METHOD OF CONSTRUCTING FROST-RESISTANT GRAVEL ROADBASES BY MEANS OF BENTONITE

VERFAHREN ZUR HERSTELLUNG VON FROSTSICHEREN KIESTRAGSCHICHTEN MIT HILFE VON BENTONIT

THE PROJECT IS THE RESULT OF AN EARLIER PROJECT (IRRD NO. 700541) IN WHICH A REPLACEMENT CRITERION FOR THE VERY STRICT CASAGRANDE FORST CRITERION WAS DERIVED AFTER ACCURATE DETERMINATION OF THE MINERALOGICAL COMPOSITION OF THE FINE CONSTITUENTS OF THE ROADBASE MATERIAL. EXTENSIVE DIRECT FROST TESTS AND BEARING CAPACITY TESTS WERE CARRIED OUT IN THE LABORATORY ON EXPERIMENTAL MIXTURES. THE PRESENT PROJECT IS A LARGE-SCALE FIELD TEST TO DETERMINE THE POSSIBILITIES OF ADDING BENTONITE TO THE MIXTURE; ROADBASES PRODUCED WITH THE MIXTURE WILL BE PROVIDED WITH A SURFACING AND EXPOSED FOR A LONG PERIOD TO NATURAL WEATHER CONDITIONS. OBSERVATIONS WILL BE MADE OF THE EXPERIMENT.