Concrete Roads
and Their Construction

34 CONCRETE ROADS For tho lower course local ballast was employed in the propor- tion of 6:1, and for the wearing course granite chippings and crushed granite graded from J in. down, and mixed in the pro- portion of 3 : 1. The original road was macadam, and since the foundation has proved to be thoroughly sound it received no special preparation other than shaping and hand ramming. The road is reinforced 1| in. from the bottom. No transverse joints were provided, the material at the com- mencement of each day’s work being butted against the vertical edge left at the end of the previous section. Next to the kerbs longitudinal joints filled with bituminous material have been provided. For purposes of surface drainage the road is shaped to a camber of 1 in 50. The surface was finished by being worked over with a shaped board or straight-edge until the mortar had been brought to the top. When the concrete was thoroughly dry and hard it was tar-sprayed. After the concreting was completed the road was kept sprinkled with water for several days ; the traffic was kept off for twenty- one days in the warmer weather, and twenty-eight days during the autumn weeks. The surveyor for the county of Essex, Mr. Percy J. Sheldon, M.Inst.C.E., under whose supervision the work was carried out. reported as follows on the condition of the road. Latest Report, November, 1920.—The cost of maintenance has been nil, and very heavy traffic conditions prevail. The road has been in use about five months. Mr. Sheldon is convinced that there is no question as to the strength and durability of concrete for roads, and that their success and efficiency are only a question of workmanship. It is interesting to note that all the bridges that are being re- newed in the area administered by the Essex County Council are being constructed in concrete, and there is every reason to anticipate an extensive development of concrete roads within the next few years. Tilbury Dock Road.—The South Ward of Tilbury immediately adjoining the huge dock of the Port of London Authority lies well below the river level—the surface level being only four