Performance of Adhesive and Cementitious Anchoring Systems
Funding Source: MassDOT
Title: Performance of Adhesive and Cementitious Anchoring Systems
Date: 2017 Completed
Summary: Post-installed anchoring systems are advantageous to Massachusetts Department of Transportation (MassDOT) projects, due to their ease of attachment to existing structures. However, recommendations on materials from various manufacturers are currently lacking for certain situations such as long-term tension loading. The purpose of the investigation presented in this report is to provide guidance to MassDOT on the use of anchoring systems. This research project evaluated the behavior of adhesive and cementitious bonded anchoring systems per the Stress-versus-Time-to-Failure (SvTTF) approach found in the provisional standard AASHTO TP-84, in order to provide recommendations pertaining to the test method. Supplemental short-term anchor pullout tests were conducted using the best-performing materials as evaluated by AASHTO TP-84, to study the effects of certain in-service and installation parameters on bond strength. The parameters studied included installation direction and extreme in-service temperatures. Polymer characterization testing of adhesive products was also conducted in order to comment on technique usefulness for quality assurance/quality control of field-installed bonded anchor materials. Results of the project support the continuation of MassDOT Engineering Directive E-10-001. An implementation plan is recommended to provide a method for acceptance on MassDOT’s Qualified Construction Materials List for uses allowed under that directive. Acceptance criteria include some testing and materials characterizations beyond ICC-ES AC308 criteria to address recommended limitations on coefficient of variation (COV) and performance at decreased temperatures that may be experienced under field conditions. Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) data are also required.