NEEDS: DOING MORE WITH LESS IN MOZAMBIQUE · gravel, Otta Seal surfacing provided • Short-term Performance • Stone loss on Single Otta Seals, however the application of fine river

SARF/IRF 2014 | 2-4 September, South Africa

ADDRESSING AFRICA’S MAINTENANCE NEEDS: DOING MORE WITH LESS IN

MOZAMBIQUE

By

Andrew Otto, BSc(Hons), MSc, CEng, MCIHT Senior Research Engineer, Transport Research Laboratory, UK


The Maintenance Burden

Maintenance Strategies

Mozambique Approach

Challenges Faced

Way Forward

1

2

3

4

5

Discussion Topics


1. Introduction: – maintenance backlog


1. Introduction: - The maintenance burden (Main Network)


1. Introduction: - The maintenance burden (Rural Network)


1. Introduction: - the importance of all roads

Agricultural produce and Rural communities

Trunk Road

Link Road

Collector/ Rural Road


Enhancing the Value of each $ spent

for road maintenance

2. Maintenance Strategies

Improving bottlenecks on the network

Efficient utilisation of resources

Techniques that increase the life of the road

Research and development


3. Mozambique Approach • Mozambique launched Rural Roads Improvement Programme (RRIP) 2007 • Department for International Development (DFID) launched African

Community Access Programme (AFCAP) 2008

Mozambique RRIP • Critical sections of

road maintained to Satisfactory level

DFID: AFCAP • Promote use of

proven low-cost solutions that maximise use of local resources

• Share research and innovation that has been tried and tested in other countries

• Access to areas cut off during the wet season

• Access to rural communities to reach to basic services and social and economic opportunities


3. Mozambique Approach: - Projects

Research and innovative solutions tried out on bottlenecks so as to apply successes on wider scale



Marracuene - Macaneta



Marracuene – Macaneta • Challenge:

• Material available in abundance was only fine non-plastic sand

• Solutions • For unpaved road, blended with clay to meet certain

engineering parameters • For paved roads, used in Emulsion Stabilised Sand Base and

Slurry Seal

• Short-term Performance • Very good no defects; only slight abrasion of slurry 0.5m2

• Cost: US$342,000/km



Cumbana - Chacane



Cumbana – Chacane • Challenge:

• Loose sand in dry season, boggy in wet season and impassable; moderate plastic calcrete gravels

• Solutions • Plastic calcrete blended with loose sand to meet certain

engineering parameters and used as base course or gravel wearing course

• Plastic calcrete screened carefully and used as an Otta Seal surfacing



Cumbana – Chacane • Short-term Performance

• For sealed sections: Very good; minor stone loss and potholing. Roughness remained constant 4.3IRI

• For gravel wearing : low gravel loss < 20mm/year. Roughness increases rapidly from 7 to 21IRI in two years, but light grading and compaction restores it to 7IRI

• Cost: US$140,000/km



Inhacufera - Machaze



Inhacufera – Machaze • Challenge:

• Very large and coarse gravels, very low vehicle speeds and impassable to cyclists

• Solutions • Large stones removed by dozer, replaced by old river bed

gravel, Otta Seal surfacing provided

• Short-term Performance • Stone loss on Single Otta Seals, however the application of

fine river sand as a “grouting” layer on Otta Seal – 5years no defects

• Cost: US$135,000/km



Beira - Savanne



Beira – Savanne • Challenge:

• Only beach-type fine sands available nearby – loose and unstable, easily eroded

• Solutions • Cement Stabilisation and Emulsion Stabilisation for base course;

followed by Sand Seal. In-situ mixing to increase productivity rate

• Short-term Performance • “Granulation” unintended occurred as a construction defect but

became advantage. Unexpected heavy trucks abraded Sand Seal but bases remained intact

• Cost: US$124,000/km



Zero - Mopeia



Zero – Mopeia • Challenge:

• Flooding on low-lying sections; slippery sections

• Solutions • Raising road level by use of “free-draining” quartzitic gravels and

then surfacing with Otta Seal

• Short-term Performance • Road passable throughout the year, and very good riding

surface 2.4IRI. Minor potholing - corrected

• Cost: US$123,000/km


4. Challenges Faced

• Small and medium scale contractors not equipped and not trained or experienced in bituminous works • No bids received • Unacceptable quality of work

• Interventions perceived as small and not given priority by big contractors. • Overpricing (US$140K/km as compared to

US$100K/km) • Delayed construction

• Equipment such as mobile jaw crushers would have made significant difference but not available


5. Way Forward

• Training of small and medium scale contractors • Guaranteeing work to small and medium scale

contractors so that they build capacity • Government equipment pools should be considered

since small contractors do not have capacity to purchase

• Transfer of research results to wider scale maintenance of roads.


Thank You

Andrew Otto; TRL;

[email protected]


Questions and Discussions

NEEDS: DOING MORE WITH LESS IN MOZAMBIQUE · gravel, Otta Seal surfacing provided • Short-term Performance • Stone loss on Single Otta Seals, however the application of fine river

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