International Journal of Engineering and Applied Physics

Mode shapes for free vibration of clamped plates with various geometries based on an quadrilateral element

2025-04-23T14:45:37+00:00

This work aims at presenting mode shapes for free vibration of clamped plates with various geometries based on a four-node quadrilateral element, CP-DSG4, related to discrete shear gap (DSG) strategy and adding a center point (CP). The efficiency of the CP-DSG4 element is demonstrated through some numerical tests.

Evaluation of production cost of bricks using clay and stone dust-cement

2025-03-11T10:31:48+00:00

This study aimed to investigate whether mixing clay soil, stone dust, and 5% cement could enhance strength, reduce water absorption, and lower production costs, without compromising the material's quality. Clay soil from near FUTA, Akure and stone dust from a quarry were used. Tests were conducted on the raw materials, including sieve analysis, moisture content, bulk density, and specific gravity. Clay soil was partially replaced with stone dust at 0% (control), 5%, 10%, 15%, 20%, and 25%, with a constant 5% cement. 288 bricks were produced, 144 air-dried and 144 fired at 1000°C. Compressive strength and water absorption tests were performed on both burnt and unburnt bricks. The results showed that for burnt bricks at 28 days, water absorption ranged from 11.11% to 20.00%, and for unburnt bricks, 3.33% to 7.69%. The compressive strength of burnt bricks increased up to 15% stone dust replacement, then decreased, while unburnt bricks showed a gradual strength reduction with increasing replacement. Both results met NIS and BS standards for normal building bricks.

Complementarity of the trombe wall effect and air distribution in passive air conditioning of a single-zone building

2025-03-15T18:29:36+00:00

The work in this article presents the study of the Complementarity of the trombe wall effect and the distribution of air to the passive air conditioning of a single-zone building by simulating the thermal behavior of a habitat located in Madagascar, in Antananarivo. The practical recommendation of the heat flow exchanged by thermocirculation is done in an ingenious system. The first part of the work will be based on the installation of a solar capture system, a vertical wall in heavy masonry facing north and equipped with two holes. It allows and facilitates the simulation of an air circulation system between this building and the greenhouse formed by the receiving surface of the wall and the glazing that precedes it. The second will develop the physical modeling of the system obtained by assembling simplified thermal models of the wall elements, glazing and air volume constituting this zone. The analysis of the system will be able to receive a well-air-conditioned home.

Multi-Criteria Evaluation of XL-Terrasil and Metakaolin Geopolymer for Subgrade Improvement in Rural Roads of Ondo State, Nigeria

2025-03-17T12:23:14+00:00

Weak lateritic soils in tropical regions present significant challenges for road construction due to their poor load-bearing capacity and high compressibility. This study evaluated the effectiveness of XL-Terrasoil (XL) and Metakaolin (MTK) in stabilizing weak lateritic soils from three locations in Ondo State, Nigeria, to enhance their suitability for subgrade applications. A laboratory-based experimental approach was adopted. Soil samples were collected from failed road sections and subjected to stabilization, XL -Terrasil and Metakaolin was incorporated into the soil as percentage of its dry weight with dosages set at (0.5%–2.5%) for XL- Terrasil and (2%–10%) for Metakaolin, while the control samples without additive (0% Dosage) was prepared for base line comparison. Tests performed include compaction, unconfined compressive strength (UCS), California Bearing Ratio (CBR), permeability, and microstructural analyses (XRF, SEM-EDX, and XRD). The untreated soil samples exhibited poor engineering properties: Location 1 had UCS of 180 kPa and CBR of 6.5%; Location 2 showed UCS of 165 kPa and CBR of 12%; while Location 3 had UCS of 195 kPa and CBR of 18%. Stabilization with 1% XL improved UCS to 340 kPa (90% increase), while 6% MTK further enhanced UCS to 420 kPa (133% increase). Similarly, soaked CBR improved to 30% with 1% XL and 40% with 6% MTK. Permeability reduced significantly, with 6% MTK decreasing hydraulic conductivity to 8.0 × 10?? m/s (65% reduction). Microstructural analyses confirmed improved bonding between grainsand better crystallinity, silica -alumina promote cohesion and decrease plasticity particularly in MTK-treated samples. The study concluded that Metakaolin outperforms XL-Terrasoil in improving soil strength, durability, and permeability, making it the preferred stabilizer for sustainable subgrade applications in tropical road construction.