Crack Inducing Products for Watertight Concrete Walls

Introduction: Why Controlled Concrete Cracking Matters

Large reinforced concrete walls—especially those exposed to water or high moisture levels—often face issues such as shrinkage, creep, and temperature fluctuations. These factors can lead to uncontrolled cracking, risking leaks, weakened structures, and expensive repairs.

By using a concrete crack inducing tube, contractors and engineers can predict and guide where cracks will form. This strategy, known as controlled crack induction, helps maintain structural integrity and water tightness. Below, we explore how the KRASO-Flex Star Tube from Kraso GMBH addresses these challenges head-on.

The Principle Behind Concrete Crack Inducing for Walls

Concrete naturally shrinks during curing and deforms under sustained loads over time (creep). When water pressure or groundwater is involved—such as in basements, tanks, or retaining walls—cracks can compromise the entire structure.

A controlled crack induction system ensures any inevitable cracks form in predefined locations rather than randomly across the surface. By deliberately weakening specific sections, it becomes easier to seal and protect the crack once it appears, reducing the likelihood of leaks and costly remediation.

Introducing the KRASO-Flex Star Tube

The KRASO-Flex Star Tube is a specialised crack inducing product developed by Kraso GMBH in Germany. Designed with precision engineering, it provides an effective means to achieve controlled concrete cracking and watertight sealing in both precast and in-situ concrete applications.

Key Features

1. Star-Shaped Profile
   A distinctive multi-fin profile creates a deliberate weak plane for vertical cracks while preserving the overall strength of the structure.
2. Integrated Sealing Anchors
   Specialised seals work in two stages: first, they initiate cracking at a specific point; then they prevent water penetration through the newly formed crack.
3. Pre-Punched Holes
   Factory-drilled openings at fixed intervals make it straightforward to attach the tube to reinforcement bars, ensuring stable, fuss-free installation.
4. High Durability
   Engineered to withstand substantial hydrostatic pressure and meet stringent water-resistance standards common in German and European regulations.

How a Concrete Crack Inducing Tube Improves Water tightness

1. Targeted Weak Plane
   Placing the KRASO-Flex Star Tube at calculated intervals ensures the crack forms exactly where you want it, reducing the likelihood of random fracturing.
2. Built-In Water Seal
   Once the controlled crack appears, internal sealing anchors block water migration, often eliminating the need for additional sealants or post-pour injections.
3. Lower Risk of Unplanned Cracks
   By directing stress into a narrow, predetermined zone, there is less strain on the surrounding concrete—helping you avoid unforeseen damage in large walls or slabs.

Best Practices for Installation

1. Determine Optimal Spacing
   Consult structural engineers to calculate the correct distance between tubes, factoring in wall height, thickness, and design loads.
   
2. Prepare the Joint Area
   For wall-slab intersections, align and trim the tube to ensure it integrates smoothly with any existing joint tapes or membranes.
3. Fix Securely
   Attach the tube to the reinforcement cage or formwork through the pre-punched holes. Adequate fixings help keep the tube stable when concrete is poured.
   
4. Balance the Concrete Pour
   Pour concrete evenly on both sides of the tube to minimise uneven stress and guarantee a uniform curing process.
   
5. Fill the hollow core 
   Filling the tube’s hollow core with concrete to enhance rigidity and reduce the need for future injection materials. Check project requirements to confirm.
   

Why Choose KRASO-Flex Star Tube for Concrete Crack Inducing

• Manufactured in Germany: Enjoy the quality and precision expected from German engineering.
• High Water tightness: Built-in sealing elements drastically reduce water seepage without extra membranes or grouts.
• Long-Term Performance: Designed to resist thermal, mechanical, and chemical stresses throughout the structure’s lifespan.
• Cost Efficiency: By minimising uncontrolled cracks, you can cut back on expensive repair work over time.

Conclusion – A Preventative Approach to Cracking

When it comes to concrete crack inducing for walls, a proactive method is often the best course of action. With the KRASO-Flex Star Tube, you can anticipate, induce, and seal cracks in a controlled manner, ultimately preserving the water tightness and structural stability of your project.

For more information on crack inducing products and the KRASO-Flex Star Tube, feel free to contact our technical support team or explore our full catalogue. Build stronger, watertight concrete walls that stand up to both time and water pressure.

Disclaimer: Always consult a structural engineer or relevant technical professionals for project-specific recommendations and compliance with local building regulations. All product data, including references to performance standards and sealing behaviour, should be verified with the manufacturer. Please check patent details or registrations directly with Kraso GMBH.