ABSTRACT
The primary objective of this work is to form the foundation of a Road
Management Maintenance System (RMMS) that Road Maintenance Agencies like
FERMA can immediately implement to make better decisions pertaining to
rehabilitation options. Further, this is to allow for appropriate decisions about the best
type of maintenance and rehabilitation interventions to apply to the poor state of
5
arterial roads taking into consideration various factors, least of which are the type and
extent of distress present and the benefit cost analysis. The outcome of this work will
assist sub-Saharan Africa, but principally Nigeria, in their goal of fostering economic
growth and creating a more sustainable transportation network. Recommendations on
how to simplify input factors necessary for Nigeria to initiate a database and prepare
more regionally specific designs have been made, including traffic, climatic and subgrade
classifications. Economic analysis included present worth of costs (PWC) that
were derived from condition rating curves specific to intervention pavement life and
performance. Based on preliminary findings, subject to field validation, a chip-seal
specific rehabilitation strategy for low volume federal roads is more cost effective
over the 20-year analysis period and 1-lift Asphalt Concrete (AC) is more cost
effective over the 20-year analysis period for high volume federal roads.
Recommendations for further research have been made.
TABLE OF CONTENTS
Title Page:- – – – – – – – – – – i
Certification: – – – – – – – – – – ii
Approval Page: – – – — – – – – – iii
Dedication: – – – – – – – — – iv
Abstract: – – – – – – – – – – v
Definitions: – – – – – – – – – – vi
List of figures: – – – – – – – – – vii
List of tables: – – – – – – – – – – ix
Table of contents: – – – – – – – – – xi
CHAPTER 1: INTRODUCTION: – – – – – – 1
1.1 Introduction : – – – – – – – 1
1.2 Objectives: – – – – – – – – – 5
1.3 Research Methodology: – – – – – – – 6
CHAPTER TWO: LITERATURE REVIEW: – – – – – 7
2.1 African Transport:- – – – – – – – 7
2.1.1 A Brief History: – – – – – – – 12
12
2.1.2 Specific Transport Issues in Africa: – – – – 14
2.2 Nigeria: – – – – – – – – – 16
2.3 Nigerian Roads Sector: – – – – – – – 19
2.3.1 Nigerian Road Distresses: – – – – – 24
2.3.2 FERMA: – – – – – – – – 27
2.4 Transparency: – – – – – – – – 30
2.5 Pavement Design Theory: – – – – – – 31
2.5.1 Nigerian Pavement Design: – – – – – 33
2.5.2 HDM-III and HDM-IV: – – – – – – 34
2.6 Pavement Design Inputs: – – – – – – 36
2.6.1 Subgrade Type: – – – – – – – 36
2.6.2 Asphalt Cement: – – – – – – – 38
2.6.3 Traffic Data: – – – – – – – – 39
2.7 Pavement Management: – – – – – – 40
2.8 Summary: – – – – – – – – – 42
CHAPTER 3: DATA SOURCES AND METHODOLOGY: – – – – 44
3.1 Data Sources: – – – – – – – – 44
3.2 Subgrades: – – – – – – – – – 47
3.3 Traffic: – – – – — – – – – 49
3.4 Environment: – – – – – – – – – 53
3.5 Conditions: – – – – – – – – – 54
3.6 Typical Pavement Designs: – – – – – – – 59
3.7 Nigerian Maintenance and Rehabilitation Costs: – – – – 64
13
3.8 Pavement Service Life: – – – – – – – 69
3.9 Summary: – – – – – – – – – 70
CHAPTER 4: FLOW DIAGRAMS, DESIGN TREES AND
LIFE CYCLE COSTING: – – – – – – – – 73
4.1 RONET: – – – – – – – – – 73
4.1.1 RONET Analysis: – – – – – – – 75
4.1.2 RONET Results: – – – – – – – 76
4.2 Optimum Maintenance Strategy: – – – – – 78
4.3 Cost Model and Life Cycle Cost Analysis: – – – – 83
4.3.1 Performance Curves: – – – – – – 86
4.3.2 PWC Calculations: – – – – – – – 90
4.4 Discussion of Results: – – – – – – –
100
4.4.1 Low Traffic Volume Road: – – – – –
101
4.4.2 High Traffic Volume Roads: – – – – –
103
4.5 Summary: – – – – – – – – –
106
CHAPTER 5: CONCLUSIONS AND RECOMMENDATIONS: – –
108
5.1 Conclusions: – – – – – – – – –
108
14
5.2 Recommendations: – – – – – – – –
111
5.3 Suggestions for Further/Future Research:- – – – –
113
REFERENCES: – – – – – – – – –
CHAPTER ONE
INTRODUCTION
As the curtains drew on the last decade, there was a paradigm shift
by International donor agencies involved in Sub Saharan Africa away
from funding of infrastructure projects toward those relating to health
and education (social projects). Between 1980 – 1984 the share of total
donor funding to infrastructure projects was close to 25%, whereas it
had decreased to less than 10% by the 21st century (AFDB working
group, 2006). Much of this has been due to the higher prevalence and
understanding of the impact of HIV/AIDS scourge, not to mention
malaria, on the economic development of the developing world.
However, this shift away from infrastructure projects has come at a cost,
as there has been an under appreciation of social and economical
impacts, that transportation infrastructure, irrespective of functional
15
classification can have on the economic growth of a country. It would
appear that the line has only just been drawn to connect the dots
between the appreciation for roads and basic access being directly
related to health and education. Clearly, there is a balance between
funding of road infrastructure and funding of health and social projects,
given the interconnection of these sectors.
