DOI: 10.17675/2305-6894-2024-13-3-20

Abstract

The work aims to evaluate the efficiency of migrating corrosion inhibitor based on organic amines called HAENYTEX Protectoseal Ci in relation to steel reinforcement in concrete. Specimens of fine-grained concrete reinforced with steel rods (O5 mm, length 120 mm) were tested. Three series: without inhibitor, with inhibitor applied, with inhibitor and moistening. Current density in specimens without inhibitor increased by 26% and 196% after 90 and 180 days. HAENYTEX Protectoseal Ci demonstrated passive state with 9.66, 0.94 and 0.65 muA/cm2 at initial, 90 and 180 days.

1. Introduction

The service life of reinforced concrete structures depends on reinforcement protection from corrosion. Concrete pore solution has alkaline environment and a protective oxide passive film on reinforcement. Carbonation and chloride attack are main corrosion causes. Corrosion inhibitors impede corrosion in aggressive medium. Migrating inhibitors are applied to finished structures, penetrate through diffusion and capillary adsorption to form protective film on steel.

2. Materials and Methods

Materials: Portland cement CEM I 42.5N, sand, superplasticizer S-3, calcium chloride (2.5% of cement mass), HAENYTEX Protectoseal Ci (organic amines, density 1.1-1.3 g/cm3, pH 7.5-9.5).

Specimens: Fine-grained concrete 40x40x160 mm with steel rods (O5 mm, 120 mm). Inhibitor applied in 2 layers (0.6 L/m2). Three series of 9 specimens each.

3. Results

Table 5. Initial state

IndicatorSeries 1 (ref)Series 2 (inhibitor)Series 3 (inhibitor + moist)
Current density at +300 mV, muA/cm226.19.663.5
Potential 60 s after shutdown, mV-240+298+445
Anodic polarization curves initial
Fig. 1. Anodic polarization curves, initial state.

Table 6. After 90 days

IndicatorSeries 1Series 2Series 3
Current density, muA/cm232.90.94 (-97.1%)1.00 (-97.0%)
Potential, mV-22.5+592+583
Anodic polarization curves 90 days
Fig. 2. Anodic polarization curves after 90 days.

Table 7. After 180 days

IndicatorSeries 1Series 2Series 3
Current density, muA/cm276.950.65 (-99%)1.79 (-98%)
Potential, mV< -1500+598+365
Anodic polarization curves 180 days
Fig. 3. Anodic polarization curves after 180 days.

After 180 days reference specimens showed corrosion damage up to 50% of rod surface. Specimens with inhibitor remained passive with no corrosion signs.

4. Conclusions

  1. Without inhibitor current density increased by 26% (90 days) and 196% (180 days).
  2. HAENYTEX Protectoseal Ci ensured passive state of reinforcement in all test periods.
  3. Most effective protection achieved without additional moistening.
  4. Inhibitor recommended for protecting reinforcement in concrete structures in aggressive environments.

Affiliations

  1. MSS JSC, Moscow, Russia
  2. NIIZHB named after A.A. Gvozdev, Moscow, Russia
  3. A.N. Frumkin Institute of Physical Chemistry and Electrochemistry RAS, Moscow, Russia
  4. Peter the Great St. Petersburg Polytechnic University, Russia
  5. RUDN University, Moscow, Russia
  6. Emperor Alexander I St. Petersburg State Transport University, Russia