Prediction of failure mechanisms in concrete is a fairly complex task due to heterogeneous concrete microstructure, localization process triggered by cracks, multiple crack interactions during their ...growth and coalescence, and different dissipative mechanisms in a fracture process zone prior to localized failure and in a localization zone during the failure. None of the currently used phenomenological models can represent the full set of 3D failure modes. This work presents an attempt to solve this with the 3D meso-scale model based on discrete lattice approach. In particular we show that we can capture such complexities at the meso-scale, which is able to represent microcracks in fracture process zone along with the localized failure represented in terms of embedded strong discontinuity and accompanied with softening constitutive law. The model can also successfully simulate salient features of concrete response, such as order of magnitude of reduction in strength in uniaxial tension versus compression, strength increase in biaxial loading or hydrostatic tension. Moreover, macro-scale representation of failure surfaces obtained with presented model for different loading programs confirms the need for failure concrete criterion of multi-surface kind. Part I of this work presents the proposed meso-scale based on extensive number of numerical simulations with multiple realizations of different concrete specimens, along as the optimal deterministic fit for several common concrete failure models. The ultimate interest of the work is to provide detailed data set for different failure modes which can be used for identification of probability distribution of material parameters for different criteria. Such task is carried in Part II of this work.
•First extensive research campaign conducted on miljevina stone.•The height to diameter ratio highly influences the peak UCS.•Influence of layers on the UCS strength is up to 35.7%.•Anisotropy ...influence on the tensile strength mounted to 13%.•Inclusion of load application requirements for mudstone in the standard.•Inclusion of specimen size requirements for mudstone for UCS in the standard.•Influence of the layer’s direction on the flexural strength on saturated samples.
The formation of the freshwater lakes and travertine limestone was caused by the tectonic depression, which occurred in the Dinarides during the Miocene. This stone has been exploited and used since far back on the territory of Bosnia and Herzegovina as a building stone and for different architectural purposes. Most of the investigations were concentrated on the “tenelija” stone due to its massive use and construction of the famous Stari Most (Old Bridge) in Mostar. Not much investigation was devoted to “miljevina” (mudstone) which belongs to the same petrographic type. This is a soft carbonate rock that is highly porous, has small density, relatively low strengths, poor wear resistance, and low resistance to frost. In this paper, the influence of layers (planes of anisotropy - foliation) of the mudstone was investigated. Within an experimental campaign, numerous sets of tests were performed on different samples. Tests include uniaxial compressive strength (UCS) on cube and cylinder specimens, flexural strength under concentrated load and constant moment, tensile strength based on Brazilian tests, determination of Young’s modulus, modulus of deformations, and Poisson ratio. Prediction of UCS and Young’s modulus, as elastic mechanical characteristics, represent the main goal in engineering projects. Additionally, the influence of sample conditions and planes of anisotropy was investigated. Results have been compared and correlations are established. As a result, a new relation between uniaxial compressive strength obtained on cube and cylinder samples for a stone of low compressive strength is proposed.
Hreša - native Sarajevo stone Kurtović, Azra; Kadrić, Nermin
e-zbornik. Elektronički zbornik radova Građevinskog fakulteta,
12/2023, Letnik:
13, Številka:
SI
Journal Article
Recenzirano
Odprti dostop
Limestone breccia of Middle Triassic age from the area of the village of Hreša, 6 km northeast of Sarajevo, was the main dimension stone for the construction of a large number of public and private ...buildings in Sarajevo from the end of the 15th century until almost the end of the 20th century, especially during the Ottoman Empire and Austro-Hungarian rule. Urbanization and the expansion of the city core created a recognizable, hewn appearance of the red stone surface of the walls, staircases, paved squares and pedestrian areas of Sarajevo. In previous mineralogical petrographic investigations, they have been identified as breccia limestone (intrasparudite), fossiliferous microcrystalline limestone (fossiliferous micrite) and fossiliferous partially lumpy limestone (fossiliferous pelmicrite). Limestone breccias and breccia limestones known under the commercial name "Hreša" are extracted in the Hreša site. The locality belongs to the structural tertiary unit Vučja Luka - Hreša - Ljubogošča (geological map of the Prača area) and D. Crepoljsko - Trebević - Treskavica - Prača (geological map of the Sarajevo area).
U radu su prikazani glavni parametri gradnje kamenih mostova te bitni čimbenici pri odabiru novog (zamjenskog) kamena i morta za gradnju. Opisani su rezultati laboratorijskog ispitivanja kamena i ...morta koji se uobičajeno koriste kod sanacije i rekonstrukcije građevina kulturno-povijesne baštine u Bosni i Hercegovini iz perioda osmanske vladavine. Posebna pažnja je posvećena ispitivanju fizikalnih i mehaničkih karakteristika sedre, travertina i vapnenaca kao osnovnih kamenih materijala koji su korišteni prilikom izgradnje takvih konstrukcija.
