Eduardo Nuno Brito Santos Júlio

Instituto Superior Técnico · Civil Engineering

Extreme events, with natural or manmade causes, such as floods, pandemics and wars, have recently brought the need to provide shelter and field hospitals in a very fast and affordable way. Prefabrication can play an relevant role in this context, by offering several advantages compared to on-site construction. The precast structural wall system is...

Concrete shells are very appealing structures. However, their use is nowadays residual due to higher construction costs, mostly related to the complex and non-reusable molds, including the falsework. This paper presents part of the research work conducted in the scope of the PRESHELL project which aims to produce concrete shells at low cost. In par...

Extreme events can potentially cause serve damage to structural systems, being one of the most concerning the local failure of primary vertical load bearing elements, since it can trigger a progressive collapse. Considering the risk of progressive collapse of framed RC structures, this paper presents the results of a numerical study carried out to...

Despite the recent technological advances, there are still no huge advances in the worldwide construction processes. With the Industrial Revolution 4.0, new possibilities emerged, being additive manufacturing, also called 3D printing, using cementitious materials, one of the most promising. This building process has numerous advantages, such as: au...

Portland cement has high influence in the greenhouse gases released to the atmosphere, being important the cement reduction towards sustainability. The optimization of the cement matrix, combined with supplementary cementitious materials (SCMs) as partial cement replacement is a proven approach to reach that goal. It has additional advantage of lea...

The concern about global warming and the environmental impact of human activities has greatly increased in recent years. The construction sector has an important role to play in reducing greenhouse gas emissions to the atmosphere, which includes the Portland cement industry.In the scope of the sustainability of the concrete sector, the addition of...

The pre-wall system can be used in the construction of buildings, with multiple advantages in terms of production time and environmental impact. This type of walls is formed by two thin precast concrete panels, linked with steel trusses to create a hollow precast wall module, which are assembled at construction site, adding reinforcement in critica...

Image-based methods have been applied to support structural monitoring, product and material testing, and quality control. Lately, deep learning for compute vision is the trend, requiring large and labelled datasets for training and validation, which is often difficult to obtain. The use of synthetic datasets is often applying for data augmentation...

Ultra-High-Performance Concrete (UHPC) is characterized by having an ultra-compact matrix resulting in ultra-high mechanical properties, low permeability to water and gases, and improved ductility provided by the addition of fibers. The production of structures with this type of concrete is advantageous in some situations, especially in aggressive...

The development of automatic methods to recognize cracks in surfaces of concrete has been under focus in recent years, firstly through computer vision methods and more recently focusing on convolutional neural networks that are delivering promising results. Challenges are still persisting in crack recognition, namely due to the confusion added by t...

During the last few years, structural concrete has experienced significant advances, stimulated by the demand for stricter requirements in terms of sustainability, durability and strength [...]

The interface between concrete layers cast at different ages is present both in new construction, e.g., precast beams with cast in place decks, and in rehabilitation, e.g., jacketing of existing beams and columns. The interface strength ensures the element's monolithic behaviour. This strength is mainly determined by the interface surface roughness...

The strengthening of concrete structures with laminates of Carbon-Fiber-Reinforced Polymers (CFRP) is a widely adopted technique. retained The application is more effective if pre-stressed CFRP laminates are adopted. The measurement of the strain level during the pre-stress application usually involves laborious and time-consuming applications of i...

Description Many relationships important to civil engineering depend on surface roughness (morphology). Examples are the bond strength between concrete layers, the adhesion of a wheel to the pavement, the angle of friction in the soil in contact with a wall surface, and many other cases when we deal with a material with a surface having the charact...

The mass of façade panels and the connections of these to the structure affect the system's safety when submitted to earthquakes. By reducing the panel's thickness, the seismic forces are also reduced, but the efficiency of the connections needs to be checked since lower embedment lengths are adopted. This paper presents a research program conducte...

The conservation of exposed concrete heritage implies repairs with restoration demands, besides mechanical and durability requirements. The main difficulty is to achieve chromatic, texture and finishing compatibility between repair mortars and concrete surfaces. The authors developed a restoration methodology for concrete heritage that comprises th...

Nowadays, the decarbonization of the concrete sector is a priority to counteract the global environmental harmful. Knowing that Portland cement is responsible for significant anthropogenic emissions worldwide, the optimization of cement dosage on concrete mixtures is a key issue, combined with the mechanical and durability performances, allowing to...

p>Strengthening of reinforced concrete (RC) structures with pre-stressed Carbon Fiber Reinforced Polymer (CFRP) laminates is a well-known application. The development of vision-based approaches for monitoring the strain imposed during the pre-stress application, with the required precision and accuracy, represents an important contribution for the...

