António C. Azevedo – författare

This book discusses the main mechanical features of masonry buildings and the peculiarities that affect their structural behaviour. It also examines technical information regarding accidents that have occurred in recent years in the Metropolitan Region of Recife, along with the historical records of these events, followed by indications of the causes for the collapse.

This book offers a new calculation procedure of the structural behavior of grouped layout of silos, easy to use and with satisfactory responses.

Groups of reinforced concrete silos are structures commonly used in the food industry, where it is usually necessary to separate the storage of different types and sources of grain.

The grouped layout of silos has numerous benefits when compared with single-cell silos in which the emphasis is on creating further space for silage, normally referred to as interstice – a space formed between the edges of the group’s cells. This economic benefit, on the other hand, raises a structural problem for the designer of this type of building, which is to assess the magnitude of bending moments and hoop forces due to the structural continuity of the walls in the interstice region of the cells. Bending moments assume extreme values exactly when the interstice is loaded and the other cells in the group are empty.

To develop the formulation of the proposed analysis models, a parametric study was carried out that allowed the adequate consideration of the variables involved.

The knowledge of moisture migration inside building materials and construction building components is decisive for the way they behave when in use. The durability, waterproofing, degrading aspect and thermal behaviour of these materials are strongly influenced by the existence of moisture within their interior, which provoke changes in their normal performance, something that is normally hard to predict. Due to the awareness of this problem, the scientific community have per-formed various studies about the existence of moisture inside porous materials. The complex aspects of moisture migration phenomenon tended to encompass monolithic building elements, since the existence of joints or layers contributes to the change of moisture transfer along the respective building element that contribute to the change of mass transfer law. The presentation of an experimental analyses concerning moisture transfer in the interface of material that makes up masonry is described in such a way as toevaluate the durability and/or avoid building damages.

In this work it was analysed, during the wetting process, the influence of different types of interface, commonly observed in masonry, such as: perfect con-tact, joints of cement mortar, lime mortar, and the air space interface. The results allow the calculation of the hygric resistance. With these results, it is possible to use any advanced hygrothermal simulation program to study the water transport in building elements, considering different interfaces and their hygric resistance.

This book discusses the effects of soluble mineral salts on ceramic brick masonry walls in Petrolina, a city in Pernambuco, Brazil, located 780 km from the ocean. To shed light on this phenomenon, the authors mapped the pathologies originating from the effects of soluble mineral salts and installed wells to monitor the underground water supply at five locations in the city where the phenomenon most frequently occurs. Further, they analyzed samples of soil, groundwater, and bricks affected by the phenomenon and measured levels of chloride in the atmosphere at these sites. The results obtained indicate that the pathological manifestations are influenced by the high levels of soluble salts observed in the soil and groundwater samples collected, and are not affected by chloride in the atmosphere.

This book offers a complete diagnosis of concrete samples collected from a pile cap block of residential buildings affected by internal swelling reactions. Covering an extensive laboratory campaign to evaluate the transport properties of concrete samples, as well as their physical and chemical composition using advanced techniques to analyse cores extracted from real buildings that have concrete elements affected by internal swelling reactions (ISR). It features several rehabilitation procedures, pile caps repair and rehabilitation design, executed using strengthening procedures to provide the complete restoration of the structural integrity of the element deteriorated. These rehabilitation procedures proved to be a good solution to retrofit pile cap deteriorated by expansions due to internal swelling reactions of concrete. The book also offers a systematic review of the current state of knowledge and it is a valuable resource for scientists, students, and practitioners in various scientific and engineering disciplines, namely, civil and materials engineering, as well as and other interested parties.

This book discusses the behaviour of isolated concrete bottle-shaped struts affected by internal expansion reactions (ISR). For that purpose, the numerical modelling of damaged concrete was performed using the Concrete Damaged Plasticity Model (CDPM) implemented in ABAQUS and validated the model through Sankovich''s tests. A procedure to automatically obtain the concrete plasticity and damage parameters, essential for CDPM, was developed in Matlab. The inputs were the characteristic compressive strength of the concrete, the equivalent length of the finite element mesh and the ratio between the plastic and inelastic compressive strains. The results showed that the CDPM could represent the load-bearing mechanisms of isolated concrete bottle-shaped struts for a range of several stress levels to which these elements may be subjected in the panels investigated. The numerical simulations for different expansion levels consistently captured the expected damage profile of the panels and theload corresponding to the formation of the first crack, the estimated crack opening, and the ultimate load. For the panels investigated, the reduction observed in the failure load reached values close to 70%, the increase of the tensile plastic deformation was more than 60%, and the maximum crack opening can reach an increase of 113% when compared with those observed experimentally in panels without internal swelling reactions The book also offers a systematic review of the current state of knowledge and it is a valuable resource for scientists, students, practitioners, and lecturers in various scientific and engineering disciplines, namely, civil and materials engineering, as well as and other interested parties.

This book presents the numerical results of the use of the chemical model to analyse the advancement of the reaction and the mechanical model to simulate creep and shrinkage phenomena in COMSOL Multiphysics®, as a way to reassess concrete structures suffering from those mechanisms. Both models were implemented separately to evaluate their responses and compare them with the theoretical results and experimental benchmarks presented in the literature. The numerical simulation results showed excellent agreement with the experimental results data, with maximum disagreement not exceeding 10%, indicating that the implementation of the developed numerical models behaved very efficiently.