Active Standard ASTM D7616 / D7616M | Developed by Subcommittee: D30.10
Book of Standards Volume: 15.03
Significance and Use
Overlap splices are used in field applications of FRP composites when site conditions prohibit continuous access to a structural element or when the specified length of the FRP composite is such that saturation and placement of the entire length would be cumbersome. This method can be used as a quality control mechanism for ensuring that overlap splices constructed under field conditions meet or exceed the requirements established by the design engineer or FRP system manufacturer. Both the saturant mixing and fiber saturation method can be verified for wet-layup FRP systems.
Caution is recommended when interpreting apparent shear strength results obtained from this method. Single shear lap splices develop non-uniform shear stress distributions within the overlap splice region during testing. Additional guidance on the interpretation and use of results obtained from lap shear testing is found in D4896.
This test method focuses on the FRP material itself, irrespective of gripping method. Therefore, strengths resulting from failure or pullout at either grip are disregarded. The strength measurements are based solely on test specimens that fail in the gage section (away from the grips) or at the splice.
1.1 This test method describes the requirements for sample preparation and tensile testing of single-lap shear splices formed with fiber-reinforced polymer (FRP) composite materials commonly used for strengthening of structures made of materials such as metals, timber, masonry, and reinforced concrete. The objective of this method is to determine the apparent shear strength of an overlap splice joint through the application of a far-field tensile force. The method applies to wet lay-up FRP material systems fabricated on site or in a laboratory setting. The FRP composite may be of either unidirectional (0°) or cross-ply (0/90 type) reinforcement. For cross-ply laminates, the construction may be achieved using multiple-layers of unidirectional fibers at either 0 or 90°, or one or more layers of stitched or woven 0/90 fabrics. The composite material forms are limited to continuous fiber or discontinuous fiber-reinforced composites in which the laminate is balanced and symmetric with respect to the test direction. The method is often used to determine the length of the overlap splice needed to ensure that a tension failure occurs in the material away from the splice rather than the splice connection itself.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.2.1 Within the text, the inch-pound units are shown in brackets.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D883 Terminology Relating to Plastics
D3039/D3039M Test Method for Tensile Properties of Polymer Matrix Composite Materials
D3878 Terminology for Composite Materials
D4896 Guide for Use of Adhesive-Bonded Single Lap-Joint Specimen Test Results
D5229/D5229M Test Method for Moisture Absorption Properties and Equilibrium Conditioning of Polymer Matrix Composite Materials
D5687/D5687M Guide for Preparation of Flat Composite Panels with Processing Guidelines for Specimen Preparation
D7565/D7565M Test Method for Determining Tensile Properties of Fiber Reinforced Polymer Matrix Composites Used for Strengthening of Civil Structures
E6 Terminology Relating to Methods of Mechanical Testing
E122 Practice for Calculating Sample Size to Estimate, With Specified Precision, the Average for a Characteristic of a Lot or Process
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E456 Terminology Relating to Quality and Statistics
Other StandardsDOT/FAA/AR-02/97 Shear Stress-Strain Data for Structural Adhesives, November 2002
ICS Number Code 83.180 (Adhesives)