Eminently hydraulic limes

The limestone is generally calcined in shaft kilns [16.59], which must be controlled closely to ensure that as much of the silica and alumina as possible reacts, without sintering the free lime, lypical calcining temperatures are 950 to 1250 °C the required temperature rises as the cementation index (see section 26.9.2) increases (i.e. from feebly to eminently hydraulic limes). 

Another classification uses the terms semi-hydraulic and hydraulic , corresponding approximately to feebly and eminently hydraulic respectively. Eminently hydraulic lime is also called Roman lime. 

Eminently hydraulic limes (also called Roman limes and hydraulic limes) are natural hydraulic limes, which have pronounced hydraulic properties. 

Eminently hydraulic limes set in five or six days, and continue to harden. 

Natural hydraulic limes have traditionally been classified in three categories feebly hydraulic, moderately hydraulic, and eminently hydraulic. 

Hydraulic limes have the property of setting and hardening under water — see natural hydraulic limes, special natural hydraulic limes and artificial hydraulic limes. The term is also used to describe eminently hydraulic and Roman limes. 

Lime is termed rich, poor, hydraulic, and eminently hydraulic, according to its properties. 

---