Public works . In making the wear test, ten blocks were arrangedaround the perimeter of the drum and an abrasive chargeused consisting of two hundred pounds of cast iron balls,ten being 334 inches in diameter and about 133 being IJ^inches. The rattler made 1,800 revolutions at the rate of30 revolutions per minute, 900 revolutions being run inone direction and then 900 in the other. The loss inweight of each block during the test was considered themeasure of its wear and was reduced to an equivalentdepth of wear in inches. While the Talbot-Jones rattler was designed manyyears ago, it has not be
Public works . In making the wear test, ten blocks were arrangedaround the perimeter of the drum and an abrasive chargeused consisting of two hundred pounds of cast iron balls,ten being 334 inches in diameter and about 133 being IJ^inches. The rattler made 1,800 revolutions at the rate of30 revolutions per minute, 900 revolutions being run inone direction and then 900 in the other. The loss inweight of each block during the test was considered themeasure of its wear and was reduced to an equivalentdepth of wear in inches. While the Talbot-Jones rattler was designed manyyears ago, it has not been used to any wide extent, andthe ordinary rattler of standard dimensions and con-struction has been almost universally employed for test-ing brick and other blocks employed in paving. Its usein these tests was considered to be entirely successfuland the results have given those in charge of the labora-tory considerable confidence in this method of consider that this rattler gives a wearing action. TALBOT-JO^ES RATTLER, BLuCK-S IN PLACE. RATTLER CLOSED, READY FOR TEST. July 19, 1919 MUNICIPAL JOURNAL AND PUBLIC WORKS 35 suited for a wide range in the .properties of very poor concrete may be entirely destroyed, while ahigh-grade concrete shows a wear of one-half inch orless. It gives a combination of abrasion and impact thatcannot be withstood by an inferior concrete. While thetest does not fully duplicate the action of traffic, it fur-nishes a valuable guide to the relative effects of differentmethods of treatment, materials, etc., for use in pavementconstruction. This method of making wear tests of concrete is be-lieved to have the following advantages as comparedwith other methods that have been used or proposed forthis purpose: (1) The concrete is subjected to a treatment whichapproximates that of service. (2) The test piece is of usual form and of sufficient sizethat representative concrete can be obtained. (3) The test pieces are convenient to make
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectmunicip, bookyear1896
