Radial cracks, further resulting in delamination of concrete
Buckled section of the silo(28 mt. level)
PT duct (About 40% empty)
Additional MS reinforcement welded with existing reinforcement and anchored to parent concrete
Patching the damaged concrete section with micro-concrete in vertical strips
Ongoing repair on the rear side (subjected to tension)
Silo after completion of repair
Make OR Break Factor
Cradles were suspended from the 85mt-high silo top to conduct repairs
THE CHALLENGE :
- A raw mill silo was tilting, bulging and buckling at a height of 28 mts. to 40 mts., resulting in unsafe operating conditions. Our initial survey revealed multiple discrepancies:
- For the required foundation size of 2720m², the actual size was 641m²
- Silo wall though 350mm thick and structurally sound had no space left to pour concrete because of the PT duct and reinforcements
- PT forces applied were 80% of hoop forces instead of the regulation 60%
- PT ducts were filled up to 60-70% instead of the regulation 97%.
THE ODDS :
- Tight deadline of 6 months
- Work to be carried out under partial operating conditions
- Local bursting of concrete encountered
- Soaring summer ambient temperatures of over 50º C
OUR RESPONSE :
- Designed and modified material and methodology
- Conducted extensive trials on site
- Grouting of the RCC sell with high-strength epoxies
- Provided additional reinforcement
- Patched damaged concrete sections with micro-concreting