Article
Construction & Building Technology
Alvaro Ruiz Emparanza, Raphael Kampmann, Francisco De Caso, Carlos Morales, Antonio Nanni
Summary: This study evaluated the durability of different physio-mechanical properties of GFRP rebars by exposing them to accelerated conditioning in seawater. Six different GFRP rebar types were tested at various temperatures for different time periods. The study found that rebars with high moisture absorption had poor durability, mainly affecting tensile strength. According to the Arrhenius model, the rebars meeting ASTM D7957 criteria are expected to retain 85% of their tensile strength capacity at 23 degrees C.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Peng Wang, Lin-yu-wen Ke, Hao-liang Wu, Christopher K. Y. Leung
Summary: This study evaluates the durability of GFRP rebars under different pH levels and finds that lowering pH from 13 to 11 reduces alkali attack damage and improves tensile strength retention. These results provide in-depth explanations and comprehensive information on the durability performance of GFRP rebars for engineering applications.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Engineering, Marine
Mudassir Iqbal, Daxu Zhang, Fazal E. Jalal
Summary: This study develops a random forest regression model to predict the tensile strength retention (TSR) of laboratory conditioned GFRP bars in alkaline environment. Sensitivity and parametric analysis show that temperature, pH, volume fraction of fibers, conditioning duration, and bar diameter are influential attributes in TSR. The existing recommendations by various structural codes regarding environmental reduction factors are conservative and need revision.
JOURNAL OF OCEAN ENGINEERING AND SCIENCE
(2022)
Article
Construction & Building Technology
Kaffayatullah Khan, Mudassir Iqbal, Fazal E. Jalal, Muhammad Nasir Amin, Mir Waqas Alam, Abidhan Bardhan
Summary: This study investigates the non-linearity of GFRP degradation and uses artificial neural network models to predict it. The optimal models were selected using optimization algorithms and their performance was evaluated through various analyses. The results show a high correlation between the TSR of GFRP rebars and different conditions.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Peng Wang, Hao-Liang Wu, Lin-yu-wen Ke, Christopher K. Y. Leung
Summary: This study evaluates the physical and mechanical properties of GFRP rebars embedded in low-pH concrete and finds that replacing ordinary Portland cement with calcium sulfoaluminate cement can enhance the tensile strength and durability of GFRP rebars. These findings provide engineers with a new approach to improve the performance of GFRP rebars.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Materials Science, Ceramics
A. I. Ismail, A. Samir, F. Ahmad, L. Soliman, A. Abdelghany
Summary: In the investigated glass system, the optical absorption of Cr ions decreases as the Li2O content increases, along with a decrease in crystal field strength and a reverse trend in Racah parameters B and C. The presence of both Cr6+ and Cr3+ states in the alkali borate glass were indicated by ESR signals, while FTIR spectra showed vibrations of B-O bonds and allowed for estimation of N-4 fraction utilizing IR parameters. Minor changes in bond angles and lengths of borate structural units post γ-irradiation indicated slight diversity in IR band intensities.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2021)
Article
Materials Science, Ceramics
Nguyen Duy Quang, Amos V. Ntarisa, Sudipta Saha, N. Wantana, Y. Tariwong, Nguyen Duc Ton, S. Kothan, J. Kaewkhao, H. J. Kim
Summary: The luminescence and scintillation properties of Ce3+ doped alkali phosphate glasses (PGAC:X, X = Li/Na/K/Rb/Cs) were studied for their potential applications in gamma and alpha detection. The red shift in the spectra was explained by the concept of optical basicity. Energy transfer from Gd3+ to Ce3+ and scintillation performance under gamma and alpha excitation were observed. All samples showed similar scintillation performance for gamma and alpha detection, but the decay time slightly increased from PGAC:Li to PGAC:Cs.
CERAMICS INTERNATIONAL
(2023)
Article
Materials Science, Ceramics
H. M. Elsaghier, M. A. Azooz, Nehad A. Zidan, W. Abbas, Aly Okasha, S. Y. Marzouk
Summary: Alkali cadmium phosphate glasses doped with erbium ions were prepared using traditional melt-quenching technique. The structure and optical properties of the doped glasses were investigated using FTIR, Raman, and UV-Vis-NIR spectroscopies. The Judd-Ofelt theory was used to analyze the structural changes and calculate radiative parameters. The results showed that the glasses had good suitability for laser and amplifier applications.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2022)
Article
Materials Science, Multidisciplinary
Ruan Carlos de Araujo Moura, Daniel Veras Ribeiro, Paulo Roberto Lopes Lima
Summary: This study investigated the effect of hydrothermal aging on GFRP rebars, revealing an increase in voids and water absorption in the rebars with accelerated aging, along with a decrease in the glass transition temperature of the resin and changes in the chemical composition of the glass fiber. Comparison of experimental results showed that vinylester resin matrix rebars had greater chemical resistance than polyester matrix rebars. The degradation of the rebars led to a decrease in tensile strength and modulus of elasticity, which was attributed to simultaneous degradation of the resin and glass fiber due to alkaline attack.
MATERIALS RESEARCH-IBERO-AMERICAN JOURNAL OF MATERIALS
(2021)
Article
Nanoscience & Nanotechnology
Wen Cheng, Yan Cao
Summary: The hygrothermal aging behavior of E-glass fiber/epoxy composites was studied, and the moisture absorption data and diffusivity of the composites were determined through aging tests at different temperatures and humidities. A relationship model between environmental parameters and moisture absorption behavior was proposed and verified using experimental data and Fick's law. The aging strength of the composites was predicted using an empirical model, and it was found that moisture absorption led to a decrease in tensile, compression, and bending strengths.
Proceedings Paper
Engineering, Civil
Mario Garrido, Joao Ramoa Correia, Md Toyob Shahid, Marina Machado
Summary: This paper assesses the design guidelines for FRP structures regarding the reduction of mechanical properties due to moisture and surveys the available test data on the effects of moisture exposure on FRP materials with E-glass fibers and unsaturated polyester or vinylester resins. The experimental data is compared with prediction models to derive a conversion factor for material degradation in high-moisture environments over a 50-year service life.
10TH INTERNATIONAL CONFERENCE ON FRP COMPOSITES IN CIVIL ENGINEERING (CICE 2020/2021)
(2022)
Article
Engineering, Civil
Hemanta Kumar Behera, Debabrata Giri, Sudhanshu Sekhar Das
Summary: This study evaluated the moisture susceptibility of polypropylene-modified bituminous mix using recycled polypropylene fiber as a modifier. The results showed that the modified mix exhibited superior thermal performance and increased stability. The 2% RPPF-enriched mix showed the highest stability and minimum durability index value.
INNOVATIVE INFRASTRUCTURE SOLUTIONS
(2023)
Proceedings Paper
Engineering, Civil
Ali F. Al-Khafaji, John J. Myers, Antonio Nanni
Summary: This study assesses the long-term durability of GFRP bars in concrete bridges under real-time weather conditions. Tests were conducted to evaluate any mechanical and chemical changes in the GFRP bars and surrounding concrete. The results showed that there were no signs of degradation in the microstructure of the GFRP bars, and the fiber content met the standard requirements. Additionally, there was no evidence of chloride attack in the concrete.
10TH INTERNATIONAL CONFERENCE ON FRP COMPOSITES IN CIVIL ENGINEERING (CICE 2020/2021)
(2022)