Show CONCRETE ROAD MATERI MATERIALS LS 1 Engineers Making Experiments to Determine De Dc termine Just What Are Arc Best and Right Proportions Experiments to determine Just what kinds of materials are best for conCrete concrete concrete con con- crete and In what proportions to mix mis them so that they will wear well In a road are being made by engineers of ot the bureau of public roads United States Department of Agriculture An apparatus will be used that consists of heavy steel wheels which guided by a mechanical arrangement roll continuously continuously back and forth forum over the time pave pave- I meat ment More than forty different sections of or concrete pavement concrete pavement each ten feet teet long will be laid Materials from many different dif cur ferent parts of ot t tie the e country are being shipped to the government go experiment farm at nt Arlington Va Ya near Washing Washing- ton They will be mixed with varyIng varying varying vary vary- ing quantities of cement and water to determine which Is best Experience ha has shown that there Is a n measurable amount of ot wear of ot the time surface of ot a concrete road rond each year |