ORIGINAL ARTICLE
MAIA, Daniel Araújo [1], SILVA FILHO, Antônio Freitas da [2]
MAIA, Daniel Araújo. SILVA FILHO, Antônio Freitas da. The impact of judicial expertise in cases of pathological manifestations in ceramic coatings. Revista Científica Multidisciplinar Núcleo do Conhecimento. Year 05, Ed. 10, Vol. 04, pp. 81-97. October 2020. ISSN: 2448-0959, Access link: https://www.nucleodoconhecimento.com.br/civil-engineering/ceramic-coatings
SUMMARY
The present work aims to present to professionals working in the area of civil construction the impact of judicial expertise in the analysis of the causes of pathological manifestations in ceramic coatings. We sought to answer whether judicial expertise has the necessary importance to serve as an investigative guide element of the causes of pathological manifestations in ceramic coating. A case study was conducted in a building located in the Neighborhood of Patamares, in the municipality of Salvador/BA. This study allowed the identification of pathological manifestations and their probable causes, as well as highlighted the importance of NBR 13755 (ABNT, 2017). The case study was based on the systematic reading of the literature review on the subject, in order to discuss the possible causes of cracks and detachments of tablets in gardeners and playground walls. We also sought to discuss the importance of judicial expertise for the analysis of these pathological manifestations and how the report produced assists the magistrates in their decisions in judicial proceedings. It was possible to prove that, in general, there is no specific cause for pathological occurrences, but rather a sum of factors. Moreover, the absence of the coating of the ceramic plates on some rods characterizes the improper use of the product, whether by specification not appropriate to the type of exposure, by defect of the material itself or the procedure of its preparation or application. Thus, it is expected that this work will serve as an example for new ventures in the field of civil engineering, in order to avoid technical problems caused by non-compliance with the Brazilian Technical Standards.
Keywords: Report, buildings, structural and aesthetic damage.
1. INTRODUCTION
The construction work unfolds in several phases. All important for the success of the construction venture, especially the final phase. Further care is demanded in the final stage, because it is the realization of the idealized project, as well as the aesthetic aspect of the work.
In particular, the quality of the coating is highlighted as an essential factor for the aesthetics of the building. Legal demands are recurrent in the constructive market, in which insatisms and requests for accountability of construction companies are narrated.
According to the National Association of Ceramic Manufacturers for Coatings, Sanitary Ware and Congeners – ANFACER (2007), Brazil is the second largest consumer of ceramics in the world, being surpassed only by China. Its intense use is due to the material being, among its advantages, low cost, good quality, aesthetically beautiful, besides increasing the real estate valuation of the property.
The buildings are built by man to house the satisfactory development of numerous activities fundamental to the prosperity of society, such as housing, work, education, health, among others (DUARTE, 2001). One of the most used materials in constructions is ceramic coating.
Among the main reasons for the use of ceramic coating, it stands out the fact that it is a material that is easy to clean, durable, which allows maintenance for long spaces of time, and can be resistant to corrosive environments. However, despite so many advantages, the detachment of ceramics is something that has become recurrent in residential, commercial and/or industrial constructions.
In view of this data, the question is: What is the impact of judicial expertise as a guide to investigate the causes of pathological manifestations in ceramic cladding, especially when complaints about the quality of buildings are brought to justice?
As a hypothesis, it is admitted that the expertise is important to assist the judge with technical and scientific information to clarify the reasons for the pathological manifestations presented in the cladding of buildings. According to the Federal Council of Engineering and Agronomy – CONFEA, through Resolution No. 345 of July 27, 1990, engineering expertise is the activity that involves the determination of the causes that motivated a given event, in which it is necessary to prepare a report, which is the technical piece in which an expert or qualified professional reports what he observed , presenting its conclusions.
The general objective of this work is to present to professionals working in the area of civil construction, the impact of judicial expertise, taking as references the causes of pathological manifestations in the ceramic coating of a building located in the Neighborhood of Patamares, in the City of Salvador/ BA.
