# Statistical Study of Corrosion Types in Constructions in South Region of Rio De Janeiro -Brazil

Carolina Lacerda da Cruz, Thalita Gonçalves de Lima, Nilo Antônio S Sampaio, José Wilson De Jesus Silva

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Carolina Lacerda da Cruz, Thalita Gonçalves de Lima, Nilo Antônio S Sampaio, José Wilson De Jesus Silva. Statistical Study of Corrosion Types in Constructions in South Region of Rio De Janeiro -Brazil. Mechanics, Materials Science & Engineering Journal, 2017, 7, 10.13140/RG.2.2.29609.60004. hal-01508598

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# Statistical Study of Corrosion Types in Constructions in South Region of Rio De Janeiro - Brazil

Carolina Lacerda da Cruz<fnref n="1" />, Thalita Gonçalves de Lima<fnref n="1" />, Nilo Antônio S. Sampaio<fnref n="1" />,<fnref n="2" />, José Wilson de Jesus Silva<fnref n="1" />,<fnref n="3" />

<figure><img src="image_2.png" /></figure>

DOI 10.13140/RG.2.2.29609.60004

**Keywords:** corrosion, construction, corrosion inhibitors, corrosion protection, corrosion in south region.

**ABSTRACT.** Some of the most difficult and troubling problems encountered in construction are those caused by corrosive processes. The corrosion processes are constituted by some material degradation, generally metallic material, by means of chemical or electrochemical actions of environment in which the material are and can or cannot be combined with mechanical stress. Corrosion is present in the materials in general. Their deterioration is caused by such physical-chemical interaction between the material and the corrosive environment where it causes major problems in several activities. In order to prevent material losses, anticorrosive techniques are used which include coatings, medium modification techniques, anodic and cathodic protection, and corrosion inhibitors such as the organic compounds use. This article analyses the statistical study of corrosion types in construction in south region of Rio de Janeiro, Brazil.

**Introduction.** The financial losses by processes of degradation and structures corrosion of metal and concrete in an engineering work are generally very high. Surveys have found that the annual corrosion cost in the United States is about 3.1% of GDP, amounting to about 276 billion [1]. While in Brazil, this cost is about 3.5% of GDP.

Corrosion may be defined as a deterioration process of the material that produces harmful and undesirable changes in the structural elements, since the corrosion product is an element different of the original material, making the alloy loses its essential qualities, (such as mechanical strength, elasticity, ductility, aesthetics) [2].

Corrosion can focus on several materials types, whether metallic or non-metallic and root causes of this deterioration are different taking into account the material and the medium. All these processes are of spontaneous nature, which occur with greater or lesser speed and intensity. The speed at which corrosion proceeds is given by the total mass of material removed in a given area during a given time. Some factors help to influence this speed, such as corrosive medium, temperature and speed effect [3].

There are some protection mechanisms whose purpose is to increase the structure life. Corrosion resistance increase by means of anticorrosive protection practices adopted in the design phase is one of the most important control forms. This resistance increase can be achieved by adopting practices that minimize the corrosion problems or using anticorrosive protection techniques [4].

For metal structures protection it is traditional to use organic paints, metallic and non-metallic coatings, which are usually effective against the corrosion process however this effectiveness will depend on some factors such as application method, environment, exposure time to weather and more.

For reinforced concrete structures in which their physical properties are result from combination of resistance to compression of concrete itself and high tensile strength which is given to the steel. Concrete consists of cement, aggregates, water and additives, therefore the defects of each of these

<footnote n="1">1 – Asociação Educacional Dom Bosco, AEDB, Resende, RJ, Brazil</footnote>

<footnote n="2">2 – Universidade do Estado do Rio de Janeiro, UERJ, Resende, RJ, Brazil</footnote>

<footnote n="3">3 – Centro Universitário Teresa D'Ávila, UNIFATEA, Lorena, SP, Brazil</footnote>
materials may influence unfavorably on the most important characteristics of the concrete: mechanical strength, stability and durability. These three characteristics are related to a number of factors among which we highlight the homogeneity and compactness [5].

In addition to structural advantages that result from combination of both materials, the concrete acts as a physical barrier of reinforcement in relation to environment and have chemical characteristics that provide the steel excellent corrosion protection. However, in the course of time it was proved that reinforced concrete also deteriorated by both degradation process of concrete itself and by corrosion of its armor.

If the concrete coating on the armor is not maintained in good condition one cannot expect a good performance of reinforced concrete, Fig. 1. Its deterioration may be caused by cracks, mechanical erosion, freezing, acid attack, attack by sulfates, alkali-aggregate reaction, biological attack, desalination [6].

