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.


Advances in FRP Applications in Masonry Structures, FRPRCS-16 Symposium, Part 7 of 14

Saturday, March 23, 2024  3:30 PM - 5:30 PM, Strand 12B

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 focus on developments of FRP systems including FRP anchors, FRP bars, and textiles used to strengthen and/or enhance masonry systems,.

Learning Objectives:
(1) Assess how FRP bars may be used as injected anchors in masonry structures;
(2) Explain how inorganic composites, namely fiber reinforced mortars, can be used for out-of-plane strengthening of masonry wallets;
(3) Explain how CFRP rebars may be used as an innovative retrofitting system for masonry panels subjected to horizontal action;
(4) Describe how CFRP spike anchors may be used at corner locations on an I-section with in-fill concrete blocks to enhance performance.

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 Efficiency of FRP Bars as Injected Anchors for Masonry Structures

Presented By: Marco Di Ludovico
Affiliation: University of Naples
Description: Masonry structures are very sensitive to out-of-plane mechanisms under horizontal actions. A common traditional technique to avoid or mitigate the activation of these mechanisms is represented by injected anchors made of steel bars aimed to improve the connections between orthogonal masonry walls or between floors and masonry walls. The bars are usually embedded in the masonry by means of cement-based grout in holes realized inside the elements to be connected. Recently, an increased interest has developed in the scientific community about the use of Fiber Reinforced Plastic (FRP) bars as alternative to the steel ones for injected anchors, mainly because of their high tensile strength and inertia to corrosion, which can give them high durability, in addition to the use of high-performance grouts. The paper reports the results of experimental pull-out tests realized by the Authors on several types of FRP bars used as injected anchors in small masonry specimens made of yellow tuff blocks. A hydraulic lime and pozzolana-based grout is used to fix the bars in holes realized in the masonry specimens along an embedded length of 250 mm. The set-up is realized in order to apply pure tension to the bars and shear stresses along the bar-grout and the grout-masonry interfaces. The results are analyzed in terms of maximum pull-out forces, failure modes and force-displacement relations in order to evidence the global performance of each tested system, especially in relation with the diameter and the surface treatment of the bars. Some comparisons with literature formulation for predicting the pull-out force are developed too.


Out of Plane Strengthening of Masonry Wallets with Inorganic Composites

Presented By: Marta Del Zoppo
Affiliation: University of Naples Federico II
Description: Unreinforced masonry buildings (URM) are particularly vulnerable to local out-of-plane failure mechanisms of the walls during earthquakes. This study investigates the effectiveness of a relatively novel class of inorganic composite materials, namely Fibre Reinforced Mortars (FRM), for the out-of-plane strengthening of masonry walls. Experimental tests by using a setup to perform out-of-plane tests on masonry panels, part of an enlarged ongoing testing campaign, are presented herein. Two types of masonry walls are investigated: solid clay brick masonry walls and tuff masonry walls. The specimens are subjected to compressive axial load and out-of-plane horizontal actions according to a “four-point bending test” scheme. Two specimens are reinforced before testing with FRM in double-side configuration, while other two specimens are tested in their bare configuration. Experimental results in terms of capacity curves and deformed shapes are reported and discussed. The preliminary results attest that FRMs are effective in increasing the out-of-plane capacity of masonry walls and in postponing the activation of the out-of-plane failure mechanism.


Discontinuous FRCM-Confinement of Masonry Columns

Presented By: Luciano Ombres
Affiliation: University of Calabria
Description: This paper presents an experimental study on the discontinuous confinement of small-scale masonry columns using a FRCM system. The study aims to investigate the effectiveness of the FRCM in enhancing compressive strength and ductility under axial loading condition. In detail, the adopted FRCM system was composed of a cementitious matrix reinforced with PBO mesh. It was applied to the masonry columns using a discontinuous wrapping technique, which involved wrapping the FRCM material around the column in segments, leaving gaps between the segments itself. More in deep, the experimental program included twelve specimens, ten (i.e. five couples) of which were wrapped with the PBO-FRCM system using the discontinuous wrapping technique, while the remaining two columns were left unconfined and served as the control group. The columns were measured concerning the load-displacement behavior, ultimate strength and failure mode and then compared between the FRCM-confined and unconfined columns. In particular, the amount of fiber in the vertical direction was kept constant, while the scheme of confinement was varied by both changing the strip width and spacing. In total, five different schemes of discontinuous confinement were proved. The performed research aims to contribute to the knowledge in the field of FRCM-masonry confinement, mainly focusing on the influence of the mentioned parameter.


Performance of CFRP Anchors and In-Fill Concrete Blocks in Shear Strengthening of I-sections

Presented By: Muhammad Arslan Yaqub
Affiliation: Ghent University
Description: Performance of carbon fiber reinforced polymers (CFRP) strengthening systems basically depends on the bond between CFRP and the concrete substrate. Particularly, in case of shear strengthening of I-shaped cross sections, this bond is inefficient due to the concave shape of this specific cross section. This will typically cause early debonding at the web-flange corners resulting in limited increase in the shear strength. This paper reports, as part of wider experimental campaign, the results of three shear strengthening configurations over I-sections using CFRP spike anchors or epoxy bonded in-fill concrete blocks. It is observed that CFRP spike anchors at the web-flange corners, for the tested configurations, helped in increasing the performance of the shear strengthening system up to 13%, whereas, with the use of epoxy bonded in-fill concrete blocks and spike anchors in the compression zone the performance of the shear strengthening system was improved up to 23%. The latter system proved to be very effective as debonding around the web-flange corner was eliminated.


Use of CFRP Rebars as Retrofitting System for Masonry Panels

Presented By: Francesca Ferretti
Affiliation: University of Bologna
Description: In the last decades, the devastating effects of earthquake events in seismic prone regions increased the attention on the vulnerability of existing constructions. Masonry walls especially experienced severe damage, both considering out-of-plane and in-plane mechanisms. To increase their resistance to horizontal forces, different strengthening systems can be applied. The objective of the present work is to study the efficiency of an innovative strengthening solution, involving the use of fiber reinforced polymer (FRP) pultruded bars. An experimental campaign is presented, in which clay-brick single-leaf masonry panels are retrofitted by carbon FRP rebars, inserted into grooves cut within the masonry panel with a cementitious mortar, and CFRP sheets applied on the panel external surfaces. A total of seven direct shear tests (ST) and four diagonal compression tests (DC) were performed on unreinforced and strengthened samples. The results of the tests showed that the strengthening technique can be effective for the improvement of the shear sliding and diagonal cracking resistances, also allowing to deepen the knowledge of the principal failure mechanisms characterizing the FRP-retrofitted masonry elements.

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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