Sessions & Events

 

All sessions and events take place in Central Daylight Time (CDT).
All events take place at the Hyatt Regency New Orleans.

On-demand sessions will be available for viewing in the convention platform/event app under "On-Demand Content" within 24-48 hours of the session premiere. Please note, on-demand sessions are not available for CEU credit. *Denotes on-demand content.


Effects of Extreme Events on FRP Reinforced/Strengthened Structures, FRPRCS-16 Symposium, Part 12 of 14

Sunday, March 24, 2024  10:30 AM - 12:30 PM, Strand 13B

This session is one of 14 sessions that form the 16th Fiber Reinforced Polymer Reinforced Concrete Structures (FRPRCS-16) Symposium. It is co-sponsored by ACI Committee 440 and the International Institute for FRP in Construction (IIFC) for the purpose of advancing the understanding and application of FRP composites in civil infrastructure to serve the engineering profession and society. FRPRCS was first held in conjunction with the ACI 1993 Spring convention in Vancouver, British Columbia, Canada. Since 1993, FRPRCS has evolved into a prestigious and reputable international conference that has been held 15 times including 5 times in conjunction with ACI: British Columbia, Canada (1993); Baltimore (1999); Kansas City (2005); Tampa (2011); and Anaheim (2017).

This session will be dedicated to the performance of FRP-reinforced and FRP-strengthened concrete and masonry structures under extreme events.

Learning Objectives:
(1) Discuss the effectiveness of FRP retrofitted concrete walls;
(2) Evaluate the Hysteretic Energy and Damping Capacity of GFRP-RC Columns Under Cyclic Loading;
(3) Analyze the residual tensile and bond response of polypara-phenylene-benzo-bisthiazole (PBO) fabric reinforced cementitious matrix (FRCM) composites;
(4) Assess the seismic behavior of CFRP-reinforced concrete beam-column joints.

This session has been approved by AIA and ICC for 2 PDHs (0.2 CEUs). Please note: You must attend the live session for the entire duration to receive credit. On-demand sessions do not qualify for PDH/CEU credit.


Experimental Assessment of Large-Scale FRP-Strengthened RC Shear Controlled Walls Subjected to Cyclic Loads

Presented By: Sheng-Hsuan Lin
Affiliation: Simpson Strong-Tie
Description: Fiber reinforced polymers (FRP) are commonly used to seismically retrofit concrete structural walls. Limited design guidance for the seismic application of FRP strengthening is currently available to designers in guidelines such as ACI PRC-440.2-17 or standards like ASCE/SEI 41-17. This paper presents the description and results of an experimental effort to investigate the effectiveness of FRP retrofitted concrete walls. The specimen wall thickness was either 6 in or 12 in, which represents a typical range of wall thickness seen in older buildings. To better reflect the most common applications seen in the industry, the walls were retrofitted with FRP, and anchored with fiber anchors only on one side of the wall. The study demonstrates that the effectiveness of FRP is reduced as the wall thickness increases and that the FRP must be anchored to the wall for any tangible benefit. The results are used to assess the current provisions in ACI PRC-440.2-17 and ASCE/SEI 41-17. It is apparent that additional testing is required to better understand the complexities involved in the FRP strengthening of shear walls and such testing is scheduled for the near future.


PBO FRCM Composite System Exposed to Elevated Temperatures: Experimental Behavior and Numerical Modelling

Presented By: Luciano Ombres
Affiliation: University of Calabria
Description: This paper presents experimental and theoretical investigations on the residual tensile and bond response of polypara-phenylene-benzo-bisthiazole (PBO) fabric reinforced cementitious matrix (FRCM) composites after the exposure to elevated temperatures ranging between 20 °C [68 ºF] and 300 °C [572 ºF]. Experimental results obtained from direct tensile (DT) and single-lap direct shear (DS) tests carried out respectively on PBO FRCM specimens and PBO FRCM-concrete elements were reported and discussed. Overall, specimens exposed to temperatures up to 200 °C [392 ºF] did not present significant reductions of both bond and tensile properties. This result can be attributed to the thermal shrinkage underwent by the inorganic matrix, which may enhance the bond between the fibers and the matrix. On the other hand, when the specimens were heated at 300 °C [572 ºF], marked reductions were observed, primarily stemming from the degradation of both mechanical properties of the FRCM constituent materials and the fiber-to-matrix bond. Subsequently, the experimental results were used for the following purposes: (i) to assess whether the Aveston–Cooper–Kelly (ACK) theory is able to describe the tensile behavior of FRCM materials at elevated temperatures; (ii) to define temperature-dependent local bond stress vs. slip law and (iii) to evaluate the ability of degradation models to simulate the variation with temperature of the FRCM tensile and bond properties. The results obtained from the theoretical analyses showed that, for all the tested temperature, the relative differences between predicted and experimental results are very low, confirming the accuracy of the proposed approaches.


