ACI Certification Practice Exam

When determining when a structure can be put in service, which curing method is appropriate for strength specimens?

1. Field cure

2. Standard lab cure

3. Conditioned cure

4. Cold weather cure

The correct answer is: Field cure

The correct answer highlights the use of field curing when considering the in-service date for a structure's strength specimens. Field curing involves maintaining the moisture and temperature conditions of the concrete in its actual environment, which reflects the real conditions that the structure will experience once it is in service. This method provides a more accurate representation of the concrete's performance in its intended application, thus leading to reliable assessments of when the structure can safely be put into use. In contrast, standard lab curing often involves more controlled conditions that may not align with the actual environmental factors present on the construction site. While this method is valuable for understanding potential concrete strength in ideal situations, it may not accurately predict how the concrete will behave in situ. Conditioned curing typically refers to controlled environments that may not represent field conditions. Similarly, cold weather curing is a specific approach meant to tackle low-temperature scenarios, focusing primarily on preventing freezing rather than accurately assessing strength under normal conditions. As a result, these methods might not provide the necessary insights into when a structure can reliably be used, making field curing the appropriate choice in this context.