May 12, 192^ 
Effect of Decomposition on Concrete Tile 
491 
a seepage line that ran along the western edge of the bog but, at the 
place where the sample was taken, cut across a point of high ground about 
200 feet wide on which there was no peat. 
Crumbs were broken off by hand from the rotted portion of all of these 
tile, powdered, shaken up with distilled water for one minute and tested 
for free alkali. All gave a violent alkaline reaction. 
The strength and absorption of these tile were tested in the drainage 
laboratory of the Minnesota Experiment Station by D. G. Miller, senior 
drainage engineer of the United States Department of Agriculture, 
and J. A. Wise of the Minnesota Experiment Station. The difference 
in porosity between the decayed tile and that which was not decayed 
is not strongly brought out. The fact is indicated that the tile were of 
high grade for the time they were made. 
Table XV.— Results of physical tests of concreate tile in peat (ij years) at Grand Rapids, 
Minn. 
Item. 
No. I. 
No. 2. 
No. 3. 
Internal diameter (in.). 
S 
8. 72 
819 
I.81 
783 
6 
12. 02 
851 
Weight (lbs.).!. 
Breaking load pounds (per linear ft.). 
Absorption, bone dry and boiling method (per cent)... 
Top in mold, lower side in marsh. 
Center piece, upper side in marsh. 
11. 8 
12. 0 
13. 6 
II. 7 
10. 2 
Center piece, side in marsh. 
13 - 7 
II. 9 
Bottom in mold, upper side in marsh. 
Bottom in mold, lower side in marsh. 
II -3 
10-5 
COON creek mOH EIME PEAT 
Early in 1921 a movement was started to show that concrete tile would 
not disintegrate in peats carrying a high percentage of lime. This claim 
was supported by most eminent authorities and there was no published 
work to contradict it. As the high lime peats include all the peat areas 
of Minnesota that are yet of economic importance and the greater part 
of those of southern Wisconsin, the point raised was paramount. For 
the investigators to be able to limit the destruction of concrete to the 
low-lime peats would be of immense benefit to the States affected, for it 
would reduce the problem to the proportions of an academic study. It 
would, however, necessitate a classification of the peat areas before 
drainage. The results of the observations on high-lime peat are there¬ 
fore given in some detail. 
A peat area was selected that was assumed to offer ideal conditions 
for the preservation of the tile, i. e., the Coon Creek experimental tract. 
Here a peat area 3 to 6 feet deep is underlain in its deeper portion with 
marl of unknown depth and extent but sounded to a thickness of 17 feet. 
The tract was selected by Dr. F. J. Alway, chief of the soils division 
of the Minnesota Agricultural Experiment Station, for experimental work 
in the agricultural utilization of high lime peats and is maintained for that 
purpose. On the south, the tract is bounded by low hills of wind-blown 
sand, derived from the limestone drift of the northwest glaciation. This 
sand extends out underneath the peat some 300 to 400 feet, where it 
drops off quite sharply, marl occupying the depression between the sand 
and the peat above. The part under cultivation extends a little beyond 
the shoulder where the sand drops away, and the outer lines of tile (laterals 
