publications

2024

1. JMCE

   Benchmarking the Bond of 19-Wire–28.6-mm-Diameter Prestressing Strands to Normal-Weight Concrete

   Fray F. Pozo-Lora, Marc Maguire, Andrew D. Sorensen, and 2 more authors

   Journal of Materials in Civil Engineering, Nov 2024

   

2023

1. Materials

   Out-of-Plane Flexural Behavior of Insulated Wall Panels Constructed with Large Insulation Thicknesses

   Jacob Luebke, Fray F. Pozo-Lora, Salam Al-Rubaye, and 1 more author

   Materials, Jun 2023

   Abs

   

   Insulated concrete sandwich wall panels (ICSWPs) are gaining popularity as energy regulations become stricter worldwide. ICSWPs are now being constructed with thinner wythes and thicker insulation to keep up with the changing market, which is reducing material costs and increasing thermal and structural efficiency. However, there is a need for adequate experimental testing to validate the current design methods for these new panels. This research aims to provide that validation by comparing the predictions of four different methods with experimental data obtained from six large-scale panels. The study found that while current design methods adequately predict the behavior of thin wythe and thick insulation ICSWPs within the elastic region, they do not accurately predict their ultimate capacity.

2022

1. JoVE

   Determination of the Mechanical Properties of Flexible Connectors for Use in Insulated Concrete Wall Panels

   Fray F. Pozo-Lora, and Marc Maguire

   JoVE, Jun 2022

   Abs

   

   This document contains recommendations for performing a non-standard, double-shear test suitable for both continuous and discrete insulated concrete sandwich wall panels (ICSWPs). Such a standardized test does not exist, but several iterations of this and similar tests have been performed in the literature to varying degrees of success. Further, the tests in the literature are rarely-if ever-described in detail or discussed at length with respect to the testing, data analysis, or safety procedures. A test specimen configuration is recommended herein, and variations are discussed. Important mechanical properties are identified from the load versus displacement data, and their extraction is detailed. The use of test data for design, such as for determining the stiffness of the connectors, is briefly demonstrated to show how ICSWP deflection and cracking behavior may be calculated. The strength behavior of panels may be determined using the full load versus displacement curve or only the maximum connector strength. Shortcomings and unknowns are acknowledged, and significant future work is delineated.

2. Polymers

   Behavior of Hybrid Reinforced Concrete Bridge Decks under Static and Fatigue Loading

   Jared W. McRory, Fray F. Pozo-Lora, Zachary Benson, and 2 more authors

   Polymers, Nov 2022

   Abs

   

   This paper presents a new bridge deck reinforcement alternative using hybrid reinforced concrete (Hybrid) consisting of Glass Fiber Reinforced Polymer (GFRP) rebar and alkali-resistant fiberglass composite macrofibers added to the concrete mixture. Fiberglass composite macrofibers are a miniaturized GFRP reinforcing bar that is a composite of resin and glass fibers. An experimental testing program and analytical modeling were conducted to evaluate the structural performance at the service and ultimate limit states. Thirteen full-scale bridge deck specimens were constructed and tested under static and fatigue loading. The fatigue loading was applied up to two million cycles at a frequency of 4 Hz. Post-fatigue, the specimens were tested to failure to compare pre-and post-fatigue behavior. Simplified and moment-curvature analytical models were used to predict the specimens’ flexural strength at the ultimate level, and both were found to be accurate for predicting pre- and post-fatigue strength. Deflection and crack width were monitored throughout the fatigue loading, and these values were compared to the recommended AASHTO LRFD serviceability limits. Testing and analytical results showed that the Hybrid deck is a viable alternative to steel-reinforced and GFRP-reinforced bridge decks for flexural behavior. The service and ultimate level behavior of each bridge deck type was adequate as compared to the AASHTO LRFD service limits. The exceptional post-peak energy absorption demonstrated by the Hybrid adds ductility to previously elastic GFRP reinforced sections.

2020

1. JOBE

   Thermal bowing of concrete sandwich panels with flexible shear connectors

   Fray Pozo-Lora, and Marc Maguire

   Journal of Building Engineering, May 2020

   
2. CI Magazine

   Partially Composite Concrete Sandwich Wall Panels

   Marc Maguire, and Fray F. Pozo-Lora

   Concrete International, May 2020

   Abs

   

   Design of insulated concrete wall panels (ICWPs) resides outside of the current building code provisions. The behavior of an ICWP is largely a function of the wythe connector stiffness and strength. Using the percent composite analogy, designers of partially composite ICWPs can follow the design process for a solid wall. However, they must be aware of the limitations of this approach and the various factors that affect the panel deflections and stresses when subjected to service and design loadings.

2019

1. Comp. Structures

   Lumped GFRP star connector system for partial composite action in insulated precast concrete sandwich panels

   Brandon Cox, Parker Syndergaard, Salam Al-Rubaye, and 3 more authors

   Composite Structures, Dec 2019

   

2023

1. PCI Convention

   Design of Wythe Connectors for Concentrated Out-of-Plane Loading of Insulated Walls

   Ammar Al-Maabreh, Fray F. Pozo, and Marc Maguire

   In PCI Convention at The Precast Show, Feb 2023

   
2. PCI Convention

   Inter-wythe Slip Design Criteria for Non-Composite Insulated Walls

   Abdelrahman Awawdeh, Fray F. Pozo-Lora, and Marc Maguire

   In PCI Convention at The Precast Show, Feb 2023

   

2021

1. PCI Convention

   Parametric Study of Pre-Tensioned Girders Reinforced With 19-Wire 1-1/8” Diameter Prestressing Strands

   Fray F. Pozo-Lora, Salam Al-Rubaye, and Marc Maguire

   In PCI Convention - Innovations in Precast Concrete Components, Feb 2021

   

2019

1. PCI Convention

   Flexural Behavior of Continuous Non-Loadbearing Insulated Wall Panels

   Fray F. Pozo-Lora, and Marc Maguire

   In PCI Committee Days and Technical Conference, Sep 2019

   

2017

1. IEEE

   Magnetizable concrete composite materials for road-embedded wireless power transfer pads

   R. Tavakoli, A. Echols, U. Pratik, and 4 more authors

   In IEEE Energy Conversion Congress and Exposition, ECCE 2017, Sep 2017