Traditional structural design is based on lifespan versus cover to reinforcing steel. Essentially the durability and serviceable lifespan of a structure would be calculated utilising the thickness of covercrete and the durability of this cover zone. Conventional designs, very often, rely on crack width design, cement content, W/C ratio and effective curing to achieve durability specifications.
These factors are ultimately placed in the hands of the contractor and concrete placing teams where many variables creep into the process. Cover, compaction, curing and thus durability, can therefore not always be guaranteed. The result may be corrosion of the reinforcement, caused by chloride ingress, carbonation or moisture ingress through cracks or capillaries into the concrete matrix.
These mechanisms would create an environment whereby the steel reinforcement would start to corrode, thus increasing in volumetric dimensions. A constant volumetric change of the steel reinforcement creates internal pressure within the structure forcing internal cracks and sections of the concrete cover to delaminate, creating spalling.
A spalled concrete surface would allow far easier access to the reinforcement for destructive elements and the process would soon accelerate more rapidly.
The use of Penetron® as an active crystalline activity within the concrete matrix , either as an admixture or a surface applied treatment, will enable the structure to protect itself from the elements, even in areas of compromised covercrete, as this would halt the moisture and chloride ingress, effectively preventing it from reaching the steel reinforcement. The concrete will also self heal in the presence of water, for the lifetime of the structure, increasing the serviceable lifespan of such treated concrete structures.
By eliminating the early effects of spalling, the long-term cost benefits in so far as the maintenance and repair cycles of a structure are vastly improved, providing the owner or developer a long-term cost-effective solution.