ABSTRACT
Predicted increases in extreme weather include greater rainfall intensities in the tropics, where highly erodible soft limestone comprises many road bases and where the existence of potholes requires two conditions: water and traffic. In Belize and Mexico, soft limestone, also called marl, was rejected as a road base in 1973 because of the low wet strength, poor grading and relatively high plasticity; crushed stone was used as a road base instead. Whereas M. E. Woodbridge showed that soft limestone road bedding performed well for at least 19 years with an effective surface seal, testing of the present materials seemed necessary to resolve the uncertainties regarding the potential road bases. As a road base with an adequately protective top dressing, untreated limestone marl performs satisfactorily in the long term and is cheaper than crushed stone by a factor of more than 2:1.
