Journal of Materials Science Research, Issue: Vol.14, No.2

Analysis of Geo-Concrete Composite for Use as a Pavement Base Course for Low-Traffic Roads

Sat, 30 Aug 2025 15:47:20 +0000

The present study concerns the improvement of the bearing capacity of a reddish clay lateritic gravel (GLAR) by adding a quantity of crushed granite 0/31.5 in order to use the mixture as a road base course. Geotechnical tests were carried out on natural GLAR, and Geo-concrete composite based on GLAR improved with 0/31.5 mm crushed granite stone at three mass ratios (20wt%, 30wt% and 40wt%). The results show a reduction in the Plasticity Index from 18.7% for the natural lateritic material, to 12.2%, 11.0% and 7.3% respectively at the 20wt%, 30wt% and 40wt% crushed granite amendment mass rates, representing a reduction from 34.76% to 60.96%. Analysis of the geo-concrete composite’s compactness showed that the dry density of the new composite increased by 2.81%, 4.75% and 17.36% with the introduction of Crushed granite 0/31.5 in the GLAR. Moreover, the 95% CBR bearing capacity of OPM has been improved by 2.94%, 5.88% and 27.94% respectively at 20wt%, 30wt% and 40wt% addition of crushed granite material. These results are in line with CEBTP 2014 specifications and indicate that these lateritic gravels reinforced with 0/31.5 mm crushed granite at rates of at least 20% can be used in road construction for the base course. Optimum mechanical stabilization or litho- stabilization is achieved with a 30% incorporation of crushed granite material in GLAR.

Work Hardening Model of Structure in Hall-Petch Strengthening

Thu, 16 Oct 2025 07:46:49 +0000

The microstructural length scale of metals changes by orders of magnitude under extreme processing conditions producing a concurrent wide range of mechanical strength and plasticity behaviors. A unified stress-strain σε model is formulated that’s based on superposing the components of asymptotic-curvilinear work hardening Θσ to qualify and quantify these mechanical behaviors. This approach accounts for the rapid strengthening of metals beyond the initial yield point, through extended steady-state deformation, to the structural instability. The relationship between the softening coefficients cbi of the work hardening formulation Θσ and strength are found to reveal the microstructural scale in the material. Specifically, the rapid decrease in the slope of the Θσ curve provides a measure for microstructural size consistent with a functional Hall-Petch relationship of strength. A successful application is shown for the tensile behavior of pure aluminum microstructures that result from extreme plastic deformation by equal-channel angle pressing.

Analytical Formulation for Larson–Miller Constant of Steel

Thu, 01 Jan 2026 11:27:59 +0000

The Larson–Miller constant (C) of martensitic steel, which is used as the Larson–Miller parameter, is considerably larger than the typically used value of 20 for many types of heat-resistant steels. To provide better understanding regarding this fact, an analytical formulation for the Larson–Miller constant is developed using a model based on interactions between moveable dislocations and elastic singularities in a system. To verify the proposed equation, eight types of Grade 91, 92, and 122 steels are used, whose maximum rupture life exceeds 1E5 h. Creep data are classified into 257 groups by temperature, stress, and strain or time. C values are obtained by applying multiple-regression analyses to time parameters that obey the exponential law, assuming a thermally activated process. C and C_cal are calculated for each data group based on an exponential law and a proposed equation, respectively. The statistical values for C and C_cal are as follows: ̄C=32.41, C_min=7.87, C_max=64.88, and (C_cal⁄C)=99.3%. Although (∆C)̄=(C_cal-C) ̅=0.02 is extremely low, the standard deviation of ∆C is large, i.e., 1.27. Results confirmed that the proposed equation can estimate wide-ranging C values, although the equation is expected to be improved. A major component of C for C>15 is an increase in the entropy change caused by elastic interactions between moveable dislocations and elastic singularities in a system.

Materials for Sustainability in Defence: Trends, Gaps, and Opportunities in Canadian Research

Wed, 31 Dec 2025 11:59:30 +0000

This report presents a comprehensive review of North American research in Materials for Sustainability, with a focus on Canadian contributions and their potential applications in defence. A combined literature review and scientometric analysis of over 10,000 publications from 2014 to 2024 identified six major research domains: recycling, advanced materials, advanced manufacturing, low-carbon raw material production, alternative fuels, and energy storage technologies. Canadian research shows particular strength in biocomposites, green concrete, and hydrogen-related materials. The study highlights emerging trends, research momentum, and topic interconnectivity, offering insights into how materials science can support climate mitigation and adaptation. Defence applications include lightweighting, infrastructure resilience, and low-emission energy systems, especially for Arctic environments. The report concludes with recommendations for targeted R&D to advance sustainable materials in dual-use and defence applications.

Use of Nanomaterials for Corrosion Protection of Steel Rebars in Concrete

Thu, 01 Jan 2026 11:40:09 +0000

The leading cause of deterioration in reinforced concrete structures is the corrosion of steel bars embedded in concrete in the aggressive environment. This includes carbonation of concrete due to high CO2 concentration, chloride rich regions such as in marine environments from the sea water or airborne chloride and the corrosive industrial zones. In the recent past, nano-materials have risen to lime-light as one of the promising class of materials providing good corrosion protection to reinforced concrete structures. This class of materials include nano-silica, nano-alumina, carbon nano-tubes, nano-clays, graphene oxide, nano-coatings, nano-inhibitors as well as nano-particles of metal oxides. The mechanism of action for these nano-materials depends on the type of material used. For instance, some may refine the pore structure of concrete and reduce the permeability of concrete. Others may enhance the interfacial transition zone between the steel reinforcement bars and concrete. All this helps to limit the ingress of harmful substances including moisture, chloride ions, carbon dioxide and oxygen. Yet some other types of nano-materials may provide a protective layer or barrier through absorption, adsorption or reaction with the steel rebar surface and/or improvement in the passive layer. Nanomaterials have a multi-functional role and may also improve the mechanical properties along with the improvement in corrosion related durability. They may also influence the electrical resistance and may provide a self-healing behavior as well. Despite all the advantages, some challenges remain to be overcome such as dispersion, long term effect, impact on environment, scale and cost-benefit ratio.