Print Email Facebook Twitter Alkali silica reaction in the afsluitdijk Title Alkali silica reaction in the afsluitdijk: Assessment of concrete damage and remaining service life using experimental and modelling research Author Kamat, Ameya (TU Delft Civil Engineering and Geosciences; TU Delft Engineering Structures) Contributor Copuroglu, Oguzhan (mentor) Schlangen, E. (graduation committee) Lukovic, M. (graduation committee) Degree granting institution Delft University of Technology Programme Civil Engineering | Structural Engineering | Concrete Structures Date 2017-10-23 Abstract Alkali Silica Reaction (ASR) is one of the degradation mechanisms in concrete that poses a threat to the service life of existing structures. This physio-chemical process is progressive and can affect the the strength, stiffness and stability of concrete structures. A lot of mitigation measures are available to prevent the deleterious effects of ASR in new structures. However, assessment and monitoring of ASR in the existing structures still remain a challenge. Thus the main aim of this thesis is to develop a simplified tool for the assessment of existing structures to assist the asset owners in decision making. This is addressed by a combination of petrographic techniques to quantify the damageand development of a numerical model to predict the remaining service life. Various existing petrographic tools (Damage rating index and image analysis) are investigated and modified to not only identify the ASR signs but also to quantify the damage. A meso-scale numerical model (ASR expansion model) is developed as an extension to the existing Delft Lattice Model to incorporate the effect of ASR by application of randomly distributed internal expansions. A case study (Afsuitdijk, The Netherlands) is used to apply these methods. The model is compared with the findings from the petrographic analysis using a physical parameter 'crack densities'. This model is able to simulate localised network of cracks typical of ASR and expansion strains as a function of time. These expansions are compared with the permissible expansion thresholds set byRILEM and CUR to assess the remaining service life. Additionally, the numerical model showcases the importance of different boundary conditions by making a comparative study between free expansions and concrete in confined state. Finally, the limitations and drawbacks of this expansion model are discussed critically. Subject Alkali silica reactionLattice modelDamage rating index To reference this document use: http://resolver.tudelft.nl/uuid:c7f81d42-0577-40ef-8808-5ec1a106a57c Part of collection Student theses Document type master thesis Rights © 2017 Ameya Kamat Files PDF Ameya_Thesis_E_copy.pdf 90.47 MB Close viewer /islandora/object/uuid:c7f81d42-0577-40ef-8808-5ec1a106a57c/datastream/OBJ/view