FRP reinforcement in RC structures

fib Bulletin 40 deals mainly with the use of FRP bars as internal reinforcement for concrete structures. The background of the main physical and mechanical properties of FRP reinforcing bars is presented, with special emphasis on durability aspects. For each of the typical ultimate and serviceability limit states, the basic mechanical model is given, followed by different design models according to existing codes or design guidelines

Probabilistic evaluation of conformity criteria for concrete families

When only a limited number of test results are available, compressive strength results of concrete family members can be combined in order to enable conformity control on a sufficient number of test results. The principles behind the conformity control of concrete families are explained and an original probabilistic evaluation of conformity criteria for concrete families is introduced. For the calculation of the corresponding operating characteristics, some approximate formulae are presented. Additionally, Monte Carlo simulation techniques are used for more exact calculations. In this way, also autocorrelation between consecutive test results can be taken into account, using an autoregressive process. The current guidelines and conformity criteria for concrete families in EN 206-1 are evaluated and discussed, based on the AOQL concept. Different conformity criteria and transformation methods are described, evaluated and discussed

Bayesian updated time-dependent chloride-induced corrosion assessment using redundancy factors

In order to assess the structural reliability and redundancy with respect to deterioration, it is required to select appropriate models which describe the deterioration process. The parameters associated with these models have to be estimated through statistical interference, which introduces uncertainties in parameter estimates. As the structural reliability indices which are incorporated in the reliability-based redundancy factor can be considered as random variable, this redundancy factor itself is a random variable as well. In case additional information becomes available, the distribution function can be updated by taking into account this extra information. In this contribution, a framework is developed, which allows for the incorporation of additional information in the uncertain reliability index and the associated redundancy factor through Bayesian updating. It is shown that in case additional information on a main variable is gathered, this has a significant effect on the (mean) value and uncertainty of the reliability index and the associated redundancy factor.Non UBCUnreviewedThis collection contains the proceedings of ICASP12, the 12th International Conference on Applications of Statistics and Probability in Civil Engineering held in Vancouver, Canada on July 12-15, 2015. Abstracts were peer-reviewed and authors of accepted abstracts were invited to submit full papers. Also full papers were peer reviewed. The editor for this collection is Professor Terje Haukaas, Department of Civil Engineering, UBC Vancouver.Facult

Towards a practical probabilistic post-fire assessment for concrete slabs

When a concrete structure has been exposed to fire, a decision has to be made whether the structure should be demolished, can be repaired, or may be used in its current state. However, many uncertainties are associated with both the fire duration and the effect of elevated temperatures on the mechanical properties of the materials. Consequently, the maximum allowable load after fire exposure should be assessed based on reliability considerations. As full-probabilistic calculations are too complex and time-consuming for normal use by practitioners, a reliability-based assessment tool has been developed which determines the maximum allowable imposed load after fire

Thermo-mechanical analysis of an underground car park structure exposed to fire

Underground concrete structures composed of flat slab-column connections are sensitive to punching failure at ambient temperatures. During fire, however, due to the restraint of thermal curvatures an increase of the punching load can occur, possibly leading to premature collapse. In this paper, this problem is studied numerically by the combination of CFD and mechanical finite element analysis, whereas further considerations are developed by the use of plasticity theory. The basis for the fire scenario used in the analysis is found in the literature as a real fire. The Belgium standard NBN S 21-208-2 for the design of the ventilation system in underground car parks with respect to car fires is used as well. The dimensions of the underground car park are based on a real fire accident that occurred in Gretzenbach, where the structure actually failed due to punching following a rather small fire. In the analysis, special attention is given to the increase of the axial load on the slab-column connection with temperature. For the mechanical properties and boundary conditions assumed, it is found that during fire the axial load may increase with a factor which, at least in the worst cases, can be close to the safety factor found from large scale fire tests

De l'utilisation de fibres métalliques comme armature complémentaire de poutres en béton armé soumises à flexion

SCOPUS: ar.jinfo:eu-repo/semantics/publishe