Accelerated action of external sulfate and chloride to study corrosion of tensile steel in reinforced concrete,
Silva, M. A. G., Cunha M. P., Pinho Ramos A., Sena da Fonseca B., and Pinho F. F. S.
, Materiales de Construcción, Volume 67, Issue 328, (2017)
Applied element method simulation of experimental failure modes in RC shear walls,
Cismasiu, Corneliu, Ramos António Pinho, Moldovan Ionut D., Ferreira Diogo F., and Filho Jorge B.
, Computers and Concrete, Volume 19, Issue 4, p.365–374, (2017)
Abstract
Assessment of SFRC flat slab punching behaviour – Part I: monotonic vertical loading,
Gouveia, Nuno D., Faria Duarte M. V., and Ramos António Pinho
, Magazine of Concrete Research, p.1-46, (2018)
AbstractThis paper presents a study of the behaviour and load capacity of Steel Fibre Reinforced Concrete (SFRC) flat slabs under monotonically increased concentrated vertical loads. The SFRC was used only in the local region of the slab-column connection, as the rest of the slab was cast using normal concrete (NC) without fibres. The six experimental test specimens had a thickness of 150 mm with different longitudinal reinforcement ratios, using a non-uniform distribution over the slab width. The concretes used were made with different Dramix® 4D 65/60 BG steel fibre contents (0%, 0.5 %, 0.75% and 1.0% volume content). The slab tests were complemented by flexural tests on notched-beams. This made it possible to determine the tension behaviour of the different concretes used, through a linear post-cracking behavior and inverse analysis. The inverse analysis made it possible to define the stress-crack opening relationship that characterize the tension behaviour of SFRC and to relate it to the observed behaviour and load capacity of the tested slabs. The tests results show that the tensile behaviour of the SFRC plays an important role in the behavioural and load capacity of the slabs and that it can be considered relevant to physically based models.
Assessment of SFRC flat slab punching behaviour – part I: monotonic vertical loading,
Gouveia, Nuno D., Faria Duarte M. V., and Ramos António Pinho
, Magazine of Concrete Research, Volume 71, Number 11, p.587-598, (2019)
AbstractThis paper presents a study of the behaviour and load capacity of steel-fibre-reinforced concrete (SFRC) flat slabs under monotonically increased concentrated vertical loads. The SFRC was used only in the local region of the slab–column connection, as the rest of the slab was cast using normal concrete without fibres. The six experimental test specimens had a thickness of 150 mm with different longitudinal reinforcement ratios, using a non-uniform distribution over the slab width. The concretes used were made with different Dramix 4D 65/60 BG steel fibre contents (0, 0·5, 0·75 and 1·0% volume content). The slab tests were complemented by flexural tests on notched beams. This made it possible to determine the tension behaviour of the different concretes used, through a linear post-cracking behaviour and inverse analysis. The inverse analysis made it possible to define the stress–crack opening relationship that characterises the tension behaviour of SFRC and to relate it to the observed behaviour and load capacity of the tested slabs. The tests results show that the tensile behaviour of the SFRC plays an important role in the behavioural and load capacity of the slabs and that it can be considered relevant to physically based models.
Assessment of SFRC flat slab punching behaviour – part II: reversed horizontal cyclic loading,
Gouveia, Nuno D., Faria Duarte M. V., and Ramos António Pinho
, Magazine of Concrete Research, p.1-17, (2018)
AbstractThis paper presents an experimental study of four flat slab specimens subjected to combined vertical and horizontal cyclic loading. Steel fibre-reinforced concrete (SFRC) was used only in the local region of the slab–column connection, while the rest of the slabs were cast using normal concrete. The specimens measured 4·15 m × 1·85 m × 0·15 m and were connected to two steel half columns by 0·25 m × 0·25 m rigid steel plates, prestressed against the slab using steel bolts, to ensure monolithic behaviour. The specimens were tested using an innovative test setup system that accounted for important factors, such as the ability of bending moment redistribution, line of inflection mobility and assured equal vertical displacements at the opposite slab borders, and symmetrical shear forces. Results show that the presence of SFRC in the slab–column connection region is effective in increasing the deformation capacity of slab–column connections, allowing the increase of horizontal drift ratios.
Assessment of SFRC flat slab punching behaviour – part II: reversed horizontal cyclic loading,
Gouveia, Nuno D., Faria Duarte M. V., and Ramos António Pinho
, Magazine of Concrete Research, Volume 71, Number 1, p.26-42, (2019)
AbstractThis paper presents an experimental study of four flat slab specimens subjected to combined vertical and horizontal cyclic loading. Steel fibre-reinforced concrete (SFRC) was used only in the local region of the slab–column connection, while the rest of the slabs were cast using normal concrete. The specimens measured 4·15 m × 1·85 m × 0·15 m and were connected to two steel half columns by 0·25 m × 0·25 m rigid steel plates, prestressed against the slab using steel bolts, to ensure monolithic behaviour. The specimens were tested using an innovative test setup system that accounted for important factors, such as the ability of bending moment redistribution, line of inflection mobility and assured equal vertical displacements at the opposite slab borders, and symmetrical shear forces. Results show that the presence of SFRC in the slab–column connection region is effective in increasing the deformation capacity of slab–column connections, allowing the increase of horizontal drift ratios.
