_applied sciences_  
_Article_  
**Composition Component Influence on Concrete Properties with the Additive of Rubber Tree Seed Shells**  
**[PERSON] 1,*\(\copyright\)**, [PERSON]' 2\(\copyright\)**, [PERSON] 3\(\copyright\)**, [PERSON] 4\(\copyright\)**,  
**[PERSON] 3\(\copyright\)**, [PERSON] 5, [PERSON] 3\(\copyright\)**, [PERSON] 6\(\copyright\)**, [PERSON] 7\(\copyright\)** and [PERSON] 8\(\copyright\)**  
\begin{tabular}{l}
1 Department of Transport Systems, Faculty of Roads and Transport Systems, Don State Technical University, 344003 Rostov-on-Don, Russia \\
2 Department of Engineering Geology, Bases, and Foundations, Don State Technical University, 344003 Rostov-on-Don, Russia \\
3 Department of Unique Buildings and Constructions Engineering, Don State Technical University, 344003 Rostov-on-Don, Russia \\
4 Department of Life Safety and Environmental Protection, Faculty of Life Safety and Environmental Engineering, Don State Technical University, 344003 Rostov-on-Don, Russia \\
5 Research and Education Center \"Materials\", Don State Technical University, 344003 Rostov-on-Don, Russia \\
6 Department of Civil Engineering, Faculty of Engineering, Nemetrin Ebrakan University, 42000 Konya, Turkey \\
7 Department of Civil Engineering, Faculty of Engineering and Natural Sciences, Konya Technical University, 42075 Konya, Turkey \\
8 Department of Civil Engineering, Faculty of Engineering, Zonguldak Bulent Ecvitt University, 67100 Zonguldak, Turkey \\
* Correspondence: [EMAIL_ADDRESS]; Tel: +7-8632738454 \\ \end{tabular}  
**Abstract:** The growth in the volume of modern construction and the manufacture of reinforced concrete structures (RCSs) presents the goal of reducing the cost of building materials without compromising structures and opens questions about the use of environmentally friendly natural raw materials as a local or full replacement of traditional mineral components. This can also solve the actual problem of disposal of unclaimed agricultural waste, the features of which may be of interest to the construction industry. This research aimed to analyze the influence of preparation factors on concrete features with partial substitution of coarse aggregate (CA) with rubber tree (RT) seed shells and to determine the optimal composition that can make it possible to attain concrete with improved strength features. CA was replaced by volume with RT seed shells in an amount from 2% to 16% in 2% increments. Scanning electronic microscopy was employed to investigate the structure of the obtained concrete examples. The maximum increase in strength features was observed when replacing coarse filler with 4% RT seed shell by volume and amounted to, for compressive and axial compressive strength (CS) and tensile and axial tensile strength (TS) in twisting, 6% and 8%, respectively. The decrease in strain features under axial compression and under axial tension was 6% and 5%, respectively. The modulus of elasticity increased to 7%. The microstructure of hardened concrete samples with partial replacement of CA with RT seed shells in the amount of 2%, 4% and 6% was the densest with the least amount of pores and microcracks in comparison with the structure of the sample of the control composition, as well as samples with the replacement of CA with RT seed shells in an amount of more than 6%. The expedient effective replacement of CA with RT shells led to a reduction in battered stone of up to 8%.  
**Keywords:** rubber tree seed shell; concrete; coarse aggregate; strength features; strain features