Spray-Lock Concrete Protection’s SCP solutions, based on state-of-the-art colloidal silica technology, are being used to significantly prolong the lifespan of reinforced concrete structures.
By helping to create tensile strength, reinforced concrete has been the most widely used construction practice globally since the late 1800s. Of concern, however, is the durability and longevity of the concrete due to the corrosion potential of the reinforcement. This remains the largest cause of failure in reinforced concrete structures.
The corrosion of reinforcing steel is an electrochemical reaction consisting of the flow of electrons and ions that deteriorate the steel and its properties.
One significant way of reducing corrosion potential is to completely encapsulate reinforcing steel in concrete with a high pH value. This is considering that the high alkaline environment acts as a protective oxide film. If no other outside forces are applied to the reinforced concrete, the steel should not rust. Unfortunately, almost all reinforced concrete is exposed to environmental conditions that shorten its lifespan, increasing the potential for corrosion.
The corrosion potential of reinforcing steel is influenced by several factors. They include moisture intrusion; reduced pH values over time; quality of the concrete and construction materials; proper concrete coverage of reinforcing steel; initial curing conditions; and the formation of cracks in the concrete. These factors can accelerate chloride movement into the concrete, disrupting the protective oxide film around the reinforcing steel that leads to rusting. This corrosion can lead to spalling and delamination of the concrete structure and reduced tensile capacity.
Carl Wite, Managing Director of SprayLock Africa, says that SCP contributes towards the durability of reinforced concrete by restricting access from outside influences.
“SCP penetrates the pores and bleed-water capillaries in concrete. These technologies restrict the movement of liquid water and contaminants that water carries, greatly slowing the corrosion of reinforcing steel,” he says.
Furthermore, the colloidal silica in SCP technology reacts with the available alkalis in the capillary and pore space to form calcium silicate hydrate (C-S-H). By filling these spaces, SCP products waterproof concrete within the interaction zone. If the concrete structure does not have any structural cracks, they also waterproof the structure in the application area. With SCP treatments preventing moisture migration from carrying chlorides within the concrete matrix, the corrosion potential is greatly reduced.
SprayLock Africa is the African representative of Spray-Lock Concrete Protection, a manufacturer of state-of-the-art colloidal silica technology in Chattanooga, Tennessee, United States.
The SprayLock Africa team continues to stand by SCP solutions, which have been based upon unique technology with a more than 40-year-long track record in the market. This is in addition to a team of experienced and skilled people who are passionate about and dedicated to solving their clients’ unique concrete challenges.
As stated, load considerations are often of greatest concern. SCP products improve compressive strength, allowing designers additional confidence that the concrete used in their designs will perform properly. Structural integrity is a subject to be taken seriously. With SCP, the overall structural integrity and durability of concrete structures can be improved.