A Non-Destructive Testing Based on Electromagnetic Measurements and Neural Networks for the Inspection of Concrete Structures

This paper presents a new non-destructive testing (NDT) for reinforced concrete structures, in order to identify the components of their reinforcement. A time varying electromagnetic field is generated close to the structure by electromagnetic devices specially designed for this purpose. The presence of ferromagnetic materials (the steel bars of the reinforcement) immersed in the concrete disturbs the magnetic field at the surface of the structure. These field alterations are detected by sensors coils placed on the concrete surface. Variations in position and cross section (the size) of steel bars immersed in concrete originate slightly different values for the induced voltages at the coils.. The values for the induced voltages were obtained in laboratory tests, and multi-layer perceptron artificial neural networks with Levemberg-Marquardt training algorithm were used to identify the location and size of the bar. Preliminary results can be considered very good.

Re-use assessment of thermoset composite wastes as aggregate and filler replacement for concrete-polymer composite materials: a case study regarding GFRP pultrusion wastes

Glass fibre-reinforced plastics (GFRP), nowadays commonly used in the construction, transportation and automobile sectors, have been considered inherently difficult to recycle due to both the cross-linked nature of thermoset resins, which cannot be remoulded, and the complex composition of the composite itself, which includes glass fibres, polymer matrix and different types of inorganic fillers. Hence, to date, most of the thermoset based GFRP waste is being incinerated or landfilled leading to negative environmental impacts and additional costs to producers and suppliers. With an increasing awareness of environmental matters and the subsequent desire to save resources, recycling would convert an expensive waste disposal into a profitable reusable material. In this study, the effect of the incorporation of mechanically recycled GFRP pultrusion wastes on flexural and compressive behaviour of polyester polymer mortars (PM) was assessed. For this purpose, different contents of GFRP recyclates (0%, 4%, 8% and 12%, w/w), with distinct size grades (coarse fibrous mixture and fine powdered mixture), were incorporated into polyester PM as sand aggregates and filler replacements. The effect of the incorporation of a silane coupling agent was also assessed. Experimental results revealed that GFRP waste filled polymer mortars show improved mechanical behaviour over unmodified polyester based mortars, thus indicating the feasibility of GFRP waste reuse as raw material in concrete-polymer composites.

A study and proposed re-design of the materials handling process for the Freeville Concrete Products Co., of Factory Street, Freeville, N. Y.

"Study made for Methods Engineering, Course 3262, Cornell University, for term paper, Fall, 1956."

Unsaturated diffusivity functions for concrete derived from NMR images

Deterioration of concrete or reinforcing steel through excessive contaminant concentration is often the result of repeated wetting and drying cycles. At each cycle, the absorption of water carries new contaminants into the unsaturated concrete. Nuclear Magnetic Resonance (NMR) is used with large concrete samples to observe the shape of the wetting profile during a simple one-dimensional wetting process. The absorption of water by dry concrete is modelled by a nonlinear diffusion equation with the unsaturated hydraulic diffusivity being a strongly nonlinear function of the moisture content. Exponential and power functions are used for the hydraulic diffusivity and corresponding solutions of the diffusion equation adequately predict the shape of the experimental wetting profile. The shape parameters, describing the wetting profile, vary little between different blends and are relatively insensitive to subsequent re-wetting experiments allowing universal parameters to be suggested for these concretes.

Re-Use Assessment of Thermoset Composite Wastes as Aggregate and Filler Replacement for Concrete-Polymer Composite Materials: A case study regarding GFRP pultrusion wastes

Glass fibre-reinforced plastics (GFRP), nowadays commonly used in the construction, transportation and automobile sectors, have been considered inherently difficult to recycle due to both the cross-linked nature of thermoset resins, which cannot be remoulded, and the complex composition of the composite itself, which includes glass fibres, polymer matrix and different types of inorganic fillers. Hence, to date, most of the thermoset based GFRP waste is being incinerated or landfilled leading to negative environmental impacts and additional costs to producers and suppliers. With an increasing awareness of environmental matters and the subsequent desire to save resources, recycling would convert an expensive waste disposal into a profitable reusable material. In this study, the effect of the incorporation of mechanically recycled GFRP pultrusion wastes on flexural and compressive behaviour of polyester polymer mortars (PM) was assessed. For this purpose, different contents of GFRP recyclates (0%, 4%, 8% and 12%, w/w), with distinct size grades (coarse fibrous mixture and fine powdered mixture), were incorporated into polyester PM as sand aggregates and filler replacements. The effect of the incorporation of a silane coupling agent was also assessed. Experimental results revealed that GFRP waste filled polymer mortars show improved mechanical behaviour over unmodified polyester based mortars, thus indicating the feasibility of GFRP waste reuse as raw material in concrete-polymer composites.

