Salts as major decay agents.

Abstract

Salts are major decay agents of porous building materials and their action is particularly relevant in old buildings. This lecture has the following structure: 1 INTRODUCTION 2 SALT DECAY PATHOLOGY 2.1 - Anomalies 2.2 - Moisture 2.3 - Soluble salts 2.4 - Damage mechanisms 2.5 - Influencing factors 2.6 - Signs 3 CONTROL AND PREVENTION 3.1 - Working principles 3.2 - Methods of control and prevention Complementarity between methods Possible approaches 3.2.1 - Mechanical removal of efflorescence 3.2.2 - Removal of contaminating materials 3.2.2 - Poultices 3.2.2 - Electrochemical removal of salts 3.2.2 - Microorganisms 3.2.2 - Crystallization modifiers 3.2.2 - Plasters and renders 3.2.2 - Environmental control 3.2.2 - Rising damp control 3.2.2 - Barium hydroxide method 3.3 - Complementarity between methods 3.4 - Possible approaches