Valter Lucio

Universidade NOVA de Lisboa | NOVA · Department of Civil Engineering (CED)

This study seeks to explore the fundamental characteristics of modular construction, which covers the details of design and construction processes, from production through to assembly. Its objective is to evaluate essential parameters, such as project timelines and costs, associated with this construction method, in comparison with traditional cons...

ATENA Engineering 3D software was used to build various numerical models of a RC specimen that was tested in the Laboratory of Heavy Structures of NOVA School of Science and Technology. Specimen CB0 was the reference one of a broader experimental campaign. The sensitivity analysis was carried out after the experimental campaign, aiming to understan...

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...

Structures are usually designed to withstand a broad set of loads (e.g., gravity, wind, temperature changes and earthquakes). However, over the last few decades, wars, terrorist attacks and accidental explosions, have raised up the need to consider blast loads in the construction of relevant public or private infrastructures. The successful design...

The paper presents a full-scale blast testing experimental campaign conducted on an energyabsorbing connector comprising thin-walled inversion tubes as kernel elements mounted in a façade protective panel. LS-DYNA finite element predictions of the global and local deformation/inversion of the panel/connectors compared reasonably well with the exper...

The seismic performance of a structural frame system can be enhanced by strengthening the RC beams’ critical zones. In this paper is presented an experimental study on the improvement of the beam behaviour, subjected to an alternative cyclic procedure which considers the gravity loads reflecting the real demands on the beams’ critical zone. Two str...

Replicating boundary conditions of slab–column connections under seismic loading in a realistic manner is difficult, and different test setups have been used throughout the years. An innovative test setup has been developed at NOVA School of Science and Technology, and it has been used to test various punching shear behavior enhancement methods, in...

One of the most common reinforced concrete (RC) structural systems are the ductile moment resisting frame structures. Although this structural system is recommended for buildings in seismic prone regions, some deficiencies have been observed in such buildings subjected to significant seismic events. Hence, the aim of the present study is to present...

At inspection and diagnostic phases of ancient masonry structures, it is often necessary to evaluate the compressive strength and stiffness of stone masonry of masonry walls. These walls are a heterogenous material, and the number of in-situ test methods is limited, being the flat jack tests the most used ones. Besides other uncertainties in the ac...

Due to the growing occurrence of abnormal or man-made extreme events (such as explosion, landslide, vehicle impact, terrorist attack, etc.), progressive collapse resistance design of structures has become an increasingly important requirement of public and private buildings, especially those of high importance classes. In order to evaluate the cost...

Horizontal cyclic loading tests of flat slab-column specimens indicate that a considerable enhancement of the drift capacity can be achieved by introducing punching shear reinforcement. However, seismic design codes either do not recommend or do not cover buildings in which flat slabs are part of the primary lateral load resisting system. Nonethele...

Brittle punching failures can occur in slab–column connections due to earthquake-induced unbalanced moments. The performance of undamaged specimens and various repair/strengthening techniques have been studied in the past. This paper investigates a less studied scenario, in which a flat slab–column connection severely damaged by an earthquake is su...

In this paper, a parametric study based on the load transfer test specified in ETAG 013 was performed with the aim of investigating the efficiency of the confining reinforcement in the local anchorage zone of post-tensioning tendons, in particular when there are two types of confining reinforcement, spiral and stirrups. The parametric study was con...

An experimental work on reinforced concrete flat slab specimens to test the efficiency of postinstalled bolts, as punching shear reinforcement in resisting vertical and cyclic horizontal loads, was conducted and is presented in this paper. The test protocol consisted in increasing horizontal drifts combined with constant vertical load until failure...

Strengthening by prestressing has been widely used in bridges but fewer applications are found in buildings due to aesthetic issues. An innovative strengthening solution was developed by using interior prestressing steel strands with adhesive anchorages. The bond behaviour of deformed bars or threaded rods has been investigated, however, there is n...

