12 



MICHIGAN ROADS AND FORESTS 



Pittsburg Shafting Co. of Detroit 



Distributors of 



Columbia Steel and Shafting Co. 

 Columbia Steel Co. 

 Seamless Tube Co. of America 

 Kidd Bros. & Burgher Steel Wire Co. 



Phone: West 2461. 



34O-35O Fort Street, W. 



Detroit, Mich. 



Conclusions of the 



International Road Congress 



Among the conclusions adopted by the sec- 

 Brussels this year were the following: 



First Question. I. Use of binding mater- 

 ials in the construction of metaled roads: 



The Congress believes that it is desirable 

 to pursue and develop the application of the 

 use of binding materials in the construction 

 of metaled roadways, special attention being 

 given : 



1. To determine, in each case, the character 

 of the binder best suited to local conditions; 



2. To determine as exactly as possible, the 

 physical and chemical characteristics to be 

 specified for tar, bituminous, asphaltic or other 

 binders as best suited; 



3. To compare the different results obtained 

 in various methods of construction; 



4. To investigate the influence that storing 

 of tarred metal, during a more or less extend- 

 ed period, before being used, may have upon 

 the perfection of the work; 



. To make a study of the deteriorations that 

 the materials are subjected to during use; 



6. To specify the system to be advised, 

 where ordinary metaling has proved deficient 

 and stone paving cannot for some reason be 

 applied; 



7. To establish for each district according 

 to local conditions, and in each case, the rela- 

 ti'.'ii between cost and the result obtained. 



II. Use of trackways in paved roads: 



(a) Apart from exceptional cases depending 

 upon local conditions, the construction of 

 trackways in paved roadways can be consider- 

 ^! hut an expedient. 



III. Progress made .in combating wear and 

 dust: 



Confirming the resolutions passed at the 

 Congress held in Paris in 1908, in further 

 reference tu the first conclusion just adopted 



and which is of interest, not only from the 

 point of view of combating wear and dust but 

 from that of binding the materials in metaled 

 roads; 

 The Congress believes: 



1. That superficial tarring may be consid- 

 ered as definittlv accepted in practice and that 

 the advantage to be derived from spreading 

 fine sand cr suitable stony material af'er 

 tarring and rolling ihe same, is not at present 

 proved and should form the object of com- 

 parative tests; 



2. That in the future applications of these 

 methods the attention of road builders may be 

 drawn with benefit to the comparison of re- 

 sults obtained by the laying of tar, bituminous 

 or asphaltic substances hot or cold, by ma- 

 chine or by hand, both from the point of view 

 of cost ant 5 from the pcint of view of the effi- 

 ciency of tlie operation; 



3. That it is desirable, in comparing results, 

 to take into account the quality of the mater- 

 ials composing the metaling, the intensity of 

 traffic and tonnage as well as the climate; 



4. That, with due regard to the resources 

 of each region in tar, bituminous or asphaltic 

 substances, it is important to specify in con- 

 tracts t'ne conditions that are to be fulfilled, 

 especially as regards the preservation of "life," 

 that is to say, the property of preserving their 

 binding power. 



5. That it would be desirable that a com- 

 parison be established between the advantages 

 of tarring this word being taken in its broad- 

 est sense in different cases, whether the oper- 

 ations are to be frequently repeated, small dos- 

 es being applied each time, or whether larger 

 quantities are to be applied at greater inter- 

 vals. Furthermore, whether, in the metaling 

 itself, a tar, bituminous or asphaltic binding 

 material has already been incorporated or 

 not; 



6. That the conclusion adopted by the first 

 Congress is to be maintained "in toto" running 



as follows: Emulsions of tar or of cil, hydros- 

 copic salts, etc., have a real but not a lasting 

 efficiency. Therefore their use should be lim- 

 ited to special constructions, such as race 

 courses, festivals, processions, etc. 



Second Question. 



I. The formation and construction of foun- 

 dations of roadways should be made the 

 stronger in proportion to the lesser compact- 

 ness of the ground. The foundation should 

 have more body and resistance the more it is 

 exposed to internal deterioration and external 

 wear. 



II. In the choice of the system of founda- 

 tions for roadways, both stone set and metal- 

 ed, stress should be laid principally on the 

 degree of dryness of the subsoils, while hav- 

 ing regard to the possibility of their drainage 

 and to their geological nature, and to the na- 

 ture of the materials of the locality. In order 

 to determine the thickness and the extent of 

 foundations, the pressure per unit area should 

 be made compatible with the bearing power 

 of the soil, observed under the most unfavor- 

 able conditions. 



III. In soils where preliminary drainage is 

 required before the construction the general 

 methods of drainage should be applied to the 

 whole or to a part of the road body and to the 

 bed of the metal if necessary. 



IV. The cross and longitudinal sections of 

 roads and those of side gutters should be es- 

 tablished so as to facilitate the flow of thi- 

 trickling water, and to prevent infiltration of 

 water into road surfaces, which should be 

 made as impermeable as possible. The evap- 

 oration of superficial dampness should be en- 

 couraged by every means. 



V. The work for the foundation and fi.r 

 drainage should be carried out simply and 

 economically and by using the materials of the 

 country as far as possible. 



Third Question. 



I. In the study of the new roads to be con- 