Task 4: Testing Iowa Portland Cement Concrete Mixtures for the AASHTO Mechanistic-Empirical Pavement Design Procedure, May 2008

The present research project was designed to identify the typical Iowa material input values that are required by the Mechanistic-Empirical Pavement Design Guide (MEPDG) for the Level 3 concrete pavement design. It was also designed to investigate the existing equations that might be used to predict Iowa pavement concrete for the Level 2 pavement design. In this project, over 20,000 data were collected from the Iowa Department of Transportation (DOT) and other sources. These data, most of which were concrete compressive strength, slump, air content, and unit weight data, were synthesized and their statistical parameters (such as the mean values and standard variations) were analyzed. Based on the analyses, the typical input values of Iowa pavement concrete, such as 28-day compressive strength (f’c), splitting tensile strength (fsp), elastic modulus (Ec), and modulus of rupture (MOR), were evaluated. The study indicates that the 28-day MOR of Iowa concrete is 646 + 51 psi, very close to the MEPDG default value (650 psi). The 28-day Ec of Iowa concrete (based only on two available data of the Iowa Curling and Warping project) is 4.82 + 0.28x106 psi, which is quite different from the MEPDG default value (3.93 x106 psi); therefore, the researchers recommend re-evaluating after more Iowa test data become available. The drying shrinkage (εc) of a typical Iowa concrete (C-3WR-C20 mix) was tested at Concrete Technology Laboratory (CTL). The test results show that the ultimate shrinkage of the concrete is about 454 microstrain and the time for the concrete to reach 50% of ultimate shrinkage is at 32 days; both of these values are very close to the MEPDG default values. The comparison of the Iowa test data and the MEPDG default values, as well as the recommendations on the input values to be used in MEPDG for Iowa PCC pavement design, are summarized in Table 20 of this report. The available equations for predicting the above-mentioned concrete properties were also assembled. The validity of these equations for Iowa concrete materials was examined. Multiple-parameters nonlinear regression analyses, along with the artificial neural network (ANN) method, were employed to investigate the relationships among Iowa concrete material properties and to modify the existing equations so as to be suitable for Iowa concrete materials. However, due to lack of necessary data sets, the relationships between Iowa concrete properties were established based on the limited data from CP Tech Center’s projects and ISU classes only. The researchers suggest that the resulting relationships be used by Iowa pavement design engineers as references only. The present study furthermore indicates that appropriately documenting concrete properties, including flexural strength, elastic modulus, and information on concrete mix design, is essential for updating the typical Iowa material input values and providing rational prediction equations for concrete pavement design in the future.

Bonding Agents for Portland Cement Concrete and Mortar, August 1983

Structural repairs of bridges piers and abutments require patching concrete or mortar be placed at various thickness. Whether concrete or mortar is use depends upon the depth of the patch to be made. In some instances, the use of a liquid bonding agent has been specified in the mixes as well as in a grout scrubbed onto the surface to be patched prior to the mix placement. Most of the bonding agents presently approved by the Iowa D.O.T. are polyvinyl acetate (PVA) or some type of latex. In a general discussion with a consultant about various types of bridge repair materials and processes, the subject of bonding agents was discussed at some length. It was the opinion of the consultant that the usage of polyvinyl acetates should be discontinued because of possible deterioration of this material with time. Some of these materials apparently re-emulsify in a high - moisture environment causing serious patch deterioration. As a result of this information, a study was initiated to determine the durability of these materials.

Recycling of Portland Cement Concrete Roads in Iowa, MLR-77-6, 1977

We are depleting the once seemingly endless supply of aggregate available for concrete paving in Iowa. At the present time, some parts of our state do not have locally available aggregates of acceptable quality for portland cement concrete paving. This necessitates lengthy truck and rail hauls which frequently more than doubles the price of aggregate. In some parts of the state, the only coarse aggregates available locally are "d-cracking" in nature. Iowa's recycling projects were devised to alleviate the shortage of aggregates wherever they were found to have an economic advantage. We completed our first recycling project in 1976 on a 1.4 project in Lyon county. The data collected in this project was used to schedule two additional projects in 1977. The larger of these two projects is located in Page and Taylor county on Highway #2 and is approximately 15 miles in length. This material is to be crushed and re-used in the concrete paving, it is to be reconstructed on approximately the same alignment. The second project is part of the construction of Interstate I-680 north of council Bluffs where an existing 24 foot portland cement concrete roadway is to be recycled and used as the aggregate in the slip form econocrete subbase and the portland cement concrete shoulders.

