UNITED STATES DEPARTMENT OF AGRICULTURE 



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BULLETIN No. 949 a 



Contribution from the Bureau of Public Roads 

 THOMAS H. MacDONALD, Chief 



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Washington, D. C. 



October 10, 1921 



STANDARD AND TENTATIVE METHODS OF SAMPLING AND 

 TESTING HIGHWAY MATERIALS. 



Recommended by the Second Conference of State Highway Testing Engineers and 

 Chemists, Washington, D. C, Feb. 23-27, 1920. 



CONTENTS. 



Page. 

 Introduction 1 



Tests for non-bituminous road materials 3 



Tests for bituminous road materials 36 



Tentative tests 62 



Page. 

 Recommended standard methods of sampling . 69 



Miscellaneous matter 75 



Forms for recording and reprinting results 79 



INTRODUCTION. 



In connection with the administration of Federal appropriations 

 for highway construction, conferences have been held from time to 

 time, between representatives of the Bureau of Public Roads and 

 of the various State highway departments, for the purpose of formu- 

 lating policies relative to matters of mutual interest. In accordance 

 with this general plan, a conference of testing engineers of the State 

 highway departments was deemed advisable in order to standardize 

 the work of the State highway department laboratories and the 

 bureau laboratories. 



The conference held at the Bureau of Public Roads, Washington, 

 was called by the committee on tests and investigations of the Ameri- 

 can Association of State Highway Officials and the following repre- 

 sentatives of State highway departments and of the Bureau of 

 Public Roads were in attendance, for all or a part of the conference: 



Agg, T. R., Iowa. 



Anderton, B. A., Bureau of Public Roads. 



Begg, R. B. H., Virginia. 



Bragg, J. G., New Jersey. 



Carmick, L. G., Bureau of Public Roads. 



29465°— 21— Ball. 949 1 



Cooper, W. F., Louisiana. 



Dayton, R. B., West Virginia. 



Dean, A. W., Massachusetts. 



Gage, R. B., New Jersey. 



Goldbeck, A. T., Bureau of Public Roads. 