In this paper, the mechanical behaviour of short rubberized concrete-filled steel tubular (RuCFST) columns with square cross-section under combined cyclic bending and (monotonic) compression is studied numerically. For this purpose, dynamic explicit analyses with kinetic energy control (for the quasi-static behavior to be obtained) using the commer...

This paper outlines a methodology for structuring a generic database of environmental impacts on the end-of-life phase of buildings, which can be used at the national level, in accordance with European standards. A number of different options are also considered for managing construction and demolition waste (CDW), as well as for promoting the circ...

The decarbonization of concrete sector is a priority to counteract the global environmental harmful. Knowing that Portland cement is responsible for huge anthropogenic emissions worldwide, the significant reduction of cement content in concrete mixtures is a key issue, combined with the optimization of mechanical and durability performances, allowi...

This paper presents a modified Mazars damage model, based on a strain formulation, for the physically nonlinear analysis of concrete structures. The main objective is to propose a modified damage model, in which both tension and compression damage evolution laws are regularized using a classical fracture energy methodology. The original loading fun...

Increasing the durability of concrete structures and reducing the environmental consequences associated with their production is essential to contribute to the sustainability of this industry. Bearing this concern in mind, a concept was developed that consists of considering an eco-friendly concrete only in the core of the structural members, combi...

This paper presents an experimental research aiming at characterizing the connections in innovative prefabricated walls, herein called ‘pre-walls’. The pre-wall system consists of prefabricated concrete twin panels, connected by steel trusses, light and thus easy to transport, which are assembled on site, allowing technical installations to be plac...

Interventions in concrete heritage deal with challenges related to conservation, and must be performed from an integrated restoration perspective. In addition to the material technical performance, the aesthetic compatibility between the repair and the structure, in terms of colour and texture, needs to be ensured. Therefore, the characterisation o...

The sustainability of the construction sector demands the reduction of CO2 emissions. The optimization of the amount of cement in concrete can be achieved either by partially replacing it by additions or by reducing the binder content. The present work aims at optimizing the properties of concrete used in the production of reinforced concrete poles...

The flexural behavior of slender (1/40) long‐span precast high‐strength concrete girders was experimentally investigated as a competing solution to steel alternatives for highway overpasses. Half‐scale specimens were produced using an economical and high‐strength (120 MPa) concrete mixture, non‐fiber reinforced, designed only with conventional raw...

The decarbonization of concrete structures sector is a priority due to the world climate. Since Portland cement is responsible for approximately 7% of the anthropogenic emissions worldwide, it is decisive to partially replace it by products with lower environmental impact. Fly ash has become highly demanded, due to its proven advantages, however, h...

This study presents the development of several concretes to be used in an innovative prefabrication application, that is based on the pre-wall system. This type of structure is characterized by pre-cast modules that are assembled in situ, allowing to deliver members that are easy to transport and simultaneously makes possible to build a reinforced...

In the study herein presented three types of nanoparticles, with different dosages, were used, namely nano-SiO2, nano-Al2O3 and nano-ZnO, which were combined with different concrete formulations. The main goal is to improve the eco-efficiency of concrete, using simultaneously a partial replacement of Portland cement by industrial by-products and re...

The unavoidable concern with developing sustainable materials in the construction sector has led to the attempts to reduce the content of Portland cement in structural concrete mixtures. Thus, the main objective of this research was to develop low cement concrete (LCC), maximizing the replacement rate of cement by additions and/or reducing the amou...

Innovative eco-efficient concrete was developed and characterized, to reduce the environmental impact related to construction and demolition waste, extraction of natural aggregates, and CO2 emissions of Portland cement. Several concrete mixtures with low cement content and incorporating construction and demolition waste (CDW) recycled aggregates, h...

This present paper describes an experimental study focused on the influence of the interface strength, between the lightweight aggregate concrete (LWAC) and the ultra-high durability concrete (UHDC), on the structural behavior of composite beams. The beams were produced with a new concept which consists of using an UHDC layer only in the cover, bei...

Reducing the cement content of concrete is of paramount importance towards sustainability, since its production process is highly energy-consuming and delivers massive CO2 emissions to the atmosphere. In this paper, the bond behaviour between steel and stainless-steel reinforcing bars and Low Binder Concrete (LBC), produced with approximately one h...

The decarbonization of the concrete sector is nowadays a priority to counteract the global environmental harmful. Since Portland cement is responsible for significant anthropogenic emissions worldwide, the optimization of cement dosage on concrete mixtures is a key issue, combined with the mechanical and durability performances, allowing to improve...

The goal of the present research is to develop a low cement concrete (LCC) with structural performance incorporating fly ash and natural pozzolan additions. The fly ash, due to its proven advantages, has become highly demanded, and its price is now higher, which can jeopardize its sustainable use. Therefore, it is also essential to seek alternative...

