Simulation of humidity fields in aerial lime mortar

Abstract

• Pioneering simulation of humidity diffusion in aerial lime mortars. • Modeling the humidity diffusion in aerial lime mortar using a model proposed to concrete. • Modeling strategy able to appropriate simulate the experimental results. • Best pair of D 1 and f boundary presenting values higher than in concrete. The structural safety of historic buildings frequently demands an advanced structural analysis. These constructions often have cultural and architectonic values and were constructed with porous materials bond with mortar. Mortar usually presents a complex composition and structural behavior. This fact supports the requirement for a meticulous analysis of the role of mortar within the scope of the structural behavior of historic masonry construction. In different parts of the world, there is a significant quantity of historic constructions comprehending binders based on aerial lime mortars. Aerial lime is one of the oldest binders discovered and used. Moisture content in aerial lime structures has an important influence on their behavior and performance. An experimental program was developed to study the humidity flux in aerial lime mortar including the self-desiccation phenomenon. In order to simulate this drying process, a software based on a Finite Difference Method Algorithm (1D and axisymmetric cases) is used. The pioneer software used to identify the main material parameters that better fit the experimental data, considering the approach presented by Model Code 2010. The modeling strategy was firstly applied to experimental results of cylinders specimens and in sequence to experimental results of a prismatic mold. In general, the model was able to satisfactory fit the experimental results. When compared to concrete material, higher values for diffusivity and for boundary coefficient were found. For the studied specimens, the experimental and numerical results indicated reduced humidity gradient. These results are probably associated with the high porosity of the mortar.