Correlation between relative humidity and the strength and deformation characteristics of unstabilised earth masonry.

[Display omitted] • Compressive strength and modulus of elasticity of earthen materials are linearly correlated with the relative humidity. • Strength and deformation characteristics of earth masonry do not depend on the temperature at constant relative humidity. • Influence of relative humidity on the strength and deformation characteristics can be approximated by a suggested equation. • The correlation is generally applicable to unstabilised earth masonry without high contents of organic aggregates. • Influence of the material moisture content can be considered in structural design without extensive testing. The mechanical properties of unstabilised earthen building materials are distinctively influenced by changes in material moisture content. However, this moisture-dependency often remains unconsidered in the calculation of the load-bearing capacity of earth constructions. This paper aims to derive a convenient way to sufficiently consider the impact of different material moisture contents on the mechanical properties of unstabilised earth masonry. Therefore, the influence of relative humidity and temperature on the strength and deformation characteristics of unstabilised earth blocks, earth mortar and earth masonry is evaluated by conducting compression tests under various climate conditions. The results show that the compressive strength and the modulus of elasticity are linearly correlated with the relative humidity, whereas changes in temperature at constant relative humidity have no significant influence. To account the distinct moisture-dependency, a general applicable modification factor for unstabilised earthen materials is provided, which enables the adjustment of the compressive strength and the modulus of elasticity in dependency of arbitrary hygroscopic material moisture contents. [ABSTRACT FROM AUTHOR]