From the details of the general objective, the research is also based on specific objectives, namely: (a) To identify the occurrence of pathological manifestations, through the technical report in judicial expertise, and its probable causes; (b) Verify the types of pathological manifestations existing and, through the expert report, identify the origin of the problem; (c) demonstrate the importance of quality and care in the final stage of the ceramic coating project in buildings; (d) Emphasize the importance of NBR 13755 (ABNT, 2017), considering its technical and legal aspects.
The study is necessary because pathological manifestations were identified in the coating, a situation that motivated ceramic detachment, cracks, cracks and stains in the building. The approach to the theme will contribute to avoid losses in the construction sector, both for construction companies and engineers, in addition to commercial repercussions in new developments, especially in the final phase of the project.
The article was elaborated using books, articles, monographs, theses, through systematized reading on the theme in question, in order to discuss the possible causes of cracks and detachments of tablets in the gardeners and playground crutches. Furthermore, we also sought to discuss the importance of judicial expertise for the analysis of these pathological manifestations, based on the observations based on the recommendations provided by the Brazilian Association of Technical Standards. After the literature review, a case study was conducted.
2. CERAMIC COATING
Ceramic cladding has been used since antiquity and was intended to coat the walls of large palaces and noble buildings. Its use became notorious in the middle of the 20th century, when its large-scale manufacture made the product more financially accessible (SILVA et al, 2015).
According to Figueiredo (2008), there are several advantages in the use of ceramic cladding on building facades. It favors aesthetics, as well as acts as a protective barrier of the façade, which suffers physical aggression and is subject to deterioration due to the weather.
For Pacheco and Vieira (2017), the coating of the facades has as its attribution to protect against the action of aggressive agents. Therefore, it is one of the most deteriorated components, which needs maintenance over time. It is subjected to thermal variations, rain, solar incidence, humidity, wind, static and dynamic loads, own weight and impact.
According to Silva et al. (2015), the great differential of the coating is in the following characteristics: hygiene, easy cleaning, thermal and acoustic insulation, water and gas tightness, protection of sealing elements, quality of finish, fire safety, aesthetic and visual appearance.
Therefore, the cladding on the façade is an excellent ally in the valuation of the property, because the first aspect that is observed in a building is the beauty of its exterior (FIGUEIREDO, 2008).
According to NBR 13755 (ABNT, 2017), which establishes procedures for the placement of ceramic inserts and plates with adhesive mortar on external walls and facades, the lack of care in the application procedures is directly linked to the detachments/unplacating of the coating. The following are the procedures to be followed and planned for execution:
- Professionals prepared and trained;
- The adhesive mortar must be suitable for the service and flexible mortar should be used, capable of dissipating the differential deformations that may occur between the finishing layer and the base;
- The mortar should be used in a maximum of 2h and 30min after its preparation, being prohibited the addition of water or other products in this period;
- The plaster of the area to be applied to ceramics should be wetd if it is exposed to the sun;
- The mortar must be applied in the thickness of 3 to 5 mm, and a toothed steel plucking machine is used;
- The mortar should be applied in limited stretches, so that the plates are still applied with fresh and moist mortar;
- On the structural joints, the coating should include the execution of drive joints with sectioning of the substrate to the base;
- It is recommended that the execution of vertical drive joints be spaced at most every 6 m and horizontal joints every 3 m. (ABNT NBR 13755 (ABNT, 2007)
As can be seen, in accordance with the technical guidelines established in the legislation for coating execution, methods, materials and tools must be used appropriately so that quality is obtained in the laying of any and all coatings.
The detachment of ceramic plates is determined by the absence of adhesion of these plates to the substrate or adhesive mortar. One of the indications is the occurrence of a cavo sound or when a stewing of the finish is observed. There are numerous causes of this problem, among them we can mention the slow deformation of the reinforced concrete structure, hydrothermal variations, unresilient grouts, laying on contaminated surface or execution of coating on newly executed base (MILITO, 2009).
According to Cascudo, Carasek and Freitas (2014), the fissures demonstrate several problems that happen with the facades, before the structure collapses they express a state of cracking.
