The question of how to handle a contractor’s failure to meet slump test requirements is a common dilemma for engineers. Two contrasting approaches exist, each with its own merits and drawbacks.
The first, more assertive approach, is to strictly adhere to the contractual terms. Under General Conditions of Contract (GCC) Clause 54(2)(c), the engineer has the authority to suspend work if the contractor fails to meet specifications. This empowers the engineer to enforce quality standards, and per GCC Clause 54(2)(a)-(d), the contractor would not be entitled to claim additional costs for rectifying the issue. While some may argue that slump tests are less critical than other tests like compression tests, this approach emphasizes the importance of adhering to all contractual requirements.
The second, more lenient approach, involves allowing the contractor to proceed with concreting and subsequently requiring proof that the finished work meets other contractual criteria, such as the compression test. This is based on the premise that workability primarily affects the design concrete’s compressive strength. Should the compression test fail, the contractor would be responsible for demolition and reconstruction. This approach is considered more passive and is generally discouraged for several reasons.
Firstly, workability isn’t solely about strength; it significantly impacts the concrete’s durability. Even if a compression test passes, a failed slump test could indicate potential long-term issues with the structure’s resilience.
Secondly, if the compression test fails, the contractor incurs significant time and cost overruns for removal and reconstruction, considerably delaying the project. Given this likelihood, exercising the engineer’s power to halt work at the outset can save valuable resources and prevent future complications.
In conclusion, while both approaches have their arguments, the first approach, which prioritizes strict adherence to contractual requirements and proactive intervention, is often recommended. It ensures that quality standards are maintained from the start, minimizing the risk of long-term durability issues and costly rework.