Due to the environment in which it will exercise its activity, a structure can require chemical and physical protection, produced by a good compact and waterproof coating. Furthermore, a structure may require additional protections, which can act directly on steel, as in the case of cathodic protection, electroplating and coating with synthetic resins or on the concrete, as with the corrosion inhibitors and the resin or asphaltic paints [7].

<figure><img src="image_3.png" /><figcaption>Fig. 1. Steel structure.</figcaption></figure>

**Materials and methods.** For metallographic analysis, cylindrical samples of CA 50 rebar were used. The sample was mechanically polished using SiC paper (80-1200). The electrochemical study was initiated by analyzing potential measurements on open circuit. For this purpose it was used a conventional thermostated glass cell, Fig. 2, and a reference electrode of Ag/AgCl KClsat. As electrolyte, it was prepared an aqueous solution from sodium chloride (NaCl) 2.0 and 4.0 g/L. The equipment used was an AUTOLAB coupled with a computer for control and data processing, Fig. 3. Prior to each measurement the alloy surface had to be finely polished, free of scratches when viewed under a microscope.

The electrochemical cell used in the test is composed of three electrodes: the polished steel surface was the working electrode; as an auxiliary electrode it was used a Pt mesh; as a reference electrode the Ag|AgCl|KClsat. and a beaker where sodium chloride is placed [8].
The equipment used in the experiment was a potentiostat/galvanostat AUTOLAB (brand: Eco Chemie B.V., Utrecht, Netherlands, model PGSTAT302). The samples were previously sanded with sandpaper SiC immediately before the test then being washed with distilled water and then were immersed in the test solution, thereby initiating polarization [9]. The tests were repeated twice per solution.

<figure><img src="image_4.png" /><figcaption>Fig. 2. Conventional electrochemical thermostatically cell of borosilicate glass.</figcaption></figure>

<figure><img src="image_5.png" /><figcaption>Fig. 3. AUTOLAB coupled to a computer.</figcaption></figure>

**Results and discussion.** In this topic it is presented and discussed the experimental results of corrosion tests of the materials described in this work.

In the figure below (Fig. 4), the curve representing the open circuit potential [10] is presented as a function of time for the steel samples studied and tested in a NaCl solution, 2.0 and 4.0 g/L at room temperature. The open circuit potential evaluation provides a comparison of corrosive material in different media, so that the higher the value of this potential, the greater its corrosion resistance in the medium considered. It is emphasized that this potential is a thermodynamic factor and is related to the tendency for corrosion to occur, i.e. with the Gibbs free energy.
According to figures (Fig. 5 and 6), a typical active state behavior was observed by the potential descending with time. Variation in solution concentration produced a significant difference (~ 0.08 V) between the two measurements when the OCP value approaches the steady state, indicating that the change in chloride ions concentration turns the medium more oxidizing.

<figure><img src="image_6.png" /><figcaption>Fig. 4. OCP curves for CA-50 steel in two concentrations of chloride ions.</figcaption></figure>

<figure><img src="image_7.png" /><figcaption>Fig. 5. Tafel curves obtained after 3 immersion hours of steel in chloride medium.</figcaption></figure>

<figure><img src="image_8.png" /><figcaption>Fig. 6. Comparison between potentiodynamic profiles of a Tafel curve and a CP curve obtained in NaCl 2.0 g/L medium.</figcaption></figure>

For this type of steel, the electrochemical mechanism of corrosion process originates in the form of
localized corrosion (crevice) usually associated with electrolyte stagnation conditions in micro-environments where there is hindrance or difficulty to the spread of chemical species.

The solution within the crack is deoxygenated due to initial corrosion that consumes, through cathodic process, the oxygen in solution: $O_2 + 2H_2O + 4e^- 4OH^-$. The oxygen diffusion rate into the crack is not fast enough to replenish the oxygen consumed in the cathodic process. The cathodic process moves out of the crack where oxygen is plentiful. There is separation of anodic and cathodic regions. The ferrous ions are formed within the crack ($Fe^{++} + 2e^-$) and hydroxyls in oxygenated regions. The ferrous ions undergo hydrolysis ($Fe^{++} + H_2O + Fe(OH)^{++} + H^+$) and decrease the pH within the crack. Due to the current flow and mass transport phenomena, aggressive ions migrate under the influence of electrostatic field into the crack, and are concentrated there, causing great changes in chemical conditions.

