Final answer:
High early strength concrete is referred to as Type III concrete. It is designed to reach strength quickly for faster project turnover and is beneficial in cold weather where strength gain in normal concrete is slower.
Step-by-step explanation:
The type of concrete that is known as high early strength concrete is Type III. This special type of concrete is designed to gain strength much faster than Types I or II. The early high strength is achieved by altering the composition of the concrete, which includes increasing the cement content and decreasing the water-cement ratio, resulting in a faster hydration process.
This kind of concrete benefits rapid construction projects where time is essential, allowing for a faster turnaround on formwork and load application. Additionally, high early strength concrete is valuable in cold weather conditions, where normal strength gain could be significantly slowed down.