From laboratory to site: Renders of Paimogo Fort, a case study

Abstract

The Paimogo Fort, is one of the several Portuguese military fortifications, built in the 17th century, with the intention to protect the Portuguese coastline territory from the constant military threat from the ocean. Abandoned since 19th century, it suffered severe damage. The latest renovation work, carried out in 2006, most of the original renders have been removed and replaced by new ones, based on hydraulic lime mortars, which show significant signs of deterioration, only few years later. Within the scope of the “Coast Memory Fort” EEA Grants project1, promoted by Lourinhã Municipality, which aims to safeguard and revitalize the Paimogo fort (EEA Grant), new repair mortars for wall renders were developed by the team of National Laboratory for Civil Engineering, that should fulfil the required functions: protection and aesthetics of the Fort walls. In this investigation, several in situ applications were made on the Fort external area, and their performance was assessed by a multidisciplinary team from different fields, with the aim to select the most balanced render formulations to be applied on the Paimogo Fort walls. The tests carried out to verify their efficacy and their compatibility with the original masonry and environmental conditions are presented; the main axes that structure the action and reflection of the working group for the intervention solutions are described; the final application aspects are presented.