As a result there is the iron hydroxide (II), white color, which due to the oxidation process is turned slowly into iron hydroxide (III), which has a brown-orange coloration according to the iron content (III). When this type of coloring appears in structures (concrete and steel), it indicates that they are suffering corrosion. The oxidized iron assumes that color and begins to crumble. In the affected areas, the metal will lose density and, if the process is not contained, it can reach the full degradation.

The curve corresponding to the steel in $NaCl$ 2.0 g/L, Fig. 5, was overlapped with the anode region of a CP curve obtained under the same experimental conditions as Fig. 6, to verify the repeatability in the current response during the scan of potentials of electroactive area and also to illustrate the active steel behavior in chloride medium within a wide potentials range, shown by the presence of positive hysteresis and the absence of a passivation region in the reverse scan, showing a generalized corrosion process. In the investigated pH range (between 5.0 and 6.0 before and after corrosion tests) the anodic reactions involve the formation of complex ions of Fe (II) and Fe (III) and possible precipitation $Fe(III)$ hydroxide.

**Statistical study.** Corrosion in civil construction is directly linked to its increase. The civil construction industry in Brazil grew above GDP in the period 2010-2013, Fig. 7. The civil construction is a featured segment in south economy in Rio de Janeiro, being responsible for almost 25% of new jobs in recent years [11].

<figure><img src="image_9.png" /><figcaption>Fig. 7. Civil Construction in Brazil grew above the GDP in the period 2010 to 2013.</figcaption></figure>

This growth was due to the need for improvements in the country boosted, for example, by the World
Cup, 2016 Olympics in Rio de Janeiro with the need for Brazil in infrastructure, the Accelerated Program for Growth (PAC, in Portuguese) and the program called "My house, my Life" (Minha Casa, Minha vida - in Portuguese) sponsored by a federal bank.

The State Government, by means of the Department of Highways and Roads (DER, in Portuguese), made in the last two years important interventions on state roads which have improved the population routine. Counties of state south were Rio Claro, Miguel Pereira and Barra do Pirai that have received improvements to their roads (paving, drainage and coasting building and extending bridges). This year, it was given to paving the RJ-151, between Visconde de Mauá and Campo Alegre. With investments of US$ 2.25 million, the work included paving, drainage, earthworks, rock blasting and track enlargement of the RJ-151, and an extension of 8.4 km. Even with Brazilian economy slowdown, the companies located in the South of Rio de Janeiro - region integrated by counties like Resende, Itatiaia, Porto Real and Volta Redonda - proceeding with their investment plans of more than US$ 3.75 billion for the period 2010-2016. It is projects like the new Nissan plant in Resende, of US$ 0.8 billion, and the expansion of the plant of PSA Peugeot Citroën, in Porto Real, US$ 1.16 billion. The number does not consider the works of Angra 3, which has received US$ 0.88 billion this year. The construction industry is one of the sectors of the economy of most impact on employment and population welfare. Investments in infrastructure and housing demand large volumes of steel (rebar for reinforced concrete CA60, CA50 and CA25, latticework frames, brackets, etc.)

The civil construction shows its importance also in the economic and social aspect. Thus, the amounts of activities are part of the construction production cycle that serves the consumer goods and services for other sectors. In addition, the civil construction, from the social point of view, is a great capacity to generate jobs and labor, direct labor and indirect absorption mainly little and unskilled. The performance of construction is influenced directly and strongly by the performance of the economy, Figs. 8 to 15 [12-15].

