Papers by Tanja Kalman Šipoš
Buildings
Despite achieving consensus and having current knowledge on the behaviour and contribution of mas... more Despite achieving consensus and having current knowledge on the behaviour and contribution of masonry infill walls, there remain unresolved issues regarding their nonlinear behaviour as a method for strengthening existing reinforced concrete (RC) frames with effective modifications, primarily infills and the interconnection of infills and frames. The challenge for safely and economically designing frames with competent walls is to utilise the stiffening benefits while ensuring that the increased lateral forces and reduced drift capacity do not hinder performance. This study aims to investigate the potential of using masonry infill to strengthen previously slightly damaged RC frames. Experimental tests were conducted on previously slightly damaged RC frame specimens infilled with vertically hollowed-clay and solid-clay masonry units, connected to the frame elements using traditional methods (i.e., avoiding the use of modern composite materials). These strengthened infilled frame stru...
Bond-slip behavior of self-consolidating rubberized concrete
Construction and Building Materials
Rad obrađuje problematiku konstruiranja i dimenzioniranja čeličnih okvira sa zidanim ispunom. Ova... more Rad obrađuje problematiku konstruiranja i dimenzioniranja čeličnih okvira sa zidanim ispunom. Ovakve su konstrukcije relativno česte, a značajnija istraživanja njihovoga ponašanja provode se od druge polovice prošloga stoljeća. Unatoč brojnim istraživanjima, još uvijek, postoji problematika procjene ponašanja konstrukcija ove vrste, osobito pri značajnijim horizontalnim djelovanjima jer zbog složenosti konstrukcijskog sustava ne postoji dovoljno pouzdana metoda procjene njezinoga ponašanja koja bi bila ugrađena u konstrukcijske norme, kao što je slučaj kod drugih uobičajenijih i jednostavnijih konstrukcija. U radu su prezentirani rezultati vlastitih provedenih istraživanja ponašanja čeličnih okvira sa zidanim ispunom. Disertacijom su obuhvaćena eksperimentalna istraživanja mehaničkih karakteristika zidnih elemenata, zidanog ispuna i čeličnog materijala, a dobiveni podatci korišteni su pri numeričkim simulacijama ponašanja jednokatnih čeličnih okvira sa zidanim ispunom izloženih hori...
Prediction of seismic behavior of reinforced self-consolidating rubberized concrete structural elements
2020 17WCEE Proceedings, 2020
Omeđeno ziđe i uokvireno ziđe
The focus of this study is to investigate the applicability of Adaptive Neuro-Fuzzy Inference Sys... more The focus of this study is to investigate the applicability of Adaptive Neuro-Fuzzy Inference System (ANFIS), Artificial Neural Network (ANN), and Multiple Linear Regression (MLR) in modeling the compressive strength of Recycled Brick Aggregate Concrete (RBAC). A comparative study on the application of the aforementioned models is developed based on statistical tools such as coefficient of determination, mean absolute error, root mean squared error, and some others, and the application potential of each of these models is investigated. To study the effects of RBAC factors on the performance of representative data-driven models, the Sensitivity Analysis (SA) method is used. The findings revealed that ANN with R2 value of 0.9102 has a great application potential in predicting the compressive strength of concrete. In the absence of ANN, ANFIS with R2 value of 0.8538 is also an excellent substitute for predictions. MLR was shown to be less effective than the preceding models and is only...
In the two past decades, ferrocement members have been with a wide variety of uses in structural ... more In the two past decades, ferrocement members have been with a wide variety of uses in structural applications because of their unique physical properties (high surface-area-to-volume ratio and possible fabrication in any shape). In this study, two models were presented for a predict of the moment capacity of ferrocement members, one based on a back-propagation multilayer perceptron artificial neural network and the other proposing a new equation based on the multilayer perceptron network trained. These models with five input parameters including volume fraction of wire mesh, tensile strength, cube compressive strength of mortar, and width and the depth of specimens are presented. The results obtained from the two models are compared with experimental data and experimental equations such as plastic analysis, mechanism, and nonlinear regression approaches. Also, these results are compared with the results of the equations that researchers have proposed in recent years with soft comput...
Elektronički časopis građevinskog fakulteta Osijek, 2014
Reinforced-concrete frames with masonry infill are composite systems, common in low and medium-hi... more Reinforced-concrete frames with masonry infill are composite systems, common in low and medium-high buildings, whose behavior under earthquake loads is difficult to predict. Because of that, most national codes ignore the contribution of infill to the structural response. In this paper, we determined the seismic behavior of infilled frames by using a numerical non-liner model (with various geometries and various masonry and r/c frame properties), using samples taken from the originally collected experimental data base on infilled frames "EDIF". We then compared these experimental results to numerical models designed using recommendations from FEMA 356 (nonlinear model), Eurocode 8 (linear model), and other published methods (Stafford-Smith and Carter, Mainstone, Žarnić, Paulay and Priestley) in order to assess the most suitable, rational macro model for evaluating the behaviour of masonry infill in a reinforcedconcrete frame during earthquake excitation.
