1.0 GENERAL REQUIREMENTS

1.1 This procedure specifies drill sizes, minimum hole depths, embedment dimensions, and installation requirements for Maxi-Bolt Coupling anchors as manufactured by Drillco Devices, Ltd. The Coupling anchor offers an internally threaded connection which is slightly recessed below the concrete surface. Allowable-loads for an installation. which utilizes the Maxi-Bolt Coupling Anchor will be based on allowable loads for the Coupling Anchor or for the bolt which is threaded into the Coupling Anchor, depending on which has the lesser material strength.

1.2 Personnel assigned to install Maxi-Bolt anchors should receive training from a Drillco Qualified Instructor before proceeding with work. If the responsible engineer or contractor so  desires, personnel will be issued a Qualified Installer's card upon satisfactory completion of such training.

2.0 DRILLING HOLES

2.1 Locating Holes

2.1.1 Mark placement of anchor(s) on concrete.

2.1.2 If required, locate placements of rebar in vicinity of  anchor(s) with a rebar locating device and make necessary corrections in location of anchor(s) on concrete.

2.1.3 If location of rebar is not required or if location of anchor(s) has been corrected per 2.1.2, proceed with 2.2.

2.2 Drilling Primary Hole

2.2.1 Holes shall be drilled with a Drillco carbide percussion drill bit, Drillco "Rebar Eater" bit, or Drillco diamond core bit.

2.2.2 Drill diameter is specified in Table I .

a. Drill diameter shall be measured with an instrument having a least division of .001 inch.

b. Drill diameter shall not exceed the specified maximum diameter.

c. A Drillco DBGNG (drill bit go  - no go gauge) may be used in lieu of the above to determine acceptability of the primary hole bit.

d. This-procedure does not specify a minimum primary hole bit diameter.

2.2.3 Drill hole to depth specified in Table I.

a. Hole depth shall not be less than hole depth specified.

b. Hole may be drilled to any depth greater than hole depth specified.

2.2.4 Holes shall be drilled within 6 degrees of perpendicular to the  nominal concrete surface.

a. The use of a guide, level, or square is recommended.

2.2.5 Clean hole of concrete dust and debris using oil free compressed air or by vacuuming.

2.2.6 Measure depth of hole to ensure that minimum hole depth has been  achieved.

2.3 Relocating of Hole

2.3.1 If anchor must be relocated and a new hole drilled, the old hole shall be repaired with dry pack grout or in accordance with contract drawings or specifications.

2.4 Drilling Undercut in Primary Hole

2.4.1 Undercut in primary hole shall be drilled only with a Drillco Undercutting Tool.

2.4.2 Cutter diameter B (diameter with cutter(s) in fully opened position) is specified in Table II and illustrated in Figures 1 and 1A.

a. Maximum cutter diameter B shall be measured with an instrument having a least division of .001 inch.

b. Diameter B shall not be larger or smaller than specified diameter plus or minus the tolerance specified in Table II.

c. A Drillco DBGNG (drill bit go  - no go gauge) may be used in lieu of the above to determine that the cutter blades are within the tolerances specified in Table II.

2.4.3 The depth at which the undercut is formed is controlled by the  position of tool's bearing sleeve (C in Figures 1 and 1A). To  achieve the correct undercut depth:

a. Set tool's bearing sleeve so that Dimension F in Figure 1 or  1A corresponds to the specified embedment depth of the anchor  being installed.

b. When anchors are to be installed prior to placement of  attachment, the bottom of the bearing sleeve should be placed  in contact with the surface of the concrete.

c. When anchors are being installed through an "in place" attachment, the bearing sleeve should be placed in contact  with the surface of the attachment. Furthermore, the attachment should be in contact with the nominal surface of  concrete.

2.4.4 With the bearing sleeve in contact with the surface of the concrete or attachment, but with no pressure applied to the drill, start drill motor.

2.4.5 With drill motor running apply a steady pressure on the drill and observe the location of Pin D (Figures 1 and 1A) in Slot E.

2.4.6 When Pin D is in contact with bottom of Slot E (as shown in Figures 1 and 1A) the undercut is complete. To verify this it may be necessary to stop the drill motor and observe pin location.

2.4.7 After the undercut has been completed, stop the drill motor and  remove the tool from the hole. Inspect tool cutter(s) to ensure that they have not been damaged during the drilling operation.

2.4.8 Clean the hole of concrete dust and debris using oil free compressed air or by vacuuming.
 
 

3.0 INSTALLING ANCHORS

3.1 The Drillco Maxi-Bolt is a single wedge type anchor with an  expansion sleeve placed between the conical nut and the  internally threaded coupling. This expansion sleeve is  designed to expand into the undercut created by the Drillco  Undercutting Tool as described in 2.4 above.

