Transactions of the American Society of Civil Engineers, vol. LXX, Dec. 1910 / Tests of Creosoted Timber, Paper No. 1168

by W. B. Gregory

Fig. 7.—DEFLECTON CURVES BEAM VII

Comparisons.

A comparison of the results obtained with tests made on untreated timber is interesting, and to this end Tables 2 and 3, from Circular 115, Forest Service, U.S. Department of Agriculture, by W. Kendrick Hatt, Assoc. M. Am. Soc. C. E., are quoted. The tests made by the writer were from timber raised in Louisiana and Mississippi, while the tests quoted were from timber raised farther north. The number of tests was not sufficient to settle questions of average strength or other qualities. It will be seen, however, that the treated timber 26 years old compares favorably with the new untreated timber.

Plate I, Fig. 1.—Specimen in Testing Machine, Showing Method of Support.

Plate I, Fig. 2.—End Views of Tested Timbers.

TABLE 2.—Bending Strength of Large Sticks.

Loblolly Pine.
Reference number.	Locality of Growth.	Dimensions.		Grade.	Condition of seasoning.		Number of tests.	Moisture, per cent.	Rings per inch.	Specific gravity, dry.	Weight per Cubic Foot, in Pounds.		Fiber stress at elastic limit, in pounds per square inch.	Modulus of rupture, in pounds per square inch.	Modulus of elasticity, in thousands of pounds per square inch.	Elastic resilience, in inch pounds per cubic inch.	Number failing by longi- tudinal shear.	Remarks.
		Section, in inches.	Span, in feet								As tested.	Oven dry.
1	South Carolina.	6 by 7 6 by 10 4 by 12 6 by 16 8 by 14 8 by 16	10 to 15.5	Square edge	Green	Average	42	48.0	5.7	0.50	46.2	31.2	3,150	5,580	1,426	0.45	7	Moisture above saturation point in all cases.
						Maximum		92.1	11.7	0.60	56.8	37.5	5,210	8,460	1,920	0.99
						Minimum		30.2	2.3	0.40	35.6	25.0	1,675	3,120	905	0.07
2	South Carolina.	6 by 7 4 by 12 6 by 10 6 by 16 8 by 16 10 by 16	10 to 16	Square edge	Partially air dry.	Average	18	27.7	5.0	0.50	40.0	31.2	3,380	5,650	1,435	0.45	0	Moisture from 25 to 30 per cent.
						Maximum		29.2	8.2	0.55	43.7	34.4	4,610	8,090	1,880	0.76
						Minimum		25.5	2.5	0.45	35.6	28.1	2,115	3,600	1,152	0.20
3	South Carolina.	6 by 7 4 by 12 6 by 10 6 by 16	10 to 15	Square edge	Partially air dry.	Average	19	21.0	5.6	0.50	37.5	31.2	2,970	5,690	1,340	0.39	2	Moisture less than 25 per cent.
						Maximum		24.9	17.2	0.58	45.6	36.2	4,850	8,100	2,040	0.69
						Minimum		15.0	2.7	0.41	31.2	25.6	1,730	2,910	906	0.10
4	Virginia.	8 by 8	6 to 16	Square edge	Partially air dry.	Average	12	22.4	4.8	0.46	35.6	28.8	3,260	5,180	1,180	0.51	0
						Maximum		27.7	8.8	0.58	43.1	36.2	5,300	8,950	1,728	1.05
						Minimum		17.8	2.5	0.37	30.0	23.1	1,280	2,180	606	0.13
5	Virginia.	8 by 8	6 to 15.5	Square edge	Green	Average	17	64.0	3.0	0.43	43.7	26.9	1,935	3,490	744	0.31	0	Very rapid growth; poor quality.
						Maximum		100.5	4.0	0.51	51.9	31.9	3,185	4,720	1,193	0.78
						Minimum		38.8	2.5	0.35	35.0	21.9	956	2,180	357	0.12
Long-Leaf Pine.
6	South Carolina.	6 by 8 10 by 16	15	Merchantable	Partially air dry	Average		25.0	13.7	0.58	45.6	36.2	3,800	7,160	1,560	0.53	9
						Maximum	22	40.3	25.4	0.76	60.0	47.5	4,970	10,020	2,010	0.78
						Minimum		17.3	6.2	0.50	39.4	31.2	2,220	5,450	1,190	0.21
7	Georgia.	10 by 12	15	Merchantable	Partially air dry.	Average		27.3	18.0	0.69	54.7	42.9	5,581	8,384	1,820		6	Excellent merchantable grade.
						Maximum	22	34.5	29.0	0.79		49.4	9,600	11,410	2,920
						Minimum		20.0	11.0	0.50		31.4	3,547	4,836	1,167