Concrete Structures Deteriorated by Delayed Ettringite Formation and Alkali-Silica Reactions (Building Pathology and Rehabilitation, 24)

Description

This book discusses the behaviour of isolated concrete bottle-shaped struts affected by internal expansion reactions (ISR). For that purpose, the numerical modelling of damaged concrete was performed using the Concrete Damaged Plasticity Model (CDPM) implemented in ABAQUS and validated the model through Sankovich's tests. A procedure to automatically obtain the concrete plasticity and damage parameters, essential for CDPM, was developed in Matlab. The inputs were the characteristic compressive strength of the concrete, the equivalent length of the finite element mesh and the ratio between the plastic and inelastic compressive strains. The results showed that the CDPM could represent the load-bearing mechanisms of isolated concrete bottle-shaped struts for a range of several stress levels to which these elements may be subjected in the panels investigated. The numerical simulations for different expansion levels consistently captured the expected damage profile of the panels and the load corresponding to the formation of the first crack, the estimated crack opening, and the ultimate load. For the panels investigated, the reduction observed in the failure load reached values close to 70%, the increase of the tensile plastic deformation was more than 60%, and the maximum crack opening can reach an increase of 113% when compared with those observed experimentally in panels without internal swelling reactions The book also offers a systematic review of the current state of knowledge and it is a valuable resource for scientists, students, practitioners, and lecturers in various scientific and engineering disciplines, namely, civil and materials engineering, as well as and other interested parties. Preface Contents 1 Introduction 1.1 Description 1.2 Objectives References 2 Brief Literature Review 2.1 Delayed Ettringite Formation (DEF) 2.2 Alkali-Silica Reaction (ASR) 2.2.1 Numerical Modelling of ASR References 3 The Plasticity Model of Concrete Damage—CDPM 3.1 Additive Decomposition of the Field of Total Deformations 3.2 Mechanical Behaviour of the Model 3.2.1 Uniaxial Behaviour in Traction and Compression 3.2.2 Nonlinear Behaviour in Traction 3.2.3 Nonlinear Behaviour in Compression 3.3 Flow Law and Flow Criterion 3.4 Routine for Parameters Needed for the Model CDP 3.4.1 Routine Description 3.4.2 Routine Implementation—Generation of Inelastic Deformations, Damage Parameters and Respective Stresses 3.5 Routine for Reducing the Mechanical Properties of Concrete by Internal Expansion Reactions (IER) References 4 Bottle-Shaped Isolated Struts Concrete Deteriorated 4.1 Materials and Methods 4.2 Experimental Program 4.2.1 Panel S1-2 4.2.2 Panel S3-1 4.2.3 Qualitative Information from Other Panels References 5 Numerical Simulation 5.1 Computational Model Description 5.2 Computational Model 5.3 Properties of Concrete—Elasticity, Plasticity and Damage 5.4 Step Definition 5.5 Assembly 5.6 Definition of Interactions in the Model 5.7 Definition of the Boundary Conditions 5.8 Processing References 6 Numerical Results and Discussion 6.1 FEM Validation 6.1.1 Qualitative Comparisons 6.1.2 Quantitative Comparisons 6.2 Panel S3-1 Deteriorated by Alkali-Silica Reaction (ASR) 6.3 Panel S2-1 Deteriorated by Delayed Ettringite Formation (DEF) References 7 Conclusions and Future Recommendations 7.1 Conclusions 7.2 Future Recommendations References