Lightweight thermal efficient repair mortars with expanded glass (EG) for repairing historical buildings: The effect of binder type and EG aggregate dosage on their performance

Lightweight thermal efficient repair mortars with expanded glass (EG) for repairing historical buildings: The effect of binder type and EG aggregate dosage on their performance

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The mutual effect of a binder type and dosage of expanded glass granules on the properties and perfor- mance of lightweight repair mortars was researched. As the problems associated with repair and renewal of heritage buildings requires complex approach and solution, broad experimental campaign was con- ducted to assess mortars’ structural, hygric, thermal, mechanical, and durability parameters and to eval- uate their applicability in buildings refurbishment and thermal efficiency improvement. Most of the tests were done for samples matured for 28, 90, and 360 days. Where applicable, the prepared mortars were classified according to the WTA directive 2-9-04/D and technical standard EN 998-1. The compatibility issues were also considered. The lime and natural lime mortars lightened with expanded glass granules were found to be applicable for repair purposes, even for historical heritage buildings, where often con- tradictory requirements of culture heritage authorities must be met. It was due to their moderate strength, high porosity, permeability for water vapour, salt crystallization resistance, and low thermal conductivity which enabled to rank these mortars in category T1, and T2, respectively. On the other hand, lime-cement mortars are inappropriate for rehabilitation of older buildings due to their composition, high mechanical strength and lower permeability for water and water vapour but can find use in new buildings or in existing buildings, where cement-based mortars are originally used. In this case, their advanced properties and durability will be exploited.

The mutual effect of a binder type and dosage of expanded glass granules on the properties and perfor- mance of lightweight repair mortars was researched. As the problems associated with repair and renewal of heritage buildings requires complex approach and solution, broad experimental campaign was con- ducted to assess mortars’ structural, hygric, thermal, mechanical, and durability parameters and to eval- uate their applicability in buildings refurbishment and thermal efficiency improvement. Most of the tests were done for samples matured for 28, 90, and 360 days. Where applicable, the prepared mortars were classified according to the WTA directive 2-9-04/D and technical standard EN 998-1. The compatibility issues were also considered. The lime and natural lime mortars lightened with expanded glass granules were found to be applicable for repair purposes, even for historical heritage buildings, where often con- tradictory requirements of culture heritage authorities must be met. It was due to their moderate strength, high porosity, permeability for water vapour, salt crystallization resistance, and low thermal conductivity which enabled to rank these mortars in category T1, and T2, respectively. On the other hand, lime-cement mortars are inappropriate for rehabilitation of older buildings due to their composition, high mechanical strength and lower permeability for water and water vapour but can find use in new buildings or in existing buildings, where cement-based mortars are originally used. In this case, their advanced properties and durability will be exploited.