When is a concrete truck considered too old to pour? Do you have to send it back? The answer is yes and no…. Yes – according to astm c-94, concrete discharge must be complete within 90 minutes of mixing water with cement and aggregates.
How Long Is Concrete Workable?
Concrete is one of the most commonly used materials in construction and many other industries due to its strength and durability.
But just how long is concrete workable? The answer depends on a few factors, including the ambient temperature, the amount of water used to mix the concrete, and the type of concrete used.
Generally speaking, concrete is workable for 4–5 hours when mixed correctly. If the ambient temperature is higher than normal, the concrete may not be workable for as long.
The same is true for colder temperatures. In addition, the amount of water used to mix the concrete will also affect its workability time.
If too much water is added, the concrete will set too quickly, making it difficult to work with. The type of concrete used also has an impact on the workability time.
Sand–based concrete, for example, has a much longer workability time than a cement–based concrete. Sand–based concrete can remain workable for up to 6–7 hours, while a cement–based concrete may only be workable for 4–5 hours.
In addition to the ambient temperature, water content, and type of concrete, the size of the batch being mixed also affects the workability time. If a
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