TEST NO. 2.

Marks on column—­Box 4.

Reinforcement—­eight 1-1/8-in. round bars vertically.

Band spacing about 13 in. vertically.

Wire spiral about 3-in. pitch.

Point of failure about 18 in. from top.

Top of cast-iron cap cracked at four corners.

Ultimate load—­1,260,000 lb.

Remarks.—­Both caps apparently well seated, as was the case with all the subsequent tests.

TEST NO. 3.

Marks on column—­4-B.

Reinforcement—­eight 7/8-in. round bars vertically.

Hoops—­1-3/4 in. x 3/16 in. x 14 in. outside diameter.

Band spacing—­13 in. vertically.

Ultimate load—­900,000 lb.

Point of failure about 2 ft. from top.

Remarks.—­Concrete, at failure, considerably disintegrated, probably due to continuance of movement of machine after failure.

TEST NO. 4.

Marks on column—­Box 4.

Reinforcement—­eight 1-in. round bars vertically.

Hoops spaced 8 in. vertically.

Wire spirals as on other columns.

Total load at failure—­1,260,000 lb.

Remarks.—­First indications of failure were nearest the bottom end of the column, but the total failure was, as in all other columns, within 2 ft. of the top.  Large cracks in the shell of the column extended from both ends to very near the middle.  This was the most satisfactory showing of all the columns, as the failure was extended over nearly the full length of the column.

TEST NO. 5.

Marks on column—­none.

Reinforcement—­eight 7/8-in. bars vertically.

Hoops spaced 10 in. vertically.

Outside diameter of hoops—­14-1/2 in.

Wire spiral as before.

Load at failure—­1,100,000 lb.

Ultimate load—­1,130,000 lb.

Remarks.—­The main point of failure in this, as in all other columns, was within 2 ft. of the top, although this column showed some scaling off at the lower end.

In these tests it will be noted that the concrete outside of the hooped area seems to have had very little value in determining the ultimate strength; that, figuring the compression on the core area and deducting the probable value of the vertical steel, these columns exhibited from 5,000 to 7,000 lb. per sq. in. as the ultimate strength of the hooped area, not considering the vertical steel.  Some of them run over 8,000 lb.

The concrete mixture was 1 part Alpena Portland cement, 1 part sand, 1-1/2 parts buckwheat gravel and 3-1/2 parts gravel ranging from 1/4 to 3/4 in. in size.

The columns were cast in the early part of December, and tested in April.  The conditions under which they hardened were not particularly favorable, owing to the season of the year.