﻿UNITED STATES DEPARTMENT OF AGRICULTURE 

 BULLETIN No. 1132 



Washington, D. C. 



PROFESSIONAL PAPER 



March 21, 1923 



THE RESULTS OF PHYSICAL TESTS 



OF ROAD-BUILDING ROCK 



FROM 1916 TO 1921, 



INCLUSIVE 



CONTENTS 



Page. 



Introduction 1 



Table I. — Results of physical tests of 

 roadbuilding rock from 1916 to 1921, 



inclusive 2 



Crushing strength or compression test . 46 



Interpretation of results of physical tests . 46 



Page. 

 Table II. — Results of compression tests 



of rock made prior to January 1, 1916 . 48 

 Table III. — General limiting test values 



for broken stone 51 



Table IV. — Geographical distribution of 



rock samples tested from January 1, 



1916, to January 1, 1922 62 



WASHINGTON 

 GOVERNMENT PRINTING OFFICE 



1923 