Behavior of RC flat slabs with shear bolts under reversed horizontal cyclic loading,
Almeida, André F. O., Ramos António P., Lúcio Válter, and Marreiros Rui
, Structural Concrete, (2019)
AbstractAbstract 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. Two different detailing solutions for the shear reinforcement were considered, one using a radial distribution around the column and another using a cross distribution, being the results compared with a previously tested reference specimen. The dimensions of the specimens were 4.25 x 1.85 x 0.15 m3. The test setup used for these tests was developed by the research team and simulates the boundary conditions with already recognized good results. Postinstalled steel bolts were proven to be an efficient solution for strengthening of existing structures, improving the structural behavior, and the punching resistance.
Behavior of RC flat slabs with shear bolts under reversed horizontal cyclic loading,
Almeida, André F. O., Ramos António P., Lúcio Válter, and Marreiros Rui
, Structural Concrete, Volume n/a, Number n/a, (2019)
AbstractAbstract 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. Two different detailing solutions for the shear reinforcement were considered, one using a radial distribution around the column and another using a cross distribution, being the results compared with a previously tested reference specimen. The dimensions of the specimens were 4.25 x 1.85 x 0.15 m3. The test setup used for these tests was developed by the research team and simulates the boundary conditions with already recognized good results. Postinstalled steel bolts were proven to be an efficient solution for strengthening of existing structures, improving the structural behavior, and the punching resistance.
Behavior of RC flat slabs with shear bolts under reversed horizontal cyclic loading,
Almeida, André F. O., Ramos António P., Lúcio Válter, and Marreiros Rui
, Structural Concrete, Volume 21, Number 2, p.501-516, (2020)
AbstractAbstract 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. Two different detailing solutions for the shear reinforcement were considered, one using a radial distribution around the column and another using a cross distribution, being the results compared with a previously tested reference specimen. The dimensions of the specimens were 4.25 x 1.85 x 0.15 m3. The test setup used for these tests was developed by the research team and simulates the boundary conditions with already recognized good results. Postinstalled steel bolts were proven to be an efficient solution for strengthening of existing structures, improving the structural behavior, and the punching resistance.
Behavior of thin lightly reinforced flat slabs under concentric loading,
Torabian, Ala, Isufi Brisid, Mostofinejad Davood, and Ramos António Pinho
, Engineering Structures, Volume 196, p.109327, (2019)
AbstractThe current research aims to study the behavior of thin reinforced concrete (RC) slabs under concentrated loads as well as to investigate the application of Critical Shear Crack Theory (CSCT) to such slabs. For this purpose, four square 100-mm-thick slabs were cast and subjected to concentrated punching monotonic loading. The experimental parameters were the flexural reinforcement ratio, 0.38% and 1.00%, and the presence or absence of shear headed stud reinforcement. It is shown that the failure criteria of CSCT describe reasonably well the observed failure modes and the ultimate loads of the specimens. However, attention is brought to some peculiarities in the analytical derivation of the load-rotation curve for thin lightly reinforced flat slabs, in which large deformations are experienced. Results showed that in such slabs, the behavior can be highly influenced by the post-yield stress-strain curve of the flexural steel reinforcement. As a result, the constitutive law of steel reinforcement should be explicitly taken into account in such cases. The versatility of CSCT to adapt to these conditions is demonstrated.
Behaviour of reinforced-concrete flat slabs with stirrups under reversed horizontal cyclic loading,
Almeida, André F. O., Alcobia Bruno, Ornelas Miguel, Marreiros Rui, and Ramos António Pinho
, Magazine of Concrete Research, Volume 72, Number 7, p.339-356, (2020)
AbstractThis paper describes the experimental campaign to study the behaviour of reinforced-concrete flat slab structures with steel stirrups as punching shear reinforcement, under combined vertical and horizontal cyclic loading. The vertical load was first applied and kept constant during the test, while, regarding the cyclic horizontal loading, imposed cyclic drifts were increased until failure. Four slab specimens with shear reinforcement were tested and the results compared to a control slab specimen without shear reinforcement. The studied variables were different shear reinforcement ratios and the number of stirrup layers. The slabs were 4·15 × 1·85 m2 and 0·15 m thick, connected to two steel half-columns. The test setup used was developed by the research team and aimed to simulate the boundary conditions of a flat slab, representing the slab between middle spans in one direction and between zero bending moment points in the other direction. Results show that the use of steel stirrups as shear reinforcement is very effective, increasing shear, drift and energy dissipation capacities. The obtained results were also compared to the provisions given by European and American codes.
Deformation capacity evaluation for flat slab seismic design,
Muttoni, A., Coronelli D., Lamperti Tornaghi M., Martinelli L., Pascu I. R., Pinho Ramos A., Tsionis G., Bamonte P., Isufi B., and Setiawan A.
, Bulletin of Earthquake Engineering, Volume 20, Number 3, p.1619 – 1654, (2022)
Abstractn/a
Design for punching of prestressed concrete slabs,
Clement, Thibault, Ramos Antonio Pinho, Ruiz Miguel Fernandez, and Muttoni Aurelio
, Structural Concrete, Volume 14, Number 2, p.157–167, (2013)
Abstract
Discussion of “Strengthening Two-Way Reinforced Concrete Floor Slabs Using Polypropylene Fiber Reinforcement” by Matthew J. Radik, Ece Erdogmus, and Travis Schafer,
Faria, Duarte M. V., Lúcio Valtér J. G., and Pinho Ramos António M.
, Journal of Materials in Civil Engineering, aug, Volume 25, Number 8, p.1142–1142, (2013)
Abstract