Natural hydraulic lime mortars: influence of the aggregates

• Autor(es): Faria, Paulina ; Silva, Vitor
• Data: 2013
• Identificador Persistente: http://hdl.handle.net/10362/11259
• Origem: Repositório Institucional da UNL
• Assunto(s): natural hydraulic lime; aggregate; particle size; mortar; characterization
• Tipo de Documento: Documento de conferência
• Idioma: Inglês

Descrição

3rd Historic Mortars Conference, 11-14 September 2013, Glasgow, Scotland Natural hydraulic lime specifications changed with the new version of standard EN 459-1: 2010 and a new Portuguese NHL3.5 appeared in the market. The characteristics of mortars depend on many different parameters such as the type of binder, the type of aggregates, the use of fillers and of superplasticizers; also on mixing and curing conditions. In this paper NHL3.5 mortars with binder:aggregate volumetric proportions1:3 were prepared, varying the aggregates type and proportions between them. Two coarse sands, a medium sand, a river sand, a finer sand, a calcareous filler and a ceramic powder were used. The two last mentioned aggregates were byproducts from industry. Prismatic mortar samples and samples of mortar applied over brick were prepared and conditioned in two different situations – following standard EN 1015-11 and at 65% relative humidity with initial daily water spray. Mortars were characterized in the fresh state and at the age of 28 days. Results showed the influence namely of the curing, particularly in terms of water capillary, of the superplasticizer and of the fillers. They also showed that NHL3.5 mortars seem to be adequate for old masonries conservation and repair and, in some situations, they can be an alternative to air lime based mortars.