3.2 Examine Assembled Anchor

3.2.1 Check to ensure that all components are present and that the bolt  is correctly assembled. See Figure 2.

3.2.2 No modification to the anchor shall be permitted.

Reference  Description A Conical Nut B Expansion Sleeve C Threaded Stud Bolt D Distance Tube E Retaining Washer F Coupling Nut Plating Non Stainless Steel Bolts come standard with plating to specification QQ-Z-325c Type II Class 3

Maxi-Bolt Material Properties for : ASTM A36 Mild Steel ASTM A193 Grade B7 High Strength Steel ASTM A193 Grade B8 - Class 1 Type 304 Stainless Steel ASTM A193 Grade B8 - Class 2 Type 304 Stainless Steel ASTM A193 Grade B8M - Class 1 Type 316 Stainless Steel ASTM A193 Grade B8M - Class 2 Type 316 Stainless Steel

3.3 Setting Anchor

3.2.1 To set the Maxi-Bolt it is necessary to draw the conical nut on  the stud bolt up into the anchor's sleeve. In so doing the  expansion sleeve will be forced to move laterally into the  undercut portion of the hole and the conical nut will seat fully inside the expansion sleeve. See (Figure 5). This process may be accomplished in one of three ways.

3.3.2 Manual Setting

3.3.2.1 Remove internally threaded coupling from anchor and thread stud extender onto the stud end of the anchor. Put setting sleeve over the stud extender. Place the end of the stud extender through the center hole of the Bolt Bushing (From Figures 3). The-Bolt Bushing should be oriented so that the 1/16" offset bears against the  anchor sleeve. Finger tighten a hex nut and washer on anchor bolt assembly.

3.3.2.2 Insert anchor into properly drilled, undercut and cleaned hole.

3.3.2.2.1 Because of close tolerance between conical nut O.D. and hole I.D. it may be necessary to lightly hammer the anchor into the hole:

a. If hammering is necessary, steps shall be employed which will prevent damage to the threads of stud bolt.

b. Anchor shall be placed in hole so that the top of the setting sleeve is flush with the nominal surface of concrete or attachment.

3.3.2.3 Use a wrench to hold the stud extender stationary while the  hex nut is tightened. The hex nut should be tightened until  the conical nut is seated and the expansion sleeve contacts  the I.D. of the conical undercut in the concrete. The  installer will note a sudden increase in torque required at  this point. During the setting operation, the orientation of  the bolt bushing shall be observed. If the bolt bushing  rotates more than 180 degrees, use a pipe wrench to prevent  further rotation.

3.3.2.4 Loosen hex nut, unscrew stud extender from anchor, and remove  setting sleeve from hole.

3.3.2.5 Insert internally threaded coupling into hole, chamfered end  first, and thread onto anchor.

3.3.3 Setting Anchor with Hand Bolt Setting Tool

3.3.3.1 Remove internally threaded coupling from anchor and thread stud 'extender onto the stud end of the anchor. Put setting sleeve over the stud extender. Thread stud extender into the bottom of the Hand Bolt Setter so that setting sleeve is firmly in contact with the 1/16" offset of the Bolt Setter's bolt bushing. Place assembly into clean undercut hole. Grasp Hand Bolt Setter handle and turn hex nut in a clockwise direction. using a box end wrench or adjustable wrench. When pin reaches top of slot, the anchor is set. Loosen hex nut. Remove Hand Bolt Setter by rotating it in a counterclockwise direction. See Figures 5.

3.3.3.2 Unscrew stud extender from anchor and remove setting sleeve from hole.

3.3.3.3 Insert internally threaded coupling into-hole, chamfered end first, and thread onto anchor.

 
 

3.3.4 Hydraulic Setting

3.3.4.1 Check to ensure that components required for hydraulic setting are present and assembled. See Figures 3.

3.3.4.2 Remove internally threaded coupling from anchor and thread stud extender onto the stud end of the anchor. Put setting sleeve over the stud extender. Place the end of the stud extender through the center hole of the Bolt Bushing. The Bolt Bushing should be oriented so that the 1/16" offset bears against the setting sleeve. Position the Bolt Bushing in the center of the Base Plate, place Draw Bar through the center hole of the hydraulic cylinder, and attach Draw Bar to the stud extender.

3.3.4.3 Place the anchor into the drilled and undercut hole so that the Base Plate on the hydraulic cylinder is in contact with the surface of the concrete or attachment. Load the bolt to the values specified in Table III. Remove the Draw Bar, Hydraulic Cylinder and Bolt Bushing from the anchor.

3.3.4.4 Unscrew stud extender from anchor and remove setting sleeve from hole.

3.3.4.5 Insert internally threaded coupling into hole, chamfered end first, and thread onto anchor.

3.4 Tensioning Anchor

 3.4.1 Thread a stud at least one stud diameter into the internally threaded coupling, place a short length of spacer sleeve over the stud, and screw a hex nut onto the stud. Torque Anchors to the values specified in Table III. Restrain the stud while loosening hex nut and then remove stud from the Anchor's coupling.

3.4.2 For torquing of 1/4" Maxi-Bolt anchors it is suggested that a click or breakaway type torque wrench be employed to insure that the maximum torque is not exceeded.

 

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