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2021 | Book

Durability of Concrete Structures

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About this book

This book provides a collection of recent research works, related to structural stability and durability, service life, reinforced concrete structures, recycled materials, and sustainability with endogenic materials. Intended as an overview of the current state of knowledge, the book will benefit scientists, students, practitioners, lecturers and other interested parties. At the same time, the topics covered are relevant to a variety of scientific and engineering disciplines, including civil, materials and mechanical engineering.

Table of Contents

Frontmatter
Application of NDT for Installation of Rooftop Solar Power Plants
Abstract
The application for Non-destructive Test (NDT) for rooftop solar power plants identifies the use of NDT for structural stability to install rooftop solar panels. Solar power plant installation on old buildings may result into structural failure due to weight of solar panel system. So, before installation of solar panels, NDT test can identify the strength of structural members. Some of the common methods used for the diagnosis of old buildings are Rebound Hammer Test (RHT) and Ultrasonic Pulse Velocity Test (UPV). In this chapter, the application of NDT test for the solar power plant installation is investigated though a case study. Then, this research illustrated the RHT application for installation of rooftop solar power plant. A case study of 700 kW solar plant on 15 buildings is illustrated by applying the NDT test. This chapter discusses how this application can be used to diagnose the building before installation of solar power plants?
Prafulla Parlewar
Local Reinforcing of RC Columns by Steelwork: A Parametric Study
Abstract
In the work the problem of local reinforcement of columns belonging to existing reinforced concrete (RC) buildings by means of steel angles and batten plates is examined. Initially, a sophisticated numerical FEM model has been calibrated through the calculation code ABAQUS on the basis of a laboratory experimental test on a RC column reinforced with the aforementioned metallic elements and subjected to both vertical loads and earthquakes actions. Subsequently, an extensive parametric analysis on the above reinforced columns has been conducted by varying the main geometric parameters characterising the reinforcement system, such as the angle height and the width and thickness of batten plates. Numerous configurations of reinforced columns have been inspected by means of static non-linear analyses, always conducted with the ABAQUS program, in order to identify a series of optimal reinforcement solutions capable of combining the best structural performances with the lowest possible cost. Finally, the selected optimal configurations have been compared to each other by performing cyclic analysis to identify the reinforcement system providing the best seismic response in terms of dissipated energy.
Antonio Formisano
Chloride Profile Modeling for Reinforced Concrete Structures Present in Marine Environment
Abstract
The durability and service life of reinforced concrete structures in the marine environment have been the subject of several studies in the literature, due to the great importance for port infrastructure and the high level of aggressiveness offered by this environment to reinforced concrete structures, mainly by the chloride ions action in the corrosion of the reinforcement. In this way, the present chapter deals with the modeling of chlorides concentration profiles, where an analysis recently developed for application of the Modified Holliday Equation is presented. For this, different profiles models were performed, representing different materials and environmental conditions using this new methodology. The results showed that the model based on the Modified Holliday Equation can represent the diffusion zone for structures with different characteristics (materials, environmental, age and location), and is also able to represent chloride concentrations in the convection zone, allowing to estimate the service life of structures built in marine environments around the world.
C. E. T. Balestra, T. A. Reichert, A. L. P. Vizzotto, G. Savaris
Concrete Electrical Resistivity as a Durability and Service Life Parameter for Reinforced Concrete Structures
Abstract
Electrical resistivity becomes one of the main non-destructive techniques in the evaluation of the service life and durability of reinforced concrete structures, considering chloride penetrability and/or the probability of reinforcement corrosion, being pointed out by different standard and studies in literature. Due to the use of a non-destructive methodology of easy operation, reliable, with expeditious results and low cost, it becomes an important tool for decision making by managers responsible for plans and strategies for concrete structures maintenance. Thus, this chapter presents definitions and aspects of electrical resistivity in concrete, test procedures and interpretation of results and, finally, the parameters that most influence concrete resistivity are discussed.
C. E. T. Balestra, T. A. Reichert, G. Savaris
Rehabilitation Technologies
Abstract
