. The street railway review . one is almost as severe as upon asphaltadjacent to the rails, and the only efTect of lining the rails withstone block is to transfer the line of wear from the edge of therails to the edge of the stone block. This is well illustrated by thephotograph of Fig. 5, of Slate St., in Grand Rapids. Mich. Thestone block in this case was unusually rough, and the destructionof the adjacent pavement is complete. The straight edge shows byin shadow how rough and uneven the surface of the pavement hasbecome. Asphalt block also has been used next to the rails, notablyin Fort Way
. The street railway review . one is almost as severe as upon asphaltadjacent to the rails, and the only efTect of lining the rails withstone block is to transfer the line of wear from the edge of therails to the edge of the stone block. This is well illustrated by thephotograph of Fig. 5, of Slate St., in Grand Rapids. Mich. Thestone block in this case was unusually rough, and the destructionof the adjacent pavement is complete. The straight edge shows byin shadow how rough and uneven the surface of the pavement hasbecome. Asphalt block also has been used next to the rails, notablyin Fort Wayne. Ind., Init lacked the rcquisile durability. The use of brick to reinforce the asphalt al tlii: rails has passedthrough experimciUal stages to determine the best manner ofarranging the brick. It was naturally at first supposed that themost satisfactory arrangement would be to tooth the brick intothe asphalt as shown in Fig. i, that is, with whole brick and halfbrick alternating, with ends against the rail. But it was found. that the portions of asplialt lying between the projecting wholebrick was soon pounded into depressions and disintegration wascommenced that spread rapidly to the adjacent pavement, besidesexposing the brick to the blows of the wheels bumping from alter-nate brick to brick. In the light of experience, it is not difficult to see why thisarrangement of the brick should have proved a failure, and thecause in this case emphasizes the necessity for certain qualities ofpaving material, and of brick especially. The failure of the pave-ment along this serrated line of brick is due to lack of uniformnityof the material. Asphalt alternates with brick in two inch spaces;the asphalt is softer than the brick, and the latter acts as anobstacle to the wheels, permitting them to drop and pound uponthe asphalt, the severity of the blows increasing with the wear;the failure of tlie softer aspliall in turn reacts upon the harderbrick by leaving it exposed to the blows. The
Size: 1782px × 1402px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., book, bookcentury1800, bookdecade1890, booksubjectstreetrailroads
