Rutting of asphalt pavement is a phenomenon that the pavement deformation increases with time under the same vehicle loading, usually under heavy, often slow-moving loading. A laboratory investigation is carried out to measure the rutting depth D (mm) in an asphalt pavement against time T (s) and the data is presented in the following table: T (s) D (mm) 178 0.75 330 0.94 521 1.12 757 1.28 1029 1.44 1297 1.56 1559 1.67 1813 1.78 2067 1.85 2321 1.93 a) Plot this data with D (mm) vertical and T (s) horizontal. 2.5% b) Assuming a linear relationship between the rutting depth and time where the rutting depth is a function of time, manually calculate and plot the least squares regression line of best fit on the same graph. Comment on the differences between the actual data and the line of best fit function. 7.5% c) The investigation suggests that the rutting depth in the asphalt pavement D can be determined by a function against time T as follows: D=KT" in which k and n are constants. Verify that D=KT" and determine values of k and n. 7.5% d) Using the proposed model in c), predict the rutting depth after 7200 seconds assuming that the pavement is left under the same loading. Discuss the limitations of this prediction. 2.5%