Several pathological manifestations existing in the buildings lead to a decrease in the durability and useful life of the building. These problems require an adequate correction to be made to restore the building’s conditions of use. To make these corrections, there are several techniques and materials that can be used, including the reconstitution of concrete, crack injection techniques, surface protection, electrochemical techniques and structural reinforcement, some of which are addressed in this work.
W. Mazer, E. O. Ferreira, M. T. Q. Simões da Silva, R. Basso Tokarski
Time Variant Assessment of Uncertainties for Various Loads Process During the Service Life of Concrete Structures
Abstract
Concrete structure may be affected due to antagonistic environment, hence responsible for reducing in their strength, stiffness and reliability. However, in general, this unreliability may damage the safety and design life of the concrete structure, therefore, in order to evaluate the current condition of such structures, time dependent reliability assessment of concrete ageing structure essentially must be considered. In this work, the influence on safety and serviceability of structures alongwith various uncertainties such as time variant loading state [i.e. considering dead, live, seismic and wind loads alongwith their effects in combination] of the structure and the effect of ageing on strength-deterioration phenomenon due to various-environmental aggressive parameters need to be extended and examining that the reliability is vulnerable to the selection of initial component strength, however, strength-deterioration models exhibits less sensitivity to the corresponding component strength within the structural system. The critical component need to be identified before performing, conversely, the system reliability helps to reduce the size of analysis. To keep sustaining of reliability, the effect of periodic inspection and maintenance presented in this study throughout the design life/service period of a structure (in order to examine/show the time variant effects in various selected inspection time intervals that yields valuable results) presented in this study.
Ghanshyam Miyani, Arjun Sil
Fly Ash and Granulated Blast Furnace Slag to Mitigate the Alkali Silica Reaction in Concretes
Abstract
The alkali silica reaction (ASR) is a pathological manifestation of chemical origin and high gravity that can negatively affect the mechanical properties and durability of important concrete structures, even with short time in service. The reaction results from the interaction of Portland cement alkalis and other sources (internal and external to concrete) with the reactive silica of the aggregate. Several studies are under development about the best approach for the mitigation of ASR. The use of supplementary cementitious materials (SCM) has been widely accepted. One of the first SCM studied was the fly ash and, in recent years, the granulated blast furnace slag has also been fairly addressed in research. To have the expected efficacy, fly ash and granulated blast furnace slag must present some peculiar characteristics such as high total concentration of silica, alumina and hematite, high fineness and reduced alkalis content. The protection mechanism offered by fly ash and granulated slag involves not only the pozzolanic action, but also the possibility of fixing the alkalis in the pozzolanic C-S-H, reducing the CaO/SiO2 ratio of the C-S-H formed by the Portland clinker and reducing the permeability of the concrete. Currently, the use of SCM is still the best approach in the ASR mitigation because, in addition to offering technical advantages, it also contributes to reducing the environmental impact caused by industries in different segments, either by reducing the CO2 released into the atmosphere or by reusing by-products.
K. M. V. Moreira, F. R. C. Ribeiro, E. P. de Deus, A. E. B. Cabral
Influence of the Addition of Sugar Cane Bagasse Ash on Durability of Concrete Structures
Abstract
The environmental impact of cement production was increased significantly in the last years. It is estimated that for each ton of cement produced, approximately one ton of carbon dioxide is emitted, divided into: decarbonation (50%), combustion in the clinker furnace (40%), transport of raw materials (5%) and electricity (5%). From a world perspective, green strategies have been advanced in order to reduce the environmental impact of the cement production. In this sense, the sugar cane bagasse ash is a by-product resulted from boilers of sugar and alcohol factories. This material, composed mainly of silica, can be used as a mineral admixture in mortar and concrete, with great economic and environmental advantages. This work intent to collaborate for the partial substitution of Portland cement by sugar cane bagasse (SCB), in order to reduce the consume of clinker by volume of concrete, which is the responsible for the high emission of CO2 to the atmosphere. For this, an experimental campaign was carried out with cementitious pastes to evaluate the changes in their properties, namely the durability, due to the use of SCB ash. Finally, it could be concluded that concrete structures with sugar cane bagasse ash presented an interesting behavior and, in terms of durability, the samples containing 15% of the ash of sugarcane bagasse showed good results, being important to highlight the need and interest of doing further research on the topic.
J. M. P. Q. Delgado, R. Berenguer, N. Lima, A. C. Valdés, M. H. F. Medeiros, A. C. Azevedo, N. B. D. Lima
Metadata
Title
Durability of Concrete Structures
Editor
Prof. J. M. P. Q. Delgado
Copyright Year
2021
Electronic ISBN
978-3-030-62825-3
Print ISBN
978-3-030-62824-6
DOI
https://doi.org/10.1007/978-3-030-62825-3