Efflorescences are whitish spots that stand out in the coating and end up being adhered to by it. It happens due to a chemical process of Portland cement, reacting with water. To hinder the appearance of these stains, we can guarantee the time required for drying all the previous layers of the ceramic coating, as well as use good quality plates and decrease the consumption of cement in the empit or use cement with low alkali content (NaO and KO). (MILITO, 2009)
Joints deteriorate due to aggressive agents such as acid rain or fissures. The joints can not have large amount of resins, because they can get old and lose their color, this is because the resins are of organic origin. The joints are responsible for the watertightness of the ceramic coating and its ability to incorporate the deformations. Therefore, the degradation of the joints implies the poor performance of ceramic coatings (MILITO, 2009).
According to Figueiredo (2008), a pathological manifestation can be considered with a case in which the building, at a certain moment of service life, does not meet the expected performance. The problem is usually pointed out based on pathological manifestations that are meant by structural and/or functional manifestations of the affected party, demonstrating the warning traces of the defects seen.
Due to the large climatic variations that occur in Brazil, significant thermal amplitudes are recorded in almost all regions of the country. Thermal amplitudes are one of the main factors to be considered in predicting the useful life of materials. According to the characteristics of each material, high thermal amplitudes may result in a rapid loss of durability and mechanical resistance and, consequently, in premature aging. (LENCIONI; LIMA; MORELLI, 2006).
For Lima and Morelli (2003), thermal variations play great power in the physical and chemical processes of wear of concrete structures, which, consequently, has an influence on facades.
According to Colen (2009) and Silva (2014), for the analysis of degradation it is important to verify the maximum and minimum values of temperature and thermal amplitude, and these variations, combined with humidity, generate hydrothermal efforts on the finishes, providing a dilation of the constructive parts according to their coefficients of potential dilation and their constructive methods.
Due to the temperature variations associated with humidity, hydrothermal stresses arise, which are groupings of efforts that act directly on the finishes. This type of environmental variation causes a dilation of the construction units due to their coefficients of potential dilation and their constructive methodologies, dilations followed by contractions when the variations are negative. Due to these variations, cracks and fissures appear. The finishes of the facades undergo these changes of dimension more directly, because they are more exposed to temperature changes. (MATOS; LIMA, 2006)
For Matos and Lima (2006), one of the reasons for the degradation of ceramic coating is exposure to rainwater, which has in its composition compounds of sulfur dioxide, carbon dioxide and nitrogen oxides, which result in compounds with specific high weights. From there, there is the formation of acids that react with materials from the facades.
Still for these authors, the aggressiveness of this air that is contaminated, often due to technological advances and chemical industries, generates a degradation in the facades of buildings, which ends up requiring a restoration and /or a more immediate prevention than it should.
According to Milito (2009), frequent infiltration causes the disaggregation of the ceramic coating, with mold formation where it has no incidence of sun or with spray. These water infiltrations occur through slabs and poorly waterproofed roofs or low-cement laying mortars.
A concept of the expert, extracted from NBR 13795 (ABNT, 1996), clarifies that the expert must meet the requirements that enable the performance of the expertise, to prove to be legally qualified by the Regional Council of Engineering, Architecture and Agronomy, with technical attributions to carry out the expertise, that is, only the one who meets the established requirements has the qualification to carry out the judicial expertise.
Another aspect to be clarified is the legal definition of expertise. The standard provided for in NBR 13795 (ABNT, 1996), clarifies that expertise is the activity that involves the determination of the causes that motivated a given event.
It is also noteworthy that the basic standard for engineering expertise, published by (Brazilian Institute of Engineering Assessments and Expertise – IBAPE-SP) (2002), classified the expertise in: a) arbitration; b) evaluation c) examination d) survey. In this article, it is not necessary to deepen the classification highlighted, in view of the proposed objective.
Effectively, judicial expertise becomes necessary when, in lawsuits, the qualified engineer is appointed by a judge to assist him with technical information, which will contribute to clarifying the facts on which the expertise became necessary.
For Professor Sérgio Cruz Arenhart, the technical collaboration of this expert evidence “comes from the need to demonstrate in the process a fact that depends on special knowledge that is beyond the knowledge that may be required of the average man and the judge of medium culture” (ARENHART, 2019, p.884).
The expert is required, in this case, impartiality, technical perfection in the preparation of the report, following professional ethics, as well as the absence of objective or subjective interests, such as friendship or enmity with one of those involved in the process, the degree of kinship, favors, etc.
