Flocculate with Expansive Clay

I wish I had found this when I was ten years old. It would have helped a whole lot w/ my crik bed dam building projects.

Google books, "Clay Materials Used in Construction " edited by G.M. Reeves, I. Sims & J.C. Cripps

12.1.2. Bentonite

The name bentonite is popularly used for a range of natural clay minerals of the smectite group, principally potassium, calcium and sodium monnnorillonites derived from the weathering of feldspars. The name derives from the discovery of large deposits near Fort Benton in Wyoming. USA. Because of the chemistry and micro-structure of the clay particles they have a strong ability to absorb water and are able to hold up to ten times their dry volume by absorption of water. Montmorillonite (after Montmorillon, southwest of Paris) consists of very thin flat crystalline sheets of clay minerals which are negatively charged and are held together in 'stacks' by positively charged sodium or calcium ions in a layer of adsorbed water. In particular the soil particles comprising a stack of sheets of sodium montmorillonite form extremely small and thin platelets, being typically of the order of 1.0 pm or less in length and 0.001 um thick. The ability to absorb water comes from the relatively low bonding energy of the sheets, which allows water molecules to be adsorbed onto the internal and external sheet surfaces. Calcium ions provide a stronger bond than sodium, so that calcium mommorillonite swells less readily than sodium monnnorillonite. Potassium ions provide much stronger bonding between clay sheets as the potassium ion is of exactly the right diameter to fit between atoms in the sheet structure with negligible gap between the clay sheets. A similar material to mommorillonite but with potassium bonding is the non-swelling clay mineral known as illite. The substitution of sodium by calcium or potassium ions in monnnorillonite greatly reduces the ability of the clay structure to hold water.

The very small particle size of bentonite results in an extremely low hydraulic conductivity for intact clay, with a coefficient of permeability of typically less than 10-1" m/s. This allows the clay to be used to form 'impermeable' or 'waterproof layers and sustain high hydraulic gradients across thin layers with negligible water flow. The swelling property is also important in such applications, since should water permeate a layer of dry bentonite it will swell even against high pressures and tend to seal any crack or fault which might otherwise develop into a leakage path. The volumetric swelling of particles can be up to 13%. but that of an agglomeration of particles is somewhat less depending on their packing.

Many applications of bentonite involve the use of slurry. Mineral particles in a slurry generally carry electrical charges, the nature and intensity of which vary with the particle surface characteristics and the chemistry of the liquid phase. Polar water molecules may then be adsorbed on to the particle surface, forming a layer of 'bound' water surrounding each particle. The result of the two effects is to produce repulsive forces between par¬ticles, which are greater than attractive Van der Waal's forces except when the particles are very close together. The particles in a slurry therefore tend to keep apart from each other in a 'dispersed' condition (Fig. 12.1a). The effects are most noticeable with small particles (clay/silt rather than sand/gravel, and in practical terms only with finer clay particles) since the relative surface areas are much larger. and gravitational forces are much smaller. Under some conditions the plate-like particles of clay minerals may have different charges on the edges and faces of the particles, and are able to clump together in a 'flocculated' structure (Fig. 12.1b). The large flocs settle out of the slurry much more readily than the small individual particles.

Some slurries demonstrate the effect known as thixotropy, whereby they 'set' into a gel if left undisturbed, but revert to a viscous fluid (sol) when sheared. The alterna¬tion between sol and gel may take place any number of times. The phenomenon is well known in 'non-drip' paints. A gelled 'house-of-cards' type of structure with edge to face connections is illustrated in Figure 12.1c; gels of thin clay particles may contain only a few per cent of solid material. The gelled structure is also able to sup¬port larger soil particles and prevent them from settling out. Bentonite slurries are thixotropic and typically form a gel at concentrations of a few per cent by mass in water: this is an important property of bentonite slurries in many applications. For a more detailed discussion of the nature and properties of bentonite slurries see Jefferis (1992).

Bentonite clays occur, and are mined and processed commercially, in many pans of the world. Some natural deposits, notably those from Wyoming, have a high proportion of sodium. These tend to produce slurries with high viscosity but relatively low gel strength. The depos¬its mined in the UK, near Woburn, are mainly of the calcium form, and these are converted by ion exchange to the sodium form by ball-milling with sodium carbonate. These materials tend to be less dispersive and give lower viscosities for the same slurry density, but higher gel strengths. As natural products, bentonites vary widely around the world in quality and content of other minerals, even after commercial processing, and these 'variations must be taken account of in their specification and use.

