Evaluation of Reinforced Concrete Structures with Views for Rehabilitation

The increasing number of pathological occurrences is found in reinforced concrete structures, so does the demand for inspection and maintenance services in residential communities in the state of Pernambuco, which aim to detect damage to the structure in a timely manner to minimize repair costs, thus applying preventive maintenance in order to guarantee the estimated useful life of the project for the building. However, it is observed that the practice of periodic inspections is not yet part of the culture of a certain segment of the population that does not have economic means and knowledge of the importance of maintenance to ensure the integrity of the structure. It was used in this work an inspection script with use of tests and methodology to quantify damage and to check the state of degradation of two residential buildings with more than 20 years and built near the seafront where environmental aggression is strong. The deterioration found in each of the buildings has been differentiated due to different corrective maintenance performed at every building. The last maintenance, performed in Building A, was performed by corrective hand of unskilled labour guided by the community itself, which has no expertise in the field of civil engineering. In Building B, the situation is similar, compounded by the opinion of some tenants that there is no need for this routine, even the structure being in critical condition, as was confirmed with the application of the methodology employ. There should be a legislation that governs the execution of inspections and maintenance programs in addition to the existing technical standards. The methodologies presented suitable for checking the degree of degradation of the structures and performed tests confirmed the diagnosis obtained by visual inspection and quantification of damage.

Stability Analysis of Tubular Steel Shores

The design of tubular steel scaffold-type shoring is usually performed by calculating the load capacity of the elements, taking into account their axial strength, mainly. Geometric stiffness effects and changes in the stiffness of connections are seldom considered. This paper assesses the stability of tubular steel shores using experimental and numerical approaches that take into account geometric nonlinearities as well as the features of the elements used to make the link between the steel tubes （pressed double coupler--right angle）. The increase in overall stiffness generated by diagonal bars used in the analyzed models was examined. The results obtained show the importance of using P-delta analyses in this kind of structure in order to evaluate structure＇s overall stability even when compressive stresses are within acceptable ranges of code limits.

Guy Structure with Galvanic Corrosion： Case Study

Reinforcement bar corrosion depends heavily on environment and the processes used. This study will address galvanic corrosion. Based on a case study of galvanic corrosion in a guyed power transmission tower, experiments using a number of methods were made on a small sample of eight poles chosen for excavation and visual inspection, to assess the various resulting diagnoses. Method that provided the best results both in location and classification of the points was adopted, where corrosion had already begun, considering the concern of finding a non-evasive process. To diagnose the status of the poles inserted in rock, after applying the methods, the main types of corrosion affecting them were listed and classified. With the results, the possible means of preventing and maintaining the structure were presented.

Analysis of a Concrete Structure that Was Exposed to Fires in the Metropolitan Region of Recife

In large cities, news about fires in buildings are powered by problems such as old wiring and no maintenance. Accidents with chemicals and human error, which when added to the different characteristics of each fire and structures can generate the factors causing these disasters. The gradual rise in temperature causes a different effect in mortar and concrete parts, verifying the change in coloring provided to loss of mechanical strength and surface crumbling, cracking and disintegration of the structure itself. This paper presents a case study in which a building that is located in the metropolitan region of Recife was exposed to a fire situation. The metropolitan region of Recife is composed of several old buildings that by virtue of their age may have delayed construction methods, and may expose the fragility of the concrete used in its construction on a fire situation. The concrete structures are recognized by the good resistance to fire because of the thermal characteristics of the material, however, the temperature rise in the concrete elements in characteristic causes a reduction in strength and modulus of elasticity of the material, the loss in stiffness leading to polyphase degradation of reinforced concrete, structural parts can lead to ruin, but when properly sized and executed, the concrete can serve as a proactive agent to be exposed to high temperatures, as the same may be subjected to high temperatures accidentally or they may be part of their normal work.

Numerical Staged Construction Analysis of Precast Concrete Bridge

The paper discussed about the staged construction analysis of two-span precast-girder bridge considering time dependent effects, namely creep and aging of concrete. Results obtained showed that it is very important to consider construction stage in the analysis of bridge because of stress resultants which are important in design process and very different from those obtained without the consideration of construction stage. This fact is especially important for bridges, because construction period continues along time and loads may change during the construction period and after.