Conservation of coral stone architectural heritage on the coast of East Africa

Much of the architectural heritage on the coast of East Africa was built with coral limestone and today it suffers from a severe decay. Swahili architecture and European colonial architecture are part of this heritage. After many observations at sites such as Inhambane, Ilha de Mocambique and Ilha de Ibo, we think that the phenomenon of regeneration of soluble salts is the main cause of degradation of coral stone buildings. Knowledge and mastery of the physical and chemical phenomena in coral stone buildings are the basis of the preservation process. But the techniques of the past, when known to the restorer, can suggest the best way for the restoration and maintenance practices (Some topics of this theme: lime from coral - sand fluvial from the Ibo Island - murrapa juice, as an additive for mortar). Finally, the paper proposes the idea of preserving historic coastal settlements in an optimal equilibrium with natural environment assets. (C) 2016 The Authors. Published by Elsevier Ltd.