One of the methods to determine the strength of concrete is to find maturity of concrete. Maturity of concrete is defined as Summation of product of age and temperature (Curing). Concrete Maturity = ∑ (Time x Temperature). Hydration can take place at minimum of -10°C, below this water crystals (ice) do not react with cement. Datum Temperature = -10°C, If

For small quantity of limestone, burning is done in a clamp. On a clear surface about 5 meters in diameter, layers of broken limestones and fuel are laid to form a heap about 4 meters high. First and the last layers should be of the fuel. In case coal is used as fuel, it could be well mixed up with limestones and lay in a heap. Sides of the heap, which incline slightly

It slakes rapidly. It consists of less than 5% of impurities such as silica and alumina (in clay form) and high %age of CaO. It is slow in setting and hardening and setting depends on CO2 from atmosphere, therefore rich lime is used for plastering but not mortar making. It may be used for inferior and temporary structures. It contains more than 5% clayey impurities

Fat lime is produced from sea shell, coral deposits etc or from lime stone containing impurities like free sand and soluble silica combined with alumina, magnesium, carbonate etc. If the proportion of free sand is large, the resulting lime becomes progressively poor and is called poor or lean lime. Fat lime slakes rapidly when water is added giving out considerable

Feebly hydraulic lime contains less than 15% of silic and alumina. It slakes slowly. The expansion on slaking is small. It produces good mortar. Moderately hydraulic lime: It contains 15-25% of silica and alumina, slakes slowly with small expansion and is stronger than feeble type. It is suitable for good class of mortar, brick work and masonry. c. Eminently hydraulic