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Concrete Sealing Systems

Have Hydrophilic and PVC tapes had their day in sealing system technology?

Concrete Sealing Systems: We recently had a paper published in Concrete Magazine on concrete sealing systems. Today sees the release of a series of mini blog posts that breaks down the article into some bite-sized advisory pieces.

Concrete Sealing Systems: Advances in the technology behind concrete mix design means that specifiers of concrete for basement construction have a broader choice to achieve the desired end product to satisfy Euro Code requirements. However, the weakness in any basement is the jointing as more joints are required in the construction to meet code requirements. This often conflicts with the contractor’s needs to pour more extensive areas to align with pressures on the program.

Concrete Sealing Systems

What choices are available for sealing systems for forming joints?

The choice of sealing systems for forming joints is varied, with many options available on the market, ranging from simple reactive systems like hydrophilic strips or active systems such as PVC tapes or coated steel strips. The choice of injection hose systems may be selected in specialised forms of construction, such as tunnels. They can be used in basement construction where joints need to be formed against existing structures, but this is a specialised area of work and requires the attendance of a specialist contractor to install and activate the system.

Each sealing system has its own merits in the development of a joint. However, as is often the case, the choice of a particular sealing system is down to preference of the specification by the designer or contractor due to personal preference or even down to the cost. Cost is another factor in the decision-making process, with the unit cost/m, being the driver but stealth expenses and post-working tasks? These are not seen in the cost and in some cases a contingency is factored in to deal with leaks. Again, these all have implications for program and project cost.

Please look out for the next blog post over the coming days.

To discuss your concrete sealing system requirements, please contact us.

Hydrophillic Water Bar

Joint Sealing Systems – Hydrophilic Strips

Joint Sealing Systems Hydrophilic Strips : Sealing systems are a fundamental part of any basement design and one that needs to be explored so that specification, site works and end-use can all be understood by all in the design process.

Joint Sealing Systems Hydrophilic Strips

Joint Sealing Systems Hydrophilic Strips: The use of hydrophilic strips as a joint sealing system has been a long stay item for many as a standard joint sealing solution. It is often seen as a simple choice by the specifier and can be changed on site to suit construction sequence, should this change be required to accommodate revisions to the pour sequence. A prescribed set number of work stages are necessary for the joint to perform correctly.

This is often left to the contractor or specialist contractor to form. A joggle joint is commonly adopted to increase water path length, the recess is just as a container for the hydrophilic strip. The surface of the new joint needs to be prepared and laitance removed. The hydrophilic strip is placed into the recess and covered with a mesh strip. A retarder on the hydrophilic strip prevents the fresh concrete reacting with the product, however, excess water on the piece may activate the system and prevent it from being used. This results in the hydrophilic section being replaced.

On completion of the joint, the hydrophilic will remain dormant until running water under hydrostatic pressure reacts with the sealing system. The reaction takes place, and the hydrophilic will swell to seal the joint. Some seepage may occur along the joint until the product has expanded to seal the joint. If the water pressure drops the reverse action happens and the hydrophilic contracts. This cyclic reaction occurs over the life of the building. In some basement specifications, this level of ingress is acceptable.

To discuss your concrete sealing system requirements, please contact us.