Author(s): Ana Sofia Moreira dos Santos Guimarães ; Vasco Peixoto de Freitas (Orientador)
Date: 2011
Persistent ID: https://hdl.handle.net/10216/96782
Origin: Repositório Aberto da Universidade do Porto
Subject(s): Engenharia civil; Civil engineering
Rising damp coming form the ground that, by cappilarity, rise through porous materials, is one of the main degradation causes of historical and ancient buildings, essentialy, of this thick walls with heterogeneous composition. In the Building Physics Laboratory - "Laboratório de Física das Construções" - LFC of Oporto University Engineering School - "Faculdade de Engenharia da Universidade do Porto - FEUP", has been developed an important research concerning rising damp. In the last years it was validated and experimentally analysed the operating principle of a technique called "wall base ventilation system" for the treatment of rising damp problems in historical and ancient buildings, consisting in enforce the circulation of air in the base of the walls of buildings with high thickness and heterogeneity in its constitution, with a relative humidity far off saturation. Studies previously developed allowed to value the viability of the proposed system, being now the moment to developed a designing methodology. In this PhD thesis it is proposed to develop a model, using the numerical simulation program WUFI 2D, and making some laboratory and in field tests to get its validation. It is developed a model that describes the behaviour of the air inside a wall base ventilation system, estimates the changes of damp created by the contact wall/system and, therefore, estimates the evaporation powerful inside it. Later on it is adapted another model existing in the bibliography, based on the theory of unsaturated flows called "Sharp Front" that describes the phenomenon of rising damp in building walls, into a new model named ACE model, capable of considering the contribution of the evaporation produced by a wall base ventilation system. At last, numerical simulations using WUFI 2D program were made to evaluated the results archived with the ACE model and some experimental essays were developed to the evaluation of the designing system model, which puts together the two models previous studied. The in field experimental studies look for, through the analysis of a church where the systems are already installed, and using monitoring equipment, registering and studying the behaviour of those buildings where this technology was introduced for the first time. In conclusion, it is considered that this is an original work, which was developed a designing model of a wall base ventilation system for the treatment of rising damp problems in buildings with high thickness and heterogeneity of its walls materials, such as historical and ancient buildings. Keywords: Rising Damp, Treatment, HUMIVENT, Historical buildings, Designing, Model, Experimental Studies.
