Wall formwork shapes fresh concrete into load-bearing or separating wall components. It governs dimensional accuracy, surface finish, and the construction sequence—from the first reinforcement layer through to safe stripping. In existing structures, the quality of the earlier wall formwork influences later interventions such as wall openings, selective deconstruction, or creating wall breakthroughs. Depending on the task, precise removal methods and separating tools are used here, for example concrete demolition shear or hydraulic rock and concrete splitters, as employed in the context of Darda GmbH. This closes the loop between proper construction and controlled demolition.
Definition: What is meant by wall formwork
Wall formwork is a temporary load-bearing auxiliary structure that shapes fresh concrete in a vertical position and keeps it stable until sufficient strength is achieved. Typical components are frame elements with formwork sheathing, connectors, alignment and shoring systems, as well as formwork anchors that tie opposite formwork faces together and resist fresh concrete pressure. Materials are often steel or aluminum in combination with timber or plastic formwork sheathing. Wall formwork is placed modularly, moved by crane, or operated as climbing formwork or sliding formwork.
Structure, systems, and components of wall formwork
Wall formwork consists of formwork sheathing, load-bearing frames or girders, connecting hardware, and an anchor system with cones and spacers. Alignment struts and a work platform complement the setup for dimensional accuracy, safety, and ergonomics. Critical factors include tight joints, a suitable formwork grid, and an anchor layout matched to fresh concrete pressure. Depending on the project, lightweight hand-set formwork, large-area frame formwork, girder formwork for high placing pressures, or climbing formwork for tall walls and cores are used.
Formwork types and typical applications
The choice of system depends on geometry, surface, schedule, and logistics. The following construction methods are common:
- Frame formwork: modular elements with a robust frame for rapid cycle construction and recurring grids.
- Girder formwork: timber or metal girders with freely selectable sheathing for great heights or elevated exposed-concrete requirements.
- Climbing formwork: systems guided with climbing brackets for high walls, shafts, and core zones, often with integrated work platforms.
- Sliding formwork: continuously climbing unit for monolithic, tall components with constant cross-section.
- Permanent formwork: remains in the component, e.g., as an insulating or casing system when dismantling is not intended.
Planning: fresh concrete pressure, anchor forces, and cycles
Design is based on fresh concrete pressure, which depends on concrete temperature, consistency, placing rate, and wall height. This determines anchor spacing, frame stiffness, and the choice of sheathing. Pour sections are selected so that joints, anchor points, and the desired joint pattern align. Low pour rates reduce pressure peaks, while targeted concrete compaction influences pore structure and thus the exposed-concrete quality.
Key planning parameters
- Intended surface quality and joint/anchor pattern
- Compaction concept (internal vibrator, external vibrator, self-compacting concrete)
- Crane use, transport routes, laydown areas, and cycle planning
- Weather, fresh concrete temperature, and heat of hydration
Surface qualities and joint patterns
The formwork sheathing determines the wall’s texture: timber yields fine grain, plastic or steel produce smooth surfaces. Decisive are joint tightness, uniform sheathing quality, and neatly placed anchors. For higher exposed-concrete requirements, joint lines are treated as design elements; anchor cones are arranged evenly and in a grid. Care and cleaning of the sheathing ensure consistently good results.
Assembly, occupational safety, and stripping
Wall formwork is set up on a load-bearing base, plumbed, and fixed with alignment struts. Work platforms, guardrail, and defined access routes are part of safe erection and dismantling. Stripping only occurs once the required concrete strength has been reached. Edges are protected to avoid spalling; anchor openings are properly closed or used as design elements.
Interfaces in existing structures: openings, adaptations, and deconstruction
In existing structures, the feasibility of subsequent wall openings or chases often depends on the former wall formwork and reinforcement layout. Tight, smooth surfaces reveal separation joints and anchor points, facilitating the planning of interventions. For precise wall breakthroughs or selective removal of wall areas, controlled methods with low vibration levels are used.
Tools for selective concrete removal
- Concrete demolition shear: for targeted biting and removal of wall areas, e.g., for door and window openings within building gutting and concrete cutting.
- Hydraulic wedge splitter: for low-stress widening of predetermined breaking lines in massive wall zones—useful in special demolition with minimal vibrations.
- Additionally, combination shears, Multi Cutters, or steel shear can be used to cut embedded components and reinforcement.
These methods are particularly relevant in the fields of concrete demolition and special demolition as well as building gutting and concrete cutting. For massive civil-engineering structures, shafts, or in rock demolition and tunnel construction, knowledge of earlier climbing or girder formwork helps position splitter cylinders and plan the sequence of interventions.
Quality assurance: tightness, dimensional accuracy, and durability
High-quality wall formwork minimizes joint steps, bleed water staining, and honeycombing. Seals at element joints, properly tightened anchors, and correct concrete compaction ensure the result. Reusable sheathing is appropriately cleaned and protected to increase the number of uses and ensure a consistent surface.
Common challenges
- Honeycombing/voids due to inadequate compaction or leaky joints
- Edge break-offs from stripping too early
- Telegraphing of anchors and joints in exposed concrete
- Warping due to uneven fresh concrete pressure
Sustainability and resource efficiency
Modular systems and durable formwork sheathing reduce material consumption and transport effort. Precise cycling, recurring grids, and accurate block-outs avoid rework. In existing structures, selective removal methods—e.g., with concrete demolition shear or hydraulic wedge splitter—reduce noise and vibrations and help preserve adjacent components.
Legal and normative aspects
Applicable technical rules govern planning, fabrication, and testing. These include requirements for load-bearing capacity, serviceability, tolerances, and occupational safety. Specifications for fresh concrete pressure, handling of anchors, and fall protection must be observed. These notes are general in nature and do not replace a project-specific assessment.
Documentation and tendering
A clear specification defines grid, sheathing quality, joint and anchor pattern, pour sections, and requirements for exposed surfaces. As-built documentation—including anchor layouts and joint runs—facilitates later repurposing, wall breakthroughs, and controlled deconstruction. In such cases, the use of precise tools, as established in the Darda GmbH environment, can accelerate execution and protect component integration.
Practice-oriented guidance for planning and execution
- Coordinate joint and anchor pattern early with the architecture and cycle planning.
- Set fresh concrete pressure realistically, considering pour rate and temperature.
- Choose sheathing uniformly and maintain it consistently to avoid color differences.
- Define stripping times based on materials and weather; protect edges.
- Provide predetermined breaking points or block-outs for future openings to facilitate interventions.
Link to deconstruction practice
Knowledge of wall formwork systems supports planned deconstruction: anchor axes indicate possible lines of weakness, and climbing cycles indicate joint locations with changed bond conditions. This enables step-by-step removal sequences and targeted tool selection—from breaking out with concrete demolition shear to force-coupled splitting with hydraulic wedge splitter. For complex Darda GmbH projects in the areas of concrete demolition and special demolition, building gutting and concrete cutting, or in tunnel construction, this interplay between construction history and tool selection is crucial for safe, low-vibration execution.