The reversed horizontal cyclic loading test of a flat slab specimen with shear stud reinforcement is described. The purpose is to investigate the post-earthquake strength and deformation capacity of the flat slab-column assembly. Shear reinforcement consisted of 5 perimeters of 8 mm bars welded into rectangular steel bars that served for anchorage...

Test setups and loading histories aim to replicate the real conditions of the building structures. However, most of the tests on beams found in literature do not include gravity loads in the cyclic loading history. An experimental campaign was carried out. Two beam specimens, named CB0 and CB1, designed to exhibit different failure modes were subje...

Moment resisting frames are one of the most common structural systems in RC buildings. This study is focused on the behaviour of beam plastic hinges and a strengthening solution using internal bonded post-tensioning strands. Two specimens have been tested in this experimental campaign, reference specimen CB1 and strengthened specimen CB2. The loadi...

Moment resisting frames are one of the most common structural systems in reinforced concrete buildings. Although a considerable research has been carried out in relation to their seismic behaviour and design codes have been continuously improved, there is a lack of research on the improvement of the seismic behaviour of beam plastic hinges. Various...

The aim of the present study was to proceed to a numerical analysis of the gravity load effects on the behaviour of reinforced concrete beam critical zones when subjected to cyclic loads. A parametric study to assess the influence of different levels of gravity load on RC beam critical zones subjected to cyclic loading was carried out. For this pur...

The results of a series of experiments on four reinforced concrete flat slab specimens with shear studs and a control specimen without any shear reinforcement are presented. The specimens were tested under constant gravity loads and reversed horizontal cyclic displacements. The main test variables were the applied gravity load and the number of per...

In order to study the efficiency of the confinement reinforcement in anchorage zones of posttensioning tendons, using both ordinary reinforced concrete (ORC) and high‐performance fiber reinforced concrete (HPFRC), an experimental research has been performed on the bearing strength of concrete prismatic specimens. This research also intended to asse...

Existem vários sistemas de pré-esforço, variando estes no modo como a força de pré-esforço é transmitida para o betão. Uma técnica recentemente desenvolvida na Faculdade de Ciências e Tecnologia da Universidade NOVA de Lisboa [1], consiste na ancoragem dos cordões por aderência, viabilizando o uso do pré-esforço no reforço de alguns tipos de estrut...

Low energy dissipation, punching shear failures and the high lateral flexibility are among the main reasons why it is not recommended to use flat slabs as primary seismic elements in buildings. Punching failures can lead to progressive collapse of the entire building if integrity reinforcement is not provided. Meanwhile, several experimental campai...

Cyclic loading protocol, including gravity load • A reference RC beam specimen, named CB1 • Four strengthened specimens, named respectively CB2 to CB5

This paper focuses on the development of energy dissipaters for rocking precast systems. The energy dissipaters developed in this work are to be used externally, having the advantages of being easy to inspect and replace after an earthquake. The main parameters to take into account for the development of the energy dissipaters are the cyclic behavi...

Stone masonry walls of ancient buildings have reasonable resistance to vertical loads but lower resistance to shear forces and reduced tensile strength. However, to achieve such compressive strength the masonry must not disaggregate when subjected to loading. This can be achieved if during the construction of the walls larger stones, usually referr...

Punching strengthening of reinforced-concrete slabs using a bonded reinforced-concrete overlay (BRCO) is an efficient alternative to traditional strengthening systems such as post-installed shear reinforcement, enlargement of the support column, or bonded fibre-reinforced polymer strips. The BRCO technique allows for both the flexural stiffness and...

Experimental test setups and loading histories should reproduce the real conditions present in structures. However, most of cyclic tests procedures on beams do not include gravity loads in the loading history. This can lead to results differ from reality. An experimental campaign was carried out to access the failure mode of beam specimens subjecte...

An experimental campaign was conducted on the behavior of flat slab – column connections with punching shear stud reinforcement under reversed lateral cyclic loading. In this communication, the test results for two specimens are described and compared to a previously tested reference slab without shear reinforcement. The specimens had nominally ide...

