ICBO Evaluation Service, Inc.

EVALUATION REPORT                                                 Report No. 4133
Copyright@ 1992 lCB0 Evaluation Service, Inc.                                                            February, 1992

DRILLCO DEVICES, LTD.
POST OFFICE BOX 2182
10-05 35TH AVENUE
LONG ISLAND CITY, NEW YORK 11102

I. Subject: Drillco Maxi-Bolt Bearing Type, Undercut Anchors.

II. Description:

A. General: The Maxi-Bolt anchor is a bearing-type undercut anchor installed in a hole with a conical undercut near its blind end. The anchor consists of a stud bolt, conical nut, expansion sleeve, distance tube, washer and heavy hex nut. See Figure No. 1 for assembly details. The stud bolt and conical nut are fabricated from ASTM Grade B7 material.
    The Maxi-Bolt is designed to be a ductile anchor which transfers loads in the anchor stud to the concrete surrounding the undercut portion of the hole through bearing.
    Table No. I notes the allowable shear and tension anchor loads and Table No. 11 notes center-to-center spacing, edge distance and embedments requirements for anchors installed in f'c = 3,000, 4,000 and 5,000 psi concrete.
    The allowable loads noted in Table No. I may be assigned to each anchor in a multiple-anchor attachment. A single anchor used to anchor an attachment shall be designed for one half of the allowable loads noted.
    Where shear loads are present, attachment displacements may exceed 1/16 inch at design load levels unless sufficient friction resistance is present.
    Component parts of the anchor must be used as a complete unit and must not be disassembled. The Maxi-Bolt is available in 1/4-, 3/8-, 1/2-, 5/8-, 3/4-, 1 - and 11/4-inch stud diameters. Table No. II lists the stud lengths for the anchors.
    Maxi-Bolt undercut anchors may be used for doweling applications to connect new concrete to existing concrete elements, provided:

1. The Maxi-Bolt is installed in accordance with this report.
2. The nut or washer bears against the surface of the existing concrete.
3. The anchor stud has two heavy hex nuts.
4. The anchor stud extends far enough into the new pour to provide the required shear strength.
    The shear stud is designed in accordance with Sections 2611 (h) and 2624 and Table No. 26-F of the code.
    For design purposes, the maximum allowable yield strength for anchor studs is 60,000 psi.

B. Installation: The Maxi-Boft is installed in four steps:

1. A hole is drilled in concrete.
2. The hole is undercut using a Drillco undercutting tool.
3. The hole is cleaned of concrete dust and debris using appropriate means such as oil-free compressed air or by vacuuming.
4. The anchor is set by drawing the stud and conical nut inside the expansion sleeve forcing the expansion sleeve to expand laterally into the undercut portion of the hole.
5. The material to be fastened is located and the stud tensioned.

    Table No. III lists drill and undercutting tool dimensions and tolerances. The undercutting tool is designed to produce a fixed angle cut in the concrete which matches the angle formed on the conical nut. Figure No. 3 depicts the undercutting tool and shows how the cutter insert blade opening (Dimension B) is measured. A proper undercut is made when Pin D is at the bottom of Slot E as noted in Figure No. 3.
    Steps four and five serve to proof load the anchor and to minimize anchor deflections upon loading of the attachment. After installation, measurement of the stud projection beyond the concrete may be used to provide additional verification that the conical nut is properly seated in the undercut portion of the hole. Stud projection from the concrete surface or from the surface of the attachment where the sleeve is allowed to extend through the hold in the plate, equals the overall stud length minus the combined distance of the anchor tube and expansion sleeve lengths with a tolerance of -1/4 inch or +1/2 inch on the measured projections.
    A special inspector, in accordance with Section 306 of the code, must be present to ensure that anchors are installed in accordance with this report. Additionally,. representative sampling of 10 percent of bolts installed must be proof tested either by direct tensioning to approximately 80 percent of the yield strength of anchor bolts or by torquing to the manufacturer's recommended torque value. If there are any failures, immediately adjacent bolts must also be tested.
    After installation Of 1/2-inch, 5/8-inch and 3/4-inch Maxi-Bolts five bolt threads should be visible above the heavy hex nut. One-inch and 1 1/4-inch Maxi-Bolts should show six threads.

C. Identification: The anchor is identified by its packaging bearing a label noting the company name, address and trade name (Maxi-Bolt) as well as the anchor size, quantity, catalog part number, lot number and carton number. There is also a distinctive end mark on the anchor. See Figure No. 2 for end-marking details.

1 . Anchors are installed as noted in this report and the manufacturer's instructions.
2. Allowable shear and tension loads are as set forth in attached tables.
3. Allowable loads for anchors subjected to combined shear and tension forces are determined by the ratio of the actual shear to the allowable shear plus the ratio of the actual tension to the allowable tension not exceeding 1.00.
4. The anchors must be Installed with drill bits manufactured by Drill co Devices Limited.
5. The anchors must be installed under special inspection In accor dance with Section 306 of the code.
6. The allowable loads may not be increased for duration of load.

A. Base overall length anchors, diameters 1/2 inch and larger, are identified by an internal hex in the end of the anchor's stud.
B. Anchors with an overall length longer than that of the base length anchor for a particular diameter have an external hex head. The external hex head is stamped with a number to indicate how many inches longer than the base length the anchor is.
C. Anchors with an overall length shorter than that of the base length anchor for a particular diameter have an external square head. The external square head is stamped with a number to indicated how many inches shorter than the base length the anchor is.
D. The 1/4-inch and %-inch anchors are manufactured to one length only and are provided with wrench flats.

NOTES:
1. Case 1 applicable for grouted plates. Case 2 applicable for plates in contact with concrete surface.
2. Use straight line interaction for combined tension and shear loading.
3. All load allowables are premised on the anchor's ability to develop 100 percent of the stud bolt's minimum ultimate capacity. Table No. II specifies combinations of concrete compressive strength, anchor embedment, center-to-center spacing and edge distance which will allow the anchor to develop its ultimate capacity.
4. The allowable loads noted in the above table may be assigned to each anchor in a multiple-anchor attachment. A single anchor used to anchor an attachment shall be designed for one half of the allowable loads noted.
 
 

*Recommendation based on independent laboratory testing. All other embedment and center to center recommendations based on design by analysis provisions of ACI 349. Appendix B.

NOTES:
1. Maximum attachment thickness is based on torque tensioning of anchor. Any lesser attachment thickness may be used. Where the anchor is to be hydraulically tensioned, maximum attachment thicknesses will be reduced by one stud diameter.
2. Consideration of stress area reduction for limited concrete depth is not reflected in the above table. Minimum concrete depth = anchor embedment plus (center-to-center spacing/2).
3. Maxi-Bolt part numbers are specified as follows: MB-Diameter Series Number --- Overall Length-Sleeve Length (combined expansion sleeve and distance tube lengths).
4. Minimum edge distances quoted are for shear or combined tension and shear. For tension loading, edge distance may be reduced to 75 percent of given value.
5. Allowable values are limited to a maximum of six bolts in a two-row, three-column, or three-row, two-column arrangement. Allowable values may also be used for anchors placed in a single line and separated from other anchor lines by a minimum distance of two times the anchor embedment length.
6. In-place embedment length is determined by subtracting the over-all length (second number shown in Anchor Part No. column) from the exposed projection.
 
 

NOTES:
1. Undercutting tool diameter A is given for identification purposes only. No tolerance applies to this dimension.
2. Undercutting tool diameters A and B are noted in Figure No. 3