Which concrete deck type is cast and cured offsite and reinforced with mild steel?

The correct choice refers to precast conventionally reinforced concrete deck panels. This type of deck is created in a controlled offsite environment where it can be properly cured and reinforced effectively with mild steel before being transported to the site for installation.

This method allows for better quality control over the concrete mix, placement, and curing conditions, which can enhance the performance and longevity of the deck. The use of mild steel as reinforcement is significant because it offers adequate tensile strength for typical bridge applications while providing an economical and manageable solution compared to other forms of reinforcement.

In contrast, the other types of decks listed may not meet the same specific criteria. For instance, PS deck panels with CIP (cast-in-place) topping involve a combination of precast elements with additional concrete poured on site, thus not being fully precast. Precast prestressed concrete typically involves high-strength concrete and prestressing strands, which are different from the conventional reinforcement specified in the question. Lastly, standard concrete slabs often refer to traditional cast-in-place concrete rather than precast methods, which rules them out as well.

Thus, the focus on precasting with conventional reinforcement and mild steel specifically highlights the characteristics of the selected answer.