What Is Stremaform®? A Complete Guide to Stay-in-Place Formwork

In reinforced concrete construction, forming joints between separate concrete pours can be one of the more labour-intensive stages of a project. Traditional methods often involve temporary timber formwork that must be fabricated, positioned, supported and later removed.

Stremaform® offers a different approach.

Stremaform® is a prefabricated stay-in-place formwork system designed for forming construction joints and other joint types within reinforced concrete. Instead of being stripped after the concrete pour, the formwork remains permanently within the structure.

For contractors working on concrete slabs, walls, foundations and major infrastructure projects, this can simplify construction sequencing, reduce on-site fabrication and eliminate the additional work associated with stripping conventional joint formwork.

What is Stremaform®?

Stremaform® is an engineered formwork system developed specifically for forming joints between concrete sections.

The system uses prefabricated formwork elements that are positioned within the reinforcement before the concrete is poured. Once the first concrete section has been completed, the Stremaform® element remains in place and forms the interface with the subsequent concrete pour.

This is why Stremaform® is commonly described as stay-in-place formwork, permanent formwork or sacrificial formwork.

Rather than constructing temporary formwork that must later be removed, Stremaform® becomes part of the completed concrete construction.

The modular system can accommodate a wide range of joint arrangements, while project-specific elements can also be produced for more complex applications.

How Does Stremaform® Work?

The principle behind Stremaform® is relatively straightforward.

Prefabricated elements are delivered to site and installed at the required joint location within the reinforcement.

The first concrete section is then poured against the Stremaform® element. Because the formwork remains permanently in position, there is no need to strip the joint before work proceeds to the adjoining concrete section.

Reinforcement and subsequent concreting can then continue according to the structural design and construction sequence.

For contractors, this removes several steps normally associated with conventional construction joint formwork.

Instead of:

fabricate → install → brace → concrete → strip → remove → dispose

the process becomes closer to:

position → secure → concrete → continue

The actual installation and engineering requirements will naturally depend on the structure, joint configuration and project specification.

What is Stay-in-Place Formwork?

Stay-in-place formwork is formwork designed to remain permanently within the completed structure.

This differs from conventional temporary formwork, which performs its function during concreting but must subsequently be removed.

For construction joints, eliminating the stripping stage can be particularly useful where access is restricted, reinforcement is congested or the construction program involves repeated concrete pours.

Stremaform® takes this principle and applies it specifically to reinforced concrete joint construction.

What Types of Joints Can Stremaform® Be Used For?

One of the major advantages of the Stremaform® system is its versatility.

Different configurations are available for several important types of concrete joints.

Construction and Working Joints

Large concrete structures generally cannot be poured as a single continuous operation.

Instead, the structure is divided into individual concreting sections. The interfaces between these pours create construction or working joints.

Stremaform® can be positioned at these locations to create a defined joint between concrete pours while allowing the required reinforcement arrangement to continue through the structure.

Applications include large floor slabs, walls, foundations and other reinforced concrete components.

Expansion Joints

Expansion joints perform a different function.

Rather than simply dividing separate concrete pours, an expansion joint separates structural components so movement can occur between them.

Stremaform® expansion joint elements can be prefabricated to suit the required dimensions and can incorporate different joint inserts depending on the application.

Specialised systems can also accommodate requirements such as sealing, sound insulation and shear force transmission.

Controlled Crack Joints

Controlled crack joints are designed to encourage cracking at a predetermined location rather than allowing uncontrolled cracking elsewhere in the concrete structure.

Stremaform® can form part of controlled crack joint systems and can be combined with appropriate sealing technology where impermeable concrete construction is required.

Where Can Stremaform® Be Used?

Stremaform® has applications across a broad range of reinforced concrete construction.

Concrete Slabs

Large slabs frequently need to be divided into manageable concreting sections.

Stay-in-place formwork allows these sections to be established before concreting while avoiding the subsequent removal of conventional joint formwork.

This makes Stremaform® particularly relevant to large ground slabs and other heavily reinforced concrete floor structures.

Concrete Walls

Stremaform® can also be incorporated into reinforced concrete walls.

The system allows defined construction or working joints to be established between wall sections and can accommodate wall-to-wall and slab-to-wall construction arrangements.

Foundations

Foundations can contain substantial reinforcement and complex structural details, making conventional joint formwork difficult to install and remove.

Prefabricated stay-in-place formwork can simplify the creation of joints within these heavily reinforced areas.

Basements and Waterproof Structures

Where water resistance is an important design requirement, construction joints require particular attention.

Stremaform® systems can be combined with suitable waterstop arrangements to provide both joint formwork and sealing as part of the construction solution.

Civil and Infrastructure Projects

The same principles make Stremaform® suitable for major civil and infrastructure construction where large concrete components, complex reinforcement and multiple concrete pours are common.

Applications can extend from major foundations and transport infrastructure to specialist structural concrete works.

Stremaform® vs Traditional Timber Formwork

The fundamental difference is what happens after the concrete is poured.

With conventional timber construction joint formwork, the temporary formwork generally needs to be removed.

That process can involve additional labour, access, handling and waste.

With Stremaform®, the element remains permanently within the concrete.

This can provide several practical advantages:

* No stripping of construction joint formwork
* Less temporary formwork material
* Reduced on-site fabrication
* Less handling and disposal
* Faster preparation of repeated joints
* Prefabricated project-specific solutions
* Greater consistency between similar joint locations

For projects involving numerous construction joints, these efficiencies can become increasingly significant.

How Can Stremaform® Improve Construction Efficiency?

The benefit is not simply that Stremaform® stays in the concrete.

The larger advantage comes from simplifying the construction process.

Traditional joint formwork can require carpenters or other site personnel to fabricate individual solutions around reinforcement and structural details. Once the concrete is poured, access may then be required to strip that formwork.

Prefabrication moves a significant portion of that work away from the construction site.

Elements can instead arrive ready for installation according to the project requirements.

This can help reduce on-site fabrication and support more predictable concrete construction sequencing.