Title: AIRPORT RUNWAY EVALUATION IN CANADA PART II, WITH DISCUSSION
Abstract: COMPACTING A CLAY SUBGRADE TO 95 PERCENT MODIFIED AASHO MAXIMUM DENSITY DEVELOPED A GREATER SUPPORTING VALUE THAN THAT OF THE UNCOMPACTED SUBGRADE AT 85 PERCENT MODIFIED AASHO. THE INCREASE IN BEARING CAPACITY PROVIDED BY THE FIRST 12-INCH LAYER OF COMPACTED SOIL WAS CONSIDERABLY GREATER THAN THAT GIVEN BY AN ADDITIONAL 12-INCH COMPACTED LAYER. SUBGRADE COMPACTION IN THE FIELD APPEARS TO CAUSE THE FIELD CBR AND CONE BEARING RATINGS OF THE SUBGRADE TO INCREASE AT A CONSIDERABLY FASTER RATE THAN THE ACTUAL SUPPORTING VALUE AS MEASURED BY THE PLATE BEARING TEST. THE HOUSEL PENETROMETER VALUE IS AFFECTED IN THIS MANNER TO A LESS SERIOUS DEGREE, WHILE THE TRIAXIAL TEST SEEMS TO MORE NEARLY PARALLEL THE INCREASE INDICATED BY THE PLATE BEARING TEST. A SIMPLE EQUATION IS PRESENTED FOR CALCULATING THE SUBGRADE MODULUS AT THE SURFACE OF ANY GIVEN THICKNESS OF WELL COMPACTED GRANULAR BASE COURSE, IF THE SUBGRADE MODULUS FOR THE UNDERLYING SUBGRADE HAS BEEN DETERMINED. THE VALUE OF K IN THE FLEXIBLE PAVEMENT DESIGN EQUATION T=K LOG (P/S) HAS BEEN FOUND TO BE DEPENDENT UPON THE SIZE OF BEARING PLATE EMPLOYED, WHEN ALL OTHER VARIABLES ARE CONSTANT. THIS HAS RESULTED IN SOME MODIFICATION OF THE PAVEMENT THICKNESS DESIGN CHARTS FOR AIRPORTS AND HIGHWAYS CONTAINED IN THE PAPER PRESENTED AT THE 1946 ANNUAL MEETING. A METHOD FOR SELECTING BASE COURSE MATERIALS AND DESIGNING FLEXIBLE WEARING COURSE MIXTURES BY MEANS OF THE TRIAXIAL COMPRESSION TEST IS OUTLINED. /AUTHOR/
Publication Year: 1948
Publication Date: 1948-01-01
Language: en
Type: article
Access and Citation
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot