FOAMED ASPHALT IN BITUMINOUS PAVING MIXTURES

Abstract

RESEARCH WAS CONDUCTED ON THE FEASIBILITY OF EFFICIENTLY AND EFFECTIVELY PRODUCING A FOAM OF A BITUMINOUS BINDER IN SEVERAL FORMS AND THE APPLICABILITY AND EFFICACY OF SUCH FOAMED BINDERS IN BITUMINOUS PAVING MIXTURES AND BITUMINOUS SOIL STABILIZATION. THE STUDY DISCLOSED THAT A BITUMINOUS BINDER CAN BE EFFICIENTLY AND EFFECTIVELY FOAMED IN SEVERAL FORMS USING SPECIAL FOAMING NOZZELS WHICH WERE DESIGNED AND DEVELOPED. THEY CAN INSTANTLY CREATE THE CHARACTER OF FOAM DESIRED AT THE TIME AND PLACE REQUIRED. THE PHYSICAL PROPERTIES OF A BITUMINOUS BINDER CAN BE TEMPORARILY MODIFIED WITHOUT ALTERING THE CHEMICAL CONSTITUTION OF THE BINDER BY FOAMING THE BINDER. BITUMINOUS MIXES CONTAINING LOCAL UNGRADED AGGREGATES CAN BE PRODUCED MORE READILY AND SAFELY BY THIS METHOD. WHEN FOAMED BINDER IS USED, HIGHER STRENGTH, GREATER RESISTANCE TO FREEZING AND THAWING, AND OTHER DESIRABLE PROPERTIES ARE OBTAINED. BITUMINOUS MIXES CONTAINING LOCAL UNGRADED AGGREGATES CAN BE PRODUCED BY FOAMED BINDER METHOD IN STANDARD TWIN SHAFT PUG MILL MIXERS WITHOUT ANY CHANGE OF MIXER PADDLE TIPS OR MODIFICATION OF MIXING PROCEDURE. PLANT MIX SOIL STABILIZATION MIXES CAN BE PRODUCED READILY AND EFFECTIVELY WITHOUT NEED OF DRY PULVERIZATION OF FINE FRACTIONS AND WITH ASPHALT CEMENT AS THE BINDER WHEN THE FOAMED BINDER METHOD IS USED. THE USE OF THIS METHOD IS READILY AND EFFECTIVELY APPLICABLE TO IN PLACE SOIL STABILIZATION OPERATIONS, USING COMMERCIALLY AVAILABLE EQUIPMENT. STANDARD SPECIFICATION HIGH AND MEDIUM TYPE ASPHALTIC CONCRETE MIXES CAN ALSO BE PRODUCED. IT IS CONCLUDED THAT THE FOAMED BINDER METHOD IS SUCCESSFUL USED IN CONJUNCTION WITH EITHER BATCH TYPE OR CONTINUOUS TYPE MIXERS.