Keywords: Ready mixed concrete, Plasticizing chemical admixture, Flowability, Workability, Compressive strength.

Abstract: The effects of raw materials that a ready mixed concrete producer will use in concrete production on fresh and hardened concrete properties were investigated. Concrete mixtures were designed and tested in both fresh and hardened state to provide the desired properties in the most appropriate way. Five different mixtures were designed with three different hyper plasticizing (HP) chemical admixtures and two different super plasticizing (SP) chemical admixtures. Test results indicated that initial slump values of the mixtures were ranged between 20 cm and 23 cm. The slump retentions of the mixtures produced by SP chemical admixtures were slightly lower than those produced by HP chemical admixtures. Improving the slump retention values of the super plasticizing admixtures used in this study can make these types of admixtures preferable by the concrete producer. While the handling levels of the mixtures produced with HP chemical admixtures were medium, the mixtures produced with SP chemical admixtures were good. It can be suggested to increase the handling levels of mixtures produced with HP and to increase the flowability of the mixtures produced with SP with minor changes that can be made in the content of the relevant admixture. Compressive strength test results indicated that 1-day compressive strength values of the mixtures were found as normal except for a mixture. Both 7-days and 28-days strengths of mixtures produced with HP chemical admixtures were slightly higher than those produced with SP chemical admixtures. Results showed that plasticizing chemical admixtures can affect both early and later age strengths of ready mixed concrete mixtures even for equal water/binder ratios.

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