STRUCTURAL ENGINEERING

Concrete is one of the most widely used construction materials in Nigeria due to its strength, durability, and versatility. However, the increasing cost of granite and the environmental impact of quarrying have created the need for alternative, sustainable materials. At the same time, palm kernel shell (PKS), a by-product of palm oil processing, is generated in large quantities and often disposed of as waste, leading to environmental pollution. This study investigates the suitability of palm kernel shell as a partial replacement for granite in Grade 20 concrete. Granite was partially replaced with PKS at 0%, 10%, 20%, and 30% by weight. The physical properties of PKS, including specific gravity, bulk density, and aggregate impact value, were
determined. Concrete mixes were produced and tested for workability using the slump test, as well as fresh and hardened density. Concrete cube specimens were cast and cured for 7, 14, and 28 days before compressive strength testing in accordance with relevant British Standards The results indicated that the incorporation of PKS reduced the density of concrete, confirming
its potential for lightweight applications. Workability and compressive strength decreased with increasing PKS content due to the high water absorption and lower strength of PKS compared to granite. However, concrete containing up to 20% PKS achieved compressive strength values close to the target strength for Grade 20 concrete at 28 days. It was concluded that palm kernel shell can be used as a partial replacement for granite up to an optimum level of 20%, offering a cost-effective and environmentally friendly alternative for sustainable concrete production

In Africa's emerging nations, the majority of the road networks are in appalling condition. In this instance, Nigeria is not an exception. With the Egba community as a case study, the study looks into the characteristics of accidents on the Benin-Auchi route caused by faulty roads. It considers the adverse effects of the poor road conditions and heavy traffic on the community,
the government, and the socioeconomic advantages for the whole nation. It also emphasizes the typical causes of road
failures on our roads. Poor building and design, poor highway maintenance, low-quality materials, shoddy craftsmanship, inadequate supervision of construction work, and the driving of heavy traffic that wasn't meant for the road were some of the causes. Three samples were taken from various locations along the Benin-Auchi road for soil testing in the structural laboratory to compare the soils' geotechnical properties and assess the strength and resistance of the subgrade material to traffic loads placed on the road. The California Bearing Ratio (CBR) test, Atterberg limits, compaction tests, specific gravity tests, and sieve analysis tests are all performed in the structural laboratory. The maximum dry unit weight (MDD) varied from 1.98g/cm3 to 2.02g/cm3, and the ideal moisture content (OMC) ranged from 11.8% to 12.8%, according to the compaction
experiment of the Atterberg limit test. A, B, and C were found to have average specific gravities of 2.54, 2.51, and 2.43, respectively, within the 2.41-2.54. For each of the three locations, the CBR varies between 8 and 11% for moist soil and 17 and 35% for unsaturated soil.
The Federal Ministry of Works (1997) judged that the CBR strength was sufficient for the subgrade component. One of the factors contributing to the rapid deterioration may be increased traffic and heavy-duty vehicle loads exceeding the design and carrying capacity of the road. Appropriate road design and reducing excessive traffic congestion are two ways to address this issue. Regular road maintenance, sufficient soil tests while building roads, the hiring of licensed engineering specialists, the use of appropriate construction materials, and the application of penalties for highway failures are also recommended.