PSI - Issue 11

Iara Silva et al. / Procedia Structural Integrity 11 (2018) 130–137 Iara Silva et al. / Structural Integrity Procedia 00 (2018) 000 – 000

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The surfaces of the concrete sleepers have been completely cleaned, free of dirt and loose materials. According to the manufacturer's recommendation, the piece was moistened with clean water, indicated by Fig. 2, to facilitate the penetration of chemical agents.

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b

Fig. 2. Preparation of sleepers for recovery: (a) surface cleaning process for product application; (b) cleaned and moistened sleeper surface

The application mixture (Fig. 3a) was made only by the addition of water in the proportion indicated by the product manufacturer, for later application with the use of a simple brush. A maximum of two coats (Fig. 3.b) were applied, according to the need perceived by the applicator, considering the manufacturer's specification of a maximum thickness of 1.25 mm in order not to hinder the curing process of the material and to maintain the dimensions and geometry of the concrete sleeper design, removing excess material, when necessary.

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Fig. 3. Procedure execution: (a) Product and water mixture; (b) Product application on the sleepers

After the initial drying of the product, shown in Fig. 4, curing was performed under normal conditions of contact with the air for two days. Then the sleepers were inspected again to verify if the repair was performed correctly.

Fig. 4. Applied product drying

Properly repaired sleepers were reclassified as Class B sleepers (or 2nd category sleepers) and identified with oil based and concrete-specific paint in orange on their two lateral sides and a strip in their central part, as demonstrated