This study presents an innovative concept of modular concrete pools (MC-Pool), based on a pre-wall system, characterized by precast modules that are easy to transport and to assemble on site. This system allows to build a reinforced concrete pool faster than the traditional method. In addition, MC-Pools also incorporates the 'Super-Skin' concept, p...

Although the recognized importance of color match both in white and gray Concrete Heritage interventions, the production and application of restoration mortars are often performed without an accurate color matching between the concrete surface and the repaired area. This paper presents the Gray Concrete Restoration Method (GCR‐method), developed to...

The sustainability concerns of concrete construction are focused both on the materials’ eco-efficiency and on the structures’ durability. The present work focuses on the characterization of low cement concrete (LCC), regarding time-dependent and durability properties. LCC studies which explore the influence of the formulation parameters, such as th...

The performance of a progressive damage model in quantitative hybrid effect prediction of a comprehensive set of different 16 unidirectional interlayer (layer-by-layer) hybrid composites was assessed. Composites, produced by the hand lay-up method, made out of four different commercially available dry unidirectional fabric materials, namely high-mo...

The present paper describes an experimental study conducted to characterize the behavior of structural members produced with a new concept, consisting of using an ultra-high durability concrete (UHDC) in the cover of structural members, being the core produced with a low-binder concrete. This solution allows to build structures more durable and sim...

The improvements observed in concrete technology in the last decades, namely the production of Portland cement CEM I 52.5 R, the development of third generation super‐plasticizers, and the commercialization of additions with high pozzolanic properties, turned possible the development of new concrete products using high performance concrete (HPC). N...

The use of spring cells as an alternative to finite element method (FEM) analysis of deformable continua has numerous advantages, such as its discrete representation and unidimensional stress states. This paper presents an innovative alternative approach to the continua FEM analysis, based on a new discrete model algorithm of bar elements framing a...

p>Strengthening reinforced concrete (RC) members with Carbon Fiber Reinforced Polymer (CFRP) solutions is currently a widespread technique. The success in increasing the strength and/or in controlling the deformation of structural members using CFRPs has been recognized worldwide, and most relevant aspects have been thoroughly studied and published...

Interventions on “Concrete Heritage” imply special aesthetic requirements, especially from the chromatic point‐of‐view, between the repair material and the substrate. Currently, there is a lack of products and methods that address these concerns. This paper presents the Colored Concrete Restoration Method (CCR‐method), to the chromatic design and a...

The main goal of the work herein presented is to propose an accurate three-dimensional finite element model topredict the compressive behaviour of hybrid FRP-confined concrete. This was achieved through the modificationof the concrete damaged plasticity model (CDPM) available in ABAQUS software, since the original CDPM hasshortcomings that make it...

Western countries are increasingly demanding for robust structures, i.e., structures capable of withstanding local damage caused by unforeseen extreme events without triggering a progressive collapse, thus reducing the magnitude and proportion of the resulting consequences. In this paper, the robustness of framed RC buildings is analysed by compari...

Despite all technological advances, mapping cracks on concrete structures mostly remains to be evaluated through sketches based on on‐site observation and photographs. Methods based on image processing have been developed with clear advantages. However, most studies rely on perfectly identified areas or on single cracks without any other pathologie...

p>The development of methods aiming at assuring the maintenance of existing bridges and at minimum cost is a priority. Inspection and diagnosis methods are usually planned based on periodic visual inspections. In the case of concrete bridges, the characterization of cracking plays an extremely important role to monitor their structural health. Howe...

This experimental study aims to characterize the behavior of LWAC-to-NWC interfaces, using a substrate of normal weight concrete (NWC) with different surface roughness and three lightweight aggregate concrete (LWAC) mixtures for the overlay, with a density ranging between 1500 and 1900 kg/m³ and a compressive strength varying between 45 and 75 MPa....

No presente trabalho apresenta-se um estudo analítico-experimental sobre o comportamento à compressão de provetes circulares em betão encamisados com um inovador sistema compósito de FRP híbrido. No referido sistema procurou-se explorar as vantagens da utilização combinada de uma única matriz epoxídica reforçada com várias mantas constituídas por f...

A preocupação ambiental relacionada com os produtos do setor da construção incentiva o desenvolvimento de betões eco eficientes, visando a redução da dosagem de cimento Portland e a incorporação de produtos naturais ou subprodutos industriais. No presente estudo apresenta-se o desenvolvimento de betões com baixo teor de cimento (LCC - low cement c...

