Precast Beam Fails Strength Test

The Supervisor has power to instruct searches and tests, including tests not described in the Scope. The compensation event question depends on what the test finds. If the Supervisor instructs a test that is not in the Scope and no defect is found, the instruction is normally a compensation event because the Contractor has been put to cost and delay for the Supervisor's additional requirement. If a defect is found, the Contractor bears the cost of the test and of correcting the defect, and there is no compensation event for the testing itself. On the stated results, the 28-day cube strength is 49.5 MPa against a specified 50 MPa, so a defect has been found. That means the PM's general position is correct for the extra cubes and ultrasonic test. The 7-day result of 28 MPa is not by itself proof of a defect, because the Scope specifies 28-day strength; early-age strength is not the acceptance criterion unless the Scope says so. The Contractor's laboratory-error argument could change the outcome, but it must be proved with calibration records, retained samples and an independent retest. If the retest shows the concrete was compliant, the 'defect' disappears and the extra test may become a compensation event.

The PM should separate the delay caused by the Supervisor's instruction from the delay caused by correcting the defect. If B7 is genuinely defective, the Contractor bears the cost of breaking out and replacing it, and the delay to Completion caused by that correction is the Contractor's risk. The PM should not grant an extension merely because B7 was on the critical path; the criticality explains the effect, not the entitlement. If, however, the Supervisor's instruction to hold B7 delayed other work that was not defective, or if the additional test was not in the Scope and no defect is ultimately found, the PM should assess a compensation event for that part. The PM should also check whether the Contractor mitigated: could another beam have been erected first, or could B7 have been recast in parallel? The 10-day claim should be tested against the Accepted Programme and the actual sequence. The PM should record the test results, the instruction dates and the replacement cost separately, so that any entitlement is not confused with the Contractor's quality risk. If the Contractor disputes the laboratory result, the PM should not simply reject the claim; it should require a proper retest and keep the assessment open on the disputed part.

The Contractor should preserve the chain of custody for the cubes, the laboratory's calibration certificates, the raw test sheets and the identity of the person who witnessed sampling. It should check whether the cubes were cured and transported in accordance with the Scope and the relevant standard, and whether the laboratory used the correct loading rate. It should request an independent laboratory retest from the same batch or from cores taken from B7, with the Supervisor invited to witness. It should also check the batch plant records, cement content, water/cement ratio and temperature records. If the original cube result is unreliable, the Contractor should notify the PM promptly that it disputes the defect finding and explain why, rather than waiting until the replacement cost is incurred. The Contractor should keep the defective beam available for inspection and should not destroy evidence. These records matter because the compensation event turns on whether a defect exists: if the concrete is compliant, the Supervisor's extra test and hold instruction may be a compensation event; if it is not, the Contractor bears the cost.