34 BULLETIN 586, U. S. DEPARTMENT OF AGRICULTURE. 
Experiment No. 17—Bituminous macadam, granite with fluxed native 
asphalt; experiment No. 18, Bituminous macadam, granite with oil- 
asphalt X.—In the spring of 1916 small areas, distributed quite gen- 
erally over the surface of both experiments, began to disintegrate so 
that numerous penetration patches were necessary. These sections 
had been laid over old macadam which was scarified and dressed 
with a layer of new stone before the penetration course was applied. 
The breaking of the newly constructed surface appeared to be due to 
movement in the wearing surface caused by the failure to fill and 
bond the new stone added to the foundation. Both sections were in 
good condition for retreatment and this was applied. The charac- 
teristics of the bituminous material used in the reseal are given in 
Table 37 and the cost data and quantities will be found in Table 38. 
TaBLE 37.—Analyses of residual asphaltic petroleum. 
General characteristics, viscous, sticky fluid. 
wae ‘ A—0.991 
sspeckielsra vaiyy2oRiOM 2D WU Mawel Peace. Oe Sea faved ces rede es ay Le | B—0. 989 
aera OO UMN GeO Rae een NA Mage ERL A aE ag Ee MES TALE te pl 1 A 100 
SE Uinsat ang OUT ep CME S (3 ad CCE ei aN ee EEL kh St ESE EE | 120 
BOA Mest OUT KON BECONGS) sey Cena. GEKe yey Ai umn peNh way chek a 0hd SEN Oe ey 
B—30 
Viscosityaemeleroo eue at LOO On Species la) mise mess a6 aan new eannes 14.2 
oss atdlGswO sor oursin2 OleramS sper Gelb hase ese en ae eee eee 14.30 
Character oi residue very viscous, sticky. 
Mloattestronresrduets0%1C: Geconds)as ease ees. 8 a 3 sees 160 
Per cent of total bitumen insoluble in 86° B. naphtha Sees Meets UR ae 17.39 
Ren Cento mice teanpOn she bray aM aa an np ae oa Me Rr a 10. 44 
Bitumen soluble in CS, (total bitumen), per cent.....-.......------.---- 99.89 
Organiematteriimsolublesypericenbse 1234 ses tees 49 e 2) eee t See ry 0.11 
Inorganic matter msoluble:spenicentic nc os ss.se ces shat see eee eee eee 0.00 
100. 00 
Expervment No. 19—Bituminous concrete, granite with oil-asphalt 
X .—This experiment showed marked deterioration and many pene- 
tration patches had to be made in the spring of 1916. It was 
brought into good condition for treatment and a new seal coat 
applied in May and June, 1916. The same bituminous material was 
used as on experiments Nos. 17 and 18, and cost data and quantities 
are given in Table 38. At the time of inspection this experiment 
showed a few wavy spots due to fat penetration patches under the 
retreatment; otherwise the experiment was in good condition. 
Experiment No. 20—-Bituminous concrete, granite with fluxed native 
asphalt A.—Except at the south end, this experiment did not disin- 
1 Samples A and B from each of 2 barrels, except where indicated tests were made on composite 
sample, 
