Frequently Asked Questions
ARE NHL PRODUCTS LIKE CEMENTS?
  NO St. Astier NHL products are burned at temperatures between 1650-1850oF. At this temperature it is chemically impossible to develop Tricalcium Silicate (C3S) and high levels of Tricalcium Aluminate (C3A) which are formed at much higher temperatures and are the main components of cement.
 
CAN SULPHATE ATTACK OCCUR WHEN USING St. ASTIER NHL LIMES?
 NO  These reactions are common when materials have high contents of C3A, sulphates (SO3) and additions such as Gypsum ( CaSO4), all present in Cement. St Astier NHLs contain none of these potentially damaging components or only naturally occurring insignificant traces.
 
WHAT ABOUT ALKALI-SILICA REACTION DUE TO THE PRESENCE OF POTASSIUM AND SODIUM OXIDES OVER 1%?
 St Astier NHL's content of these components is below 0.3% and totally safe to use.
 
WILL St. ASTIER NHL PRODUCTS DETERIORATE IN A MARINE ENVIRONMENT DUE TO CONTACT WITH SEA SALT?
 NO  Gypsum added to cement and to some 'hydraulic limes' and C3A above 3% will react with the sulphates contained in sea salt. It is not possible for St Astier NHL's to react as they do not contain the necessary agents.
 
CAN St. ASTIER NATURAL HYDRAULIC LIMES BE REWORKED?
 YES  This is due to the absence of gypsum or additions of cement and the low content of alumina in the raw materials. Reworked mortars ensure less wastage.
 
ARE St. ASTIER NATURAL HYDRAULIC LIMES TOO STRONG?
 NO Not if one uses the correct grade and mix.
 
CAN St. ASTIER LIMES BE BLENDED WITH PUTTIES, POZZALANIC MATERIALS OR CEMENT?
 YES...but WHY? As there is a range of products available we do not see any necessity for blending. Furthermore, blending will affect the performance of the mortar with potentially undesirable results.
   
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