# Nanmodified Concrete with Enhanced Characteristics Based on River Snail Shell Powder
## 3 Results
The \"dependence of the tensile strength in bending of concrete on the amount of snail shell powder was approximated by a function with a determination coefficient\" of 0.978. \[R_{bbb}=4.74+0.137\cdot x^{0.733}\cdot\sin(0.342x+0.32);\ \ R^{2}=0.978 \tag{4}\]  
The data presented in Figure 6 confirm the effectiveness of the 6% RSSP dosage: the flexural tensile strength increased by up to 9% compared to the 0% RSSP control formulation. At the same time, the behavior of the dependence curve of Rbtb on the amount of RSSP is approximately similar to the dependence curves in Figures 4 and 5, that is, a smooth increase in tensile strength in bending was observed with an increase in the dosage of RSSP from 0 to 6% (from 2 to 9% in comparison with the control composition); at 6% a peak (9%) was observed, followed by a sharper decrease in strength at dosages of 8, 10 and 12% (up to 17.6%). Figure 7 \"shows the effect of the amount of snail shell powder on the axial tensile strength of concrete\". Figure 6: Tensile strength in bending of snail shell powder concrete. Figure 7: Axial tensile strength of snail shell powder concrete. The \"dependence of the axial tensile strength of concrete on the amount of snail shell powder is approximated by a formula with a determination coefficient\" of 0.988. \[R_{bt}=2.62+0.148\cdot x^{0.4}\cdot\sin(0.408x-0.4);\ \ \ R^{2}=0.988 \tag{5}\]  
The axial tensile strength of concrete when 6% cement was replaced with snail shell powder was 2.91 MPa, which is 11% higher than that of the control composition without replacing cement with a nanomodifying additive. When replacing 2, 4 and 8% cement, Rbt increased from 1.5 to 6.5%. At dosages of the nanomodifying additive of more than 6 to 12%, a drop in axial tensile strength to 16.5% was observed. Thus, the dependence considered in Figure 7 only confirmed the previously considered dependences in Figures 4-6 in terms of the nature of the change in the strength characteristics and effective dosages of the nanomodifying additive in the form of a powder of snail shells. Figure 8 the effect of the amount of snail shell powder on the modulus of elasticity of concrete is shown. The \"dependence of the modulus of elasticity of concrete on the amount of snail shell powder is approximated by a formula with a determination coefficient\" of 0.996. \[E=27.4+0.261\cdot x^{1.18}\cdot\sin(0.36x+0.11);\ \ \ R^{2}=0.996 \tag{6}\]  
The maximum value of the \(E\) was recorded when replacing 6% of the cement with the RSSP nanomodifying additive. The values of the elasticity modulus increased with an increase in the dosage of the nanomodifying additive from 0 to 6%, and when the cement was replaced by more than 6%, a drop in the elasticity modulus was observed. The \"effect of the dosage of snail shell powder on the strain characteristics of concrete is shown in Figure 9\". Figure 8: Modulus of elasticity of river snail shell powder concrete. The dependences of the strain characteristics of concrete on the dosage of snail shell powder are approximated by formulas with determination coefficients of 0.989 and 0.992. \[R_{b,cub}=39.4+1.277\cdot x^{0.698}\cdot\sin(0.363x);\ \ R^{2}=0.983 \tag{2}\]0  
\[R_{b,cub}=39.4+1.277\cdot x^{0.698}\cdot\sin(0.363x);\ \ R^{2}=0.983 \tag{2}\]1  
The influence of the dosage of snail shell powder on the deformation characteristics of concrete was also evaluated by plotting compression diagrams \"\(\varepsilon_{b}-\sigma_{b}\)\" and tension \"\(\varepsilon_{bt}-\sigma_{bt}\)\". Stress-strain diagrams are shown in Figures 10 and 11. Analyzing the \"stress-strain\" diagrams during compression in Figure 9, we can conclude that the best properties are characteristic of concrete nanomodified with snail shell powder in the amount of 6%. The \"peak of its diagram is shifted upwards and to the left relative to other diagrams, which indicates its high strength and low deformation characteristics\". Concrete has the worst deformation characteristics, \"in which 12% of the cement was replaced by the powder of snail shells\".