8 



MICHIGAN ROADS AND FORESTS 



MICHIGAN 



ROADS AND FORESTS 



Official Paper of The Michigan Road Makers Association and 

 Michigan Forestry Association. 



70 Lamed Street West, Detroit, Michigan. 



Entered as Second-class Matter April 27. 1907, at the Post Office at De- 

 troit. Michigan, tinder the Act of Congress of March 3. 1879. 



Frank E. Carter Editor 



PUBLISHED EVERY MONTH 



BY 

 THE STATE REVIEW PUBLISHING CO.. 



SUBSCRIPTION: ONE DOLLAR A YEAR, 

 PAYABLE IN ADVANCE. 



SALTING THE HIGHWAYS. 



The uses of calcium chloride as a dust layer 

 are interestingly treated in the following pa- 

 per written some time ago by Provost Hub- 

 bard of the United States Office of Public 

 Roads: 



"Calcium chloride, which is obtained for the 

 most part as a by-product in the manufacture 

 of soda, has been used to a considerable ex- 

 tent as a dust layer," says Mr. Hubbard. "It 

 is a more hygroscopic than magnesium chlor- 

 ide and can be obtained at a moderate price 

 in an almost pure state. It is sold either in 

 solution or in a solid, fused or granular con- 

 dition. The solid material contains about 25 

 per cent moisture and 75 per cent calcium 

 chloride, while the solutions run from a sat- 

 urated condition to various weaker strengths. 

 The ordinary concentrated solution carries 

 about 40 per cent calcium chloride and has a 

 specific gravity of 1,400. Both the solid and 

 solution are sold on a basis of the actual salt 

 content, and the solid is therefore cheaper 

 when the cost of transportation is taken into 

 account. It can at the present time be pur- 

 chased at about $16 a ton f. o. b. at points of 

 manufacture. 



"Calcium chloride has been used to a slight 

 extent in the United States for the purpose 

 of laying dust and when properly applied has 

 proved successful. The amount of salt and 

 number of applications required to keep down 

 the dust satisfactorily for a season will vary 

 greatly with local conditions, but the exercise 

 of a little judgment makes it possible to ob- 

 tain good results with a minimum expense. 

 Before considering its advantages and disad- 

 vantages, however, its method of application 

 should be taken up. 



"In most cases it is applied for the first time 

 on the unprepared road. The solution is 

 sprinkled from an ordinary watering cart, so 

 that on an average .4 gallon is applied a square 

 yard, although by regulating the spread of 

 the sprinkler to about two-thirds the width of 

 the road the middle receives twice the amount 

 the sides when the sprinkler passes over 

 the road twice. While the center receives a 

 double application by this means there is 

 tendency for the whole surface to receive' an 

 equal share, owing to the fact that rains tend 



n '/"I l , he <llssl - lv < 1 ' 1 sa " to the side of the 

 road A IS or 20 p er cent solution is first 

 employed, and at least two of these applica- 

 tions are made in the first week or two o - 

 der to impregnate the surface thoroughly w j th 

 t n c SHI t. 



''The salt thus apptied has a tendency 'to 



retain the mo.sture for a considerable length 



time after an ordinary application of water 



would hav,- evaporated. On hot, d,- v days 



however, the road does dry out, especially 

 .Hi portions unprotected by shade, and it has 

 been found necessary to feed the salt by ordi- 

 nary applications of water. The number of 

 sprinklings necessary will, however, be greatly 

 reduced. It is of course cheaper to feed the 

 c;>.]eium chloride already on the road with 

 water than to apply a fresh solution each time 

 the road becomes dry. In humid weather it 

 is often unnecessary to apply water for days 

 at a time, as the salt absorbs sufficient mois- 

 ture from the damp night air to keep -the road 

 in good condition throughout the succeeding 

 day. 



"In the course of time much of the calcium 

 chloride is washed out cf the road and has 

 to be replaced by fresh material. Single ap- 

 plications of an 8 or 10 per cent solution, 

 applied at intervals varying from two to five 

 weeks apart, according to conditions, are usu- 

 ally sufficient to maintain the proper amount, 

 and these may be made in the same manner 

 as described for the first two. A too rapid 

 drying of the road is an indication that more 

 salt is needed, and a little experience will 

 soon enable the overseer or experimenter to 

 determine just how often and at just what 

 time to make a fresh application. The same 

 is also true with respect to feeding the salt 

 with water. 



"The principal advantages of calcium chlor- 

 ide as a dust layer are that it is odorless 

 and clean. When present in sufficient quan- 

 tity it is undoubtedly a good dust layer if 

 the atmosphere is somewhat humid or if it is 

 fed occasionally with water in dry weather. 

 While it is true that the formation of mud in 

 wet weather is not lessened, this mud is not 

 more objectionable than that ordinarily en- 

 countered, as not enough salt is present to 

 give it the undesirable qualities produced by 

 the application of sea water. In addition, cal- 

 cium chloride tends to distribute the moisture 

 evenly over the read surface and it can be eas- 

 ily and quickly applied. Its use, like that of 

 any other good dust layer, prolongs the life 

 of a road by retaining the products of wear, 

 and in some cases it may by chemical action 

 increase the cementing value of the rock pow- 

 der. 



"On the other hand, it is not essentially a 

 road builder, and at the end of a season's 

 treatment, while the road may be in better 

 condition than at the start, no additional wear- 

 ing material will be present. Heavy rains are 

 likely to wash most of it from the road, and 

 it a number of showers follow soon after an 

 application much of its value will be lost. 

