The Marshall method was used to design an asphalt concrete mixture. A PG 64-22 asphalt cement with a specific gravity (Gp) of 1.031 was used. The mixture contains a 9.5 mm nominal maximum particle size aggregate with a bulk specific gravity (Gab) of 2.696. The theoretical maximum specific gravity of the mix (Gmm) at asphalt con- tent of 5.0% is 2.470. Trial mixes were made with average results as shown in the following table: Asphalt Content (P.) (% by Weight of Mix) Bulk Specific Gravity (Gmb) Corrected Stability (kN) Flow (0.25 mm) 4.0 2.360 6.3 4.5 2.378 6.7 10 5.0 2.395 5.4 12 5.5 2.405 5.1 15 6.0 2.415 4.7 22 Determine the design asphalt content using the Asphalt Institute design criteria for medium traffic (Table 9.15). Assume a design air void content of 4% when using Table 9.16.

Q. 3 a) Distinguish clearly between hot-mix asphalt and warm-mix asphalt. Why is the latter set to become the mix of the future in asphalt pavement works? b) Explain why asphalt concrete samples from the hot-mix plant are taken for compaction in the laboratory during asphalt overlay construction. c) The following data was taken from a laboratory work sheet on the design of asphalt concrete by the Superpave procedure for a selected aggregate structure: Trial Mix 1 %Gmm@Ndegn=96%, Qam=2470kg/m Trial Mix 2 P.=5.0%, Gmb@Nasgn=2.305 Based on the data, determine the following: i. P, of Mix 1 11. VMA of Mix 1 111. Gmm of Mix 2 Take Ga =2.65, G=2.69, for the aggregates and G,=1.02 for the bitumen used.

Problem No: 20%) 1. In a Marshall test, the percentage of asphalt binder by total weight of aggregate is 5.3%. The bulk specific gravity of aggregate (G) -2.582, the specific gravity of asphalt binder (G)=1.000, and the density of water (7)=1.000 g/cm If the voids filled with asphalt (VFA) is 70.0% and the effective asphalt binder (P) is 4.0% by total weight of mixture, determine the following properties(10%); a. The absorbed asphalt binder (P). b. The bulk specific gravity of the compacted mixture (G) c. The voids in mineral aggregate (VMA) d. The voids in total mixture (VTM). e. The theoretical maximum specific gravity of the loose mixture (G). f. The effective specific gravity of the aggregate (G). atical specific gravity of asphalt pavement mixture necessary for Nation 91% and Marshall Density

Define temperature susceptibility in Asphalt producrion.