17. Strength of cements of different fineness.... 18. Strength of ordinary and finely ground Portland cement. PAGE 27 27 ... 34 37 38 38 39 54 60 68 69 86 86 99 100 101 102 102 19. Strength of coarse and fine Rosendale cement...... 20. Strength of same cement from different laboratories.. 102 103 21. Showing importance of sand tests for cement. 22. Strength of cement with long- and short-time tests... 23. Strength of cement with long-time sand and neat tests. 24. Requirements of tensile strength for cements... 25, 26. Showing material required for one cubic yard of mortar. 104 105 106 107 110 111 ... 112 29. Showing strength of Portland-cement mortar when immersed in and mixed with salt and fresh water.... 112 30. Showing strength of mortar when mixed with salt water.. 31-33. Showing effect of freezing and subsequent thawing on mortar. 114, 116 34. Showing effect of freezing and subsequent thawing on concrete cubes 117 TABLE NO. 35. Showing strength of mortar after second mixing.... ... 36. Showing strength of briquettes made at different times after the mix. ing of the mortar... 37. Showing volume of concrete from certain mixtures. 38. Showing voids in stone, gravel, and mixtures of both... PAGE 118 119 123 124 124 133 133 134 138 156 46. Showing result of traction experiments at Atlantic Exposition........ 157 47. Showing tractive force required to draw one ton on different streets according to Prof. Haupt...... 158 48. Showing effect of size of wheels and width of tire on tractive force... 158 49. Showing tractive force per ton according to London experiments... 159 50. Showing tractive force per ton according to different authorities...... 159 51. Showing accidents to horses on London streets........ 52. Showing accidents to horses on different London pavements.... 161 161 53. Showing accidents to horses on different London pavements under different conditions...... 162 167 172 54. Showing relative value of different paving materials.... 55. Showing comparative costs of different pavements... 56. Showing increase of pavement mileage in different American cities... 173 57. Showing sizes of granite blocks used in American and European cities. 191 58. Showing sizes of stone blocks used in European cities...... 192 59. Showing crowns for street pavements..... 202 60. Showing methods of laying out cross-section of pavement. 218 61. Showing sizes of certain sands,. 226 62. Showing sizes of sands used in different pavements. 227 63. Showing cost per yard of repairs to asphalt pavements in different cities..... ... 246 64. Showing cost per yard for each year after expiration of guarantee in different cities..... 247 65. Showing analysis of different bricks...... 260 66. Showing loss by abrasion to bricks of different degrees of hardness... 266 67. Showing water evaporated from different bricks.... 271 68. Showing water absorbed by different bricks.... 271 69. Showing results of different tests upon different bricks. 275 70. Showing condition of hard-wood pavements in London. 298 71. Showing mileage of street-car tracks in American and European cities. 458 72, 73. Showing analyses of different asphalts..... 495, 496 12. Cross-section of granite pavement on concrete base.. 199 13 Example of steep grade on asphalt-paved street in Pittsburg. 217 14. Cross-section of asphalt pavement..... 235 15. Showing plan and section of noiseless manhole-cover.. 249 16. Showing expansion-joint in asphalt pavement on Denver viaduct..... 252 35. Tie-construction of track, Department of Highways, Brooklyn... FIGURE 34. Another form of track-construction in Buffalo................. PAGE 439 441 36. Concrete-beam construction, Department of Highways, Brooklyn..... 441 47. Track-construction recommended in granite pavement.. 52. Curb set in concrete, granite pavement. 54. Plan of stone sidewalk 55. Plan of brick sidewalk.... 445 445 446 447 447 448 448 453 453 455 457 466. 467 470 476. 477 STREET PAVEMENTS AND PAVING MATERIALS. CHAPTER I. THE HISTORY AND DEVELOPMENT OF PAVEMENTS. His PRIMEVAL man had no pavements nor any use for them. wants were few and easily satisfied. He knew of nothing outside of his own range of vision. Knowing but little, his desires were few and in almost every instance could be satisfied by the fruits of the soil or the results of the chase. But this could not continue; as the race increased and scattered over the then known world the different divisions settled down into communities or became nomadic tribes. Different localities produced different articles, and in their wanderings and communications with each other they became acquainted with their different products, and the spirit of interchange and commerce sprung up among them. Feelings of rivalry arose, producing wars, and there is no doubt that the commercial and warlike interests were most powerful in promoting exchanges between tribes and later between nations. At first tracks were established across the country, but as time went on these tracks grew to be paths, and the paths roads, and the roads developed into our modern highways, paved streets, and magnificent system of railroads. All of this, however, consumed a vast amount of time, and many centuries elapsed after the building of the first road before much similar work was undertaken or the modern boulevard completed. While war-chariots are mentioned in |