Normally the thought of ash brings to mind volcano eruptions, funerals, and maybe religious holidays but for us and green builders it’s about flyash and foundations. So, when discussing the topic with one of San Francisco’s up and coming LEED-AP architects (Melanie Jacobson) she mentioned that the CHPS school they are building in the Sacramento area will have a fifteen percent flyash concrete foundation we looked quizzically at her. Why only fifteen percent? She mentioned that that percentage was about as high as their structural engineers deemed to be sound.
We’ve heard other local green buildings contain as high as thirty percent flyash. So, why the discrepancy? It depends on the configuration of the building, the weight on the structure and most importantly what the structural engineer says. (more…)