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Numerical models of corroded reinforced concrete beams are often based on damage relations. The choice of relations and modelling approaches have varied in the literature. Therefore, the paper explains the choice of a proper set of damage relations and validates the approach on the results of three-point bending tests in terms of load-displacement relations, crack patterns and failure mode. The damage to the reinforcement is input as average and variable cross-section loss which is coupled by a model to reduce its material properties. The bond loss is based on calibrated multi-linear curves from pull-out tests done in the framework of the same project. The results show that reducing the steel material properties is important while both the average and the variable section loss yield good predictions for the considered corrosion range. Incorporating the suggested bond-slip law in the corroded beam model affects the cracking pattern, however, no full agreement between numerical and experimental crack patterns was obtained. ispartof: pages:312-319 ispartof: Proceedings of the 2020 session of the 13th fib international PhD symposium in civil engineering pages:312-319 ispartof: 13th fib International PhD Symposium in Civil Engineering location:Paris date:26 Aug - 28 Aug 2020 status: Published online

Une étude expérimentale a été menée sur 21 formulations avec des fractions volumiques en fibres comprises entre 0 et 0.8 %, ainsi qu’avec trois fractions volumiques en granulats différentes : 20, 40 et 60 %. A l’état frais, la consistance et la teneur en air ont été mesurées. A l’état durci, les résistances en compression et flexion, ainsi que la résistivité électrique ont été mesurées. Lorsque la fraction volumique en sable est de 20 ou 40 %, les fibres carbone causent une importante diminution de la résistivité électrique des mortiers, contrairement aux formulations comportant une fraction volumique de sable de 60 %. L’influence directe des fibres sur la résistance à la compression est négligeable, cependant les fibres peuvent causer une légère augmentation de l’air entraîné, et donc provoquer de manière indirecte une légère diminution de la résistance en compression. Les fibres carbone permettent une augmentation de la résistance en flexion, qui est d’autant plus notable lorsque leur matrice cimentaire comporte une fraction volumique de sable faible, et donc une résistance en flexion peu élevée., Academic Journal of Civil Engineering, Vol 34 No 1 (2016): Special Issue - RUGC 2016 Liège

This paper presents an assessment of the efficiency of different end zone reinforcement detailing for pre-tensioned concrete girders. The evaluation is performed through a numerical parametric study of 10 different reinforcement lay-outs. The implemented lay-outs are compared in terms of crack control and design recommendations for efficient end zone reinforcement detailing are formulated.

Since the ultimate porosity, and consequently the durability, of concrete is not only determined by the microstructural built-up, but also by the formation of (micro)cracks in the cement matrix caused by the differential shrinkage of the composing phases in the concrete matrix, a study of the microstructural built-up and the formation of (micro)cracks during hardening and curing is inevitable when dealing with durability of cementitious materials. For this reason, the influence of mineral additions and chemical admixtures in SCC on microcracking and durability are studied in the Belgian research project G.0311.06, sponsored by the Research Programme of the Research Foundation - Flanders (F.W.O.). The research project is a cooperation between the Reyntjens Laboratory (K.U.Leuven), the Magnel Laboratory for Concrete Research (Ghent University) and the Royal Military Academy Brussels. The main objectives of the ongoing research project are: (1) determination of the influence of the different parameters on the formation of microcracks, (2) determination of the influence of these parameters on the microstructural built-up and (3) formulation of porosity and flow models which simulate the durability behaviour of SCC. An overview of the research project is presented. ispartof: pages:773-778 ispartof: Proc. of the 5th Int. RILEM Symp. on Self-Compacting Concrete (SCC2007) pages:773-778 ispartof: 5th Int. RILEM Symp. on Self-Compacting Concrete (SCC2007) location:Ghent date:3 Sep - 5 Sep 2007 status: published