3.Expansion Shells All expansion shells shall conform to the requirements of ASTM A 47, Specification for Malleable Iron Castings, Grade 32510. Tapered plugs used with expansion shells shall be forged from steel conforming to the requirements of ASTM A 663 and A 675, Grade 60 to 65.
4.Roof Plates All roof plates shall be steel conforming to the requirements of ASTM A 242, Type 2, or ASTM A 588, Grade A.
217.03 Construction Details.
1.General. Rock bolts shall be installed at the direction of the Engineer at any point where the stability of the rock cut is questionable. When bolting is deemed desirable, it shall be done as quickly as possible. Rocks should be kept tight and not pulled back into place once it has been loosened by successive blasting or construction operations. The holes for the rock bolts shall be drilled as closely as possible to the diameter recommended by the manufacturer of the wedge or shell. SECTION 217 SPECIAL PROTECTION FOR ROCK SLOPES
2.Torque. The diameter and length of the rock bolt to be used shall be determined by the Engineer. All installations shall be in accordance with the recommended procedure or method as given by the manufacturer of the rock bolts. When directed by the Engineer, proper tests will be made to determine what torque the rock can withstand. If the tests show that the highest torque practical is of a certain value for a particular grade of rock, then torque shall be applied to the rock bolt provided the torque does not exceed the maximum recommended by the manufacturer of the rock bolts. It is recognized that any over-application of torque will only destroy the anchorage in the rock and in due time destroy the initial tightness of the bolt. It is desired that a minimum torque of 125 foot pounds {170 N•m} be applied in all cases where the rock will withstand such pressure.
3.Installation Details. Extreme care shall be taken to keep the drill hole aligned perpendicular to the plate bearing surface. The diameter of the drill hole shall be as recommended by the manufacturer for the type of expansion unit to be used for anchorage into the rock. Expansion units shall not be used in holes larger than that for which they are designed. When slotted type rock bolts are used, the bolt with wedge shall be inserted in the hole until the wedge hits the bottom of the hole. The bolt shall then be driven into the hole with an air-percussion hammer forcing the wedge into the slotted end of the bolt, thus anchoring the bolt in the hole. The plate and nut shall then be installed on the collar end of the bolt and the nut tightened to the torque recommended by the manufacturer.
1.General. The seam designated by the Engineer for sealing shall be examined carefully during the grading operations for evidence of seepage which will require construction of weep holes in the sealing cap as well as for the best method for placing the sealing cap.
2.Cleaning of the Seam. The material in the seam to be treated shall be routed out or otherwise removed to a depth at least equal to the thickness of the seam or layer to be treated or to a depth which will give firm support to the sealing material.
3.Sealing the Seam, The clean seam shall be sealed or packed with one of the following types of concrete mixes. The method of packing or placing the sealant shall be left to the Contractor provided the method used produces the desired results and presents an acceptable appearance. Weep holes, when deemed necessary, shall be placed as directed.
a.Low Slump - Class A concrete as provided by Section 501 of the Standard Specifications. b.Pneumatic Concrete of an approved mix of cement, additives, aggregates, and water applied pneumatically. (Mix designed by the Contractor to produce a 28-day cylinder strength of 5000 psi {35 Mpa})
c.Retempered - Class A concrete.
1.General. An Asphalt Surface shall be placed on areas designated by the Engineer to prevent excessive erosion from surface runoff over relatively soft and erodible materials.
2.Preparation of Surface. The surface to receive the asphalt surfacing shall be fairly uniform, without excessive high and low spots, suitable for coverage with asphalt. The surface shall be clean and free from loose rock fragments before applying the surfacing material.
3.Surfacing Material. The surfacing material shall be Asphalt Cement Grade 40 or an approved equal. The bituminous material shall be applied at the rate of 1.25 gallons per square yard {5 L/m²}. The method of application shall be that of the Contractor's provided it is approved by the Engineer, and it produces the desired results and presents a pleasing appearance.