Actual Microscopic Analysis of VPI 580 in concrete
The following pictures are 50x Microscopic Photographs of steel reinforcement in concrete, taken by an Independent Laboratory (Bierrum Ltd) who prepared and tested these on QED's behalf.
This sample below was taken from a 25cm x 25cm x 25cm cube, with a standard steel rebar. The concrete was prepared with an average of 2% calcium chloride % of weight per mass of cement.
It was untreated and was left for 6 months exposed to normal weathering, before being cut open and analysed. It shows severe corrosion to the the steel reinfocement and massive structural weakening.
This sample below was indentical in size, time and exposure to the sample above, but had QED's VPI580 product inserted into the concrete according to our standard treatment procedures. It shows no corrosion to the steel reinforcement and remained in perfect structural condition.
Migration Verification
In the above tests, it was found that QED's 580 product travelled at an average rate of 147mm per day in regular density concrete. This was calculated by testing samples of the concrete to detect the presence of VPI vapour at intervals from the inserted 580 capsule. The presence of VPI was discovered at a distance of 1 metre from the embedded capsule after 7 days. The 3 components in the 580 will travel at different rates (through differening vapour pressures), the fastest component (i.e. the product that was detected at 1 metre with 7 days) being the component that is included for short to medium term protection. It was noted the longer term protection produced lower pressure, and was detected at 0.75m in a period of 46 days.
The above results are currently being verified by an Independent laboratory in the UK and we aim to have the results available for inclusion on this website in July 2008.