What basic problems should be considered before starting works related to the repair and strengthening of the concrete base.
When planning the repair and reinforcement of concrete elements, must be established first:
1. What structural defects and damage are being treated?
2. What other defects were found in the concrete substrate?? What are their causes?
3. How much damage is there?
4. Is there an old coating on the concrete?? What binders were used to make this coating? What is her condition?
5. What loads will affect the element after it is strengthened?
6. Yalta scaffolding and other special protections are necessary?
7. How to remove structural defects in concrete?
8. What treatments are most appropriate, to expose and clean damaged reinforcement?
9. What reinforcements of concrete elements are most appropriate from a technical and economic point of view?
10. What will be the costs of strengthening the concrete base??
How can you determine the depth of carbonation in concrete?
Break the concrete and sprinkle the fracture with phenolphthalein or universal indicator solution. Concrete in the alkaline zone turns purple (in the phenolphthalein test) or in blue (when tested with a universal indicator solution).
What should be the slope of the concrete edge in the places of defects with exposed reinforcement, if these losses are to be filled with cement mortar refined with dispersion mass?
The angle of the concrete edge should be 45°.
What should be the maximum thickness of each mortar layer when filling a cavity with exposed reinforcement?
The maximum thickness of the mortar layer depends on the maximum size of the aggregate grain. The thickness of the layer should be at least 3 times the diameter of the largest grain, however, it should not exceed 10 times the grain diameter. Too thin a layer comes off easily, too thick is exposed to the formation of scratches.
What should be done when filling cavities in places of damage to the concrete base?
Filling cavities in places of damage to the concrete base, belongs:
1) Prime the damaged areas with adhesion-improving compound;
2) fill the gap in the place of damage with well-thickened mortar;
3) treat the surface of the mortar filling the defect.
Please list the tasks, which should be met by the topcoat applied to the mortar filling the cavity
Such a coating should:
1) provide a shield against carbonation and prevent the penetration of carbon dioxide;
2) protect against the effects of acidic liquids (np. acid rain);
3) have aesthetic values.