formwork

Formwork, also known as shuttering, is a temporary or permanent mold into which concrete or other materials are poured to shape structural elements such as walls, slabs, beams, and columns. It supports the concrete’s weight and lateral pressures and ensures the desired dimensions, alignment, and surface finish until the concrete gains sufficient strength.

Formwork design considers geometry, loads, and construction tolerances. It must resist dead load from the formwork itself, live load from wet concrete (hydrostatic pressure), wind, and any movement from workers. It uses bracing, ties, studs, and shores to maintain position and rigidity. Selection of materials and connections aims to balance strength, surface quality, ease of stripping, and reuse potential.

Common materials include conventional timber and plywood; steel or aluminum modular panels; and plastic or composite forms for repetition. System formwork offers rapid erection and easy reuse, while stay-in-place forms can provide insulation or reduce stripping work. Types range from wooden formwork to steel, aluminum modular systems, and plastic or stay-in-place forms, with combinations tailored to project needs.

Construction sequence typically begins with formwork design and planning, followed by erection and alignment checks. Reinforcement is placed and secured, concrete is poured and compacted, and the assembly is monitored for leakage, alignment, and surface quality. After curing to adequate strength, forms are stripped and inspected. Proper form release agents, access for inspection, and clean-out procedures help extend reuse life and ensure surface finish quality.

Formwork offers accurate geometry and favorable surface finishes, supports rapid construction, and enables repetitive use with modular systems. Its drawbacks include capital and storage costs, labor requirements, and the risk of leakage or deformation if not properly designed and maintained. Standards and best practices emphasize safety, stability, and proper sequencing to ensure successful formwork performance.