In some lawsuits, the judge needs to analyze and issue a decision on complex facts, often these issues involve specialized technical knowledge that go beyond their training.
In such cases, the assistance of qualified professionals who are legally qualified to transmit the necessary information to you is essential.
Thus, given the complexity of situations involving constructive works, the expert is necessary, assisting justice when the situation in question depends on technical or scientific knowledge.
3. CASE STUDY
The forensics involved a lawsuit motivated by the detachment and unplacating of plaques from the façade of a building in the urban area of the municipality of Salvador / Ba.
The residents of the units, upon realizing the problems arising from the detachment and unplacating of the ceramic plates, sought the judiciary, reporting the facts related to the problem of façade plates.
Because it was a discussion that required specialized knowledge, it was necessary to conduct judicial engineering expertise to investigate the occurrences of pathological manifestations.
Given the need to confirm the reason for the existence of pathological manifestations, the expertise will support the magistrate’s conclusions regarding the quality of the work.
3.1 CHARACTERIZATION OF THE ENTERPRISE
The object was a building located in Patamares – Colina A, a neighborhood of the capital of Bahia, located in a region close to the sea.
As already mentioned, the aim of this article was to identify the factors that led to the detachment of ceramics in the studied building and the importance of judicial expertise to prove the fact.
For the exact understanding of the situation, it is necessary to indicate the location, according to Figure 01, of the enterprise, that is, the geographic coordinates, thus defined: latitude -12.9522 and longitude -38.402.
The municipality of Salvador/Ba has a tropical climate, with an average annual temperature of around 25 °C and abundant rainfall throughout the year, with no discernible dry season. Coastal neighborhoods outside the Bay of All Saints, such as Pituba, Patamares and Praia do Flamengo, receive strong wind s from the sea, with approximately 2,500 hours of sunshine per year, the humidity is relatively high, with monthly averages between 79% and 83%, with an annual average of 81%, according to data extracted from the Wikipedia site.
Figure 01 – Location of the Building.
3.2 APPLIED METHODOLOGY
The building under analysis had its construction completed around the year 2012, which had its entire façade, swimming pool and garden gardens of the playground coated in ceramic. According to the liquidator’s manual, adhesive mortar was used for the laying of ceramic plates, and for the roundup a commercial industrialized grout was used, both materials are not specified in the document analyzed
The ceramics used were NGK (5×5 cm) tablets, in white color, however, around two years began to appear some cracks and several plates took off and / or deplacated, even with its residents claiming that some maintenance had been carried out as directed by the construction company at the time of delivery, considering that maintenance is necessary to ensure the durability of the product.
Some visits were made to the building in question, in order to verify what types of pathological manifestations exist in the building, in addition to observing which construction failures cause discomfort to the population, that is, errors that are impairing the performance of buildings, regarding safety, aesthetics and habitability.
3.3 RESULTS AND DISCUSSIONS
Horizontal cracks were observed in the playground floor, illustrated in Figure 02, which usually coincide with the end or direction of the asphalt blanket of the waterproofing system.
Figure 02 – Pathologies in Jardineira.
According to the technical report carried out by the judicial expertise, this situation indicates that the movement of the asphalt blanket does not have the ability to absorb masonry efforts; the plastic screen, placed in these situations, as an element of transition of effortstemming the different materials and connection between the materials, did not work correctly in this scenario.
After carrying out judicial expertise, another problem found in this building was the detachment of the tablets, indicated in Figure 03, which has several origins, and the most current stems from: marked movement of the structural part of the wrap (concrete and masonry structure set); deficiency of adhesive mortar, shrinkage of the emboço mortar, inadequate settlement, etc. The impairment of the performance of the adhesive mortar, in turn, has several causes, such as: use of the product outside the expiration date; inadequate preparation – excess water in the mixture; non-attendance to the rest time established by the manufacturer; not meeting the open time for your application; use after the maximum time of 2h and 30min allowed and discontinuous distribution of the mortar on the surface.
Figure 03 – Detachment of tablets on the wall.
