The restoration of masonry, whether it is of residential buildings or buildings of historical and artistic interest, myst only be carried out after establishing the exact cause of the deterioration or the actual state of the structure by means of a thorough
visual inspection and, where necessary, diagnostic analysis. The correct intervention techniques and the most suitable materials for each phase of the intervention must then be identified, based on the performance requirements and characteristics
of the products employed.
From traditional to modern pozzolan: Eco-Pozzolan
The rediscovery of the extraordinary chemical and mechanical performance characteristics of lime combined with natural pozzolan or terracotta has inspired the Mapei Research & Development laboratories into developing innovative products and systems
for the restoration of buildings, including those of historical and artistic interest, using “modern” pozzolanic materials.
The result of the research work carried out is the use of a special product with a pozzolanic reaction, Eco-Pozzolan; a very light coloured inorganic material particularly rich in amorphous silica, with a highly-reactive, large specific surface area.
Eco-Pozzolan has the capacity to set off the hardening process of the lime after a very short time, unlike in the past when the process was extremely slow, so that restoration mortar and injection slurries are highly resistant to soluble salts just
a few days after application.
The combined use of lime and Eco-Pozzolan has led to Mapei formulating a specific range of dedicated products called Mape-Antique for the consolidation and restoration of brick, stone, tuff and mixed masonry, including masonry of buildings of historical
or artistic interest.
The products in the Mape-Antique Range have physical and mechanical characteristics similar to masonry mortar and render used in the past and, as such, are more compatible with any type of original structure. At the same time, they have high mechanical
strength and resistance to the aggressive chemical action from both the environment, such as acid rain, freeze thaw cycles and pollutant gases and from within the masonry itself, such as soluble salts and damp. Thanks to their macro-porous structure,
most of the products in the Mape Antique Range are highly transpirant and porous, with a much higher capacity to encourage the evaporation of water from the masonry compared with traditional cementitious or lime-cement rendering mortar. Whether
humidity or damp is caused by weather conditions or rising damp, this process allows damp structures to dry off and provide healthier more comfortable surroundings. Also, if soluble salts are present in the masonry, they crystallise in the pores
without generating stresses which could potentially deteriorate the render. Unlike mortars normally used for repair work, such as those made from aerated lime, hydraulic lime and natural hydraulic lime which also harden.
Through a process of carbonation, the reaction between lime and Eco-pozzolan forms silica-aumina compounds whereby the “free” lime is completely “consumed” after just a few days, so that restoration mortar and injected slurries
are completely resistant to soluble salts present in the masonry. The mortars, however, even if they are sufficiently porous and mechanically compatible with the materials originally used, are not immune to the risk of aggression from chemicals.
In fact, the “free” lime contained in these materials may chemically react with the sulphates in the masonry and with C-A-H (Calcium alumina hydrates) and C-S-H (Calcium silica hydrates) in the original mortar or in mortar used for repair,
to produce compounds called ettringite and thaumasite, which then expand and cause the render to crack and / or crumble.
With the products in the MAPE-ANTIQUE range, on the other hand, this phenomenon does not occur because there is absolutely no “free” lime after just a few days. From a morphological point of view, the structure of the products from the
MAPE-ANTIQIE is similar to that of “historical mortar” made from aerated lime and pozzolan, but which only forms after a number of years.
The MAPE-ANTIQUE Range of products include:
• Injection Slurries Mape-Antique 1 : Super fluid, salt resistant lime and Eco-pozzalan based hydraulic binder with fillers to make injectable slurry for consolidating masonry. Mapei Antique F12: Super-fluid, salt resistant lime and Eco-pozzolan
based hydraulic binder with fillers to make injectable slurry for consolidating masonry and mortar including renders with frescoes.
• Binder for making mortars Mape-Antique LC : Salt resistant lime and Eco-pozzolan based hydraulic binder mixed
with assorted aggregates to make de-humidifying mortar and masonry mortar.
• Mortars for dehumidifying renders Mape-Antique Rinzaffo: Salt resistant, transpirant lime and eco pozzolan based scratch-coat mortar applied as a base layer for dehumidifying transpirant and “structural” mortar. Mape-Antique
CC/MC: Macro porous, salt resistant lime and Eco pozzolan based dehumidifying render for the restoration of the existinng masonry, incuding masonry of historical interest. Mape-Antique MC Macchina: Macro-porus, salt resistant, lime and Eco Pozzolan based
demudifying render for the restoration of existing masonry including masonry of historical interest.
• Mortars for transpirant and structural renders Ape-Antique Intonaco NHL : Transpirant natural hydraulic lime and Eco Pozzolan based base
render for existing masonry, including masonry historical interest and new builds.
• Masonry mortars Mapei-Antique Allettamento: Salt resistant natural hydraulic lime and Eco Pozzolan masonry mortar for pointing and installing “exposed”
masonry. Mapei-Antique Strutturale NHL: High strength, transpirant natural hydraulic lime and Eco Pozzolan based rendering and masonry mortar particularly suitable for making “reinforced” mortar and installation mortar
. • Skimming mortars Mape-Antique FC Ultrafine : Salt resistant, ultra smooth texture natural hydraulic lime and Eco pozzolan based transpirant skimming mortar for a smooth finish on render. Mape-Antique FC Civile: Salt resistant, smooth
texture natural hydraulic lime and Eco Pozzolan based transpirant skimming mortar for a natural finish on render. Mape-Antique FC
Grosso: Salt resistant, coarse texture natural hydraulic lime and Eco Pozzolan based transpirant skimming mortar for a coarse
finish on render. All the products in the range are cement-free and are based on lime and Eco-Pozzolan, and their transpiration capacity, porosity, thermal conductivity and very low emission of volatile organic compounds (VOC) meet today’s application
requirements and the fundamental principles of eco-sustainability to protect the environment, and bio-compatibility to safeguard people’s health. Also, their elastic and mechanical properties are similar to those of existing masonries, including
the ones of historical and artistic interest.
Mape-Antique range: properties
- Mechanical strength similar to the one of traditional hydrated lime and hydraulic lime-based systems.
- Elastic and mechanical properties compatible with those of the materials originally used to construct buildings.
- Workability similar to the one of the highest quality hydrated lime-based systems.
- Highly transpirant and porous, with the capacity to eliminate the risk of condensation forming on the surface, meaning healthier, more comfortable surroundings.
- High resistance to soluble salts thanks to the chemical reaction between the lime and the Eco-Pozzolan, which “consumes” all the “free” lime very quickly.
- No alkali-aggregate reaction.
- Negligible thermal conductivity due to the low level of “free” lime, which also eliminates the formation of efflorescence.
- It may be tinted on site with coloured powders or oxides.
To know more about Mape-Antique range of products, please contact:
Mapei Construction Products India Pvt. Ltd.,
A01, B01, 1st Floor Solus Jain Heights, 1st Cross J C Road
Bangalore 560 002
Ph.: 080 22221820