Single Lap Test– Determine Bond Properties of FRCM/SRG Composites Applied to Quasibrittle Substrates

🎤 Speaker: Christian Carloni - Associate Professor, Case Western University 📍 Presented at the NEx Workshop during the ACI Concrete Convention 📌 Baltimore, MD – October 29th, 2025 Debonding of fiber-reinforced cementitious material (FRCM) composites from substrate can limit the increase of strength that a reinforced concrete (RC) or masonry structural member can achieve due to the addition of the external layer of reinforcement provided by the composite. The bond behavior of FRCM composites depends on the properties of matrix and fiber mesh used for the composite system as well as the properties of the substrate. Small-scale direct shear tests can help understand the debonding phenomenon. This presentation focuses on the document that has been developed by ACI 549 committee, which provides guidance to conduct single-lap tests of FRCM composites bonded to concrete or masonry. The relationship between the results of single-lap test and the strain limit used in the design of the FRCM strengthening system is discussed. Christian Carloni is an Associate Professor in the Department of Civil and Environmental Engineering at Case Western Reserve University. Dr. Carloni is a structural engineer with research interests in fracture mechanics, concrete and masonry structures, and composites materials. He co-authored 70+ peer-reviewed journal papers, 100+ conference papers, and 7 book chapters. His research has been funded by federal agencies, private industry, and the American Concrete Institute (ACI). He is an active voting member of ASTM D30 and ACI 440, 440K, 440H, 446, 549, and 549K technical committees. He was the leading author of an ASTM standard. This session is part of the NEx Workshop, hosted by NEx: An ACI Center of Excellence for Nonmetallic Building Materials, focused on “New Advancements in FRP & FRCM Materials for Repair and Rehabilitation of Concrete Structures.” The ideas expressed in this seminar are those of the speakers and do not necessarily reflect the views of NEx, ACI, or its committees. To earn continuing education credits, visit ACI University. Learn More: nonmetallic.org 👍 Like | 💬 Comment | 🔔 Subscribe for more expert insights on nonmetallic innovation and sustainable infrastructure.