Author: Mezie Ethelbert

Reading Time: < 1 minute Construction wastes are usually encountered in construction works. There are many things that bring about the wastage of materials in construction sites. These may include: i. Frequent design and client’s changes; ii. Rework due to worker’s mistakes; iii.  Poor contract documents; iv. Wrong and lack of storage of materials; v. Poor strategy for waste minimization; vi. Shortage and lack of skilled workers; vii. Poor site conditions; viii. Damage during transportation; ix. Theft and vandalism; x. Mistakes in quantity surveying and allowances. Wastes in construction industries affect the economy of a nation and have adverse environmental impacts. Efforts should be made…

Reading Time: 3 minutes Project duration entails the probable time it would take to complete a given project. Accurate assignment of project duration is very important because it affects the overall cost or expenditures involved in the project. Two types of expenditures are usually encountered in every project. These are capital expenditures and recurrent expenditures. Capital expenditures are expenditures made in the creation of fixed assets and on the acquisition of land, buildings, and intangible assets. Recurrent expenditures on the other hand are expenditures made on operations, payment of wages and salaries to unskilled and skilled labour force, purchases of goods and services, and…

Reading Time: 4 minutes Expansive soils and collapsible soils are among the commonest problem soils that pose a great challenge to construction professionals.  Expansive soils tend to expand excessively when in the presence of water and shrink excessively when dry. Most expansive soils are noted to possess the mineral montmorillonite. The collapsible behaviour of soils depends on: (1) The percentage of fines present (2) Initial water content (3) Initial dry density (4) The energy and process used in compaction Foundations on these soils are usually difficult and costly. I would dwell only on expansive soils because they seem to be more widespread in the…

Reading Time: 3 minutes One of the things young engineers learn on-site as part of necessary site experience is that when setting out a foundation for walls, the width of the foundation should be three (3) times the width of the block. The reason usually cited is to give masons enough space to work. Using a 225 mm thick block, the footing width should be (3 x 225) = 675 mm. Using a 150 mm thick block, the footing width should be (3 x 150) = 450 mm. Some site supervisors usually consider these spaces as waste. Some may use 600 mm width for…

Reading Time: 6 minutes Introduction: Compaction of soils is one of the most popular means of mechanical stabilization of soil. The primary aim of this process is to increase the bearing capacity of soil and reduce soil settlement. This can be made possible by the reduction of pore spaces in the soil through the expulsion of pore air, rearrangement of soil particles, densification of soil, and reduction of volume. Compaction is employed in the construction of buildings, roads, airfields/runways, wharves, earth dams, retaining walls, etc. Field compaction of soil can be achieved through the use of various mechanical equipment broadly classified into: Impact compactors…

Reading Time: 2 minutes Lateritic soils are rich in iron and aluminum and formed in wet and hot tropical areas. Nearly all lateritic soils are rusty red because of iron oxides. They develop by intensive and long-lasting weathering of the underlying parent rock. They cover about one-third of the earth’s continental land area with the majority of that in the land areas between the tropics of Cancer and Capricorn. It is a highly weathered material rich in secondary oxides of Iron, Aluminum, or both. It is void or nearly void of bases, and primary silicates, but may contain large amounts of quartz and kaolinite.…