 Water does not, however, always carry away 

 so much of the salt as might be supposed, ow- 

 ing to the absorbent qualities of many rock 

 powders. Another objection to its use is that 

 in hot dry weather it requires feeding with 

 water sometimes as often as once a day In 

 common with all other temporary binders 

 which are applied in solution or emulsion, it 

 can only be employed in localities favored 

 with a convenient water supply. 



"As a rule it is sHghtly more expensive than 

 water alone, but when applied intelligently 

 according to a system similar to that described 

 the cost of treatment is in some measure 

 reduced. In one case, under severe traffic 

 conditions on a macadam road, the cost of 

 laying the dust tor one season was reduced 

 three cents a square yard with water 

 alone to two and seven-tenths cents with the 

 use of calcium chloride. Six applications were 

 ma<ie. two in June and one each in July Aug- 

 ust. September and October, and on very dfv 

 days the road had one light sprinkling with 

 f n f? f , h ' S treatmc t the dust was suc- 

 ce.S8fully laid throughout the season, while in 

 previous 'seasons four applications of water a 

 day often proved ineffective. Under certain 

 conditions therefore calcium chloride may no" 

 >nly prove to be a good dust layer been 

 "mica, as .veil; and even if the cost is some 

 greater than for the application O? water 



"'" "'" '>"" elicial effects produced upon the 



MOLLASSES OIL LIME ROADS. 



The Public R.,ad> Department of the Agri- 

 cultural Department at Washington advocates 

 the use of reiuse molasses from sugar refin- 

 eries in building good roacls. In 1i)08 the de- 

 partment selected a section of Summit street, 

 Xewton. Mass., for the experiment. This 

 street has a grade varying fr,.m 4.3 to 8 per 

 cent. The section was badly in need of re- 

 surfacing. The binding materiad used for the 

 upper course was composed of a mixture of 

 molasses, oil and lime. The report says: 



"In certain sections of the country consider- 

 able quantities of waste molasses or black- 

 strap are produced in the manufacture of 

 sugar. This material has but few uses, and is 

 therefore sold at a low figure in the neighbor- 

 hood of the sugar refineries where it is pro- 

 duced. It is of an exceedingly sticky nature, 

 and when combined with quicklime produces 

 calcium sucrate, which upon standing. se ts 

 into a dense sticky cement. This cement is 

 somewhat soluble in water, and for this reason 

 can not._ in its natural state, be used in locali- 

 ties subjected to frequent rains. An attempt 

 was therefore made to waterproof it by the 

 addition of a semi-asphaltic oil, with which it 

 would be emulsified for the time being. From 

 laboratory experiments a combination of these 

 materials was devised which gave indications 

 ef suitability as a road binder. As the policy 

 of the Office of Public Roads has always been 

 t" further the use of local products in the 

 construction and treatment of local roads 

 whenever possible, it was thought worth while 

 to construct a short experimental section of 

 road using this material as a binder, in order 

 to determine its practical value. In the neigh- 

 borhood of Boston, blackstrap molasses is sold 

 at a very much higher figure than in localities 

 near where it is produced, so that the cost 

 of construction of this section of road was 

 much greater thar, it would be in those locali- 

 ties. 



The binder was prepared in a large mortar 

 box by first slaking 320 pounds of, quick-lime 

 With 1(18 gallons of water; as soon as the lime 

 was completely slaked. '.):.' gallons of molasses 

 was added and thoroughly mixed with it. after 

 which :>(] gallons ( f the semi-asphaltic oil was 

 stirred in. While the preparation was still hot 

 it was mixed with the graded stone in the 

 same manner as has been described in other 

 experiments for bituminous mixtures, except 

 that in this case the stone was not heated 

 Eighteen gallons was applied to every 1310 

 pounds ot stone, and the concrete thus pro- 

 duced was hauled to the road and laid as si on 

 alter mixing a- possible. When rolled it pro- 

 duced a firm and resilient surface upon which 

 heavily loaded teams produced no wheel 

 marks one half hour after it had been laid 

 Under the action of the roller a small portion 

 "t the (Ml came t;- the surface, so that a light 

 application of stone chips was required to put 

 the surface in good condition. 



."''I"' section treated was 3:>l feet in length, 



(. feet ot which was !?;/> feet wide; and 

 '<>> feet K: feet wide. The total area covered 

 was <i()0 square yards, and 0.92 gallon of 

 molasses, 0.5 gallon of oil and 3.2 pounds of 

 Hme per square yard was used. The labor 

 item was exceedingly high in this experiment 

 because ql (he inexperience of the workmen 

 i" preparing and handling the material The 

 < '"-, t "' molasses was fi su red at 11 cents per 

 gallon, and lime at <i() cents per 100 pounds" 



\\ . Ross ot Xewton wrote last January that 

 the molasses-oil-lime road that was built en 



umtnrt Street. Newton, in IllOS, has ,.,'ven 

 very ood satisfaction. It has never" re- 

 c . elved a "y repairs, and is i,, first- 

 class condition at the present time. It has 

 icen subjected to quite heavy traffic and was 

 built on a poor foundation. 1 must say that 

 we lavi ' I" 1 ''" more than .satisfied with the 

 l ' Mllts - llu ' only objection that I can see is 

 the expense of the material, which could be 

 much reduced in places where it could be oh- 

 tamed at a lower price than we were oUied 

 to pay for it in Boston. 



