MICHIGAN ROADS AND FORESTS 



having a specific gravity of 1.22, diluted with 

 an equal volume of water, was applied at the 

 rate of 0.44 gal. per sq. yd. in the same manner 

 as in experiment No. 2. The results obtained 

 were similar to those obtained in the first ex- 

 periment. 



The fifth and last experiment was conducted 

 in the same manner as the fourth except that 

 the liquor was used undiluted. It was not 

 readily absorbed but after being broomed into 

 the surface produced a well bonded road. 



The report states that the cost can not be 

 calculated exactly as the materials were con- 

 tributed, and the work was done partially by 

 engineer students. Figuring the cost of the 

 sulphite liquor at 12 cts. per gal. and basing 

 the computation on eight hour labor, the fol- 

 lowing is given as the approximate cost for 

 the several experiments. 



EXPERIMENT NO. 1. 

 First application: 

 2 laborers for bailing liquor, fjj 



day at $2.00...- $1.50 



1 sprinkling cart, 3-jj day at $5.00. 1.88 



Total $3.38 



Cost of labor per sq. yd. (1,093 



sq. yds., total) 0.0031 



Cost of material per sq. yd 0.0324 



Total cost per sq. yd $0.0355 



Second application: 



2 laborers for bailing liquor, 



1-16 day, at $2.00 $0.25 



1 sprinkling cart, 3-16 day, at $5. 0.94 



Total $1.19 



Cost of labor per sq. yd 0.0011 



Cost of materials, per sq. yd.. 0.0088 



Total cost per sq. yd 0.0099 



Total cost per sq. yd., both 



applications $0.0454 



EXPERIMENTS NOS. 2, 3, 4 AND 5. 



4 laborers, Y^ day, at $2.00 $2.00 



1 foreman, Vt day, at $3.00 75 



. Total : $2.75 



Cost per sq. yd. (339 sq. yds., total) .0081 



The results of the experiments are given in 

 the following summary: 



"The use of crude waste sulphite liquors as 

 described under experiments Nos. 2 and 3 

 proved but little more effective than water so 

 far as laying the dust was concerned. For the 

 first six weeks experiments Nos. 4 and 5 

 were as satisfactory as experiment No. 1, but 

 owing to lack of material it was impossible 

 to make a second application. With the ex- 

 ception of No. 1 all of these experiments were 

 made upon such short stretches of road that 

 no very definite conclusions could be drawn, 

 but all indications point to the fact that the 

 application of a solution of about 1.13 specific 

 gravity at the rate of approximately 0.5 gal- 

 lon per square yard is fully as effective as 

 the more concentrated material. The second 

 application described under experiment No. 1 

 laid the dust satisfactorily for a period of six 

 weeks, after which the road slowly reverted 

 to its original condition, although the excel- 

 lent binding value of the material was appar- 

 ent for some time later. 



"From these experiments it would seem that 

 crude waste sulphite liquor in single applica- 

 tions has but little value for road treatment, 

 but that the concentrated material may be 

 classed as a temporary or semipermanent dust 

 preventive and road binder. It is possible, 

 however, that, if crude liquor were applied 

 daily as in ordinary water sprinkling, its use 

 would prove economical in localities where it 

 is produced, and that the base would concen- 

 trate in the road and eventually become a val- 

 uable binder." 



The experiments comprising the second set 

 described in the circular were conducted at 

 Youngstown, O., to determine the most satis- 

 factory method of utilizing slag in road build- 

 ing. The work was carried out by the Office 

 of Public Roads in co-operation with the Car- 



PATENTED. 



"ECONOMY" 



THE ROAD DRAG OF MERIT 



SPECIAL OFFER 



Cut out this advertisement : Write your name and address plainly 

 in the lower left-hand corner and mail it to us at once. Upon 

 receipt of same at this office, we will promptly send you full 

 information, how to get an ECONOMY ROAD DRAG, 

 FREE. This OFFER IS LIMITED. Write to-day. 



F. L. GAINES, 



Ashton BIdg., Grand Rapids, Mich. 



negie Steel Co., from whom the slag was ob- 

 tained. 



The road used for the work was situated 

 just outside the city limits and was 2,754 ft. in 

 length. The soil was a gravelly clay that 

 became sticky in wet weather and dusty in 

 dry weather. A section of the road about 100 

 ft. in length was level; the remainder was 

 rolling with a maximum grade of about 4^2 

 per cent. It carried a heavy automobile traffic 

 and a light carriage traffic and was used to a 

 considerable extent by farmers in hauling pro- 

 duce to town. It was graded by the county 

 at a cost of about $2,000. 



