Design and Construction of NBRRI Pozzolana Cement Pilot Plant Access Road

Abstract

Nigerian Building and Road Research Institute (NBRRI), in trying to solve the menace of housing deficit ravaging the country, established a Pozzolana Cement Pilot Plant at its Laboratory Complex, Ota, Ogun State. When the plant is fully in operation, it would bring respite/succour to the low-medium class citizenry as the cost of pozzolana cement will be affordable to build a light weight/bungalow structures. This gave rise to the birth of this access road, as it became imperative to design and construct an access road to the Pozzolana Cement Plant using a ‘’stage construction’’ approach. The ‘’stage construction’’ approach/method was adopted to construct a 300m long by 7m wide roadway, where the subgrade (poorly graded sand and clay) was stabilized by proportioning technique of mechanical stabilization with well graded lateritic sub-base and base layers of 100mm thickness each. With the development of the bitumen sprayer by the Engineering Material Research Department, the pozzolana access road was used to test the effectiveness and efficiency of the innovation. The combined lateritic road surfacing of 200mm thickness was overlaid with 80mm thick stone-dust (8mm; ø) interface which was smeared with a thin layer of bitumen MC1. The bitumen surface was then covered with a 100mm thick granite (10mm; ø) layer. All the layers were well compacted using a 730kg pedestrian roller to an average of 20 passes on each layer.  However, when the plant is fully operational, the road would facilitate the movement of goods/ NBRRI Pozzolana cements in and out of the Institute (NBRRI) as this would contribute greatly to the economy of the nation after being adopted/accepted by the larger masses as an affordable alternative to conventional Ordinary Portland Cement (OPC) to erect their light weight concrete structures.

Keywords: Pozzolana cement, Subgrade, Subbase, Base, Pedestrian roller, Light weight, Stabilization, Ordinary Portland Cement (OPC), Bitumen MC1.