PSI - Issue 33

8

Fabrizio Pittau et al. / Procedia Structural Integrity 33 (2021) 630–645 Author name / Structural Integrity Procedia 00 (2019) 000–000

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(a) (b) Fig. 8. Details of leveling with epoxy-cement mortar, (a) corner and (b) lid.

3.1.2. Application The product application was carried out in the following phases (Fig. 9): • surface cleaning; • application first layer of epoxy-cement mortar; • application of the epoxy primer; • application of the waterproofing membrane.

After polishing, the leveling compound with the epoxy-cement mortar was prepared and applied. The preparation involves mixing the three components with an electric mixer in the absence of water. The application was carried out by spray and finished with a brush (2 kg / m 2 per mm of thickness). The epoxy primer was prepared by mixing the two components and its application was done with a brush. The application took place more than 15 hours after the shaving application. Finally, the membrane was produced by hot mixing the component using a special tool and then applied by spray the temperature of the compost at about 70 ° C. The application took place more than 12 hours after applying the primer. The membrane has a curing time of 24 hours.

(a)

(b)

Fig. 9. Details of Polyurea layer on specimen A.

3.2. Specimen B – Mineral coating

3.2.1. Type of Coating Specimen B was coated with the following layers of material: • primer; • mineral-based waterproofing system resistant to sulphates.

This is mineral coating with enriched with crystallizing components that seal the pores of the structure (Fig. 10). It guarantees both positive and negative pressure tightness (internal or external pressure) up to 13 bar. A specific primer was used to ensure sealing against negative pressures. It is a liquid primer based on polymers and silicates. The product is able to penetrate the concrete substrate up to 20 mm depending on the type of the latter.