Juan also quoted "cyclopean backfill" as a proposed solution to stabilising the down-stream side of Oroville's emergency spillway. Like Juan, I had to look it up - that gave me a little frisson of patriarchy because look it up was the standard response from my father when we bothered him with questions. It wasn't very engaging or empathic but it threw me back on my own resources rather than looking for The Answer from an authority figure. Also, finding information was, back then, work: you had to decide which book to read (or whom to ask) and then maybe read through several. A good index was often key and most indexes were not--so-good because they cost money to include. Many of my students at The Institute are more or less incapable of doing things without being told in detail what is required. They're pretty good at looking stuff up because google, the universal index, will even correct their weak spelling and return the answer without them having to stand up and find a book. Harrrrumph! Why is that bad, because the work I had to do schlepping to and through libraries and writing notes on what I found embedded the information. It was a key part of the very expensive education I received which still makes me an asset at the Pub Quiz table.
Cyclopean backfill has quite a lot to do with banana-bread, of which I am currently making a good bit nowadays to make inroads on the banana glut. Some of the banana bread is also made <ho ho> currantly (ie with dried grapes). If you mash up the bananas then they make a uniform slurry which binds with the flour eggs butter and sugar and, as the heat of the oven penetrates, the gloop sets into cake. If you slice or chop the bananas then the lumps tend to sink to the bottom of the cake mix before the matrix sets. You can make a virtue of this by slicing the bananas and putting them into the base of the dish and adding the cake mix on top: best served with custard or cream. Same issue applies if making cherry cake (or simnel cake with little cubes of marzipan); you can slow their fall if you coat the cherries in a dusting of flour. The example [above R] shows a partial sinking failure: cherries more dense at the base.
Concrete is an interesting material because its strength and functionality depends on an appropriate mix of cement (expensive), sand (cheaper) and gravel (cheapest). Pure cement and water and pure sand/gravel and water are less strong than a mixture and experience or engineering text-books tell you what proportions to use under given circumstances. The gravel provides discontinuities in the matrix which usefully prevents cracks from propagating; similar reasoning staggers the courses of bricks in a wall [R for beautiful example of Flemish bond]. Cyclopean concrete adds a judicious mix of rocks, which if locally available are so cheap as to be free. Engineers must be bakers at heart because the added rocks are called 'plums'. There are rules for their application:
- no plum shall be larger than a third of the width of the smallest dimension of the site to fill
- the total plums shall be not more than 25% of the total mass
- each plum must have at least 100mm of concrete surrounding it all round
- air voids must be prevented under the plums
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