There are a variety of common causes of formwork failure during concrete construction. Being familiar with them is a good start for preventing formwork failure when concrete is poured or when the formwork is dismantled. But more importantly, a proactive approach to formwork safety that addresses these and other potential problems is essential.
Below are some general best practices for preventing formwork failure that span the stages of planning and erecting the formwork, pouring the concrete, and removing the formwork.
Precautions for Preventing Formwork Failure
- Formwork should always be designed by a qualified, competent person who’s experienced with the type of formwork being used.
- A formwork design engineer should create any customized formwork plans.
- The original design must specify a minimum concrete curing time before dismantling of the formwork system may begin.
- Ensure that formwork is installed exactly as specified in the original design. If for some reason it must be altered, have the original designer review any and all changes to ensure they won’t compromise the system’s structural integrity.
- Always follow all recommendations by the manufacturer of the formwork system.
- Thoroughly inspect all components of the formwork system prior to installation. Replace or repair and piece that shows signs of damage. Never use any materials or equipment that are in questionable or poor condition.
- A qualified person must inspect the formwork once it’s erected to ensure it was properly installed and it complies with the approved design. This should be done before any crew or subcontractors gain access to the site and before any concrete is poured.
- Confirm that the formwork inspection was completed, documented, and signed off on before concrete pouring begins.
- Establish a safety zone under the formwork where workers aren’t allowed once pouring begins and until the concrete hardens to an appropriate strength.
- Keep watch for signs of formwork strain or failure during concrete pouring. Immediately cease pouring and ensure that there’s nobody in the safety zone around the structure. A qualified person must promptly determine how to address the developing problem.
- Never start removing any part of the formwork system before reaching the minimum concrete curing time defined in the design.