Engineering Structures, 2013
Reinforced-concrete frames with masonry wall infill, ''framed-masonry'', is a composite structura... more Reinforced-concrete frames with masonry wall infill, ''framed-masonry'', is a composite structural system proven to be effective and efficient in the case of in plane horizontal excitations. Its behaviour depends on mechanical characteristics of its components but its performance is different than the sum of its components. Modelling and seismic design verifications of ''framed-masonry'' system that embraces all of the important aspects of behaviour, failure mechanism, shear strength and deformation capacity, are required. In this work we have tried to put the ''frame-masonry'' composite as a full-fledged building element whose performance could be determined quantitatively on the basis of data obtained from the performed tests. Frame-masonry composite was analyzed using neural networks trained on the experimental database that contains results of 113 published tests of one-story one-bay masonry infilled frames. In order to reduce the dimensionality of input data and achieve better performance of neural network, dimensionality reduction techniques: Principal Component Analysis, Forward stepwise sensitivity analysis and dimensionless modelling parameter approach were applied. A multilayered back propagation neural network with adaptive weight function was applied and the optimal network topology, for each required output value, was been chosen. The obtained results indicated that neural network, trained on the database, could be used for predicting the seismic behaviour of framed-masonry structural elements, with limitation of inputs according to the statistical range of input data. Sensitivity analysis of the important factors that affect the performance indicated that the most important ones were height/ length ratio (a), material properties of masonry infill and frame (fk, fck), reinforcement ratio of columns (rc) and the amount of vertical loading (N).
Materials, 2019
One of the major causes of ecological and environmental problems comes from the enormous number o... more One of the major causes of ecological and environmental problems comes from the enormous number of discarded waste tires, which is directly connected to the exponential growth of the world’s population. In this paper, previous works carried out on the effects of partial or full replacement of aggregate in concrete with waste rubber on some properties of concrete were investigated. A database containing 457 mixtures with partial or full replacement of natural aggregate with waste rubber in concrete provided by different researchers was formed. This database served as the basis for investigating the influence of partial or full replacement of natural aggregate with waste rubber in concrete on compressive strength. With the aid of the database, the possibility of achieving reliable prediction of the compressive strength of concrete with tire rubber is explored using neural network modelling.
Evaluation of Masonry Panel Models for Nonlinear Analysis of Infilled R/C Frames
Performance of buildings in the last earthquakes clearly illustrated that presence of infill in t... more Performance of buildings in the last earthquakes clearly illustrated that presence of infill in the frames had significant structural implications. Masonry infill plays a crucial role in lateral load response of reinforced concrete frame buildings, especially in the initial phases of earthquakes. Structural contribution of infill to the frame lateral stiffness cannot be neglected. However, most design codes give only wage provisions for modeling such composite structures. The objective of this paper is to compare the existing macro models for masonry infill panels in the r/c frames. Considered macro models cover presently available suggested models. Reinforced concrete frames with different height/length ratios have been considered with three different strength types of masonry infill, namely: weak, intermediate and strong. Verification of the various models is carried out by comparing the results obtained from numerical analysis with the results from experimental database that incl...
Tehnički Vjesnik, 2018
Seismic risk is fundamental for the establishment of priorities in long-term prevention policy si... more Seismic risk is fundamental for the establishment of priorities in long-term prevention policy since urbanization and concentration of population in earthquake prone areas are increasing. To assess seismic risk, it is necessary to determine seismic hazard and vulnerability for which large amount of input data is required. Therefore, a rapid seismic risk assessment is proposed, based on seismic hazard maps and on statistical Census data for buildings. A case study is illustrated for Croatian cities in order to provide an overview of the overall relative risk in Croatia. As a result, the prediction model for threatened buildings in Croatia in function of peak ground acceleration is proposed. The prediction model gives an indicative outcome after possible earthquake event expressed in terms of percentage of threatened buildings. Most vulnerable cities according to prediction model are Dubrovnik, Zagreb, Split and Rijeka in accordance with their buildings distribution by age.
Strengthening techniques for masonry structures of cultural heritage according to recent Croatian provisions
Earthquakes and Structures, 2018
The buildings of architectural and cultural heritage are mostly built with stone or brick wall el... more The buildings of architectural and cultural heritage are mostly built with stone or brick wall elements, which are connected using limestone or limestone cement mortar, without a full knowledge of the mechanical properties of masonry structures. The compatibility of heritage masonry buildings with valid technical specifications and the rules for earthquake resistance implies the need for construction work such as repairs, strengthening or reconstruction. By strengthening the masonry buildings, ductility and bearing capacity are increased to a level, which, in the case of the earthquake design, allows for some damage to happen, however the structure retains sufficient usability and bearing capacity without the possibility of collapse. Comparison between traditional and modern techniques for seismic strengthening of masonry buildings is given according to their effects, benefits and disadvantages. Recent Croatian provisions provided for heritage buildings enabling deviation of technic...
Rad obrađuje problematiku konstruiranja i dimenzioniranja celicnih okvira sa zidanim ispunom. Ova... more Rad obrađuje problematiku konstruiranja i dimenzioniranja celicnih okvira sa zidanim ispunom. Ovakve su konstrukcije relativno ceste, a znacajnij
Multi-hazard effect on structures
Seismic Fragility Assessment of Masonry Infilled Reinforced Concrete Frames
Seismic fragility assessment of masonry infilled reinforced‒concrete frames was analysed. Three m... more Seismic fragility assessment of masonry infilled reinforced‒concrete frames was analysed. Three model structures with different infill configurations, were used. Developed and interpreted were the probabilistic fragility curves using Incremental Dynamic Analysis (IDA) and a set of seven earthquake records was used. Influence and contribution of infill walls to the system behaviour was evaluated. Results are presented as median values of the fragility curve for four limit states corresponding to the damage scale and damage measure of interest (Inter‒storey Drift Ratio, IDR). It could be concluded that fully‒infilled frame had 50% lower values of maximum Inter‒storey Drifts and had probability to survive up to 3 times higher intensities of spectral acceleration in regard to the bare frame.
Blind test prediction of an infilled RC building with OpenSees
Potential Use of Recycled Aggregate in Structural Concrete Elements
Tehnike ojačanja zidanih zgrada graditeljske povijesne baštine
The impact of recycled rubber aggregates on material nonlinearity of concrete
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Papers by Tanja Kalman Šipoš