The Transport & Pavement Laboratory specialises in the materials and design of roads — asphalt and bituminous mixtures, aggregates and pavement structures. Roads are Liberia’s largest infrastructure investment category, and the durability of every kilometre depends on the quality of its aggregates, the performance of its bitumen and the soundness of its pavement design. This laboratory provides the testing, mix design and quality control that determine whether a road survives the traffic and intense rainfall of West Africa or fails within a few seasons.
Standards: ASTM · AASHTO · BS EN · ISO | Quality system: ISO/IEC 17025-aligned procedures with full sample traceability
What the laboratory does
The laboratory covers the full road-materials chain, for new construction, rehabilitation and periodic maintenance:
- Aggregates — characterising strength, shape and durability for base courses and surfacing.
- Asphalt mixtures — designing and verifying asphalt mixes, and checking produced asphalt against the design.
- Bitumen and binders — grading and verifying bituminous binders for the local climate.
- Pavement design and QA/QC — supporting structural design and as-built quality control, working closely with our Geotechnical Laboratory on subgrade and pavement-layer interaction.
Tests and services
Aggregates & Bitumen
| Test / service | Standard(s) | Engineering purpose |
|---|---|---|
| Aggregate crushing & impact value (ACV / AIV) | BS 812 / ASTM | Assess aggregate strength and resistance to traffic loading |
| Los Angeles abrasion | ASTM C131 / AASHTO T96 | Measure aggregate resistance to wear and degradation |
| Aggregate grading, shape & soundness | ASTM C136 / C88 | Ensure correct gradation and durability for asphalt and base layers |
| Bitumen penetration & softening point | ASTM D5 / D36 | Grade and verify bituminous binder consistency and temperature behaviour |
| Bitumen ductility & viscosity | ASTM D113 / D2170 | Confirm binder flexibility and workability for the local climate |
Asphalt Mix & Pavement Design
| Test / service | Standard(s) | Engineering purpose |
|---|---|---|
| Marshall mix design & stability / flow | ASTM D6927 / AASHTO | Design optimum asphalt mixes and verify stability under load |
| Bitumen content & extraction | ASTM D2172 | Verify binder content of produced asphalt against the design |
| Asphalt core density & compaction | ASTM D2726 | Confirm in-place compaction quality of laid asphalt |
| Pavement layer design (CBR / AASHTO method) | AASHTO / TRL | Determine pavement thickness for design traffic and subgrade |
| Field QA/QC of base & surfacing | ASTM / AASHTO | Control material and workmanship quality during road construction |
Engineering problems we solve
Liberia’s roads face heavy axle loads, abundant but variable local aggregates and some of the highest rainfall in West Africa — a combination that punishes any weakness in materials or design. This laboratory addresses the core failure modes:
- Weak or wrongly graded aggregates: testing aggregate strength, abrasion and grading so that only durable materials enter base courses and asphalt — preventing the rutting and ravelling that destroy road surfaces.
- Poorly performing asphalt: Marshall mix design and binder testing that produce asphalt able to resist deformation in the heat and cracking in the wet, extending pavement life.
- Inadequate pavement design: linking subgrade CBR to AASHTO/TRL pavement design so road thickness matches real traffic and ground conditions, avoiding both early failure and wasteful over-build.
- Construction quality slippage: field QA/QC of compaction and binder content that holds contractors to specification and protects the public investment in every kilometre built.
Why it matters for Liberia and West Africa
Roads dominate Liberia’s infrastructure agenda. Over US$925 million is committed under the Ministry of Public Works Five-Year Strategic Plan (2025–2029), with a target to bring hundreds of additional kilometres to paved standard while only about 8.7% of the network is paved today. Donor-financed road programmes — including the World Bank’s LIBRAMP and AfDB Mano River Union transport corridors — require ISO/IEC 17025-grade testing throughout delivery. This laboratory provides that capability onshore, ending the delay and expense of overseas testing, safeguarding the durability of the national road network and serving the cross-border corridors that link the Mano River Union and wider West African trade routes.
Building or rehabilitating a road?
Tell us about your project and the tests you need. Our team will come back to you with a scope of work, schedule and quotation.
Our other laboratories: Environmental, GIS & Urban Resilience Laboratory · Geotechnical & Soil Investigation Laboratory · Building Materials Laboratory