According to NBR 13755 (ABNT, 2007), during the laying one should remove a ceramic plate every 5 m2, seated no later than 30 minutes, which must have the tardoz entirely impregnated with adhesive mortar, for the purpose of verifying the service. In addition, it is recommended to verify adherence, which, in eight determinations, after 28 days of age, at least four values should be equal to or greater than 0.3 MPa. There is no information on the quality control inspections carried out by the manufacturer during the laying of ceramic tablets.
Through judicial expertise, it can be proven, from an expert report presented to the magistrate in the judicial process under process, that in the building in question, it is observed that the detachments of ceramic tablets occur, in most situations, due to deficiency of the adhesive mortar, either by the disrespect of the “open time”, “maturation”, “useful life” or inappropriate mortar, and can be proven by the “clean” aspect of the tardoz of the cool ceramic plates , as shown in Figure 04.
Figure 04 – Tardoz of the mureta ceramics.
In the case of gardeners, it was found, through the expert report, that detachment, in addition to the differentiated movement of materials, also results from the effort generated by the land layer and the type of vegetation with roots not appropriate for this situation.
Figure 05 – Building Mureta.
Also according to the procedure established in NBR 13755 (ABNT, 2017), at least three days after laying, the coating of the ceramic tablets with the appropriate mortar for the type of exposure should be performed. The absence of the coating of the ceramic plates on the mureta, Figure 05, suggests that the round-up mortar used was not suitable for use, or mortar was used outside the shelf life, or with inadequate preparation, or even that the maintenance did not occur adequately.
The structure, sealing, waterproofing and coating systems, which constitute the building wrap, must have characteristics compatible with each other, so that their functions and performance requirements are met. The appearance of cracks in buildings occurs frequently and affects, especially, the watertightness and aesthetics of the property, which causes great discomfort to residents.
Cracks occur in a seemingly random manner, but most often succeed chemical, mechanical or physical phenomena. They may arise congenitally, because of deficiency of projects or their incompatibilization; during the implementation of the building; by the use of inappropriate materials and traces; by the action of degrading agents; exposure conditions and; even, for misuse of the building. In addition to these probable agents, the occurrence of cracks is accentuated by thermal and hygroscopic movements (ability of the material to absorb water), normal in the decorative finishes of the buildings.
The shape, degree of intensity and dimensions of the fissures generate indications for the possible causes of their occurrence.
4. FINAL CONSIDERATIONS
Through the investigation of the causes of pathological manifestations in the ceramic coating, through judicial expertise, it was possible, after the issuance of an engineering expert report, to prove that, in general, there is no specific cause for pathological occurrences, but rather a sum of factors, which results in the appearance of fissures, the detachment of ceramic tablets and other anomalies in the coating system , which can be detected visually and, if necessary, proven by expeditious testing or laboratory testing.
The cracks are probably due to the movement of materials and building construction systems. Similarly, the cause of the detachment of ceramic tablets is characteristicized by the deficiency of the adhesive mortar.
Until then, it cannot be affirmed, in all situations, whether the failure is the product or execution, however, in cases where we have the absence of mortar in the tardoz of the tablet, it can be affirmed that the detachment was caused by poor execution. The absence of the coating of the ceramic plates characterizes the improper use of the product, whether by specification not appropriate to the type of exposure, by defect of the material itself or the procedure of its preparation or application, or also by the lack of adequate maintenance.
The accomplishment of this work was important because it showed that the expert proof of engineering is a collaborative technique that serves not only to form the conviction of the judge in cases, but also, contributes to assess the quality of civil construction works, especially ceramic coatings, essential to avoid accountability for poor product quality.
Thus, it is expected that this work will serve as an example for new ventures in the field of civil engineering, in order to avoid technical problems caused by non-compliance with the Brazilian Technical Standards, in this case NBR 13755 (ABNT, 2017); As a consequence of possible non-compliance, the importance of judicial expertise as a guide for the investigation of the causes and for technical engineering clarifications, for which it is necessary to issue the expert report, is also emphasized.
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[1] Specialist in electrical engineering and energy systems, Postgraduate MBA in human resources management, Postgraduate in evaluation and expertise engineering, Degree in civil engineering, Graduation in business administration.
[2] Master’s degree in Engineering. Graduation in Civil Engineering.
Sent: April, 2020.
Approved: October, 2020.