Seven experiments were made, in all of 

 which blast furnace slag was used. For the 

 several experiments binders were employed as 

 follows: 



Experiments Nos. 1, 2 and 3, blast furnace 

 slag screnings; experiment No. 4, open-hearth 

 slag screenings; experiment No. 5, blast furn- 

 ace slag screenings mixed with lime; experi- 

 ment No. 6, blast furnace slag screenings and 

 sulphite liquor; experiment No. 7, blast furn- 

 ace slag screenings and refined coke over tar. 



In experiment No. 1 the material was laid 

 in two courses. The first consisted of slag 

 ranging from \ l / 2 ins. to 3^ ins. in size laid 

 to a depth of 9 ins. and compacted by rolling. 

 The' second course consisted of the same kind 

 of material varying from % in. to 1^4 ins. in 

 size, laid 4 ins. deep at the center and 2 1 A ins. 

 at the sides. The road was then rolled until 

 a smooth surface was obtained and then the 

 binder, consisting of screenings ranging from 

 H_ in. to dust, was put on. After rolling 

 slightly water was applied by means . of a 

 sprinkler and rolling continued. 



The results are summed up as follows: 



"In a very short time the water began to 

 run off the surface, which then became quite 

 solid. As the road dried out, "however, the 

 surface became crumbly and required addi- 

 tional rolling and sprinkling. When the work- 

 was completed, about the middle of August, 

 this section was in good condition except for 

 one or two small places. From the behavior 

 of this material indications point to the ad- 

 visability of sprinkling the surface every day 

 for about ten days in order to develop the 

 full binding value of the slag screenings." 



Experiment No. 2 consisted cf the construc- 

 tion of a section of road using only one course 

 of slag. The material was laid to a depth 

 of 12 ins. at the center and 9 ins. at the sides. 



and was composed of pieces ranging from % 

 in. to 3*/2 ins. in size. There was a consider- 

 able lack of uniformity in different loads of 

 the material and the depth to which it was 

 laid necessitated more rolling than was re- 

 quired in other cases. The road was finished 

 with screenings in the same manner as in the 

 preceding experiment. The report states that. 

 "The surface was well bonded when inspected 

 at the beginning of last fall." 



In experiment No. 3 the material 

 in two courses, the first, 9 ins. deep, cons 

 ing of slag ranging from 3 l /-> ins. to dust, 

 the second, 6 ins. deep at the center nnc 

 ins. at the sides, composed of 3^2-in. to 

 material. The road was finished in the 

 ner previously described and the results 

 similar to those noted in the second expe 

 ment. 



The section built as experiment Xo. 4 

 constructed in the same manner as in exp 

 ment No. 3 except that the binder used 

 sisted of open-hearth slag screenings ran.a 

 in size from ;4 in. to dust. The screenir 

 were spread about \ l /2 ins. deep and when 

 died set very quickly, producing a hard 

 face. This open-hearth slag frequently 

 tains free lime and silicate minerals. \vhi> 

 in the presence of mcisture produce a 

 hydraulic set, hence the addition of Irme. 

 in the next experiment, in which blast fur 

 ace slag binder was used, was not considered 

 necessary. 



In experiment No. 5 the road vvas constr 

 ed as in No. 1 except that with the bli 

 furnace slag screenings there was mixed 

 per cent, of powdered quicklime. The s 

 varying from fa in. to dust, and the lime 

 mixed by hand on a mixing board and 

 shoveled directly upon the road or carrfe< 

 to it in wheelbarrows. After sprinkling an 

 rolling the surface bonded and became solk 

 very quickly. The surface did not becoim 

 crumbly as on the first section and it 

 noted that better results were obtained I 1 : 

 the use of very fine screenings than by th> 

 use of coarser material. 



The section built in experiment No. fi wa 

 constructed like that in No. 1 except that : 

 sulphite liquor was used in finishing, 

 liquor used had a specific gravity of 1.273 an< 

 was similar to that employed in the work a 

 Washington, D. C. For the first treatment : 

 mixture of 1 part of the liquor to 7 parts 

 water was used. This made a very thin solu 

 tion and as the applications were continuec 



