1. What is meant by the ecological metaphor? What does it suggest about ways to use materials in a sustainable way? 2. Use Figure 11.7 to estimate the thickness of a sandstone wall required to give a...

1. What is meant by the ecological metaphor? What does it suggest about ways to use materials in a sustainable way?

2. Use Figure 11.7 to estimate the thickness of a sandstone wall required to give a thermal delay time of 12 hours.

3. What are the thermal characteristics of a straw-bale wall construction? Use Figure 11.7 to find out. The insulating ability or thermal resistance of a wall is measured by its R value, equal to its thickness (in meters) divided by its thermal conductivity (in W/m K). What is the R value of a 200 mm straw-bale wall?

Q104;

1. The following table lists the thermal properties of rammed earth (adobe). If an adobe house has walls 300 mm thick, how long will it take the interior temperature to start changing after the exterior is exposed to a sudden drop in temperature?

2. Oak with a stress grading G of 60 is to be used to construct a bridge. Using data for Hardwood from Chapter 15 and a typical safety factor of 2.25, what is the acceptable maximum design stress for the material of the bridge?