Question

1. Find the optimum asphalt content and check with the requirements. Draw all the plots. (25) [Show your calculation] For Marshall mix design the specimens were drawn from the following aggregate blend: Component Mass(g) Agg-1 798.3 Agg-2 1102.2 Agg-3 349.3 Agg-4 149.7 Specific Gravity 2.62 2.53 2.49 2.44 | Data from Marshall stability and flow test: VFA %Air Voids VMA (%) AC% 4.5 5 5.5 6 6.5 Specific Gravity of Mix 2.268 2.2896 2.28942 2.281576 2.277396 Stability (KN) 9.3 9.8 8.3 7.7 6.2 Flow (mm) 2.6 3.1 3.5 3.8 4.6 Given: Asphalt specific gravity = 1.05 Requirements: Minimum Stability = 9 KN Minimum Flow = 2 Maximum Flow = 4 VFA = 65-75% VMA = 14-17%

Answer 1

Optimum asphalt content= 5%
: Xloo X100 AC (7) = weight of asphalt - Total weight AC = WA 798.3 + 1102.2 +349.3 +149.7+WA Ac = WA 2399.5+WA - X100 WA = 2399.5 . 100 CAC AC Theoritical or apparent specific gravity- GA = WitW2 + Wg + Wy+WA - W+W2+ Wz Wy WA tt GI 612 V3 Gly GA G = 2399.5+WA 79813 1102.2, 349.3 149.7 WA 2.62 2.53 2.4g + 2.44 Tos 6145 2399.5+WA 94.98 + WA 1.05 11) AC = 4.5% Was 2399.5 - 113.07 gm G = 2399.5+ 113.07 941,98 + 113-07 -= 2.394 7.05

e same steps & Calculations are repeated for all other asphalt contents and table is prepared. (ii) AC=5% (iii) AC=5.54 WA = 126.299m WA = 139.65 gm Gt = 2.378 Gt=2.362 V = 3.72%. Vua 3.071 VA= 10.90% VA = 11.99./. VMA = 14,6272 UMA = 15.0.6.nl VFA = 74.57% VFA = 79.63 ). (v) (IV) AC=6.5.1. 6.1. Ac= WA= 153.16gm WA WA=166 81 G+2 2.347 Gt² 2.331 V=2.77% V=2. 31% VA= 13.04% NA 214,104 VMA = 16,41.1. VMA = 15.81% TUFA=85.92.1.) NEA= 82.46%

TEA Gm ( 2 ACC..) 4.5 5 5, 263 9.3 . L 2.268 2.2896 / Air voids I stability, flow I UMA (KN) (mm (..) 7 2.6 114,98364.87 3.1 /14,62 / 74.57 3.72 9.8 8.3 2.28942 5.5 3.5 3.07 2.77 7.7 6:2 3.8 2.281576 2.277396 115.06 / 79,63 115.81 82.46 l 16.40 85.92 6.5 2.31 4,6 Plotssa 4 107 en og stability S26 Value y (mm 3. n (KN8 7+ 6t ot 23+ 0 4.5 5 o 4,5 5 6.5 4.5 5 5.5 6 6.5 c). Asphalt 5.5 6 6.5 AC 5.5 6 A t 4 4 907 VFA Bot 70 7 & S 6.5 4. s.5 6 Aco 4,5 S Al

Requirements minimum stability = 9 KN minimum flow = 2 man flow = 4 VFA= 65-75% UMA = 14,141 so af the observing table, to for asphalt content (AC= 5%) all the requirements are fulfilled and stability is maximum, so loptimum asphalt content = 5%