# Sustainable Development of Concrete through Aggregates and Innovative Materials: A Review
## 2 Recycled Materials
### Recycled Tire Rubber
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Rubber** & **Bulk** & **Ultrasonic** & **Bulk** & **Compressive** & **Young’s** & **Bending** & **Toughness** & **TI** \\  & **Density** & **Modulus** & **Porosity** & **Strength** & **Modulus** & **Strength** & **Toughness** & **TI** \\ \hline
**Substitution** & **(kg/m3)** & **(GPa)** & **(\%)** & **(MPa)** & **(GPa)** & **(MPa)** & **(kJ)** & \\ \hline
0\% (Ref. & & & & & & & & \\ concrete) & 2422 (15.2) & 49.5 (12.10) & 9.04 (15.8) & 47.78 (12.6) & 8.88 & 4.75 (14.5) & 6970 & 1 \\
20\% CR & 2264 (16.2) & 42.1 (11.50) & 8.97 (15.9) & 27.71 (15.3) & 5.91 & 3.75 (18.6) & 5500 & 1 \\
40\% CR & 2156 (17.5) & 31.2 (9.80) & 9.29 (18.2) & 17.71 (16.8) & 3.93 & 2.90 (17.8) & 2610 & 1 \\
60\% CR & 2026 (14.5) & 27.5 (11.6) & 9.11 (14.8) & 13.58 (19.5) & 3.80 & 2.75 (22.5) & 7120 & 1 \\
80\% CR & 1858 (18.5) & 18.9 (14.6) & 9.68 (18.6) & 8.60 (25.5) & 1.06 & 2.05 (19.9) & 1490 & 1 \\
100\% CR & 1742 (21.3) & 13.4 (10.2) & 11.54 (20.8) & 6.33 (26.8) & 0.39 & 1.86 (22.6) & 1810 & 1 \\
20\% FCR & 2313 (17.5) & 44.0 (11.4) & 9.17 (17.6) & 30.09 (18.9) & 5.71 & 4.30 (19.2) & 6120 & 1 \\
40\% FCR & 2139 (16.4) & 34.4 (16.5) & 11.38 (16.8) & 22.84 (19.5) & 4.63 & 3.43 (21.5) & 6280 & 3.70 \\
60\% FCR & 2032 (17.1) & 28.5 (17.8) & 14.01 (17.9) & 15.82 (20.6) & 3.60 & 3.32 (20.3) & 3430 & 7.16 \\
80\% FCR & 1851 (18.2) & 22.3 (15.6) & 18.31 (17.9) & 9.60 (20.5) & 2.05 & 3.24 (28.5) & 8410 & 2.54 \\
100\% FCR & 1668 (19.5) & 7.3 (18.9) & 21.37 (19.6) & 4.64 (28.5) & 0.77 & 1.68 (22.8) & 4910 & 1.56 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Bulk density, bulk porosity, compressive strength, Young’s modulus, bending strength, toughness and toughness index (TI) results of concrete samples with CR an FCR. Deviation factor (%) is indicated between brackets [34]. Copyright© 2017, Elsevier B.V. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Composition by Weight** & **FCR (\% Weight)** & **CR (\% Weight)** \\ \hline Rubber & 50.35 & 96.90 \\ Textile fiber & 2.07 & 0.01 \\ Steel fiber & 5.04 & 0.00 \\ Rubber linked to steel fiber & 9.43 & 1.67 \\ Rubber + textile fiber + steel fiber & 5.81 & 0.01 \\ Rubber linked to textile fiber & 27.00 & 1.41 \\ Powder & 0.30 & 0.00 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Weight analysis of the main components of the two types of recycled rubber [34]. Copyright© 2017, Elsevier B.V. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Rubber** & **Cement 42.5 MPa** & **Aggregate 4–8 mm** & **Recycled Rubber 4–8 mm** & **Sand 0–4 mm** & **Water** \\ \hline
**Substitution (CR and** & & & & \\
**FCR) (\% Volume)** & **(kg/m3)** & **(kg/m3)** & **(kg/m3)** & **(kg/m3)** & **(kg/m3)** \\ \hline
0\% (Ref. concrete) & 360 & 1103.0 & 0.0 & 722.8 & 180 \\
20\% & 360 & 882.4 & 84.5 & 722.8 & 180 \\
40\% & 360 & 661.8 & 169.0 & 722.8 & 180 \\
60\% & 360 & 441.2 & 253.5 & 722.8 & 180 \\
80\% & 360 & 220.6 & 338.1 & 722.8 & 180 \\
100\% & 360 & 0.0 & 422.6 & 722.8 & 180 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Mix proportions of the different concrete mixtures [34]. Copyright © 2017, Elsevier B.V.