Evaluation of the Durability of Hydrophobic Treatments on Concrete Architectural Heritage
Abstract The protection of historical concrete structures is a challenge for the coming years. Hydrophobic treatment may reduce the deterioration process while providing protection against water penetration. Existing commercial products - mainly silane or siloxane in either water or solvent based formulations - were submitted to different ageing processes including UV radiation, dry-wet cycles, thermal shocks, freeze-thaw cycles, carbonation and their effectiveness has been evaluated on the basis of contact angle, vapour and chloride permeability and, capillarity water absorption. The results obtained clearly show that hydrophobic treatments display a good behaviour under the main ageing conditions.
Durability of hydrophobic treatment of concrete
The subject of this study was the performance of hydrophobic treatment to protect concrete against chloride penetration from de-icing salts. Hydrophobic treatment makes a concrete surface absorb less water and less chloride. Test methods and requirements for commercial products were established. In most cases, the water absorption was strongly reduced and the penetration depth could be well over 2 mm. Several types of tests were carried out to study the perforrnrice of hydrophobised concrete. After 52 weekly salt ponding/drying cycles the penetration of chloride was reduced by about 80% due to hydrophobic treatment. The water repellent effect remained constant over three years outdoor exposure. Corrosion which had already started before application of the hydrophobic agent was not influenced by hydrophobic treatment
Phenomenology and Existentialism
Chapter 1 Preface to the 2001 Edition Chapter 2 Introduction Part 3 The Phenomenology of Edmund Husserl Chapter 4 The Attack on Psychologism Chapter 5 The Phenomenological Reductions Chapter 6 Phenomena and Phenomenological Reflection Chapter 7 Intentionality Chapter 8 Meaning and Constitution Chapter 9 Essences and Necessary Truth Part 10 Existential Phenomenology Chapter 11 Phenomenology and Ontology Chapter 12 Existence Chapter 13 The Life World Part 14 Self and Others Chapter 15 Consciousness and the Ego Chapter 16 Intersubjectivity Chapter 17 Freedom Chapter 18 Existentialist Ethics Chapter 19 Bibliography