A.O. Afolabi

Statistical exploration of dataset examining key indicators influencing housing and urban infrastructure investments in megacities

Lagos, by the UN standards, has attained the megacity status, with the attendant challenges of living up to that titanic position; regrettably it struggles with its present stock of housing and infrastructural facilities to match its new status. Based on a survey of construction professionals’ perception residing within the state, a questionnaire instrument was used to gather the dataset. The statistical exploration contains dataset on the state of housing and urban infrastructural deficit, key indicators spurring the investment by government to upturn the deficit and improvement mechanisms to tackle the infrastructural dearth. Descriptive statistics and inferential statistics were used to present the dataset. The dataset when analyzed can be useful for policy makers, local and international governments, world funding bodies, researchers and infrastructural investors.

Appraising the Barriers to Public-Private Partnership as a Tool for Sustainable Development of Infrastructures in a Developing Economy

The quest for sustainable development has been a subject discourse across the globe. Sustainable development has been deemed to be the pathway to all that is good and desirable in the society. Undoubtedly, social and economic infrastructure desirability in any economy is nsecond-to-none and its sustainability needs to be prioritised. The worsened state of infrastructures and wide gap in its supply in developing economy have warranted this study. The study identified the sustainable tool (PPP) through which infrastructural supply can be enhanced and sustained and it revealed through literature review the major barriers to the tool performance in delivering infrastructures in developing country. Among the major challenges identified from literatures include inadequate consultation of stakeholders for greater acceptance of PPP, conflict of interest among PPP stakeholders, negative behaviour of the people towards PPP, lack of confidence and mistrust in PPP by stakeholders, poor enabling environment for PPP, weak or poor regulatory frameworks, law and regulation changes and weak and poor enabling policies. The barriers identified are due to more to the public than the nprivate and the people. Therefore, the study recommends that beyond the need for stronger collaboration between the public and private sector, government should integrate the people in planning phase of the sustainable tool adoption for public infrastructures delivery. Also, government should build confidence and trust in the parties to PPP by creating enabling environment that can guarantee investors security.

Cost Management Practice of Construction Firms and Its Influencing Factors: Lessons from Southwestern Nigeria

The growing need at maintaining steady cost projection of construction projects has been an issue of serious concern to both the clients and the construction practitioners on sites. Also, cost deviation from initial cost plan and cost budget has been prevalent on construction sites and no concerted efforts have been made at addressing this phenomenon. This study therefore examined the factors that are considered to be affecting the cost management practice of construction firms in the southwestern Nigeria and also proffered possible ways of ameliorating the factors. Using survey approach, one hundred copies each of structured questionnaires were distributed to clients, contractors and consultants on construction sites in the study area while 72, 77 and 78 copies were duly filled and returned by the respondents respectively. Relative Importance Index (RII) technique was used for the analysis. The results revealed that poor leadership and in appropriate management, inefficient deployment of resources, excessive wastage of materials on sites, complex payment mechanisms, theft of materials on sites and variation during construction works are the prevailing factors affecting construction cost management practice in the study area. It was concluded that extra focus should be placed on the identified factors with a nview to reducing cost of construction, enhancing construction performance and building confidence within the construction industry in the study area.

A Framework for Enhancing Contractor-Subcontractor Relationships in Construction Projects in Nigeria

The delivery capability of main contractors depends largely on the quality of their nsubcontractors and the harmonious relationships that exist between them. Research work was ntherefore conducted to identify the mechanisms to facilitate the understanding between these npairs and also develop a model that puts emphasis on the factors. To achieve this aim, one nhundred questionnaires each were administered randomly to main contractors and labor-only nsubcontractors in the study area. Seventy-five and eighty-eight questionnaires were respectively nfilled and returned in this regard. The application of total weight value and rating index techniques shows that type of contract, scope of contract, payment terms, cooperative attitudes, third-party involvement are the main factors that influence this relationship and this was further validated by a model. The paper concludes that this methodology could culminate into a useful decision making tool for both main contractors and subcontractors during the development and nexecution stages of construction projects in the study area.

Pulverized Calcined Clay and Carbide Waste as Alternative Binder in Concrete and Mortar Applications for Sustainable Construction

Portland cement (PC) based concrete is the world’s most consumed man-made material and this consequently puts lots of demand on cement as a binder. The CO2 gas emission during cement clinker production has placed this important material into non-environmental-friendly classification with quest for greener alternatives being on the rise. A recent study showed combination of Pulverized Calcined Clay (PCC) and Calcium Carbide Waste (CCW) as possible alternative for total PC replacement with resulting appreciable mortar strength but delayed setting times and lower strength than PC mortars. This paper reports on effects of PCC-CCW as alternative binder on strength properties of mortars. The mortar mixes had superplasticizers added to reduce water/binder ratio while the CCW was treated to reduce impurities with a view to improving the strength development and a bid to mitigate the observed setbacks of earlier study. The pozzolanic activity indices of the PCC was determined via X-Ray Fluorescence(XRF) and strength determination (strength activity index). The PCC was combined with Purified CCW to determine the binder’s strengths at varying PCC:CCW replacements to determine the prescribed mix combination for optimum strength. Improved optimised mortar strength of 13.11MPa was achieved compared to 11.89MPa in the previous study