| Show ROCK FOR HIGHWAY BUILDING First Systematic Efforts to Determine Value Were Made In French Labor ry In 1878 S The first systematic attempts to determine determine de do termine the value of rock for road building purposes by means of ot laboratory labor atory tests were made In France Franc where In 1878 a road materials laboratory lab oratory was founded In the French of Bridges and Roads Here Dere the Deval abrasion test was adopted and this test with slight modification modification tion has been accepted as standard throughout the United States The test is named from Its Inventor It was vas first used in connection with contract contract con tract work In the city of ot Paris Many valuable data were collected In this laboratory on the hardness and toughness tough tough- ness nes ness of ot rock and tests fo for these properties prop s ertie-s were developed which were In principle the same as those In use today |
