Aspects and optimization of the mixture for high performance concrete

High-performance concrete is currently receiving a lot ofattention in research due to its properties and wide range of uses. This paperis focused on HPC, where the optimization of the mixture is specificallyaddressed regarding the technological solution of construction. The firstreference variant uses an approach that is suitable for processing at aconcrete plant. An alternative solution is intended for the processing of dryconcrete mixture, which can be bagged and the concrete itself produced atthe construction site. The paper deals with the comparison of two HPC basedon the same input and quantity of raw materials except for thesuperplasticizer. The purpose is to determine the HPC behaviour andproperties of a reference mixture with conventional liquid superplasticizersand a mixture using powdered superplasticizer. The experimental programincludes tests of the mechanical properties of compressive strength andflexural strength, where growth was monitored during the first 28 days, splittensile strength and velocity of ultrasound wave. Attention is also paid tofresh mixture tests. Although in the long term the mechanical properties oftested materials were very similar, the difference was determined during thefirst few days and weeks of hardening, when in mixture using powderedsuperplasticizer strength characteristics were increasing noticeably slowerthan in case of referential mixture.