Combined photogrammetry and mechanical testing of fired clay brick Kombination aus Photogrammetrie und mechanischem Testen von gebrannten Ziegeln M. Batinic´ 1 , M. Galic´ 1 , B. Trogrlic´ 1 , V. Divic´ 1 , I. Racetin 1 , A. Mihanovic´ 1 A novel experimental tensile apparatus and testing methodology, developed in or- der to define necessary material parameters for mathematical formulation of a con- stitutive model of fired clay brick is presented in this paper. In order to account for irregularities in sample geometry, a photogrammetry workflow for digital 3D re- construction of samples was conducted, and non-dimensional coefficients account- ing for geometric irregularities of test specimen was introduced. Mechanical tests were carried out on a series of fired clay brick specimens, sampled from brick blocks. Statistically analysed experimental data, corrected with the aforementioned coefficients, yielded modulus of elasticity, Poisson’s coefficient, and extreme ten- sile stress/strain relationships that, were used in the proposed numerical con- stitutive model. Keywords: Fired clay brick / photogrammetry workflow / mechanical properties / tensile testing / tensile strength Schlu¨ sselwo¨ rter: Gebrannte Ziegel / photogrammetrischer Arbeitsablauf / mechanische Eigenschaften / Zugfestigkeitspru¨ fung / Zugfestigkeit 1 Introduction Masonry structures, due to their mechanical and thermal characteristics, construction flexibility and practicality, have many advantages in comparison to other building materials, and are the focus of scien- tific analyses in last decades [1]. Masonry structures are subjected to static, cyclic and dynamic loads. Among other properties, behaviour under static compression tensile fracture and crack propagation, brick and mortar interaction is analysed [2-4]. All these studies have led to conclusions about mechan- ical properties of masonry walls in their totality, showing that the properties greatly depend on me- chanical properties of brick blocks and mortar, as well as mortar bed thickness and quality, and boun- dary conditions of masonry walls [5-7]. In terms of the stress-strain relationship, the properties depend on the orientation of main stresses in relation to the mortar bed placement. Masonry wall mechanical properties, including compression, tensile and shear strength, are defined based on measurements. In case of special mortar, e. g. epoxy resin, etc. [8], they are homogenised, i. e. local fracture and cracks occur in brick blocks, or on the mortar bed. So far, most tests have been per- formed on masonry walls as a whole, and the ob- tained properties are defined for integrated masonry Corresponding author: M. Batinic´, Faculty of Civil En- gineering, Architecture and Geodesy, University of Split, Ulica Matice hrvatske 15, 21000 SPLIT, CROA- TIA, E-Mail: milko.batinic@gradst.hr 1 Faculty of Civil Engineering, Architecture and Ge- odesy, University of Split, Ulica Matice hrvatske 15, 21000 SPLIT, CROATIA Materialwiss. Werkstofftech. 2018, 49, 1399–1408 DOI 10.1002/mawe.201700106 1399 © 2018 WILEY-VCH Verlag GmbH & CO. KGaA, Weinheim www.wiley-vch.de/home/muw