The present paper aims to examine the potential of the Applied Element Method (AEM) in simulating the blast effects in RC panels. The numerical estimates are compared with the results obtained in an experimental campaign designed to investigate the effectiveness of fibre grout for strengthening full scale RC panels by comparing the effects that a s...

The structural rehabilitation of ancient buildings has increasingly become more important in the search for integrated solutions which includes the local and the global strengthening of the structure, promoting the three-dimensional behavior of the building. Such solutions should improve the resistance of the building for vertical (gravity) forces...

A significant proportion of Portuguese ancient buildings have structural masonry walls. Therefore, it is important to study this building typology in order to define appropriate structural rehabilitation interventions, whenever necessary. This article presents the results of research carried out at Universidade NOVA de Lisboa on the material proper...

As one solution to the problem for condition assessment of existing short and medium span (10-30m) reinforced/prestressed concrete bridges, a new monitoring method using a public bus as part of a public transit system (called "Bus monitoring system") was proposed, along with safety indices, namely, "characteristic deflection", which is relatively f...

The main goal of the present research work is to characterise a unidirectional fibre reinforced grout (UFRG), developed as an alternative material to strengthen RC structures using small thickness jacketing. A high performance cementitious grout reinforced with continuous and unidirectional non-woven steel fibre mat has been developed for this purp...

Strengthening of concrete structures with a new concrete layer has been commonly used for columns, beams and slabs. This technique is economic and efficient for structural strengthening since it uses the same base materials, steel and concrete. It is usually applied on the compressed face of the concrete element due to concrete's recognized behavio...

The anchorage corner blisters of internal continuity post-tensioning tendons of bridges built with the cantilever method are singular zones where the simplified formulas for the design of the reinforcement required to resist transverse tensile forces due to the application of point loads, proposed by the current standards, are not sufficient as the...

Strengthening of concrete slabs with a new reinforced concrete layer applied on the tensile face has proved effective for service and ultimate limit states. Although it requires the consideration for the premature failure, correctly designed it stands as an efficient and economical method for structural strengthening. Different detailing solutions...

The design of anchorage corner blisters of internal continuity post-tensioning tendons of bridges built with the cantilever method presents some peculiarities because they are intermediate eccentric anchorages. The simplified formulas for the design of the reinforcement required to resist transverse tensile forces due to the application of point lo...

Structural rehabilitation of ancient buildings has been the interest of many researchers, searching for integrated solutions that include the strengthening of global structure and of local elements, in order to improve the tridimensional behavior of the building. Rehabilitation solutions should provide suitable horizontal (wind and seismic actions)...

The aim of this work is to study the behaviour of reinforced concrete flat slab structures under combined vertical and horizontal cyclic loading. A total of five specimens were cast and tested: a control specimen was punched without eccentricity, one specimen was tested under constant vertical loading and monotonically increased eccentricity until...

The experimental research carried out to study the punching behavior of high strength concrete (HSC) flat slabs is reported in the present work. Three flat slab specimens were cast using HSC and another one with normal strength concrete (NSC), to be used as a reference slab. The HSC mix presented a compressive strength of about 130. MPa, with a bas...

Um dos principais problemas associados ao comportamento estrutural de edifícios antigos diz respeito à deficiente ligação entre pavimentos e paredes exteriores. Como tal, sempre que possível e oportuno, estas ligações devem ser reforçadas, utilizando soluções seguras, pouco intrusivas e de modo a não comprometerem a autenticidade da solução origina...

This experimental work aims to study the behaviour of reinforced concrete flat slabs, without shear reinforcement, under gravity and horizontal loading. The effect of gravity load ratio, drift amplitude and horizontal loading nature (cyclic or monotonic) were the studied variables, to ascertain its influence in load and drift capacity, as well the...

