Mississippi Lime’s Standard Hydrated Lime (calcium hydroxide) is used as a multi-functional filler/anti-strip agent and CalCarb® M2 Asphalt Mineral Filler (calcium carbonate) is used strictly as a functional filler in asphalt mixtures.
In the United States, lime has been used in hot mix asphalt (HMA) to reduce moisture sensitivity and stripping since 1910. But while hydrated lime has long been an acknowledged anti-strip additive for asphalt pavements, it also imparts other important benefits:
- Lime stiffens the binder and HMA to resist rutting
- Lime improves toughness and resistance to fracture growth at low temperatures
- Lime changes oxidation chemistry in the binder to reduce age hardening
- Lime alters clay fines to improve moisture stability and durability
Limestone (ground calcium carbonate) is used as a functional filler in asphalt mixtures. Stone mastic asphalt (SMA) has recently been introduced as a high performance asphalt. SMA requires a higher loading of asphalt mineral filler to achieve the higher performance design requirements. CalCarb® M2 is designed to meet critical particle size requirements in order to serve as a functional but cost effective asphalt additive.
For more information on the use of Mississippi Lime products in asphalt, see