<table><caption>Tabela 1: Crescimento (%) do Número de Estabelecimentos por Setores do IBGE na Região Médio-Paraíba do Estado do Rio de Janeiro (2011)</caption><thead><tr><th>Regiões Geográficas</th><th>Total</th><th>Extrativa Mineral</th><th>Indústria de Transformação</th><th>Serviços de Utilidade Pública</th><th>Construção Civil</th><th>Comércio</th><th>Serviços</th><th>Administração Pública</th><th>Agropecuária, extração vegetal, caça e pesca</th></tr></thead><tbody><tr><td>Estado do Rio de Janeiro</td><td>17,8%</td><td>17,8%</td><td>14,2%</td><td>22,5%</td><td>50,1%</td><td>18,9%</td><td>17,1%</td><td>22,6%</td><td>-4,0%</td></tr><tr><td>Região do Médio-Paraíba</td><td>19,5%</td><td>-17,1%</td><td>17,7%</td><td>0,0%</td><td>48,4%</td><td>19,2%</td><td>24,1%</td><td>27,0%</td><td>-3,4%</td></tr><tr><td>Porto Real</td><td>65,8%</td><td>-</td><td>24,1%</td><td>-</td><td>60,0%</td><td>84,4%</td><td>65,0%</td><td>0,0%</td><td>100,0%</td></tr><tr><td>Itatiaia</td><td>38,4%</td><td>-</td><td>90,5%</td><td>0,0%</td><td>31,3%</td><td>34,8%</td><td>43,4%</td><td>-66,7%</td><td>-29,4%</td></tr><tr><td>Pinheiral</td><td>32,9%</td><td>-100,0%</td><td>-16,7%</td><td>-</td><td>71,4%</td><td>36,6%</td><td>45,6%</td><td>50,0%</td><td>55,6%</td></tr><tr><td>Resende</td><td>27,6%</td><td>25,0%</td><td>26,1%</td><td>0,0%</td><td>164,4%</td><td>26,2%</td><td>25,6%</td><td>75,0%</td><td>9,1%</td></tr><tr><td>Quatis</td><td>27,4%</td><td>-50,0%</td><td>62,5%</td><td>0,0%</td><td>12,5%</td><td>34,3%</td><td>15,0%</td><td>100,0%</td><td>26,8%</td></tr><tr><td>Volta Redonda</td><td>19,0%</td><td>-33,3%</td><td>10,5%</td><td>40,0%</td><td>34,4%</td><td>15,7%</td><td>24,0%</td><td>16,7%</td><td>9,5%</td></tr><tr><td>Barra Mansa</td><td>18,0%</td><td>-14,3%</td><td>31,0%</td><td>-40,0%</td><td>45,0%</td><td>17,3%</td><td>23,4%</td><td>40,0%</td><td>-23,6%</td></tr><tr><td>Barra do Pirai</td><td>11,7%</td><td>33,3%</td><td>-9,2%</td><td>33,3%</td><td>43,6%</td><td>11,5%</td><td>15,4%</td><td>100,0%</td><td>6,6%</td></tr><tr><td>Rio Claro</td><td>10,4%</td><td>-</td><td>-18,2%</td><td>100,0%</td><td>0,0%</td><td>32,0%</td><td>24,2%</td><td>100,0%</td><td>-7,0%</td></tr><tr><td>Pirai</td><td>9,5%</td><td>-</td><td>-25,6%</td><td>-16,7%</td><td>-8,7%</td><td>18,8%</td><td>33,7%</td><td>-25,0%</td><td>-7,2%</td></tr><tr><td>Valença</td><td>9,4%</td><td>-42,9%</td><td>46,3%</td><td>-33,3%</td><td>6,9%</td><td>16,4%</td><td>9,5%</td><td>0,0%</td><td>-7,3%</td></tr><tr><td>Rio das Flores</td><td>8,1%</td><td>0,0%</td><td>36,4%</td><td>-</td><td>50,0%</td><td>17,6%</td><td>11,8%</td><td>0,0%</td><td>-2,4%</td></tr></tbody></table>

Fonte: Ministério do Trabalho e Emprego, Relação Anual de Informações Sociais - RAIS (2011).

