FUNDAMENTAL RESEARCH IN BITUMINOUS SOIL STABILIZATION
V A Endersby, D. P. Krynine · Highway Research Board Proceedings · 1943
INFORMATION NOW AVAILABLE INDICATES A POSSIBILITY OF STEPPING UP SOIL STABILIZATION TO A HIGHER CLASS OF CONSTRUCTION. THE TERM 'BITUMINOUS SOIL STABILIZATION' DESCRIBES A SOIL-OIL-WATER SYSTEM IN WHICH THE COHESIVE AGENT IS CLAY, AND IN WHICH THE WATER CONTENT, UPON WHICH COHESION IS DEPENDENT, IS CONTROLLED BY THE OIL. 'CLAY' INDICATES THE PARTICLE SIZE IN WHICH HYDRAULIC COHESION IS MOST FULLY DEVELOPED. A DEFINITE SOIL SYSTEM EXISTS, WHICH CHANGES WITH THE DEGREE AND METHOD OF MIXING, THE PROCESS PASSES THROUGH AN OPTIMUM PHASE DURING MIXING. THE IMPORTANCE OF WATER CONTROL IS SHOWN. THERE ARE VITAL DIFFERENCES IN THE PHASE ASPECTS OF DIFFERENT MIXERS. IF A LABORATORY SPECIMEN IS CURED AT HIGH TEMPERATURE, THE WATERPROOFING WILL BE MISLEADINGLY HIGH. EXCEPT WHERE HIGH TEMPERATURES ARE USED, THE WATER CONTENT TENDS TO REACH THE SAME MAGNITUDE REGARDLESS OF CURING METHODS. HOWEVER, THE LONGER THE TIME REQUIRED, THE LESS THE STRUCTURAL DAMAGE. SHORT-TIME CAPILLARY ABSORPTION IS DANGEROUSLY LENIENT. LIQUID OILS VARY AS TO VISCOSITY, CURING PROPERTIES, AND CHEMICAL NATURE. GREAT VARIATIONS ARE POSSIBLE. DIFFERENT TYPES OF OIL HAVE DIFFERENT PHASE EFFECTS. IN AN ORDINARY SOIL-OIL-WATER SYSTEM, A LARGE PART OF THE OIL IS MERELY MECHANICALLY INCLUDED. AN EFFECTIVE ALTERATION RESULTS IN SPREADING OF OIL AND DISPLACEMENT OF WATER. AS OIL CONTENT IS INCREASED, THE SOIL WILL TOLERATE MORE WATER FOR THE SAME SWELL. THIS IS ALSO TRUE OF IMPROVEMENT IN STABILIZER. NO SIMPLE RELATION EXISTS BETWEEN WATER ABSORPTION AND MECHANICAL STABILITY. THE FACTOR OF FRICTION IS IMPERFECTLY REPRESENTED IN COMPRESSIVE STRENGTH. FRICTION DOES NOT VARY TO THE SAME EXTENT OR IN THE SAME DIRECTION AS COHESION. IT IS INDICATED THAT IT IS POSSIBLE TO IMPROVE SOIL STABILIZATION WITH LIQUID OILS SEVERAL-FOLD BY PROPER RELATION BETWEEN OIL AND WATER CONTENT, PHASE MIXING, PROPER CURING, SELECTION OF STABILIZER, SELECTION OF STABILIZER CONTENT. FOR CONTROL TEST PROCEDURE: CURING SHOULD BE DONE IN A MANNER APPROXIMATING FEILD CONDITIONS, EXPOSURE TO WATER SHOULD BE MORE SEVERE THAN CAPILLARY METHODS, SWELL SHOULD BE REGARDED AS NOT PROPORTIONAL TO LOSS OF BEARING POWER AND FOR THE EVALUATION OF BEARING POWER, BOTH FRICTION AND COHESION MUST BE TAKEN INTO ACCOUNT. /AUTHOR/ ACCOUNT. /AUTHOR/