LABORATORY AND IN-SITU STUDY OF THE POSSIBILITY OF IMPROVING THE QUALITY OF FLY-ASH FOR USE IN ROAD CONSTRUCTION

ETUDE EN LABORATOIRE ET SUR CHANTIER DES POSSIBILITES DE VALORISATION DES CENDRES VOLANTES EN CONSTRUCTION ROUTIERE

ROAD CONSTRUCTION TECHNIQUES INCREASINGLY USE WASTE PRODUCTS OF VARIOUS ORIGINS. AMONG THOSE FLY-ASH AFFORDS SEVERAL POSSIBILITIES OF USE. IN THE FIRST PART OF THE RESEARCH, AN ATTEMPT IS MADE TO CHARACTERIZE AND DETERMINE THE POSSIBILITY OF USING FLY-ASH IN ROAD CONSTRUCTION. VARIOUS SAMPLES WERE PREPARED WITH A VIEW TO DETERMINING THEIR CHARACTERISTICS BY MEANS OF CONVENTIONAL TEST METHODS AND OTHER METHODS DEVELOPED WITH THIS AIM IN VIEW. A STUDY WILL BE CONDUCTED OF THE CHEMICAL COMPOSITION OF THESE ASHES, DISTRIBUTION OF THEIR GRADING ENVELOPE, THEIR BULK DENSITY, CONTENT OF INGREDIENTS SUCH AS CALCIUM OXIDE, ALUMINA, SILICA, IRON OXIDE, TOGETHER WITH THEIR POZZOLAN PROPERTIES. THE SPECIFIC CHARACTERISTICS AND APTITUDES OF THIS MATERIAL WILL ALSO BE INVESTIGATED WITH A VIEW TO DETERMINING POSSIBLE USE AS: (1) FILLER FOR BITUMINOUS MIXTURES; (2) EMBANKMENT FILL; (3) MATERIAL FOR SUB-BASES AND CAPPING LAYERS; (4) GRADING CORRECTOR OF SOIL. BASED ON THE RESULTS OBTAINED IN THE FIRST PART OF THE RESEARCH, (1) AN EXPERIMENTAL EMBANKMENT WILL BE BUILT; (2) EXPERIMENTAL CAPPING LAYERS AND SUB-BASES WILL BE CONSTRUCTED. OBSERVATIONS MADE DURING THE PREPARATION, CONSTRUCTION AND CONTROL OF THESE EXPERIMENTAL SITES SHOULD LEAD TO PRACTICAL RECOMMENDATIONS GOVERNING THE USE OF FLY-ASH IN THESE STRUCTURES.