The setting time of concrete depends upon following factors, such as
Type of cement used
Use of mineral admixture
Use of chemical admixture (such as plasticizer)
Other factors which may affect the setting time of concrete includes
Absorption of mixing water by aggregates
Grinding of aggregates in the mixer
Of all the factors discussed above, the rate at which the concrete stiffens is greatly affected by temperature i.e. stiffening is unduly delayed at low temperature while it is accelerated in high temperature.