Goteras procedentes de viviendas contiguas o superiores

Care must be taken in storing, handling, and erecting ornamental handrail so as not to permanently mar or injure the finish on the post and rail elements. Aluminum ornamental handrail which is to be stored in the open should be removed from the cardboard cartons since cartons may stain the handrail when they become wet and considerable effort is required to remove these stains.

Ornamental handrail inspection is not generally waived at the fabrication plant even if small quantities are involved. If the Project Manager does not have a copy of a shop inspection report on file indicating inspected material, the material should be inspected by Materials and Research Division. If there is a question of whether the material has been inspected or not, the Materials and Research Division should be contacted for clarification.

The Project Manager should make a visual check of the handrail before placing it in the structure. In the case of aluminum tubing, "carbon streaks" that develop in the

manufacturing process are not cause for rejection. However, the carbon streaks should be limited to one 90-degree segment of the surface of any rail. Particular attention is necessary at the time of erection. Tubing should be placed in the bridge railing in such a manner that the carbon streaks are not visible to traffic.

416 • County bridges usually only get one coat. • New state structures usually get two coats.

• Repainting an existing structure usually means adding a third coat.

The Project Manager or inspector should check the dry film thickness of the shop and field coats of paint applied on structural steel in accordance with the following instructions: Shop Coat - The shop coat of paint may or may not have been checked in the fabricator's shop; nevertheless the shop coat should always be checked in the field, and any deficiency in paint film thickness corrected, before the second coat is started. When the dry film thickness of the shop coat is found to be inadequate, the Materials and Research Engineer should be notified in order that the particular fabricator involved may be made aware of the situation.

Second and Third Coats - Checking the thickness of the second and third coat with the magnetic gauge is accomplished by measuring the cumulative thickness of the first (or shop coat) and the additional coats. The dry film thickness of the second coat should always be checked and any deficiency in paint film thickness corrected before the third coat is started. Any deficiency in paint film thickness must be corrected before the work can be considered complete and consideration of acceptance given.

The equipment used to check the dry film paint thickness is called a magnetic dry film thickness gauge. One or two of these gauges are being furnished to each District Office for use in the District in checking the painting of steel structures. These gauges are expensive, delicate instruments and must be carefully handled and always kept in the carrying case when not in use. The procedure for using the gauge is as follows:

1. Turn dial to maximum reading.

2. Place pole on the surface to be measured.

3. Be sure the magnetic contact is touching the painted surface.

4. Slowly and as continuously as possible, rotate the dial clockwise until magnetic contact breaks. A click will be heard when the pin breaks contact. At this point the coating thickness can be read on the dial indicator. The reading will remain on the dial when the gauge is removed from the surface being checked. The gauge can also be held in any position to take a reading. The magnetic gauge reads directly in mils. A reading of 2 on the dial indicates that the thickness of the paint film is 2 mils or .002 inch.

The frequency of testing for paint thickness should be as follows:

1. Girders - Each line of girders should be checked at a maximum interval of 15 m (200 ft) and at each check point, 3 or 4 tests should be made. For example, on a 60 m (50 ft) bridge each line of girders should be checked at the abutments and at 3 intermediate points. At each one of these points three or four places should be checked such as a point on the web, a point on each flange, and a point on a stiffener.

Culverts

418 710.00 CULVERTS (SSHC Sections 717 to 726) 710.01 GENERAL

The backfill near a pipe or box culvert is more expensive than excavation in the surrounding area. Therefore, in the SSHC Subsection 702.03, limits are placed on the quantities “Excavation for Box Culvert” and “Excavation for Pipe, Pipe-Arch Culverts, and Headwalls.”

710.03 CONCRETE BOX CULVERTS (SSHC Section 717) 710.10 DESCRIPTION

A culvert may be defined as a structure to convey water under a roadway. Concrete box or arch culverts are used when drainage areas are too large for the conventional culvert pipe or when cattle passes under the roadway are desired. These structures are cast-in-place according to standard or special plans under SSHC Sections 702, 704, 705 and 717. The contractor may request that culverts be built to the nearest whole English units. Any material savings will be deducted from the payments due the contractor.