This paper addresses the results of a structural strengthening solution for rubble stone masonry walls. The strengthening includes inserting three-dimensional steel ties across the thickness of the walls and a 30 mm layer of air-lime and cement mortar render reinforced with glass fibre mesh (textile reinforced mortar), on both sides of the wall. Th...

Este trabalho visa estudar o comportamento de lajes fungiformes quando sujeitas à ação combinada de carga gravítica e solicitações horizontais cíclicas. As variáveis em estudo foram o efeito da ação cíclica e da carga gravítica na degradação da ligação pilar-laje. Com este objectivo foram ensaiados quatro modelos de laje fungiforme com característi...

Neste trabalho é apresentada a campanha experimental cujo objetivo foi o de estudar o comportamento ao punçoamento de lajes fungiformes em betão de elevada resistência (BER). Foram ensaiados 4 modelos quadrados de laje fungiforme com 1650 mm de lado e 125 mm de espessura, sendo 3 deles em BER, com uma resistência à compressão de cerca de 130 MPa, e...

A solução estrutural de lajes de betão armado apoiadas diretamente nos pilares é uma alternativa cada vez mais frequente nos projetos de construção civil. O estudo experimental do punçoamento em pilares internos as estimativas dos códigos: NBR 6118 (2007), EUROCODE 2 (2004), ACI 318 (2008) e MC2010 (2013) mediante algumas adaptações.

The use of prestress in flat slabs is a common solution, mainly because it allows larger spans and thinner slabs. Nevertheless, smaller thicknesses near the slab-column connections, along with the superposition of high shear and flexural stresses, arise the question of the slab capacity to resist punching. The punching failure results from the supe...

Long and short steel anchorages are often used in the strengthening of rubble stone (heterogeneous) masonry walls. At design stage it is important to predict mechanical behaviour and durability of such anchorages, used for rehabilitation of masonry buildings. This paper presents the results of a study related to an anchoring system, developed by th...

RESUMO No reforço de edifícios com estrutura de betão armado podem ser usadas diferentes soluções, devendo o projetista selecionar a mais eficiente em função das anomalias existentes e das condicionantes técnicas, económicas e funcionais de cada caso particular. O reforço com pós-esforço, como o termo indica, introduz esforços na estrutura que dimi...

Segundo dados oficiais [1], existiam em Portugal no início do séc. XXI mais de três milhões de edifícios, sendo as construções de “alvenaria” preponderantes em relação às de betão armado, para edifícios de um e dois pisos, e o inverso para edifícios com mais de quatro pisos. A maioria dos centros históricos é ocupada por edifícios antigos com pared...

This article concerns the results of a structural strengthening solution for rubble stone masonry walls. The strengthening involved inserting three-dimensional steel ties through the thickness of the walls and applying a 30 mm layer of air-lime/cement mortar render, reinforced with glass fiber mesh (textile reinforced mortar), on both sides of the...

Despite research works that have been published about anchorage zones in post-tensioned structures, problems during construction and throughout the life of these structures (cracking or local failures) still occur. These problems are mainly due to congestion of steel reinforcement, resulting in sections with low concrete compacity which may lead to...

Gravity loads can affect a reinforced concrete structure’s response to seismic actions, however, traditional procedures for testing the beam behaviour do not take this effect into consideration. An experimental campaign was carried out in order to assess the influence of the gravity load on RC beam connection to the column subjected to cyclic loadi...

When mixed to concrete, discrete steel fibres "work" as a smeared reinforcement, being able to bridge flexural and/or shear cracks. So, steel fibres may replace part of the usual reinforcement bars, allowing to eventually decrease costs. In this work, the results of an experimental investigation regarding punching behaviour of normal strength Steel...

In this work, the development of a design proposal regarding the application of a new strengthening technique of flat slabs, consisting of post-tensioning with anchorages by bonding is presented. This design proposal is based in experimental tests results, namely, pull-out and push-in bond tests of prestress strands and slab punching tests, whose m...

