Sandy Loam conditioning

Right now the soil that was dug up from the bottom of the beam trenches where the slab will be poured this morning and packed around the forms is sinking.  Or worse than that, actually, parts of the sides have collapsed leaving a number of 6" gaps beneath the forms and some dirt above the compacted fill (but still below the supported rebar).  The soil was compacted, but that does little good when it is very hot and the clay soil has high plasticity index.  Ronnie has said it will not be a problem.  But I think it would have been better not to do that at least.  I'd feel much more worried about it if I were still planning to do brick, which has immense weight, and would need all the strength the engineer intended.

I just took another look with flashlight, and it still looks exactly like some photos I took last week.  The dirt clumps are still appear at least 1.5 inches from rebar, and mostly just fractions of an inch above the base.  The poured concrete will probably flatten the larger clumps.  Over time, the base in the beams will probably get saturated with dirt anyway, so a little on top probably makes little difference.

I have similar problem with the ground all around my house.  In spite of weekly watering sufficient to keep grass around the house growing pretty well, the soil sinks and cracks in the soil open up between the soil and the foundation beams around the perimeter of my house.  I think I lay down as much or more water than anyone who uses soaker hoses.  An underground watering system would probably be best.

I've obsessed about those cracks, and determined that it would be better not to have cracks.  When there is an open crack going down 30 inches or more, that provides even more surface area for water to evaporate. The drying process then accelerates in a vicious circle, with far more cracking going on than you can see.  You can see the effect of this hyper drying in dead grass, that gets as much water as other grass, but dies anyway because of the drying effect of runaway subsurface cracking.

My previous solution (and I don't recommend this anymore) was to pour sand in the cracks until they filled up.  The sand is easy to pour and extremely stable with respect to drying.  However sand may not be the best material to support a foundation.

Now I've found the perfect fill.  It's sandy loam.  Sandy loam is also called "select fill" because it has ideal properties for an earthen fill material.  It remains stable in wet and dry states,  It should not be used for base (limestone gravel mixed with sand is better for that) but fill along the sides of houses.

After I put a mere 100 lbs of sandy loam in the worst looking crack at the lowest point of my house on Saturday, then did a thorough soaking, it already seems that I'm hearing less snap crackle pop settling noises from my house.

Actually it isn't labeled sandy loam any more, it's now called "Lawn Conditioner" at Keller Materials.  Maybe it's not exactly the same, but they say it's the closest thing they have.  For lawns here, you would rake it around and fill in all the lawn cracks.  Reduces subsurface drying.

I might try another dealer New Earth and see if they have actual sandy loam.