Evaluation of the Concrete Admixture Gla-Zit, MLR-81-5, 1983

A concrete admixture, Gla-Zit, was evaluated in 1970 by the Iowa State Highway Commission and found to be lacking in providing beneficial effects to concrete. This current evaluation is similar to that conducted in 1970 with slight modifications in the actual concrete mixes studied. At the request of the manufacturer, all concrete mixes containing Gla-Zit were non-air entrained. Concrete properties examined were compressive strength, salt scaling resistance, absorption, resistance to chloride penetration, and freeze-thaw durability. The differences found in the mixes studied are much more attributible to air entrainment, or the lack thereof, than the influence of Gla-Zit. The study re-affirms that it is necessary to have properly air entrained concrete to lessen the detrimental effects of freeze and thaw and scaling caused by salting. There is no data in the study to suggest that Gla-Zit has any significant effect on any of the concrete properties examined.

Uma visita ao universo matemático de Lewis Carrol e o (re)encontro com sua lógica do nonsense

Notable mathematics teacher, Lewis Carroll, pseudonym of Charles Lutwidge Dodgson (1832-1898), made the mixture of mathematics with literature a ludic environment for learning that discipline. Author of Alice s Adventures In Wonderland and its sequel Alice Through The Looking Glass, he eventually created a real and complex universe which uses what we call the logic of the nonsense as an element to motivate the development of mathematical thinking of the reader, taking it as well, learn by establishing a link between the concrete (mathematics) and the imaginary (their universe). In order to investigate and discuss the educational potential of their works and state some elements that can contribute to a decentralized math education from the traditional method of following the models and decorate formulas, we visited his works based on the studies of archeology of knowledge (FOUCAULT, 2007), the rational thought and symbolic thinking (VERGANI, 2003) and about the importance of stories and narratives to the development of human cognition (FARIAS, 2006). Through a descriptive, analytical study, we used the literary construction and presented part of our study in form of a mathematical novel, to give the mathematical school a particular charm, without depriving it of its basics properties as discipline and content. Our study showed how the works of Carroll have a strong didactic element that can deploy in various activities of study and teaching for mathematics classes

A (re)significação conceptual nas práticas colaborativas com professores do Ensino Fundamental

The work objectified to apprehend the degree of the teachers' concept concerning the territory concept and to intervene with situations of critical reflections to accompany and to analyze the process of conceptual elaboration. It contemplates on the (new)meaning of knowledge and (new)elaboration of the concept in study done inside a pedagogic intervention. The Municipal School Dr. Julio Senna - Ceará-Mirim/RN and six (6) teacher-collaborators that taught in the 3rd and 4th grades of the fundamental teaching, constitutes the empiric field of the research. Its theoretical-methodological contributions are built in the studies of Vigotski (2000a, 2000b and 2001) on the formation process and development of concepts; in the methodology colaborate (Ibiapina (2004), Bartomé (1986), Kemmis and Mctaggart (1988), Arnal, Del Ricon and Latorre (1992), Pepper and Ghedin (2002), among others) and in the critical-reflexive conception of the Geography (Soares Júnior (2000 and 1994), Silva (1998), Raffestin (1993), Santos (1994), Felipe (1998), among others). The accomplishment of the work presupposed starting from the reflections on the following subjects: which the teachers' understanding in the school space concerning the territory concept? How does happen the process of conceptual construction territory for the teachers? The analysis of the teachers' previous knowledge on the concept in study, evidenced that its apprehensions on the attributes of the referred concept went mentioned the to light of the perceptible dimension of the real-concrete relationships of the reality linked to the degree of the spontaneous concepts and followed by the ideas of the traditional, humanistic and cultural geographical conceptions (positivism and phenomenology), restricting the territory meaning the notion of State-Nation and place of the men's dwelling. In the intervention process, it was verified to real possibility of the acquisition of indispensable scientific concepts to the process of (new)meaning conceptual of geographical knowledge through the continuous practice of the educational formation, when it was evidenced that the teacher-collaborators acquired high degrees of attributions of the significance of the territory concept to the they elaborate generalizations by means of analyses and syntheses of the concept-attribute (essential and multiples) of the reference conceptual in study