An experimental research was conducted to investigate the punching behaviour of high strength concrete (HSC) flat slabs, presenting a compressive concrete strength of 130 MPa. The tested specimens were 1650 mm square and 125mm thick and had different longitudinal reinforcement ratios varying between 0.94% and 1.48%. The central column was simulated...

Cement bonded particle board (CBPB) is a composite material produced in plates consisting mainly of wood and cement, and may contain additives. This material is currently used in cladding, raised floors, dropped ceilings, prefabricated houses, office containers and various supplies to the building industry such as kitchens, bathrooms and furniture....

This paper deals with the coupled effect of temperature and silica fume addition on rheological, mechanical behaviour and porosity of grouts based on CEMI 42.5R, proportioned with a polycarboxylate-based high range water reducer. Preliminary tests were conducted to focus on the grout best able to fill a fibrous network since the goal of this study...

This work presents an experimental study concerning the post-punching behaviour of flat slabs strengthened with a new technique based on post-tensioning with anchorages by bonding using an epoxy adhesive. This strengthening technique proved efficient with respect to ultimate and serviceability states. Five slab specimens were tested in the post-pun...

No presente trabalho é apresentado o estudo experimental desenvolvido com o objetivo de analisar o efeito da área de ancoragem e do seu posicionamento, no comportamento de lajes fungiformes maciças reforçadas ao punçoamento com recurso a parafusos pré-esforçados pós-instalados. Foram elaborados e ensaiados sete modelos de laje fungiforme, dos quais...

Este trabalho visa apresentar uma investigação experimental, cujo objectivo foi o de estudar um sistema de reforço de lajes fungiformes de betão armado que permite a redução das deformações e da fendilhação, assim como a redução dos esforços de flexão e de punçoamento. Consiste na introdução de pós-tensão com ancoragens por aderência entre os cordõ...

One of the most critical aspects in post-tensioned structures is the anchorage zones. Despite research works that have been published on this subject, problems during construction and throughout the life of these structures, such as cracking or local failures in anchorages zones, still occur. Apart from issues related to the design and safety asses...

Nowadays, flat slabs are a common solution for buildings because they are economical, easy and fast to build. There are many reasons to repair and/or strengthen flat slabs (e.g. construction or design errors, poor quality or inadequate materials, overloading and accidents), and so it becomes imperative to study suitable strengthening and/or repairi...

This paper describes and analyses the performance of two structural strengthening solutions for rubble stone masonry walls. The strengthening solutions are characterised by: sprayed micro-concrete steel reinforced layers on both lateral faces of the walls, with transversal steel ties through the thickness of the specimens, not in contact with the b...

In a frame system, the seismic energy is mostly dissipated through the development of plastic hinges located, in general, at the extremities of the elements. Thus, assuming a strong-column-weak-beam seismic design, the global structure response improvement can be attained through the strengthening of the beams in the beam column connections. This f...

The present study is part of an extensive research project, where the main objective is to evaluate a strengthening solution for reinforced concrete structures using a small thickness jacketing in the compression side of the RC element with unidirectional fiber reinforced grout - UFRG. For this purpose a high performance cementitious grout reinfor...

The windpower market has evolved and grown dramatically around the world. This, combined with the equipment evolution, has created new challenges to structural engineering both for onshore and offshore facilities. This document brings together the presentations that took place at PrecastWind 2012, a seminar held at Faculdade de Ciências e Tecnolog...

A indústria do betão pré fabricado é, por tradição, inovadora, precursora de novas tecnologias e de novos materiais. O processo produtivo de estruturas com elementos pré-fabricados difere significativamente do das estruturas betonadas em obra pelo facto de uma parte, ou a totalidade, dos elementos da estrutura serem produzidos em fábrica, em condiç...

Since the 1980’s, several buildings throughout the world have been subject to gas explosions, impact by cars or airplanes, or car bomb attacks. In many cases the effect of the impact or explosion has been the failure of a critical structural member at the perimeter of the building. After the failure, the load supported by that member could not be r...