Fig. 8. Growth (%) of establishments number by sectors of IBGE (Brazilian Institute of Geography and Statistics, in Portuguese) in the Mid-Paraíba region of Rio de Janeiro (2011).
<table><caption>Tabela 2: Crescimento do Número de Estabelecimentos por Setores do IBGE na Região Centro-Sul Fluminense do Estado do Rio de Janeiro (2011)</caption><thead><tr><th>Regiões Geográficas</th><th>Total</th><th>Extrativa Mineral</th><th>Indústria de Transformação</th><th>Serviços de Utilidade Pública</th><th>Construção Civil</th><th>Comércio</th><th>Serviços</th><th>Administração Pública</th><th>Agropecuária, extração vegetal, caça e pesca</th></tr></thead><tbody><tr><td>Estado do Rio de Janeiro</td><td>17,8%</td><td>17,8%</td><td>14,2%</td><td>22,5%</td><td>50,1%</td><td>18,9%</td><td>17,1%</td><td>22,6%</td><td>-4,0%</td></tr><tr><td>Região Centro-Sul Fluminense</td><td>19,4%</td><td>-4,2%</td><td>39,2%</td><td>-10,0%</td><td>33,3%</td><td>19,4%</td><td>22,8%</td><td>31,8%</td><td>-3,9%</td></tr><tr><td>Três Rios</td><td>30,4%</td><td>-12,5%</td><td>109,8%</td><td>66,7%</td><td>41,0%</td><td>26,5%</td><td>23,7%</td><td>150,0%</td><td>-15,3%</td></tr><tr><td>Sapucaia</td><td>27,0%</td><td>33,3%</td><td>21,4%</td><td>33,3%</td><td>71,4%</td><td>37,3%</td><td>49,1%</td><td>-25,0%</td><td>2,6%</td></tr><tr><td>Paty do Alferes</td><td>21,2%</td><td>-</td><td>6,7%</td><td>-100,0%</td><td>33,3%</td><td>28,1%</td><td>33,3%</td><td>0,0%</td><td>-3,6%</td></tr><tr><td>Paraíba do Sul</td><td>19,7%</td><td>50,0%</td><td>23,0%</td><td>0,0%</td><td>133,3%</td><td>21,7%</td><td>37,4%</td><td>0,0%</td><td>-15,0%</td></tr><tr><td>Engenheiro Paulo de Frontin</td><td>17,7%</td><td>-</td><td>-28,0%</td><td>0,0%</td><td>-</td><td>38,3%</td><td>11,1%</td><td>0,0%</td><td>41,7%</td></tr><tr><td>Mendes</td><td>9,9%</td><td>-</td><td>-26,1%</td><td>-100,0%</td><td>0,0%</td><td>13,0%</td><td>22,6%</td><td>150,0%</td><td>-42,9%</td></tr><tr><td>Vassouras</td><td>9,4%</td><td>-</td><td>4,5%</td><td>0,0%</td><td>25,0%</td><td>2,8%</td><td>20,6%</td><td>100,0%</td><td>1,2%</td></tr><tr><td>Miguel Pereira</td><td>9,0%</td><td>-75,0%</td><td>0,0%</td><td>-50,0%</td><td>20,0%</td><td>-2,5%</td><td>23,8%</td><td>0,0%</td><td>22,2%</td></tr><tr><td>Areal</td><td>6,8%</td><td>-</td><td>14,3%</td><td>-33,3%</td><td>41,7%</td><td>5,3%</td><td>4,3%</td><td>0,0%</td><td>3,3%</td></tr><tr><td>Comendador Levy Gasparian</td><td>-1,7%</td><td>-60,0%</td><td>48,3%</td><td>-100,0%</td><td>-57,9%</td><td>26,7%</td><td>-24,1%</td><td>0,0%</td><td>0,0%</td></tr></tbody></table>

Fonte: Ministério do Trabalho e Emprego, Relação Anual de Informações Sociais - RAIS (2011).

Fig. 9. Growth of Establishment number by IBGE Sectors in the South Central Region of the State of Rio de Janeiro (2011).

<table><caption>Tabela 3: Crescimento (%) do Número de Estabelecimentos por Setores do IBGE na Região Costa Verde do Estado do Rio de Janeiro (2011)</caption><thead><tr><th>Regiões Geográficas</th><th>Total</th><th>Extrativa Mineral</th><th>Indústria de Transformação</th><th>Serviços de Utilidade Pública</th><th>Construção Civil</th><th>Comércio</th><th>Serviços</th><th>Administração Pública</th><th>Agropecuária, extração vegetal, caça e pesca</th></tr></thead><tbody><tr><td>Estado do Rio de Janeiro</td><td>17,8%</td><td>17,8%</td><td>14,2%</td><td>22,5%</td><td>50,1%</td><td>18,9%</td><td>17,1%</td><td>22,6%</td><td>-4,0%</td></tr><tr><td>Região da Costa Verde</td><td>28,5%</td><td>-25,0%</td><td>21,4%</td><td>20,0%</td><td>39,0%</td><td>29,2%</td><td>29,4%</td><td>16,7%</td><td>5,3%</td></tr><tr><td>Paraty</td><td>34,5%</td><td>50,0%</td><td>23,8%</td><td>-</td><td>300,0%</td><td>24,4%</td><td>37,6%</td><td>0,0%</td><td>57,1%</td></tr><tr><td>Angra dos Reis</td><td>28,9%</td><td>-40,0%</td><td>18,0%</td><td>20,0%</td><td>11,0%</td><td>31,8%</td><td>30,1%</td><td>66,7%</td><td>12,2%</td></tr><tr><td>Mangaratiba</td><td>17,3%</td><td>-100,0%</td><td>50,0%</td><td>-</td><td>82,4%</td><td>19,7%</td><td>14,7%</td><td>0,0%</td><td>-30,0%</td></tr></tbody></table>

Fonte: Ministério do Trabalho e Emprego, Relação Anual de Informações Sociais - RAIS (2011).

