Category:1044 Posts for Markers and Delineators

From Engineering_Policy_Guide
Jump to navigation Jump to search
Upgrading delineator posts

This article establishes procedures for inspecting galvanized steel posts used for mounting mile and object markers, delineators, drain and right of way markers and other similar purposes. Refer to Sec 1044 for MoDOT’s specifications.

For Laboratory testing and sample reporting procedures, refer to EPG 1044.5 Laboratory Testing Guidelines for Sec 1044.

1044.1 Apparatus

(a) Scales or balance accurate to within 0.5 percent of the weight (mass) of the sample to be weighed.
(b) Rule with suitable graduations to accurately measure the material to be inspected.
(c) Micrometer or vernier caliper capable of measuring to 0.0001 in. (0.00254 mm) and accurate to within 0.001 in. (0.0254 mm).
MGS Information
Current General Services Specifications (MGS) By Subject
(d) Magnetic gauge, reading range of 0-40 mils (0-1000 m).

1044.2 Procedure

Posts for markers and delineator acceptance will be based on the procedures detailed in EPG 1040.2 Procedure.

These posts are to be inspected for shape, length, weight (mass), fabrication and galvanized coating. For field inspection purposes the minimum number of posts inspected should be three. Samples may be submitted to the Laboratory when field inspection indicates questionable compliance. A sample for Laboratory testing shall consist of two complete posts.

1044.2.1 Mile and Object Marker, and Delineator Posts

The required shape, length, weight (mass) and hole punching diagram for mile marker and delineator posts may be found on Standard Plan 903.03. The inspector should be aware that minimum and maximum weights (masses) and shape dimensions found on the Standard Plan are absolute and no additional tolerance is allowed. The specified weight (mass) of these posts is before galvanizing and before fabrication. Therefore, if the posts are weighed after fabrication and galvanizing and the weight (mass) per linear ft. (meter) is found to be at the specified limit or slightly out, the weight (mass) of the steel in the post will have to be calculated by adding the theoretical weight (mass) of the steel punched out to form the holes and deducting the theoretical weight of the galvanized coating. An example calculation is available.

Field determination of weight (mass) of coating is to be made. The magnetic gauge is to be operated and calibrated in accordance with ASTM E376. A single-spot test is to be comprised of five readings of the magnetic gauge taken in a small area and averaged to obtain a single test result. Three such areas should be tested, one area near each end and one near the center. This would yield three single-spot test results for that specimen. Average the three test results to obtain the average coating weight (mass) for that specimen. Average all test results from all specimens to obtain the average coating weight (mass) to be reported. The minimum result would be the lowest average coating weight (mass) found on any one specimen. Material may be accepted or rejected for galvanized coating on the basis of magnetic gauge results. If a test result fails to comply with the specifications, that lot should be re-sampled at double the original rate. If any of the re-samples fail to comply with the specifications, that lot is to be rejected. The contractor or supplier is to be given the option of sampling for Laboratory testing if the magnetic gauge test results are within minus 15 percent of the specified coating weight (mass).

1044.2.2 Drain and Right of Way Markers

Steel posts for drain and right of way markers are to be of channel or modified channel shape and of the length shown on the plans or Standard Plan 602.00. Weight (mass), hole punching details and tolerances for weight (mass) and length are to be inspected for conformance to Sec 1044.2.2. Field inspection procedures, minimum number of posts selected for field inspection and sampling for Laboratory testing are the same as shown in EPG 1044.2 Procedure.

1044.3 Calculations

Shown below is an example calculation for determining, after fabrication, the mass per meter of a galvanized steel post.

(a) Values Determined by Test

Average mass of zinc coating = 605 g/m2

Number of punched holes = 3

Diameter of holes = 8 mm

Total Mass of post = 5 kg

L = Length of post = 2400 mm

T = Thickness of channel = 4 mm

A = Overall height of channel = 32 mm

B = Overall width of channel = 56 mm

C = Width of outside face of channel bottom = 25 mm

D = Length of channel leg = 16 mm

(b) Calculated Surface Area of Channel

W = Width of channel

= 2 (D) + 2 (A-T) + C - 2(T)
= 2 (16) + 2(32 - 4) + 25 - 2 (4)
= 105 mm

Surface area = 2 (W x L) = 2(T x L)

= (2 x 105 x 2400) + (2 x 4 x 2400)
= 523,200 mm2
= 0.523 m2

(c) Calculated Total Mass of Zinc

Total Mass of Zinc = (Surface Area) x (Avg mass per sq. meter of zinc coating)

Total Mass of Zinc = (0.523 m2) x (605 g/m2)

= 316.5 g

(d) Calculated Mass of Steel Punched Out

Area of one hole = 3.1416 x (Diameter) 2/4

= 3.1416 x (8) 2/4
= 50.265 mm2

Volume of steel for one hole= (Area of one hole) x (T)

= 50.265 x 4
= 201.06 mm3

(Steel weighs 7840 kg/m3)

Mass of steel from three punched holes= 3 x 7840 kg/m3 x 201.06 mm3

= 4.73 g

(e) Calculated Mass per Linear Meter

Mass per linear meter of steel post= (Post mass-Zinc Mass+Punchout Mass)/(Length of post)

= (5 kg - 316.5 g + 4.73 g)/2400 mm
= 1.95 kg/m

1044.4 Report

AASHTOWARE Project (AWP) is to be used for identifying and submitting samples to the Laboratory and as an acceptance report. The Laboratory will perform the designated tests, complete the report form, and distribute the necessary copies. The report is to indicate acceptance, qualified acceptance, or rejection. Appropriate remarks, as described in EPG 106.20 Reporting, are to be included in the report to clarify conditions of acceptance or rejection.

Distribution of reports for materials purchased under a MoDOT purchase order is to be as described in EPG 1101 Materials Purchased by a Department Purchase Order.

Articles in "1044 Posts for Markers and Delineators"

This category contains only the following page.