Production of Portland cement starts with two basic materials; a Calcareous material and an Argillaceous material. The calcareous material is a calcium oxide, such as limestone, chalk, or oyster shells, the Argillaceous material is combination of alumina and silica obtainable from clay, shale, and blast furnace. the materials are passed through a grinding mill, using wet or dry process to the kiln. In the kiln, the raw materials are melted at temperature of 1400 oC to 1650 oC, changing the raw materials into Cement clinker which is then cooled and stored. The final process involved grinding the clinker into a fine powder, adding gypsum to regulate the setting time if the cement in the concrete.
The final product can be transported in stored bulk or sacks.
Surface water ( i.e., rain water) that falls on the ground surface such as; open field, paved areas or road surface, roof tops etc are channeled to a main drain naturally or through a constructed channel which is referred to as drainage. Procedure for construction of a common drainage (trench) (1m x 1m U drainage) (reinforced). includes; I. Marking Of Alignment: The surveyor marked out the alignment for the trench to be dug. II. Digging/Excavation: The surveyor marked out the dept of the trench to be excavated with a mechanical excavating machine. For a 1m x 1m drainage, the mathematical process of obtaining the required dept is to sum together the dept of the required drain + base + blinding. For dept: A drain of dept1000 mm, base of 150 mm and blinding of 50 mm. Hence 1000mm + 150mm + 50mm = 1200mm (1.2 m) So an excavation of 1200mm (1.2m) is required...
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