RESUMO A ideia inovadora do uso de uma superskin em elementos estruturais foi desenvolvida no âmbito do projeto "Intelligent Super Skin-Enhanced Durability for Concrete Members" no que se refere à componente material, propriedades mecânicas e durabilidade, e consiste na utilização de betões de ultra-elevada durabilidade apenas na camada de recobrim...

RESUMO A sustentabilidade do setor da construção incentiva o desenvolvimento de betões eco eficientes. No presente trabalho apresenta-se o desenvolvimento de um betão com baixo teor de cimento e com incorporação de agregados reciclados provenientes de resíduos de construção e demolição (RCD). O principal objetivo consistiu em otimizar a composição,...

An experimental study is herein presented focusing the physical properties of fibre-reinforced mortar. A reference mortar mixture was adopted and three different types of reinforcement with micro fibres (steel, polypropylene and glass) were adopted, adding different volumetric dosages, ranging from 0.5% to 2%, in 0.5% increments. The influence of e...

Inspection and maintenance of civil infrastructures require structural assessment, usually performed based on the monitoring of critical sections. For concrete structures, the identification and characterization of the crack patterns is an important task to a rigorous evaluation of the structural performance. In the case of concrete dams, the timel...

The main goal of the study herein described was to evaluate the performance of an innovative confining unidirectional hybrid FRP solution for circular concrete columns, exploiting the hybrid effect and pseudo-ductility of FRP jackets made of different fibres. First, an experimental study on the compressive stress-strain curves of small-scale plain...

p>For concrete structures, the characterization of cracks, namely initiation, opening, and propagation, as well as of cracking pattern, plays an extremely important role in the scope of structural health monitoring. The authors have already developed a method, MCrack, based on computer vision and image processing with this goal. However, this is fo...

The effectiveness of masonry infill wall on behavior of a Reinforced Concrete (RC) frame subjected to a column failure is studied experimentally. For this reason, one full scale RC frame designed according to Eurocode is statically tested to investigate the behavior of the frame with and without masonry infill wall. The obtained results show that i...

An experimental study carried out to characterize the bond strength of lightweight aggregate concrete (LWAC) to normal density concrete (NDC) and LWAC-to-LWAC interfaces is presented, also including NDC-to-NDC interfaces as reference. A single NDC mixture, with a compressive strength of 50 MPa, and three LWAC mixtures, with density range between 15...

Hybridisation, i.e., the incorporation of two different types of fibres, namely low strain (LS) and high strain (HS) fibres, within the same polymeric matrix is an established approach to promote the appearance of a gradual and non-fragile tensile failure mode of unidirectional Fibre Reinforced Polymers (FRP). This behaviour is known as pseudo-duct...

Fibre Reinforced Polymers (FRP) composites can be effectively used as passive confinement system of concrete columns. Regarding to this option, however, two main drawbacks can be pointed out: (i) in several cases the ultimate lateral strain in the confinement is significantly lower than the tensile strain at failure of the composite, and (ii) the c...

In this paper, mechanical properties of a new structural and eco-efficient hollow clay bricks are investigated. The principal goal was to recycle residual sludge from aluminium anodizing industries by incorporating it in the raw material of bricks, thus contributing for the sustainability of the construction sector. It was also an objective to enha...

Abstract An experimental study on the tensile stress-strain curves of interlayer (layer-by-layer) unidirectional hybrid FRP composites was conducted aiming at evaluating the corresponding hybrid effect and pseudo-ductility of this innovative solution. Different combinations of the following dry unidirectional fabric materials, also varying the numb...

Fibre reinforced polymer (FRP) composites have been increasingly used worldwide in the strengthening of civil engineering structures. As FRP becomes more common in structural strengthening, the development of probability-based limit state design codes will require accurate models for the prediction of the mechanical properties of the FRPs. Existing...

A research and development project has been conducted aiming to design and produce ultra-thin concrete shells. In this paper, the first part of the project is described, consisting of an innovative method for shape generation and the consequent production of reduced-scale models of the selected geometries. First, the shape generation is explained,...

Link for full-text until November 30, 2017: https://authors.elsevier.com/a/1Vst23QCo9NFjH ______________________________________________________________________________________________________________This work presents a comparative assessment of the sustainability, from a life cycle perspective, of a concrete filled square steel tubular (CFSST) co...

Today, the concrete sector is being pushed to innovate in order to better address current challenges with higher competitiveness and more sustainable solutions. Different research studies have been conducted all over the world in which novel approaches and paths were proposed. It is important to spread information to define new strategies for the f...

In the last decades, steel fibres have been widely used to reinforce the binding paste of concrete, mainly aiming at preventing/controlling cracking, by significantly increasing the (low) tensile strength and deformation capacity of current concretes. In this scope, the bond between steel fibres and the binding paste is of paramount importance. Fol...