In-Situ Evaluation of Two Concrete Slab Systems. II: Evaluation Criteria and Outcomes

The primary objective of in-situ load testing is to evaluate the safety and serviceability of an existing structural system with respect to a particular load condition and effect. In light of technological advances in construction methods, analytical tools and monitoring instrumentation, new different evaluation criteria are being proposed in addition to different in-situ load test methods. Some criteria may be more appropriate than others based on the expected damage and failure mechanisms of the structure being considered. The companion paper describes the rationale and application of both a consolidated and an alternative approach to the determination of load level, loading procedure and instrumentation requirements for two case studies. This paper discusses in detail the evaluation criteria and outcomes of these two field projects consisting of a posttensioned concrete slab with structural deficiencies due to tendon and mild reinforcement misplacement and a floor bay of a two-way reinforced concrete slab showing cracking at the positive and negative moment regions. After discussing the relative merits of the evaluation methodologies and the significance of their respective acceptance thresholds, concepts for the development of a new global criterion are discussed.