Increased concrete strength due to early loading is one of the priorities of concrete technology. Many articles contain data on changes in compressive strength after early loading. The first person to test early concrete loading was Satalkin. He tested bridge supports for static and dynamic loads. The results of his work became the basis for further research in the field of early loading of concrete. The objective of this work is to study the tensile strength in bending after early loading and to check the influence of the orientation of the samples under load. Also we considered the effect of active mineral additives on this parameter. The object of study is samples of cement-sand dough prepared on a Portland cement binder of various manufacturers. We noted a difference in the strength characteristics in bending by changing the orientation of the samples when testing them after early loading. The maximum increment of strength is noted in a plane perpendicular to the direction of compressive force. The use of a mineral additive with the replacement of a fraction of cement gave the attenuation of the observed effect.

Keywords: anisotropy of strength properties, early loading of concrete, cement composite, flexural strength, mineral additive