Ruba Ahmad Odeh
@staff.hu.edu.jo
Department of allied engineering science / faculty of engineering-
lecturer
EDUCATION
Master of structural engineering - Jordan University of Science and Technology
Bachelor of civil Engineering - Jordan University of Science and Technology
RESEARCH, TEACHING, or OTHER INTERESTS
Civil and Structural Engineering, Building and Construction
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Ruba Odeh and Roaa Alawadi
MDPI AG
The assessment of shear behavior in SFRC beams is a complex problem that depends on several parameters. This research aims to develop an artificial neural network (ANN) model that has six inputs nodes that represent the fiber volume (Vf), fiber factor (F), shear span to depth ratio (a/d), reinforcement ratio (ρ), effective depth (d), and concrete compressive strength (fc′) to predict shear capacity of steel fiber-reinforced concrete beams, using 241 data test gathered from previous researchers. The proposed ANN model provides a good implementation and superior accuracy for predicting shear strength compared to previous literature, with a Root Mean Square Error (RMSE) of 0.87, the average ratio (vtest/vpredicted) of 1.00, and the coefficient of variation of 22%. It was shown from parametric analysis the reinforcement ratio and shear span to depth ratio contributed the most impact on the shear strength. It can also be noticed that all parameters have a nearly linear impact on the shear strength except the shear span to depth ratio has an exponential effect.
Md Azree Othuman Mydin, Mohd Nasrun Mohd Nawi, Ruba A. Odeh, and Anas A. Salameh
MDPI AG
Worldwide concern and ascendancy of emissions and carbon footprints have propelled a substantial number of explorations into green concrete technology. Furthermore, construction material costs have increased along with their gradual impact on the environment, which has led researchers to recognize the importance of natural fibers in improving the durability and mechanical properties of concrete. Natural fibers are abundantly available making them relatively relevant as a reinforcing material in concrete. Presently, it should be recognized that most construction products are manufactured using resources that demand a high quantity of energy and are not sustainable, which may lead to a global crisis. Consequently, the use of plant fibers in lightweight foamed concrete (LFC) is deemed a practical possibility for making concrete a sustainable material that responds to this dilemma. The main objective of this study is to investigate the effect of the addition of lignocellulosic fibers on the performance of LFC. In this investigation, four different types of lignocellulosic plant fibers were considered which were kenaf, ramie, hemp and jute fibers. A total of ten mixes were made and tested in this study. LFC samples with a density of 700 kg/m3 and 1400 kg/m3 were fabricated. The weight fraction for the lignocellulosic plant fibers was kept at 0.45%. The durability parameters assessed were flowability, water absorption capability, porosity and ultrasonic pulse velocity (UPV). The results revealed that the presence of cellulosic plant fibers in LFC plays an important role in enhancing all the durability parameters considered in this study. For workability, the addition of ramie fiber led to the lowest slump while the inclusion of kenaf fiber provided optimum UPV. For porosity and water absorption, the addition of jute fiber led to the best results.
Md Azree Othuman Mydin, Mohd Nasrun Mohd Nawi, Ruba A. Odeh, and Anas A. Salameh
MDPI AG
Currently, the cost of construction rises along with the ongoing impact on the environment, and it has led the researchers to the acceptance of biomass natural fibers, such as biomass frond fiber (BFF), for the improvement of the mechanical properties of cement-based materials. BFF is abundantly accessible, making it relatively pertinent as a reinforcing material in foamed concrete (FC). In addition, natural fiber-reinforced concrete has been progressively employed in construction for several decades to reduce the crack growth under the static load. This paper intends to experimentally investigate the effectiveness of the addition of BFF to FC to improve its mechanical properties. The FC samples were strengthened with BFF at the weight fractions of 0.12%, 0.24%, 0.36%, 0.48%, and 0.60%. This study used three FC densities: 600 kg/m3, 800 kg/m3, and 1000 kg/m3, with fixed constitutions with 0.45 and 1:1.5 cement-to-water and cement-to-sand ratios, respectively. The evaluated strength characteristics included bending, splitting tensile, and compressive strengths. The experimental outcomes indicated that adding 0.36% BFF to FC facilitates optimal splitting tensile, compressive, and bending strength results. BFF enhances material strength by filling the spaces, microcracks, and gaps inside the FC structure. The BFF helped to reduce crack spreading when the plastic state of the FC cementitious matrix was loaded. Furthermore, the optimum level of BFF inclusion and the accumulation and the non-uniform distribution of BFF were detected, which caused the lowering of the strengths of the FC significantly. Beyond the optimum level of BFF, the agglomeration and the non-uniform dispersion of the BFF were seen, which resulted in a drop in mechanical properties. The output from this research will give a better insight into the potential utilization of plant fiber in FC. It is of profound significance to guide the sustainable development and application of FC material and infrastructures.
Rami H. Haddad, Ruba A. Odeh, Hala A. Amawi, and Ayman N. Ababneh
Canadian Science Publishing
Recently, self-compacting concrete (SCC) has been increasingly used in high-rise buildings and industrial units, susceptible to accidental fires. The probable degradation of these structures necessitates understanding SCC behavior under elevated temperatures. For this, an extensive experimental investigation was undertaken to evaluate the effect of elevated temperature (300–600 °C) on the mechanical compressive properties of SCC; considering the effect of water-to-cement ratio (0.40–0.50), type of mineral aggregate and filler (limestone and basalt), and internal humidity. Standard cylinder (150 mm × 300 mm) and prism (100 mm × 100 mm × 300 mm) specimens were prepared from various SCC mixtures, cured for 28 d in limewater, and then stored at different environments for an additional 90 d to create varying internal humidity levels; ranging from 28 to 95%. Later, specimens were subjected to elevated temperatures in an electrical furnace, then cooled and tested for compressive mechanical response or non-destructively using resonance frequency, ultrasonic pulse velocity, and rebound hammer evaluation techniques. The results showed significant reduction in residual compressive strength, and elastic modulus, and an increase in compressive strain at peak stress and toughness as elevated temperature was increased. The SCC mixtures at upper water-to-cement ratios with basalt aggregate showed higher resistance to elevated temperatures than corresponding ones with limestone. Internal humidity in SCC had a detrimental impact on compressive strength and elastic modulus; especially at exposure temperatures below 400 °C. The statistical correlations between residuals for compressive strength or elastic modulus and nondestructive damage indices can be classified as very good. Furthermore, the nonlinear empirical models, developed to predict residuals for compressive strength and elastic modulus in terms of the study parameters, showed relatively high prediction potential, hence are recommended to be used in designing SCC mixtures for best resistance against possible fire attack.