Structural Audit & Assessment

Why carry out a structural audit?

A structural audit is an in-depth evaluation of the condition of an existing structure — whether a building, a bridge, a tank, or any other concrete construction. The objective is to determine the residual load-bearing capacity of the structure, identify any pathologies, and formulate recommendations for its rehabilitation, strengthening, or, in extreme cases, demolition.

There are many situations that call for a structural audit: natural ageing of the structure, visible damage (cracks, delamination, apparent corrosion), a planned change of use (converting an industrial building into housing, for example), an incident (fire, earthquake, impact), a dispute between owner and contractor, or simply a preventive check as part of an asset maintenance policy.

The BEPCO methodology

Our approach follows a rigorous four-phase protocol. Phase 1 (visual inspection) consists of a comprehensive survey of the apparent condition of the structure: cracks (orientation, width, depth), corrosion traces, deformations, damp stains, and facing deterioration. Each anomaly is located, measured, photographed, and classified by severity.

Phase 2 (further investigations) employs non-destructive testing (NDT) and targeted destructive tests: Schmidt hammer (surface concrete strength), ultrasound (internal homogeneity), ground-penetrating radar (location of reinforcement and cables), coring (actual mechanical strength), carbonation (neutralization front depth), and chloride content (corrosion risk). For post-tensioned structures, specialized techniques allow the condition of the prestressing cables to be assessed without exposing them.

Phase 3 (analysis and calculation) compares the inspection data against current code requirements. Our engineers recalculate the residual load-bearing capacity of the structure, taking into account the actual condition of the materials and the deterioration observed. This analysis determines whether the structure can continue to carry its current loads, accept new loads, or whether strengthening is required.

Phase 4 (report and recommendations) synthesizes all findings in a detailed report accompanied by drawings, photographs, and prioritized recommendations: urgent interventions, short-term scheduled works, and monitoring to be implemented. For structures requiring strengthening, we propose costed technical solutions (external prestressing, carbon fibre bonding, resin injection, etc.).

Specialist expertise in post-tensioned structures

Diagnosing post-tensioned structures requires specialist expertise that few engineering consultancies possess in West Africa. BEPCO has this rare capability: our engineers have intimate knowledge of the behaviour of prestressing cables, the specific degradation modes (stress corrosion, relaxation, grouting defects), and the appropriate remediation methods.

For post-tensioned buildings showing signs of distress, we carry out specific investigations: opening inspection windows on the cables, measuring residual force in the strands, checking the quality of duct grouting, and analysing the condition of the corrosion protection. These diagnostics distinguish minor pathologies from critical situations requiring urgent intervention.

Typical applications

Our audit assignments cover ageing buildings over 20 years old, structures damaged by an incident, public structures requiring compliance certification, buildings undergoing change of use, and forensic assessments in the context of construction disputes. BEPCO works on all types of structures — reinforced concrete, prestressed concrete, and composite — across West Africa.