Plasticizing and setting-retardant additives are widely used in dosages to ensure adequate workability for the work and slow drying. However, the use of these materials requires prior study to choose the best content and meet the specifications of the work. Based on the experience of the Civil Engineering Laboratory of UFPA in providing dosage consultancy to companies that supply ready-mixed concrete, it was observed that some concrete companies do not perform these studies and end up using existing mixes, without taking into account the influence of the type of manufacturer or even the type of cement. Therefore, the objective of the research is to demonstrate what happens to the setting time and consistency of cement mixes when the type of additive and the type of cement are varied, thus avoiding dosage results that do not comply with the customer's expectations. To this end, setting time tests were first performed, in accordance with ABNT NBR 16607/2018, on pastes composed of three additives
with the same content (A, B and C) and two cements used in the region (CP-II-E-32 and CPIVRS-32). Secondly, consistency index tests were performed on mortar mixes, in accordance with ABNT NBR 7215/2019, using the same materials as the setting time, in order to assess the implications on the time taken to start setting and on the spreading of the mortar. It was concluded that for the same cements, even using similar additive contents in the mixes, the setting times varied greatly, revealing that the type of manufacturer influences the results and that mixes with the same contents, but with different cements, also behave differently in the setting. The consistency of the mixes also underwent changes, analyzing the aspects of manufacturer type and cement type, thus reinforcing the importance of carrying out prior and specific studies for the needs of the work, thus reducing problems in the concrete application stage, for example
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