Fig. 10. Growth (%) of Establishment Number by IBGE sectors in the Costa Verde region of Rio de Janeiro State (2011).

<figure><img src="image_10.png" /></figure>

Fig. 11. Establishment numbers in some cities in the southern state.
<table><caption>Tabela 4: Distribuição (%) do Número de Empregados por Municípios da Região Centro-Sul Fluminense do Estado do Rio de Janeiro / Setores IBGE (2011)</caption><thead><tr><th>Regiões de Governo</th><th>Total</th><th>Extrativa Mineral</th><th>Indústria de Transformação</th><th>Serviços de Utilidade Pública</th><th>Construção Civil</th><th>Comércio</th><th>Serviços</th><th>Administração Pública</th><th>Agropecuária, extração vegetal, caça e pesca</th></tr></thead><tbody><tr><td>Região Centro-Sul Fluminense</td><td>100,0%</td><td>0,8%</td><td>18,1%</td><td>0,2%</td><td>3,1%</td><td>19,9%</td><td>35,8%</td><td>18,8%</td><td>3,3%</td></tr><tr><td>Três Rios</td><td>100,0%</td><td>1,8%</td><td>26,5%</td><td>0,3%</td><td>5,6%</td><td>22,7%</td><td>31,8%</td><td>10,0%</td><td>1,3%</td></tr><tr><td>Areal</td><td>100,0%</td><td>0,0%</td><td>4,4%</td><td>0,4%</td><td>2,2%</td><td>4,9%</td><td>76,6%</td><td>10,1%</td><td>1,4%</td></tr><tr><td>Paraíba do Sul</td><td>100,0%</td><td>0,8%</td><td>27,4%</td><td>0,1%</td><td>1,7%</td><td>19,4%</td><td>26,2%</td><td>16,9%</td><td>7,4%</td></tr><tr><td>Vassouras</td><td>100,0%</td><td>0,0%</td><td>9,5%</td><td>0,1%</td><td>1,6%</td><td>18,0%</td><td>42,0%</td><td>24,0%</td><td>4,9%</td></tr><tr><td>Miguel Pereira</td><td>100,0%</td><td>0,0%</td><td>4,0%</td><td>0,5%</td><td>4,2%</td><td>23,4%</td><td>35,4%</td><td>28,8%</td><td>3,7%</td></tr><tr><td>Sapucaia</td><td>100,0%</td><td>0,9%</td><td>16,0%</td><td>0,3%</td><td>1,0%</td><td>37,3%</td><td>14,0%</td><td>21,4%</td><td>9,0%</td></tr><tr><td>Comendador Levy Gasparian</td><td>100,0%</td><td>0,0%</td><td>20,4%</td><td>0,0%</td><td>1,4%</td><td>11,6%</td><td>47,8%</td><td>17,8%</td><td>0,9%</td></tr><tr><td>Paty do Alferes</td><td>100,0%</td><td>0,7%</td><td>14,9%</td><td>0,0%</td><td>0,4%</td><td>26,3%</td><td>13,1%</td><td>39,2%</td><td>5,5%</td></tr><tr><td>Mendes</td><td>100,0%</td><td>0,0%</td><td>6,4%</td><td>0,0%</td><td>0,3%</td><td>22,2%</td><td>13,1%</td><td>57,5%</td><td>0,5%</td></tr><tr><td>Engenheiro Paulo de Frontin</td><td>100,0%</td><td>0,0%</td><td>22,2%</td><td>0,7%</td><td>0,1%</td><td>15,1%</td><td>18,0%</td><td>40,3%</td><td>3,7%</td></tr></tbody></table>

Fonte: Ministério do Trabalho e Emprego, Relação Anual de Informações Sociais - RAIS (2011).

Fig. 12. Distribution (%) of Employees Number by Counties of Fluminense South Central Region of Rio de Janeiro State / IBGE Sectors (2011).