Bentonite is available commercially in a variety of forms. but nearly always in a dry state, as powder (in bulk or bags. like cement), pellets or blocks. For applications in construction it will usually be hydrated, although in some waterproofing materials the hydration is allowed to occur in situ. For use as a slurry, the bentonite is mixed with water at a rate of a few per cent of solids by mass. The aim is normally to produce a slurry in which the bentonite particles are well dispersed and fully hydrated. For good mixing and rapid hydration, a high-shear colloidal mixer (shear rate >900/s) should be used, and the slurry then left to stand for some time while the clay particles hydrate. The quality of the slurry obtained depends on the hydrogen ion concentration (pH) of the water used in mixing; saline or acidic water or water containing impurities may cause the clay particles in the slurry to flocculate. This may initially cause the slurry to 'thicken', but there will then be a tendency for the flocculated particles to settle out of suspension and form a sludge. However there is not normally a practical problem with seawater coming into contact with a slurry, provided the slurry cannot mix freely with the seawater and has previously been fully hydrated with fresh water. Deliberate flocculation with flocculating agents may be used to help remove bentonite from suspension when the slurry is no longer required or has become too contaminated with cement, clay or silt. A combination of low hydraulic flow into the slurry (so long as hydraulic heads are low), and long diffusion times for salt compared with exposure times, usually causes few problems in the presence of seawater.

Bentonite is also used in combination with other materials, in particular other soil materials and Portland cement. At one extreme a small quantity of bentonite may be added to a concrete mix to produce highly plastic concrete able to undergo quite large deformations without cracking: while a small quantity of cement in a bentonite slurry can produce a hardening slurry with a small shear strength. Natural clay, silt and sand may be used as 'fillers' to produce cheaper material while keeping most of the benefits of the scaling ability and low permeability of the bentonite. Gleason et al. (1997) found that about 5% of sodium bentonite and 10-15% of calcium bentonite had to be added to fine sands to achieve a sand-bentonite mix with a permeability of less than 10-9m/s. Hardened bentonite-cement slurry mixes containing 180 kg/m3 of cement and 60 kg/m3 of bentonite had permeabilities of about 10-7m/s with calcium bentonite and 10-8m/s with sodium bentonite. These mixtures arc discussed further below in relation to various different applications. Small quantities of polymers and other chemical additives may also be used to enhance or modify the properties of bentonite slurries for particular applications. These are also discussed further below. [not below here, though, you gotta go read the book if you want more!]

What I am working on getting shorter and shorter...

frm Randall Brown in comment to a previous entry that I made to this blog -- “With your own writing, GO, how have you approached "short prose"? I'm curious about what you are currently working on to meet the demands imposed upon the writer of these short forms? Also, I've recently read some discussions about making Twitter's "character limit" add up to so much more than those 140 characters. Any thoughts about how that might be accomplished?”

I can give a long or short answer. I will try short and hope that it does not take too long to read.

I am not sure that I see short prose as being demanding any more or less than other forms, in general, possibly less demanding than say a good sonnet. A bad sonnet is not very demanding unless a reader considers bored doggerel a chore.

Demands are either external or internal. External being expectations of readers, critics, I suppose, the world-at-large, and internal being the demands the writer places on themselves.

Rowing a small boat is demanding on the rower, but if you do it regularly and often then it becomes a pleasure. So I would want to frame the question, How do we meet the pleasures of the short form?

So, as to working on, I am working on enjoyment in writing of the short form.

Other than that I spend a good deal of time looking around at what people are writing and what readers are reading. I could present my analysis of what I am reading, but here and now I will not.

Short prose, for me, is not new. My life, in construction, building a business, building community, networking at-large has been active and it has always been spattered with bursts of short prose as that is how it happens for me. My attention has always wandered and skipped about. I am happy that the world is catching up with what works for me, though as I have complained elsewhere everyone important in my life seems to be getting younger and younger.

I am intrigued by the interest in flash with a sort of humor one has of new people, curious strangers that show up in the side yard to pet an old dog.

There are so many young lions and fresh priestesses that it is all a dazzle to behold!

I recently ran across a quote from Cyril Connolly, it has been a long time since I have read his critical work, but it seems apt enough, “The true function of a writer is to produce a masterpiece and no other task is of any consequence.” Note that there is no indication here as to requirement of length.

As to Twitter, at one time I was told by a distraught reader that I should never write an e-mail longer than one page on the screen. So I wrote a serial novelette in weekly e-mails that went on, engaged with an active audience, for two plus years. Now we have Twitter, even shorter yet. I use it for glitter sprinkled in the hair or the bulbous red nose of a clown. Though I feel the best thing to do with Twitter is to point at other things.

Samuel R. Delany (I happened to meet and spend an hour talking with him one cold night in a bookstore, it was snowing, it was supposed to be a reading, but I was the only audience that showed – he has been teaching Creative Writing for 30+ years) in About Writing, his interview/essay Inside and Outside the Canon talks a whole lot about pointing at things. The more a thing is pointed at, let us say the more an author or a flash is pointed at the more likely it is that people will look at it. The more often it is looked at the more likely it will have an opportunity to be considered worthwhile.

Even if for no other reason it is worthless, trite, possibly drab, clumsy or stupid if enough people look at a thing it gains value for having been looked at. We are fortunate that eventually the collective forgets a whole bunch of stuff in fairly short order of appearance.