Kulturno-povijesna baština sadrži pokretnu baštinu (naslijeđe) koju čine sva ostvarenja likovne i primljenjene umjetnosti, a koja nisu organski vezana sa građevinom. Nepokretnu kulturno-povijesnu ...baštinu (graditeljsko naslijeđe) predstavljaju nepokretna kulturna dobra nastala ljudskim radom od prahistorije do danas. Poznato je da je pri obnovi kulturno-povijesne baštine od prirodnog kamena posebna problematika na izboru zamjenskog kamena. Građevine govore o tome, koliko smo bili uspješni u odabiru zamjesnog kamena kada nisu dostupni izvorni nacrti i projekt, a uspjevamo uraditi vrlo dobru identifikaciju postojećeg kamena. Primjer takvog slučaja je dat u ovom radu na projektu obnove vrlo kompleksnog objekta sa stanovišta vrste i načina primjene prirodnog kamena: povijesne građevine Gradska vijećnica u Sarajevu.
Main parameters for the construction of stone bridges, and major factors for selection of new (replacement) stone and mortar, are presented in the paper. Laboratory test results are given for the ...stone and mortar normally used in the rehabilitation and reconstruction of cultural and historical heritage structures from the Ottoman period in Bosnia and Herzegovina. A special attention is paid to physical and mechanical characteristics of tufa, travertine and limestone, as basic materials used in the construction of such structures.
ostovi iz osmanskog perioda predstavljaju remek djelo ne samo tadašnjeg graditeljstva nego i današnjice zahvaljujući metodologiji izgradnje. Moderna arhitektura je nezamisliva bez povijesne pozadine. ...Konstrukcije su među najtrajnijim svjedocima povijesti - one pružaju pouzdane informacije o stvaralačkim moćima toga vremena. Utvrđivanje trenutnog stanja konstrukcije i provođenje određenih mjera restauracije je jedini način očuvanja ovih objekata za nadolazeće generacije. Ovdje će se dati osvrt na tri mosta koja su jedinstvena i prepoznatljiva, a nalaze se na značajnim pravcima tj. na mostarskoj džadi i carigradskom drumu. Sva tri mosta bila su izložena sličnim dejstvima, oštećena tijekom vremena, sanirana i rekonstruirana na načine koji će se kasnije pokazati neadekvatnim i koji su na određeni način narušili njihov autentični izgled, a u nekim slučajevima čak i doprinijeli daljnjoj degradaciji. No, zahvaljujući osiguranim financijskim sredstvima vraćeni su u prvobitno stanje - pješački most i ponovno zasijali svojom punom ljepotom iznad rijeka. U dijelu dva ovoga rada prikazati će se metodologija izrade i specifičnosti materijala od kojih su građeni mostovi, te dati osvrt na materijale koji s trebaju koristiti prilikom rekonstrukcije.
U današnje doba vrlo je korisno znati što je autorsko djelo i autorsko pravo, tko su ovlašteni nositelji autorskog prava, kako se ono štiti te koje su posljedice njegovog kršenja. Autorskopravnu ...zaštitu uživaju mnoga djela s kojima se susrećemo u svakodnevnom životu, kao što su književna djela, računalni programi, muzika, filmovi, baze podataka, naučni i stručni radovi, itd. Prema primjenjivim propisima autorskopravnu zaštitu uživaju i djela arhitekture, što uključuje izvedene objekte i pojedine dijelove arhitektonske projektne dokumentacije. U radu je dat pregled zakonske regulative o autorskom i srodnim pravima. Usvajanjem novog Zakona o autorskom i srodnim pravima izvršeno je potpuno usklađivanje Bosne i Hercegovine sa pravnim poretkom Evropske unije. U radu su dati postupci i rezultati ispitivanja kvaliteta zamjenskog kamena pri obnovi podloge Trga Bosne i Hercegovine. Obnova trga obuhvatala je isključivo zahvate koji su bili potrebni da bi se trgu vratio njegov prijeratni izgled, kako ga je projektirao Dušan Džamonja.
Structural condition and repair of the Careva Ćuprija Bridge in Sarajevo is presented in the paper. This historic structure has been exposed to various atmospheric influences during its use, and also ...to significant traffic load for which it was not initially designed, which has ultimately resulted in degradation of its structure. To enable continued functioning of this bridge its structure must be repaired taking into account the fact that the bridge was proclaimed a national monument of Bosnia and Herzegovina on 11 March 2009.
PDF
