Preetham Granites are largest manufacturers, suppliers and exporters of INDIAN GRANITES, especially, Black Galaxy Granite, Absolute Black Granite, Black Forest Granite, Black Pearl Granite, Stel Grey Granite, Viscont White Granite, Imperial White Granite, Colonial White Granite, Asian Top Granite, Shiva Gold Granite, Dindigul pink Granite, Ghibli Pink Granite, Ghibli Grey Granite, Paradiso Granite, Tan Brown Granite,Red Multi Granite, Columbu Juparana Granite, Colonial Gold Granite, Imperial Gold granite slabs and countertops. These granite slabs and countertops are mainly exported to USA, Europe, Canada and Australia.
Preetham Granite M.D addressed the gathering of engineers (Association of Madurai Civil Engineers) on Cracks in Buildings – Causes & Remedies at Hotel Weshtern Park ( 01.09.2016).
Carbonation
While concrete hardens calcium hydroxide gets liberated. This alkaline medium protects steel. If the surface is porous, air reacts with calcium hydroxide and forms calcium carbonate. This process is carbonation. This carbonation affects reinforcement and corrodes
PERMEABILITY OF CONCRETE – This is a major factor attending corrosion of reinforcement. From this consideration quantity of cement in concrete should not be less than 350kg m3 and water-cement ratio should not exceed 0.55 for ordinary structures and 0.45 for marine structures. All other normal requirements of good quality concrete namely grading and cleanliness of aggregates through mixing adequate compaction and curing etc, should be taken care of.
Glass panes to be fixed with adequate space alround for thermal expansion.
Steel windows – effect of rusting results in cracking in glass panes.
Glass blocks – space for expansion when exposed to sun and rain
