Which three tests must be conducted along with strength specimens?

The correct choice of tests to be conducted alongside strength specimens is the combination of Slump, Air Content, and Temperature.

Each of these tests plays a crucial role in assessing the quality and characteristics of concrete before it sets. The slump test measures the consistency or workability of fresh concrete. This is essential because workability affects the ease of placement, compaction, and finishing of the concrete, which in turn influences the strength and durability of the final product.

The air content test determines the amount of entrained air in the concrete, which is particularly important for freeze-thaw durability in colder climates. Adequate air content helps to prevent damage due to ice formation, ensuring that the concrete can withstand environmental stresses over time.

Finally, measuring the temperature of the concrete is critical as it can impact hydration rates and curing processes. The temperature can influence the setting time and strength development, which are key factors in achieving the desired performance of concrete.

Together, these tests provide a comprehensive assessment of the concrete's quality and workability, thereby contributing to the reliability of strength tests conducted later.