# Evaluation of the Long-Term Performances of SMA-13 Containing Different Fibers
## 3 Test Scope and Methods  
In this paper, the effect of fiber types on the performance of SMA under different aged states was explored. First, mixture specimen under different aged states were fabricated. The short-term aged mixtures were used to simulate asphalt mixtures during construction, and the long-term aged mixtures were prepared to simulate asphalt mixtures that have been paved for five to seven years. The aged BFSMA-13 and LFSMA-13 were prepared following the steps provided by AASHTO R30 [32]. Then, the performances of these specimen were checked with several test methods. The wheel tracking test and the uniaxial penetration test were adopted to reveal the deformation resistance of asphalt mixtures. The three-point bending test was used to represent the low-temperature performance of the mixtures. The immersion Marshall test was chosen to reflect the water stability, and the SCB test was conducted to check the cracking resistance (at medium temperature) of the mixtures. The SEM test was used to show the distribution of the fibers in the mixture to reveal the physical structure strengthening mechanism of the fibers. The FTIR test was used to analyze the chemical composition of the asphalt extracted from the asphalt mixture samples under different aging degrees to better explain the effect of the aging process on the chemical composition of the asphalt material used in the mixture. The test plan is shown in Table 6.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Aging Condition** & **Performance** & **Method** \\ \hline \multirow{4}{*}{Unaged} & high-temperature performance & Wheel tracking test, Uniaxial penetration test \\  & Cracking resistance & Three-point bending test, SCB \\  & Water stability & Immersion Marshall test \\  & Functional group analysis & FTIR \\  & Microscopic characteristics & SEM \\ \hline \multirow{4}{*}{Short-term aged, Long-term aged} & high-temperature performance & Wheel tracking test, Uniaxial penetration test \\  & Cracking resistance & Three-point bending test, SCB \\  & Water stability & Immersion Marshall test \\  & Functional group analysis & FTIR \\ \hline \hline \end{tabular}
\end{table}
Table 6: Test plan.  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Mixture Type** &
\begin{tabular}{c} **Optimal Asphal-Aggregate** \\ **Ratio (\%)** \\ \end{tabular} & **VV (\%)** & **VMA (\%)** & **VFA (\%)** & **VCAmin** & **Stability (kN)** & **Flow Value (mm)** \\ \hline BFSMA-13 & 5.8 & 4.2 & 16.7 & 74.9 & 39.3 & 9.8 & 3.0 \\ LFSMA-13 & 6.0 & 4.1 & 17.1 & 76.0 & 39.8 & 8.2 & 2.8 \\ Requirements & / & 3–4.5 & \(\geq\)16.5 & 70–85 & \(\leq\)VCA\({}_{\text{BRC}}\) & \(\geq\)6 & 2.0–4.0 \\ \hline \hline \end{tabular}
\end{table}
Table 4: [PERSON] design results of SMA-13.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**Sieve (mm)** & **16** & **13.2** & **9.5** & **4.75** & **2.36** & **1.18** & **0.6** & **0.3** & **0.15** & **0.075** \\ \hline \multirow{4}{*}{**Percentage passing (\%)**} & **Upper limit** & 100.0 & 100.0 & 75.0 & 34.0 & 26.0 & 24.0 & 20.0 & 16.0 & 15.0 & 12.0 \\ \cline{2-11}  & **Lower limit** & 100.0 & 90.0 & 50.0 & 20.0 & 15.0 & 14.0 & 12.0 & 10.0 & 9.0 & 8.0 \\ \cline{1-1} \cline{2-11}  & **Design value** & 100.0 & 95.0 & 62.8 & 27.2 & 22.5 & 19.7 & 16.8 & 14.3 & 12.9 & 11.0 \\ \hline \hline \end{tabular}
\end{table}
Table 5: Aggregate gradation of SMA-13.