With the exception of few Countries, Sub Saharan Africa is unique
in that roads that have been created are inefficient and insufficient to
spawn and sustain growth. Also these roads require not only substantial
maintaining and rehabilitation, but also substantial new road
construction. Many nations that have not had the opportunity to fully
develop road infrastructure systems are now discovering that the
standards and methods from neighbouring or western countries which
they have been relying upon are not altogether applicable to their
circumstances (Arumala and Akpokodje, 1987). This inapplicability stems
from differing climatic circumstances (heavy rain events) complex and
deep stratography of soils, highly plastic and highly decomposed
materials, and increasing transport distances of materials to the
construction site. There is also a difference in terms of need that is not
addressed in the standard manuals and application guidelines of other
countries.
Road infrastructure is critical to economic development, both low
volume/rural roads and major arterials. There is a direct relationship
between a country’s economic prosperity and kilometres of paved road.
(Owen, 1964; Queiroz and Gantam, 1992). There are many papers and
reports on the merits of the rural road sector, World Bank’s sub Saharan
African Transport Policy being a major source, (World Bank, 1996). It is
16
also a fact that all-season passability and lack of basic access to rural
communities impedes economic growth. There is also need to further
develop, effectively manage maintenance practices on and rehabilitate
the major trunk system within these countries. These will enable the
countries to sustain and accommodate economic growth brought about
by improved rural mobility.
In the case of Nigeria, as the thesis demands, the major arterial
network is in such disrepair and dilapidation that sustained immediate
action is required.
The period between 1970 and 1982 played the most part in
Nigerian road development efforts. Most of the roads were constructed
with a life span of between ten and fifteen years. While there was
nothing wrong with this design life span, it was the neglect of a followup
maintenance regime that did worst damage to the road network. So,
by 1982, therefore, the roads built in 1970 had completed their
functional lifespan with their optimal performance life cycle between
1992 and 1995.
In other words, most of the roads constructed during the oil boom
years had collapsed by 1995. (FERMA 2008).
Looking back with hindsight now, the travesty that occurred was
instead of developing a programme of back rolling the terrible situation
in which we found ourselves we embarked on an unending journey of
rehabilitation of road network. In a country that is so rich in potential,
pavement infrastructure is critical. The enactment of FERMA ACT on
30th November, 2002 gave Nigeria, a singular platform for structured
and institutional mechanisms to address road maintenance.
17
“Transport is the lifeline of the economy and social interactions. An
inefficient transport system implies stagnation in all sectors” (Olusegun
Obasanjo, 1999). The formation of Federal roads Maintenance Agency
(FERMA), the publication of its strategy for roads sector maintenance
management (FERMA, 2003) and most recently “Preventive Road
maintenance initiative, (FERMA 2012) may be the injection needed to
realise this.
After decades of Civil strife and repression Nigeria has finally
embarked upon what appears to be a more democratic chapter in its
history. Unfortunately, the years of negligent spending and misdirected
national policy have left a national transportation infrastructure system
in need of desperate rehabilitation and modernisation, especially if the
millennium development goals are to be realised, and the 20-2020 plan
of becoming the 20th largest economy in the world by 2020 is to be
realised (FERMA 2008). Much of the road network requires some form or
other of maintenance, rehabilitation and reconstruction (MR&R).
However, this must be done with historical data and funding. What are
abundant is desire and seeming commitment to improvement.
The intent of this work is to assist sub-saharan African Countries,
principally Nigeria through FERMA, streamline its MR&R interventions. It
is particularly poignant given that African Development Bank’s country
strategy Paper (AFAS, 2005) identifies one of the major transportation
issues as the absence of a maintenance plan and the primary objective
of Nigeria’s Medium Term Road Maintenance Management Strategy
(MTRSMMS) or to apply preventive measures that will help to stabilize
the structural strength of Road pavement. To accomplish these a
generic framework that includes a series of decision tables and flow
18
charts will be developed based on the functional class of the road, traffic
volumes and loads, distress type and event, and the existing pavement
layer design. It is envisaged that engineers at the Federal, Zonal and
State levels with be able to utilize this proposed framework to determine
one of a suite of focussed and appropriate MR&R alternatives that can
be used to better assess, based on available budget and ability to carry
our maintenance, which intervention is most appropriate.
In essence a tool kit by which engineer can make appropriate
decisions would be ideal. Further, with respect to those roads that
require major rehabilitation or reconstruction, mix design guidelines
should be provided to ensure that layers that are reconstructed are
completed to meet the climate, load and future traffic volume.
1.2 OBJECTIVES
The objective of this thesis is to provide assistance to sub-saharan
African nations in making appropriate decision about the best type of
MR&R intervention to apply to the poor state of arterial roads. Such
decisions will be contextual and would answer various questions, least of
which are the type and extent of distress present and the benefit cost
Analysis.
A secondary objective is to provide FERMA with analysis of its mix
designs and re-evaluate them to allow for more appropriate pavements
to be constructed. It is recognised that these objectives need to be
balanced against regional issues that include;
Ø Soils – condition and variability
19
Ø Materials – quality and availability
Ø Budget constraints
Ø Maintenance capacity
Ø Traffic type and volume
Ø Experience and availability of partitions
1.3 RESEARCH METHODOLOGY
The methodology for this research includes an in-depth review of
current road building practices in Africa with a special focus on Nigeria.
Determination and expansion on data sources and how they can be
better formatted for use by pavement Engineers, and life cycle cost
analysis will be performed on various rehabilitation options. This will
provide FERMA with logical information on when to implement
rehabilitation interventions.
IF YOU CAN'T FIND YOUR TOPIC, CLICK HERE TO HIRE A WRITER»
