I see cement trucks constantly turning the cement, I get that it may just be keeping it thoroughly mixed so no one part becomes more dried than the rest. Is that all that’s happening here?
In: 252
There are two ways to take concrete to the site in mixer trucks. Either they are prepared at plants (mist probably and better controlled mix) or the water is added during the haul time(usually not preferred as the water mix might not be as per design). While calculating the concrete mix, they factor the cure time ( what you are calling drying/hardening), and add retarders to it that slow the curing time so that there is ample time for the concrete to reach the site as well as have enough time for any on site delay that might make the concrete batch be left for extended period in the mixer. If the plant operator or the mixer operator / driver are oblivious to this , they sometimes suffer the cimcrete drying inside and they have to then break and clean the whole thing. Sometimes there are on site delays that can be a day or two so they have to dump the concrete . While on site, i have witnessed two three times where the contractor made some safety errors but called on the first batch, which then were dumped, and funnily the local rural community gets benefit from it as they usually ask them to pour it in their lawns or sitting areas. Also the concept of retarder and accelerator can be extended that if you are living in a cold area where curing is slow, you add accelerators to concrete for fast curing, and if living in hot regions, you add retarders so that mix doesnt cure faster
Latest Answers