This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1906 edition. Excerpt: ...atmospheric agencies, as well as wear under hoofs and wheels, the rocks would stand about as follows in their proper order of value as road-surface material: (1) Trap, (2) syenite, (3) granite, (4) schist, (5) gneiss, (6) limestone, (7) quartzite, (8) sandstone, (9) slate, (10) mica schist, (11) marble. While ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1906 edition. Excerpt: ...atmospheric agencies, as well as wear under hoofs and wheels, the rocks would stand about as follows in their proper order of value as road-surface material: (1) Trap, (2) syenite, (3) granite, (4) schist, (5) gneiss, (6) limestone, (7) quartzite, (8) sandstone, (9) slate, (10) mica schist, (11) marble. While the order of durability above given applies to rock in the surface coat of a macadam road, it must not be assumed that rocks even low down on the list are not suitable for the bottom course of a macadam road. Both in the State of New York and in Massachusetts it is common to make the lower course of local stone, surfacing it with 2 or 3 ins. of trap-rock, and this is usually good practice, for the trap will outwear limestone, or any of the softer rocks, several times over. We pass now to the consideration of the form of cross-section of the macadam itself. In Massachusetts and New York the standard section is about 6 ins. thick by 12 to 16 ft. wide, as shown in Fig. 1; but as above stated, the writer considers it better practice not to have the shoulders necessitated by this construction, recommending in place thereof a crescent cross-section of the macadam shown in Fig. 7. The advantages of this cross-section are obvious. The sub-grade can be surfaced by road-scrapers and rolled its full width, while the macadam tapering from nothing at the edges to 7 or 8 ins. at the center has the greatest thickness at the place subject to the greatest wear. There is the additional advantage that water collecting under the macadam will quickly drain off and not be held by the shoulders. It may be objected that wheels will cut through the thin crust at the edge, but it is a fact that even 2 ins. of macadam will carry a heavy load if the sub-soil is not...
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Add this copy of Economics of Road Construction to cart. $13.70, new condition, Sold by Ingram Customer Returns Center rated 5.0 out of 5 stars, ships from NV, USA, published 2022 by Legare Street Press.
Add this copy of Economics of Road Construction to cart. $25.72, new condition, Sold by Ingram Customer Returns Center rated 5.0 out of 5 stars, ships from NV, USA, published 2022 by Legare Street Press.
