Developing and validating HMA Workability Prediction Model for Determining the best Paddle as a Machine component for Workability Device

In extending the previous work in which the authors develop a workability measuring device, this paper presents a laboratory assessment which looks into the relationship between Temperature (T), speed (S), torque (Tq), power (P) and Energy E, under different types of asphaltic concrete mixes using transducer recording devices. Seven types of mix and 210 samples at six different mixing temperatures were used and at five different RPMs on three types of Paddle configurations (A, B & C) to determine the Paddle which produces the highest R2 and P- values. Statistical analyses by the MINITAB software was used to develop and validate the model for Energy (workability) for the HMA and the selection of the best Paddle for inclusion, as the component for the workability measuring device. It was found that paddle B was the most suitable and the model was therefore developed using this paddle, as a result of the significant P-value and the highest coefficient of domination (R2) for mixing Temperature, Speed, Power, Energy and Torque. The results of the sensitivity analyses demonstrate that Energy exhibits the highest increase when Speed is kept at minimum, mean and maximum values.