Concrete Roads
and Their Construction

76 CONCRETE ROADS The foundation consisted of a mixture of clinker and ballast, well rolled and consolidated. The kerbing, which was laid first, is 1 ft. in depth, and is battered on both sides, being 6 in. wide at the top and 9 in. at the bottom. The concrete for the road it- self is 6 in. in thickness, and was laid in two courses, a lower course of 4 in., consisting of a mixture of one part Portland cement and five parts coarse material, and an upper layer of 2 in., consisting of one part Portland cement, one part sand, and two parts pea shingle, graded up to J in. diameter. The reinforcement consists of steel mesh. Adopting the principle to which, where reinforce- ment is used, recent experiments seem to point as being sound, no expansion joints were provided. The concrete was laid in alternate bays, and the material in the intervening spaces was laid close up to the concrete already in position. The surface was worked over by a trammel, shaped to the camber of the road, and was afterwards finished with a wooden float. When the concrete was sufficiently hard, the road was covered to a depth of about 2 in. with ashes, which were kept constantly moist, and allowed to remain, for three or four weeks. The road so far constructed is about 200 yds. in length and 24 ft. wide, and the result is satisfactory in every way. The sur- face is even, but not smooth, and presents a dead, face which affords an excellent grip for horses and motor vehicles, and enables each to work up to its maximum power ; and although some two or three hundred tons of traffic pass over the road daily, there is in it neither crack nor flaw. Indeed, so satisfied is the engineei with the result of this experiment, that the company has in contemplation the construction of concrete roadways throughout the whole of its yards. Latest Report.—Mr. S. Moscrip, the company’s engineer, writing in November, 1920, states : “ The road has been in use now just over three years and has cost nothing for maintenance or repairs. When the concrete was thoroughly dry we gave it a good coat of tar and sand and this has not worn off yet. Heavy loads up to 13 tons have been over the road in motor, steam and horse wagons. “ Messrs. Joseph Baker, Sons & Perkins are thoroughly satis- fied with this kind of road, construction and will certainly use it in future extensions of their works.” Empire Paper Mills, Greenhithe, Kent—This road forms the approach to the Empire Paper Mills, Limited, at Greenhithe, and was