One can do same serializing w/ Twitter, but it needs to be kept exciting, lots of cliff hangers and plot twists... it needs to be fun. It also takes a bit of energy to consistently keep doing it and finding ways to make it work. I would tend to suggest that several writers could gather together as a collaborative and write line by line, hitting off of each other, trying to trip each other up, but there would need to be an overall structure of background rules for everyone to maintain their focus, and to make sure the story does not fall flat or meet a timely death.

Learn Flash in a Flash

Field Guide to Writing Flash Fiction, Tips from Editors, Teachers and Writers in the Field, edited by Tara L. Masih, published by The Rose Metal Press.

For me an early experience of learning to write stories, of any length, was reading Aristotle’s Poetics. What I mainly learned from that was that reading about how to write usually does more to ruin one’s writing than never reading about writing at all. That said, I own a whole slew of books about the process of writing, and when I am not writing I am often reading them. There is a way to read books about writing, a sort of offhand, “Yes, yes, I get what this says but I will do my best to forget it as quickly as possible.” This is not a book to be forgotten so easily.

This is a book for writers. That is, most readers who are not writers, and who may not have a specific interest in learning to write in the short prose form, would not find this collection of brief essays (most of them brief, as can be expected from writers who are used to cutting their word count to the bone) interesting other than from an historic perspective. By that I mean, this collection may have greater value to the general reader years from now than it does today, particularly after it has made it through a decade of classroom use, as it should. For a writer, however, particularly one who is writing short prose, this is an invaluable resource right now.

As the title suggests, this is a collection of essays, comments, from people who have some sort of international experience with the activity of creation and propagation/distribution of short prose. I know of or have read other work by most of the essayists contained here, and with a few of them I correspond. The ones I do not know, I will seek out, because they all are interesting, experienced, and at the top of their game. If as a writer you want to know what is going on in short prose - I am avoiding use of the word “flash” for no particular reason - then this is the essential guide.

Apparently each contributor was asked to write a brief essay to provide an example, and to suggest an exercise. There is material here to explore for several months of scribbling; for a writer looking for inspiration from which to step forward to write, the exercises should be a good resource. Over time it should be interesting to trace the influence of this book on short prose writing. I believe it will introduce new themes and fuel the current Internet trend toward short “bits” of attention-deficit feeding prose, and also, of course, help us see where the authors featured in this collection are going with their own work.

The caveat, my detraction, goes back to my initial encounter with Aristotle. Although I believe the material in this book is essential, I also find it to be confining, not for any fault of the editor, who has performed an admirable task, but exactly because of the way the approach to short prose of each essayist is revealed. It can be confusing to find so many divergent opinions and viewpoints all together in one swarm. Nevertheless, I suddenly find that I have a better idea of what I did not previously understand. I do not know how long it will take for me to adjust... like finding out that driving your foot on the brake, as you have done for twenty years, is not the optimal method.

My advice for the writer who is learning to write in short prose is to get into the book, sink deep, follow the examples and exercises, explore as many comments and threads to their infinite conclusion... and then walk away and forget all of it, or at least most of it. By then it should be about June of 2015.

Copies may be ordered directly from the publisher at The Rose Metal Press

Writer's Apartment Building Falls Over

When we found out that we had been assigned an apartment on the eleventh floor and that we would have a view out over the city with an enclosed balcony we were very excited. Kim and I had waited a number of years on the list to be housed in the newly built exclusive writer’s building, “弯曲泥泞的沼泽”. It was only last week that we visited the apartment. We had the library and the locations of our writing desks all worked out. We both appreciated that it would be a perfect setting for us to finish my last novel and for Kim to complete her poetry collection. Unfortunate for us, I suppose, the last week has been something of a let down.

Ladders Can Be Dangerous

The only time I fell off a ladder, and want to tell about it, was when it was hit by a boxcar that had been let loose to roll down a slope. It was when I worked at the salt mine.

I was running electrical conduit at the entrance to a tunnel below the salt sifter building. I had five bosses on the ground telling me what to do. The classic too many chiefs, not enough Indians.

Regardless, the rail car was let loose, nothing unusual in that at the salt mine -- but this time it rolled toward me. I saw it and started to climb down off the ladder. The bosses all yelled at me to climb up the ladder saying the rail car would miss me. They were correct, it did miss me. But it did not miss the ladder.

I jumped atop the rail car and thought that was OK. But there was only about three feet of space between the ceiling of the tunnel and the top of the rail car. The ceiling was very rough, blown on clumps of concrete. All would have been fine at this point except it being an active construction site there was a large electrical cable draped down. I got tangled up in it and was worried if I did not get loose then I would be hanging quite a distance up in the air when the rail car went away without me. Let alone I was worried I might get a bit bashed up dragged along the top of the rail car more than absolutely necessary.

So in the three foot of space I did a summersault around the cable. I then lay down on the top of the rail car… on that long steel platform where you see dandies in the movies that walk a train.

When the car came out of the other side of the tunnel I staid down and there was no sign of me. All of the bosses were mystified that I had vanished.

This was one lesson; it was fairly quick and over with, where I learned to suspect authority figures of being full of crap and it being dangerous for me to pay too much attention to them.

A bit of history about the salt mine here.

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