High temperature is quite related to drying shrinkage. Change of volume, partial reaction, cracking and unconvenient locked stresses may result. So anywhere that cracks or residual stresses are thought to be relevant to the performance of the structure is quite convenient to follow quite closely the temperature aspect.
Strength is also adversely affected; ACI Special Publication 139 Durable Concrete in Hot Climates has at p. 141 a table that relates curing temperature to compressive strength, for a loss of 2000 psi in the range of curing temperatures between 50 and 120 ºF.
Another special publication of ACI, ACI SP-152 Design and performance of mat foundations at p. 190 suggests that as soon as the gradient within the concrete attains around 35ºF cracking ensues. This puts if not a limit on the higher temperature within the concrete one to its gradient, except that cracked concrete be acceptable, which is not the case for any wanted structural and less sanitary or alike. At page 193 states something that can be of your interest, for it is said that at the time (SP-152 is of 1995) "the ACI Code of Standard practice (in the knowledge of the authors) does not limit the maximum temperature rise in the concrete". A check of the documents standing in the current Manual of Concrete Practice regarding things related to this issue may show if something as of now is at variance with such statement.
