Scopus Research — Haneen Mohammed Hadi Al_Tamimi

In order to decrease the greenhouse gas emissions generated by regular Portland cement (OPC), additional cementitious ingredients have been frequently employed, even while building road bases. OPC's susceptibility to moisture and lack of flexibility make it ineffective for stabilizing road bases. This research used alkali-activated materials (AAM) with fly ash to investigate the mechanical properties of cold asphalt binder (freeze-thaw cycles) including the compressive, flexural strength, workability and porosity of cement. Dry specimens and specimens in distilled water have both been used in the experiments to study these temperature correlations. One sample was tested at 20 °C, and the other was frozen and thawed five times at a temperature of −5 °C (cold region environment). The resulting mixtures' morphologies and microstructures were analyzed via SEM images. During the 7 to 28-day curing period, the mixture's growth ratio rose. The combination registered both the greatest and lowest robust elastic modulus. The total compressive strength of the material decreased as the water-to-cement ratio increased due to the greater amount of free water accessible with a higher cationic asphalt emulsion (CAE) content. The moderate loss of flexural strength with increasing CAE concentration after 7 and 28 days of curing was seen. There is not a major impact on flexural strength in the materials by looking at the very modest gaps in flexural strength between 7 and 28 days curing periods. Due to the particle shape and size of this precursor, FA's inclusion allowed for a lower water to binder rate while maintaining a similar level of workability. The porosity and water absorption values rose with FA substitutions. Further studies might clarify the lower flexural strength observed in this study by adding other hybrids plus fly ash such as lime or nanoparticles. © 2023 Elsevier Ltd

This investigation studies the characteristics of wave dispersion in sigmoid functionally graded (SFG) curved beams lying on an elastic substrate for the first time. Homogenization process was performed with the help of sigmoid function and two power laws. Moreover, various materials such as Zirconia, Alumina, Monel and Nickel steel were explored as curved beams materials. In addition, curved beams were rested on an elastic substrate which was modelled based on Winkler–Pasternak foundation. The SFG curved beams’ governing equations were derived according to Euler-Bernoulli curved beam theory which is known as classic beam theory and Hamilton’s principle. The resulted governing equations were solved via an analytical method. In order to validate the utilized method, the obtained outcomes were compared with other researches. Finally, the influences of various parameters, including wave number, opening angle, gradient index, Winkler coefficient and Pasternak coefficient were evaluated and indicated in the form of diagrams. © 2022 Techno-Press, Ltd.

The compressive strength, shrinkage, elasticity, and electrical resistivity of the cement-soil pastes (slag, fly ash) of self-healing of cementitious concrete have been studied while adding hydrogels with nano silica (NSi) in this research. Defining the hydraulic and mechanical properties of these materials requires improvement to motivate more uptake for new buildings. Initially, examining the impact of different synthesized hydrogels on cement-soil pastes showed that solid particles in the mixtures highly affected the absorption capacity of NSi, representing the importance of direct interactions between solid particles and hydrogels in a cementitious matrix. All test results were analyzed by use of a hybridized soft computing model such as the adaptive neuro fuzzy inference system (ANFIS) and support vector regression (SVR) for precise studying and the avoidance of few empirical tests or error percentages. Subsequently, the best RMSE of ANFIS is 0.6568 and the best RMSE of SVM is 1.2564; the RMSE of ANFIS-SVM (0.5643) in the test phase is also close to zero, showing a better performance in hypothesizing self-healing soil-cementitious hydrogel materials in mine backfill. The R2 value for ANFIS-SVM is 0.9547, proving that it is a proper model for predicting the study’s goal. Electrical resistivity and compressive strength declined in the cement-soil pastes including hydrogels according to experimental outcomes; it was lowered by the increase of NSi concentration in the hydrogel. There was a decrement in the autogenous shrinkage of cement-soil pastes while adding hydrogel, depending on the NSi concentration in the hydrogels. The findings of this research are pivotal for the internal curing of cementitious materials to define the absorption of hydrogels. © 2022 by the authors.

Due to their excellent physicochemical and structural characteristics, aluminum oxide (AL2O3) nanoparticles (AlNPs), a family of metal oxide nanoparticles, offer a variety of biological uses. Bitumen binds a high percentage (>95%) of inorganic macrometer-sized particles to provide a cohesive material suitable for use in road pavement. In this study, AL2O3 was added to bitumen as a new bitumen modification to improve the fatigue and rutting performance of bitumen or the base cement asphalt cement (AC) at ratios of 5, 7, and 10% wt by weight of the cement AC. Rheological tests were performed on modified bitumen containing nanoparticles. An extreme learning machine (ELM) analyzes each test outcome. In this case, the properties of AC are greatly affected by the rise in AL2O3 concentration. In comparison to the basic AC, the modified AC's viscosity rose by 90 and 104%, respectively. The outcomes also demonstrated the excellent compatibility and storage stability of both modifiers at high temperatures. A hot mix of AL2O3 modified bitumen was utilized to produce hot cement asphalt samples, and moisture susceptibility was assessed. As a result, the optimal nanoparticle content was chosen, and 7% AL2O3 produced the best results. © 2022 John Wiley & Sons Ltd.

This paper examined the impact of the cross-sectional structure on the structural results under different loading conditions of reinforced concrete (RC) members’ management limited in Carbon Fiber Reinforced Polymers (CFRP). The mechanical properties of CFRC was investigated, then, totally 32 samples were examined. Test parameters included the cross-sectional shape as square, rectangular and circular with two various aspect rates and loading statues. The loading involved concentrated loading, eccentric loading with a ratio of 0.46 to 0.6 and pure bending. The results of the test revealed that the CFRP increased ductility and load during concentrated processing. A cross sectional shape from 23 to 44 percent was increased in load capacity and from 250 to 350 percent increase in axial deformation in rectangular and circular sections respectively, affecting greatly the accomplishment of load capacity and ductility of the concentrated members. Two Artificial Intelligence Models as Extreme Learning Machine (ELM) and Particle Swarm Optimization (PSO) were used to estimating the tensile and flexural strength of specimen. On the basis of the performance from RMSE and RSQR, C-Shape CFRC was greater tensile and flexural strength than any other FRP composite design. Because of the mechanical anchorage into the matrix, C-shaped CFRCC was noted to have greater fiber-matrix interfacial adhesive strength. However, with the increase of the aspect ratio and fiber volume fraction, the compressive strength of CFRCC was reduced. This possibly was due to the fact that during the blending of each fiber, the volume of air input was increased. In addition, by adding silica fumed to composites, the tensile and flexural strength of CFRCC is greatly improved. Copyright © 2022 Techno-Press, Ltd.

In this research, a numerical study has been provided for examining the nonlinear stability behaviors of sandwich beams having a cellular core and two face sheets made of nanocomposites. The nonlinear stability behaviors of the sandwich beam having geometrically perfect/imperfect shapes have been studied when it is subjected to a compressive buckling load. The nanocomposite face sheets are made of epoxy reinforced by graphene oxide powders (GOPs). Also, the core has the shape of a honeycomb with regular configuration. Using finite element method based on a higher-order deformation beam element, the system of equations of motions have been solved to derive the stability curves. Several parameters such as face sheet thickness, core wall thickness, graphene oxide amount and boundary conditions have remarkable influences on stability curves of geometrically perfect/imperfect sandwich beams. Copyright © 2022 Techno-Press, Ltd.