials and equipment in the worksite during the listing
- Required vehicle load capacity
- Where the prefabricated elements will be stored
- Clearance of the lifting activity to adjacent structures
- If the assembly will take place on the ground or at a height
- If cranes and lifting equipment are needed
Along with specific details of the lift, part of the proprietary documentation for safe lifting is a design safe report [3], which includes structural and shop drawings. These drawings highlight the following:
- The element layout plan
- Structurally critical dimensions
- Required reinforcements
- Concrete specifications
- Base connection details
- Location of the lifting and fixing inserts and any safety specifications
- Details on the reinforcement for element transport and lifting
- Details about welding and bolted connections
- Required compressive strength for the element and brace footing/foundations
- Bracing requirements, orientation of elements, and various rigging details
Centre of Gravity
Shop drawings also indicate the precast element’s centre of gravity [3]. Identifying the exact centre of gravity ensures balance during lifting, preventing tilting, rotation, or swinging uncontrollably once the element is suspended. Correct positioning of lifting points helps maintain stability and reduces the risk of sudden load shifts that could endanger workers or cause damage to the element.
Site Conditions
Before lifting activities can start, ground conditions and weather must be carefully assessed to ensure crane outriggers are properly supported and stable even under heavy loads. Weather conditions, specifically wind speed, are closely monitored, as large precast elements can act like sails when suspended during lifting and installation. Strong winds can cause uncontrolled movement of the elements [3], making it dangerous to proceed with lifting activities due to a higher risk of load instability and crane overturning.
Execution: Best Practices for the Ground Crew and Operator
During execution, strict coordination between the crane operator and the ground crew is critical. Having clear operational protocols ensures the safe movement of the load and the safety of workers.
Communication
There must be clear and continuous communication between the dogman or rigger and the crane operator throughout the activity. They use radios or standardised hand signals for precise instructions at every stage of the lift.
Exclusion Zones
Establishing exclusion zones around the lifting area is crucial to prevent workers from entering dangerous areas. There must be no personnel standing or passing underneath a suspended load [3].
Taglines
Taglines are ropes attached to the load that allow the ground crew to control its rotation and stabilise it during lifting. mTaglines guide the movement of the precast panels into their final position while maintaining a safe distance from the suspended load. st standards. Contact Ozcast today to discuss your precast requirements.
Ensure Safe Lifts With High Quality Precast. Contact Our Team Today
Precast concrete delivers uncompromised efficiency and structural integrity across various infrastructure projects. But its full potential can only be realised by practising safe lifting.
Ensure your next civil infrastructure project is supported by industry expertise and high-quality precast elements. Contact the team at Ozcast today to discuss your upcoming project.