<table><caption>Tabela 5: Distribuição (%) do Número de Empregados por Municípios da Região do Médio-Paraíba do Estado do Rio de Janeiro / Setores IBGE (2011)</caption><thead><tr><th>Regiões de Governo</th><th>Total</th><th>Extrativa Mineral</th><th>Indústria de Transformação</th><th>Serviços de Utilidade Pública</th><th>Construção Civil</th><th>Comércio</th><th>Serviços</th><th>Administração Pública</th><th>Agropecuária, extração vegetal, caça e pesca</th></tr></thead><tbody><tr><td>Região do Médio-Paraíba</td><td>100,0%</td><td>0,2%</td><td>22,2%</td><td>0,6%</td><td>7,5%</td><td>20,6%</td><td>33,3%</td><td>14,1%</td><td>1,6%</td></tr><tr><td>Volta Redonda</td><td>100,0%</td><td>0,1%</td><td>19,8%</td><td>0,7%</td><td>12,7%</td><td>22,1%</td><td>38,4%</td><td>6,2%</td><td>0,1%</td></tr><tr><td>Barra Mansa</td><td>100,0%</td><td>0,3%</td><td>17,8%</td><td>0,3%</td><td>3,8%</td><td>24,5%</td><td>39,4%</td><td>12,9%</td><td>1,0%</td></tr><tr><td>Resende</td><td>100,0%</td><td>0,3%</td><td>19,7%</td><td>0,9%</td><td>3,6%</td><td>23,3%</td><td>35,8%</td><td>15,1%</td><td>1,3%</td></tr><tr><td>Barra do Piraí</td><td>100,0%</td><td>0,3%</td><td>21,1%</td><td>0,8%</td><td>6,3%</td><td>26,3%</td><td>28,6%</td><td>13,9%</td><td>2,6%</td></tr><tr><td>Valença</td><td>100,0%</td><td>0,2%</td><td>20,0%</td><td>0,2%</td><td>1,3%</td><td>21,5%</td><td>23,4%</td><td>28,8%</td><td>4,7%</td></tr><tr><td>Porto Real</td><td>100,0%</td><td>0,1%</td><td>72,9%</td><td>0,1%</td><td>1,6%</td><td>2,9%</td><td>11,2%</td><td>10,6%</td><td>0,7%</td></tr><tr><td>Itatiaia</td><td>100,0%</td><td>0,0%</td><td>20,3%</td><td>0,7%</td><td>2,1%</td><td>10,8%</td><td>33,0%</td><td>32,7%</td><td>0,4%</td></tr><tr><td>Piraí</td><td>100,0%</td><td>0,0%</td><td>27,3%</td><td>1,8%</td><td>8,2%</td><td>10,1%</td><td>17,2%</td><td>30,6%</td><td>4,8%</td></tr><tr><td>Rio das Flores</td><td>100,0%</td><td>0,0%</td><td>9,5%</td><td>0,0%</td><td>22,5%</td><td>3,6%</td><td>35,3%</td><td>24,2%</td><td>4,9%</td></tr><tr><td>Pinheiral</td><td>100,0%</td><td>0,0%</td><td>13,4%</td><td>0,0%</td><td>4,8%</td><td>17,6%</td><td>25,9%</td><td>33,5%</td><td>4,7%</td></tr><tr><td>Quatis</td><td>100,0%</td><td>1,0%</td><td>5,2%</td><td>0,2%</td><td>21,9%</td><td>16,0%</td><td>15,4%</td><td>34,9%</td><td>5,5%</td></tr><tr><td>Rio Claro</td><td>100,0%</td><td>0,0%</td><td>2,8%</td><td>0,4%</td><td>1,0%</td><td>13,0%</td><td>8,6%</td><td>48,1%</td><td>26,2%</td></tr></tbody></table>

Fonte: Ministério do Trabalho e Emprego, Relação Anual de Informações Sociais - RAIS (2011).

Fig. 13. Distribution (%) of Employees Number by Counties of Middle Paraíba Region of Rio de Janeiro State / IBGE Sectors (2011).

<table><caption>Tabela 6: Distribuição (%) do Número de Empregados por Municípios da Região da Costa Verde do Estado do Rio de Janeiro / Setores IBGE (2011)</caption><thead><tr><th>Regiões de Governo</th><th>Total</th><th>Extrativa Mineral</th><th>Indústria de Transformação</th><th>Serviços de Utilidade Pública</th><th>Construção Civil</th><th>Comércio</th><th>Serviços</th><th>Administração Pública</th><th>Agropecuária, extração vegetal, caça e pesca</th></tr></thead><tbody><tr><td>Região da Costa Verde</td><td>100,0%</td><td>0,2%</td><td>13,8%</td><td>3,5%</td><td>10,3%</td><td>14,4%</td><td>31,0%</td><td>26,2%</td><td>0,5%</td></tr><tr><td>Angra dos Reis</td><td>100,0%</td><td>0,3%</td><td>19,9%</td><td>5,1%</td><td>14,0%</td><td>16,3%</td><td>28,2%</td><td>15,6%</td><td>0,5%</td></tr><tr><td>Mangaratiba</td><td>100,0%</td><td>0,0%</td><td>0,4%</td><td>0,0%</td><td>1,8%</td><td>4,7%</td><td>32,9%</td><td>59,7%</td><td>0,5%</td></tr><tr><td>Paraty</td><td>100,0%</td><td>0,3%</td><td>1,0%</td><td>0,0%</td><td>2,4%</td><td>22,6%</td><td>46,1%</td><td>26,7%</td><td>1,0%</td></tr></tbody></table>

Fonte: Ministério do Trabalho e Emprego, Relação Anual de Informações Sociais - RAIS (2011).

