A bond breaker is a separator substance applied in between adjoining solid surfaces to ensure that there is no adhesive molecular bond between the surfaces.
Image Credits: Constrip Bond Breaker
Bond breakers are commonly used for tilt-up walls and precast segments so that the right pieces are cast together. They can be flexible sealants in the form of liquid, spray, rods, or tapes.
This article explores the features and benefits of bond breakers in construction.
Features of Bond Breakers Used in Construction
- Bond breakers are anti-stick materials used on adjacent metallic or non-metallic substrates, such as concrete and steel.
- Bond breakers can be used to improve joint performance. Without bond breakers, the joint sealer tears apart to accommodate movement. As shown in figure-2, a bond breaker tape in-between the joint sealant and joint filler is provided to facilitate free movement.
- Bond breakers are used to break the bond between the substrate and the waterproofing membrane, forming an adjustable bridge, which resists the movement of water or moisture.
- Bond breakers minimize the varying dynamic loads on the precast components during their lifting and stripping from the casting molds.
- They are also applied on concrete surfaces to reduce the cracking of slabs caused due to temperature and moisture fluctuations.
Types of Bond Breakers Used in Construction
- Bond breakers can be classified into two major groups: membrane-forming and non-membrane forming. They can also be water-based or non-water-based products.
- Membrane-forming bond breakers are formulated as per ASTM C-309, the standard specification for liquid-membrane-forming compounds. These bond breakers have the property to hold the water in the casting slab.
- Non-membrane bond breakers can be either reactive or non-reactive. Reactive bond breakers react with the concrete surface and form a crude soap layer. A non-reactive bond breaker interacts with the concrete surface to create a waterproof surface.
- Most bond breakers are designed to provide curing compounds to cure the slabs and precast members because the use of chemical curing compounds prevents the proper functioning of bond breakers.
Advantages of Bond Breakers in Construction
- Bond breakers reduce the time required to move heavily loaded precast elements.
- Bond breakers do not affect the characteristics of concrete surfaces.
- Their usage does not demand any repainting or modification to other architectural components.
- The application of bond breakers does not affect the adhesion of adhesives, epoxies, or any other floor finishes.
FAQs
A bond breaker is a separator substance applied in between adjoining solid surfaces to ensure that there is no adhesive molecular bond between the surfaces.
Bond breakers can be classified as membrane-forming and non-membrane forming. Membrane-forming bond breakers have the property to hold the water in the casting slab. Non-membrane bond breakers can be either reactive or non-reactive. Reactive bond breakers react with the concrete surface and form a crude soap layer, whereas non-reactive bond breakers interact with the concrete surface to create a waterproof surface.
Read More
Repair of Dormant Cracks in Concrete
Demolition or Refurbishment: What are the Factors Controlling Decision-Making?