Historic trass - lime mortars with expansive reactions: Characterization and repair strategies
conference paper
The characterisation of two ancient mortars in historic bridges, suffering damage due to
thaumasite and other swelling compounds is described. Characterisation was part of the
analysis of damage occurring to the brick masonry structure. Expansive reactions were found
to have taken place, being the cause of the damage to the masonry. In both cases hydraulic
mortars were involved: lime mortars with pozzolanic aggregate. One case concerned the
mortar of a 18th century canal bridge in Amsterdam, the other the mortar of a 19th century
railway bridge. In both cases the strategy to deal with the problem should consist of a
combination of reduction of moisture penetration, combined with a mortar meant to be better
compatible with the conditions of the masonr y (i.e. the presence of moisture and of sulfate).
Generally a trass-lime mortar is considered to be a good choice under the described
conditions. Possible explanations for its failure are discussed
thaumasite and other swelling compounds is described. Characterisation was part of the
analysis of damage occurring to the brick masonry structure. Expansive reactions were found
to have taken place, being the cause of the damage to the masonry. In both cases hydraulic
mortars were involved: lime mortars with pozzolanic aggregate. One case concerned the
mortar of a 18th century canal bridge in Amsterdam, the other the mortar of a 19th century
railway bridge. In both cases the strategy to deal with the problem should consist of a
combination of reduction of moisture penetration, combined with a mortar meant to be better
compatible with the conditions of the masonr y (i.e. the presence of moisture and of sulfate).
Generally a trass-lime mortar is considered to be a good choice under the described
conditions. Possible explanations for its failure are discussed
TNO Identifier
330843
Source title
RILEM Workshop Historic Mortars, Delft, January 2005
Pages
11
Files
To receive the publication files, please send an e-mail request to TNO Repository.