The Implementation of Fire Resistance Recommendations in ACI Code-440.11

Presented By: Mark Green
Affiliation: Queen's University
Description: Glass fibre reinforced polymer (GFRP) bars are a viable solution for corrosion-prone steel bars in reinforced concrete structures. However, the fire performance of GFRP reinforced concrete has been a major concern due to the degradation of GFRP material properties at high temperatures. The consideration of fire resistance in GFRP reinforced concrete has come a long way from not recommending GFRP internal reinforcement for structures, in which fire resistance is essential to maintain structural integrity, to providing design provisions to achieve the desired fire resistance. The former was from ACI 440.1R (2006) and the latter is from ACI CODE-440.11-22. Canadian standard CSA-S806-12 provides a semi-empirical approach for determining the fire resistance of FRP reinforced concrete slabs based on the minimum concrete cover which is overdue for an update incorporating the recent advances in the field. Several full-scale fire tests have shown that GFRP reinforced concrete structures can maintain stability in a fire if measures have been implemented. Past experimental studies aimed to represent the behavior of common GFRP reinforced concrete members such as with bar splices in the fire-exposed regions. The results had shown that the loss of GFRP bond to concrete can cause a premature failure of such members. Later experimental studies avoided the spliced GFRP bars and focused on providing protected cool zones to guarantee adequate bond strength. This study will provide some examples of how to effectively apply the fire provisions in the design of GFRP reinforced beams and slabs. The practical implications of this paper will answer the concerns of designers and GFRP producers on implementing the suggested fire provisions in ACI CODE-440.11-22.


Active Strengthening with Post-Tensioned CFRP Tendons

Presented By: Erblina Vokshi
Affiliation: Sika
Description: External post-tensioning of structures is a known and understood strengthening method. Over the past twenty years, the use of externally bonded FRP, including pre-cured CFRP plates, has been widely adopted as an alternative strengthening solution to mechanically bonded steel plates. FRP materials are light, easy to deliver on jobsites, and corrosion resistant. Their strength utilization, however, is limited to the bond strength between the substrate and the FRP. External post-tensioning of CFRP plates allows for an excellent use of the material properties by introducing a post-tensioning load to a structure via two concentrated anchors. This type of CFRP system has been used for strengthening of bridges, buildings, caissons, tanks. This presentation will describe successful installation of external post-tensioned FRP systems, anchoring methods, and design considerations.


Seismic Performance of Concrete Beam-Column Joints Reinforced with Carbon Fiber-Reinforced Polymer (CFRP) Bars and Stirrups

Presented By: Ligang Qi
Affiliation: China Construction Eight Engineering Division
Description: Concrete beam-column joints are critical elements in the seismic performance of reinforced concrete (RC) structures. The use of carbon fiber-reinforced polymer (CFRP) reinforcement in these joints has gained attention due to its superior mechanical properties and corrosion resistance. This paper presents a comprehensive study of the seismic performance of CFRP-reinforced concrete beam-column joints, focusing on the development of a suitable formula for estimating the seismic shear capacity. Utilizing a finite element analysis (FEA) that was both developed and validated using pre-existing test data, a comprehensive parametric study was undertaken to explore the impact of several factors. These factors encompassed axial load, longitudinal reinforcement ratio, and transverse reinforcement ratio, and their effects on the seismic performance of CFRP-RC joints were thoroughly investigated. Eventually, a suitable formula was proposed for estimating the seismic shear capacity of CFRP-RC joints. Research results will lead in a better understanding of the seismic behavior of CFRP-reinforced concrete beam-column joints, which will consequently guide the design and analysis of CFRP-reinforced concrete structures for enhanced seismic performance.


Seismic Confinement of Brick Masonry Structure with CFRP

Presented By: Samiullah Qazi
Affiliation: UET Peshawar
Description: This research study explores the impact of carbon fiber-reinforced polymer (CFRP) in enhancing the strength of a traditional residential masonry structure. Previous studies have focused on strengthening masonry cantilever walls with CFRP, but these walls do not accurately mimic the seismic behavior of an entire masonry structure. Some studies have also examined modified masonry structures with added openings in parallel walls to counteract torsion caused by differences in stiffness. However, these modifications deviate from the representation of a real rural structure. The present research specifically targets typical rural structures found in central Asia, where approximately ninety percent of masonry buildings lack reinforcement and are vulnerable to seismic activity. Given the circumstances, it becomes crucial to strengthen these structures using an economical, efficient, and feasible technique. Partial bonding with CFRP proves to be more cost-effective than complete jacketing. However, it is prone to issues such as interface delamination. Consequently, this research employs the partial bonding technique along with a CFRP anchorage system only on the walls external side. Two unreinforced masonry (URM) structures resembling a typical village room are constructed for testing purposes at a one-third scale. The specimens were subjected to displacement controlled lateral load along with a constant vertical load. The CFRP strengthened specimen performed well in terms of observed failure modes, load response curve, and seismic performance levels as compared to URM structure.

Upper Level Sponsors

ACI Northern California and Western Nevada Chapter
Baker
Conseal
Euclid Chemical
FullForce Solutions
Master Builders
Natural Resources Research Institute - University of Minnesota
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