Fig. 14. Distribution (%) of Employees Number by Counties in Costa Verde region in Rio de Janeiro State / IBGE Sectors (2011).
<figure><img src="image_11.png" /><figcaption>Fig. 15. Numbers of employees in some cities in the southern state.</figcaption></figure>

**Summary.** With the end of the work, it is presented by means of researches and tests, the causes of corrosion of the studied area, which are directly influenced by the location in which the buildings are, influenced by salt spray and different climates present throughout southern Rio de Janeiro. With the construction boom, it tends to be more careful with concrete for durability achieve as much as possible.

**References**

[1] Koch, G. H., Brongers, M. P., Thomson, N. G., Virmanio, Y. P., & Payer, J. H. (2005). Cost of corrosion in the United States. *Handbook of environmental degradation of materials*, 3-24.

[2] OLIVARI, G. (2003). Patologia em edificações. São Paulo: Universidade Anhembi Morumbi.

[3] V. GENTIL - Corrosão. Rio de Janeiro: LTC – Livros Técnicos e Científicos Editora, 1994.

[4] Portella, K. F., Garcia, C. M., Vergés, G. R., Joukoski, A., Freire, K. R. R., & de PCorrea, A. (2006). Desempenho físico-químico de metais e estruturas de concreto de redes de distribuição de energia: Estudo de caso na região de Manaus. *Química Nova*, 29(4), 724.

[5] Cánovas, M. F. (1988). *Patologia e terapia do concreto armado*. Pini.

[6] Hoar, T. P., & Mears, D. C. (1966, October). Corrosion-resistant alloys in chloride solutions: materials for surgical implants. In *Proceedings of the Royal Society of London A: Mathematical, Physical and Engineering Sciences* (Vol. 294, No. 1439, pp. 486-510). The Royal Society.

[7] Marino, C., & de Titânio, Ó. A. (1997). *um estudo do crescimento e estabilidade em meio ácido. 1997. 135f* (Doctoral dissertation, Dissertação (Mestrado em Físico-Química)-Universidade Federal de São Carlos, São Carlos).

[8] Silva, L. L. G. (2001). Eletrodos em diamante CVD para estudos eletroquímicos. *Eletrodos em diamante CVD para estudos eletroquímicos*.

[9] de Macena Rezende, D. (2014). *ESTUDO DA FRAGILIZAÇÃO PELO HIDROGÊNIO NO AÇO SUPER 13Cr MODIFICADO* (Doctoral dissertation, Departamento de Engenharia Metalúrgica e de Materiais da Escola Politécnica, Universidade Federal do Rio de Janeiro).

[10] Greaney, M. J., Das, S., Webber, D. H., Bradforth, S. E., & Brutchey, R. L. (2012). Improving open circuit potential in hybrid P3HT: CdSe bulk heterojunction solar cells via colloidal tert-butylthiol ligand exchange. *Acs Nano*, 6(5), 4222-4230.
[11] Lins, L. M., Salerno, M. S., Araújo, B. C., Gomes, L. A. V., Nascimento, P. A. M. M., & Toledo, D. (2014). Escassez de engenheiros no Brasil? Uma proposta de sistematização do debate. *Novos Estudos-CEBRAP*, (98), 43-67.

[12] Sociais, R. A. D. I. Ministério Do Trabalho E Emprego (RAIS/MET). 2006-2011. *Base de Dados*.

[13] Sawacha, E., Naoum, S., & Fong, D. (1999). Factors affecting safety performance on construction sites. *International journal of project management*, 17(5), 309-315.

[14] Porter, M. (2003). The economic performance of regions. *Regional studies*, 37(6-7), 549-578.

[15] Leiblein, M. J., Reuer, J. J., & Dalsace, F. (2002). Do make or buy decisions matter? The influence of organizational governance on technological performance. *Strategic management journal*, 23(9), 817-833.