Proposta Curricular para Educação infantil: (re) significando saberes docentes

The theory contemporary in the field of early children education, as well the legal discourse and official texts valid in our country point to the need for systematization of proposals pedagogic / curriculum in institutions, built and carried out by subjects that act as factor of assurance care quality. Quest us about what knowledge are required to teachers in developing a proposed curriculum for children education. Defined as an object of study, the knowledge teachers necessary for the development of a proposed curriculum for children education. As goals, assume: investigate teachers knowledge necessary for the development of a proposed curriculum in a Public Institution for children education and contribute to the (new) meaning on the part of teachers, knowledge needed to build a proposed curriculum for children education. Assuming the principles of the paradigm of qualitative research, we have developed a research institution of a children education Network Public Hall of Ceará-Mirim-RN, which serves children of four and five years old (preschool) with the participation of 17 teachers and two supervisory (teachers) that institution - subject of our research. Therefore, we have adopted the principles of action research, according to which the knowledge gained through research should build so shared / dialogue in the relationship between researcher and participants, what is the implementation of an effective action formative. As the search procedures developed observations no-teaching participants in the meetings and activities of the classroom; semi-structured interviews (individual and collective) with teachers and supervisors; analysis of school documents and participant observation in the seminars of studies reflective. The latter is implemented as key moments of speech and thought, and finally to (new) meaning of knowledge, the subject of the research-action. For these knowledge, the systematization of the register built was developed based on the principles of analysis of Content that guided us to the definition of two categories 1) knowledge teachers concerning conceptions of curriculum / proposed curriculum and 2) knowledge teachers concerning specifics of children education. From these were built subs representing thematings more specific and significant, among the many that emerged in the analysis: 1.1) Definitions of curriculum and curriculum proposal; 1.2) The subjects makers / implementing a curriculum / proposed curriculum; 1.3) elements constituting a curriculum / proposed curriculum for children education and 2.1) Functions of children education and conception of child; 2.2) The space of the play in the organization of routine. Under the intervention could significant advances with regard to (new) meaning of such knowledge from the subjects, with major disruptions to their original designs. These are presented and reflected in this work. In front of this movement, transformation, made the need for a permanent work in the context of the institution of in-service training, or mediated by pedagogical coordinator or other to assume this role with teachers, in order to provide the development and effectiveness of proposed curriculum consistent and contextualized in practice effective with the children concrete envisage the service to their specificities and a quality education

Projeto político de formação do enfermeiro: contextos, textos, (re)construções

This research analyses politic Project for nursing education, in its articulation with economical, political and social context of 1970s and 1980s in national level and, in special, nurse formation process in FAEN/UERN space, situating it on the context of Brazilian sanitary reformation movement and participation movement. The thesis is firmed on the sense of explaining whether that movement circa the nurse formation process has been able to build necessary instruments for the transformation of biomedical formation model historically consolidated, in the perspective of conceiving another model anchored on social determination of health/illness process, with the purpose of assuring ethical and political commitment with the SUS praised by sanitary reformation. The study visualized the object considering its specificity, its concrete historical determinations and institutional as well as organizational relationships that permeate possibilities of valorizing it, analyzing it, interpreting it and rebuilding it. Its operationalization occurred in three movements, it means, bibliographical review; documents study; interviews and focal groups realized with professors of the institution. We can apprehend as main results that the nurse formation process has incorporated widely spread conceptions by the sanitary reformation movement and participation movement, assuming the commitment with transformation of health services and social reality. Nevertheless it prevails, still, amongst some professors in the same institutional space, the commitment to a predominantly technicist formation, focused on instrumental knowledge. Opinion divergence explicit diversity of conceptions circa education and, as consequence, distinct political commitments, also contradictory to formation. Thus, there is a lacuna between what is foreseen on political pedagogical project and what is rendered in FAEN/UERN, evidencing the clash related to conceptual bases of formation project. Interpretations, divergent political attitudes and resistances to the process allowed several formation ways. However, formation under new conceptual bases, find limits on the context of social politics implemented in Brazil during the 1990s, neoliberal-based, expressed on expansion and consolidation of health private system, managed by market rules, strengthening biomedical formation model. Notwithstanding, there is a favorable to its implementation, starting from the first years of 21st century, moment when Brazilian sanitary reformation reappear on health speech, as well as facing the policy of permanent education in health. This reality explicit a process of dialectical tension between instituted and institutor, anticipating the moment of scission or adaptation and return to what is already known. Despite of clashed, knowledge, accumulated experience, contribution to services, the construction of partnerships out of university space and articulation with national movement of (re)orientation of nurse formation, have been constituted as vital instruments to offer support to formation in FAEN/UERN. Still, we consider necessary the (re)visitation to FAEN/UERN politic pedagogical Project considering the existing and implemented construction, without, yet, depreciate the norther axis of the project at the reaching of its intentionality

Um olhar sobre o cotidiano e as re-definições espaciais no Bairro Potengi, Natal/RN

This work aims to conduct an analysis on the production of space and the dynamics between social agents that act and interact, albeit in different ways, in the production and re-production space in the Neighborhood Potengi in Natal, Rio Grande do Norte. The neighborhood is undergoing a process of dynamism undeniable and has a daily marked by heterogeneity, especially as a neighborhood in transition. So your analysis, from the perspective of the dialectical method, contributes to the understanding of the production space can be analyzed through the study of the forms and content, and may contribute to its real apprehension. After all, the city reflects forms, assumes functions, features and content that dynamic influences and is influenced by human relationships. Thus, this research seeks to analyze the production of space, based on the observation and study of the rich daily life of different social agents that operate within concrete quoted

Supervisão de estágio em serviço social: tempos de mundialização do capital - desafios cotidianos e (re)significados

Pós-graduação em Serviço Social - FCHS