STUDY THE RETARDANT EFFECT OF USING DIFFERENT SUGAR'S TYPES ON SETTING TIME AND TEMPERATURE OF CEMENT PASTE

This paper present the study of the effect of adding different sugar types such as (Granular, Caster, Brown and Beet) on setting time and temperatures of hydration of cement paste. The effect of sugar on the setting times was checked by testing numbers of cement paste samples, that produce from 35% w/c ratio and different sugar type and ratio (0.5%, 1.5%, 2.5% and 5%) by the cement weight using Vi-cat needle apparatus. While the temperatures of hydration heat were measured by using Thermocouples, and changes in the heat of hydration were clearly recognised. The results of the experimental works show that: adding any type of cane sugar (Granulated, Caster and Brown sugar) in proportion (0.5% and 1.5%) the sugar was works as a concrete retardant, but these type of sugar worked as concrete accelerator when used in proportion (2.5% and 5%). However; adding Beet sugar in proportion (0.5%, 1.5%, 2.5% and 5%) was working as a concrete retardant. On the other hand, the hydration temperatures increased by adding sugar and the high peak they reached was about 33.890C at 0.30 water ratio with 1.5% sugar content. It obvious, for all sugar type (1.5% by cement weight) was the optimum sugar proportion to retard the final setting time of the cement pastes of different w/c ratios, but the higher sugar contents cause a decrease in the final setting time. On other hand, the initial setting time was decreased and accelerated when sugar was added to the paste. As well as adding sugar to the cement paste improved it physically by reduced the cracking and the bleeding on the surface of the sample.