Dr. Abel Castañeda, Dr. Francisco Corvo, Dr. Juan.J. Howland, Atmospheric corrosion aggressivity study to reinforcement steel in the reinforced concrete in Havana city. Dr. Abel Castañeda, Dr. Francisco Corvo, Dr. Juan.J. Howland, Dr. Rigoberto Marrero.

INTRODUCTION Atmospheric corrosion in reinforcement steel on reinforced concrete Studies under accelerated test in outdoor exposure condition and salt chambers Diagnostic work on site where the structures have a deterioration very advanced. Studies in outdoor exposure condition HAVE NOT BEEN CARRIED OUT Map of Corrosive aggressiveness of atmospheres in Cuba Very High C5: Up to 1 km to the shoreline in zone without secreening condition. High C4: Between 1 y 3 km in by north cost and 1 km by south cost without screening condition

OBJECTIVES INTRODUCTION Demonstrate how atmospheric corrosion on steel reinforced concrete can be studied following the methodology established for atmospheric corrosion of the metallic materials most used in the construction industry. Establishment of corrosivity categories of the atmospheres on different types of concrete in a coastal city located in a tropical island. Demonstrate other factor that influence in atmospheric corrosion on steel reinforced concrete in outdoor exposure condition.

MATERIALS AND METHODS

RESULTS TOW Ʈ4(2 500 < Ʈ ≤ 5 500) Year 1 3 408 h/y Year 2 3 120 h/y

RESULTS Behavior of Cl-DR respecting time of exposure in summer and winter seasons. Cl- DR (a and b) in the exposure site at 20 m and remaining at different distances from the sea respectively.

RESULTS Behavior of SOx-DR respecting time of exposure in summer and winter seasons.

RESULTS Behavior of annual average Cl-DR a) and SOx-DR b) respecting distance from the sea.

RESULTS Exposure site (m) Carbon steel Zinc Copper Atmospheres rcorr Corrosivity categories estimated for different exposure sites using dose-response functions established by ISO 9223:2012. Exposure site (m) Carbon steel Zinc Copper Atmospheres rcorr (µm y-1) C 20 407.16 CX 21.81 4.52 C5 Coastal-Industrial 170 35.49 C3 1.84 1.02 Urban 600 32.24 1.63 0.92 1 375 50.31 C4 2.80 1.38 Industrial 1 772 28.31 1.36 0.79 2 365 26.09 1.18 0.78 4 911 25.48 1.17 0.71

RESULTS Behavior of atmospheric corrosion in the time of exposure and water cement ratio. Covering thickness of 20 mm a). Covering thickness of 40 mm b), in the exposure site located at 20 m from the sea

RESULTS rcorr =atb rcorr =atb Fitted regressions for values of atmospheric corrosion in the time of exposure Covering thickness 20 mm n = 24 Covering thickness 40 mm w c Regression r R2 (%) p 0.4 0.95 91.0 0.0000 - 0.5 0.94 98.0 0.99 0,0000 0.6 81.0 rcorr =atb rcorr =atb rcorr =0.02t1.49 rcorr =0.18t2.13 rcorr =0.06t1.72 rcorr =0.11t2.43 rcorr =0.14t2.01

0.4 0.5 0.6 Covering thickness 20 mm Covering thickness 40 mm Water/cement ratio Covering thickness 20 mm Covering thickness 40 mm ti (years) tp UL 0.4 3 < 20 ±23 - 0.5 1 4 2 5 0.6 0.4 0.5 0.6 Covering thickness 20 mm Covering thickness 40 mm

Behavior of atmospheric corrosion at different distances from the sea. RESULTS Behavior of atmospheric corrosion at different distances from the sea.

RESULTS Outdoor exposure site (m) Water/cement ratio w/c 0,4 w/c 0,5 Recovering thickness (mm) 20 40 C5 C2 170 600 1 365 1 772 2 365 4 911

RESULTS

CONCLUSIONS Atmospheric corrosion on steel reinforced concrete can be studied following the methodology established for atmospheric corrosion of the metallic materials most used in the construction industry. Corrosion aggressivity level for reinforcement steel embedded to concrete quality and recovering thickness were established as sure and effective tool allowing prevent the very advanced deterioration of the structures that are intended to build a short distance from the sea, without the presence of artificial and natural screening in the northern coast of Havana. The corrosion aggressivity level of very high (C5) established in the ISO 9223 standard for the metallic materials more used in the construction industry, it can be taken into account too for the reinforced steel embedded in the reinforced concrete for the water/cement 0.5 and 0.6 to recovering thickness 20 and 40 mm and water/cement 0.4 too but for recovering thickness of 20 mm. This result was confirmed with visual observation of the reinforced concrete probes. Another factor that influence on atmopheric corrosion on steel reinforced concrete as time of exposure and distance from the sea were showed