The Oyo State Chapter of the Nigerian Institution of Highway and Transportation Engineers (NIHTE), led by their chairperson, Engineer Esther Oluwakemi Oladeji, visited the Oyo-Ogbomoso Federal road construction project last Thursday.
Engineer Olusola Olalerin, the Chief Engineer of the project was there to receive the delegation at km 43 and there, explained that the project is a link section of the 52km-long Ibadan-Ilorin road stretching from where they were to km 95.
The visiting delegation was also introduced to Engineer ‘Niyi Olowoyeye; the representative of the contractors in charge of the project, Reynolds Construction Company (RCC).
Engineer Olowoyeye, along with the company safety officer; Mr John Jimoh together took members of the visiting delegation to the strategic locations on the project to show them how much progress had been made.
According to a statement made available to the press: “All the hydraulic structures mainly Pipe and Box culverts are 95% completed. Major parts of the cutting areas on earthworks are underwater. Consequently, the volume of unsuitable materials on earthworks was enormous. These have to be removed and replaced by suitable lateritic materials hauled from a borrow pit.”
“Coupled with this exercise is the laying of 150mm plastic pipes, unevenly perforated, surrounded by granite filters and rapped with geotextile materials as weep pipes to drain off underground water that may otherwise constitute a serious failure to the road pavement. This idea is to ensure the drainpipes are constantly receiving clean water and permanently impervious to silt.”
“The pavement width on subgrade formation is 20cm lateritic sub-base, 20cm stone base, twin binder of 6cm each and 4cm wearing course. The central median is closed in urban area and opened on rural alignment. The open median width is 6.6m each from the inner side of pavement on either road direction.”
“There are five major structures consisting of 4 flyovers on water location and 1 bridge on water locations over Oba River. The structures on dry locations are essentially to control traffic volume as grade-separated interchanges with a minimum of 5.4m headroom. One of these flyovers is designed with 4 clover leaves at each of its entry and exit locations.”
“These concrete structures are of circular piers with abutments loaded with 0.5m x 1.6m depth prestressed post-tension concrete beams. The contractor was magnanimous to oblige us with a company crane to lift members to the top deck of one of the flyovers to view reinforcement arrangements on a deck ready for in situ concrete casts.”
“The particular flyover has a length of 50 meters in 2 spans of 25m. The beams were already loaded with 11cm thick reinforced precast concrete slabs on which the reinforcements were arranged while 11cm concrete is to be cast in situ. This brings the total deck thickness to 22cm.”
“Essentially, the importance of quality control on road project cannot be overemphasized. Members visited the contractor’s material laboratory where all materials are regularly tested, ascertained and controlled. The laboratory contains Asphalt Compactor Factor Machine, Extractor to determine bitumen content and Oven Dryer. Others are Bitumen Stability Tester, Vacuum Machine, Bitumen Penetration Machine, Concrete Crushing Machine and Hot Plate.”
“The project as at the time of visit is 50% completed and with scheduled funding, it is expected to be fully completed in June 2023.”