The required SN of an asphalt pavement to protect the roadbed soil is 5.1. The required SN to protect the sub-base material is 3.1. The required structural number for the base material is 2.3.The layer structural coefficients for sand sub-base, crushed stone base and asphalt concrete are 0.12, 0.15, and 0.42. The drainage coefficients for the sub-base and base are 0.8 and 0.9 respectively. What are the required thicknesses of the layers

Acommercial grade cubical freezer, 4 m on a side, has a composite wall consisting of an exterior sheet of 5.0-mm thick plain carbon steel (kst= 60.5 w/m k), an intermediate layer of 100-mm thick polyurethane insulation (kins 0.02 w/m k), and an inner sheet of 5.0- mm thick aluminium alloy (kal polyurethane insulation and both metallic sheets are each characterized by a thermal contact resistance of r 2.5 x 104 m2 k/w. (a) what is the steady-state cooling load that must be maintained by the refrigerator under conditions for which the outer and inner surface temperatures are 25°c and -5°c, respectively? (b) for power saving purpose, which wall material should be increased/reduced in. thickness in order to reduce 50% of the cooling load found in part (a)? redesign the thickness of the proposed material. 177 w/m-k). adhesive interfaces between the q=575.93 w