Relative density tests (ASTM D4253) are used for cohesion-less soils like a poorly graded sand with little or no fines for another way of determining what the optimums are. SPs don't display a normal moisture to density relationship so doing a proctor on them doesn't yield a good curve with a...
Are there many fines in the crushed concrete? Sounds kind of like you're getting the wave action of a clean sand which would require a relative density. Or maybe your sample came in from the field past optimum and you need to dry it out to get below optimum and then go from there.
Ah, Humboldt sells them, kind of pricey. Don't know why our project manager wouldn't have used one of those, he's been in the industry for probably 30 years. I'll have to check with him when I see him next. Thanks VAD. What's the accuracy like on them as compared to an overnight oven sample?
Bigh, what do you mean by speedy Moist. determ.? Do you mean like a burn off in the field with dry gas or something, or a microwave burn-off? We were reluctant to try a micro. The problem was that the moisture correction varied from time to time and also that it was a 4% range. The moisture...
I'm sorry, I keep calling the material fly ash when it was actually bottom ash and they are not the same thing at all.
casimmons, sorry I remembered the DDs wrong. You're right the moisture density relationships still worked. Let me try and elaborate:
-For a typical failing test the numbers...
That's neat. I have noticed that before when the surface of crushed concrete hardens up. Wasn't sure if there was actually unused cement left over causing that. Yeah I thought that was the problem in my case, they put in way too big of a lift and then used the wrong type of compactor on it...
I'm using a troxler guage and this is quoted from their website "Why is my gauge moisture result higher/lower than the oven dry/speedy moisture results?
The oven dry tells the true moisture content by removing all water from the sample. The gauge measures the hydrogen present in the material...
This is kind of a late response, but I ran into that problem in the last two weeks in Colorado as well. I assume that’s where you’re at since you mention CDOT. What was your proctor like for the material? The material I was testing was crushed concrete, kind of reddish brown. I did the mod...
Oh we had a proctor, a standard proctor of 105.9 p.c.f. at 19.7 %M. The trouble was the that the DDs the gauge would give us were typically around 88 p.c.f. and the M%s were around 8-10%, however the WDs were around 118-125 p.c.f. After taking back the sample to determine the true M% overnight...
I work for an engineering services firm in Colorado Springs, Colorado and I recently had to help our Pueblo branch for a month and a half at Xcel's new Comanche 3 power plant expansion. This was my first experience on a jobsite of "industrial" stature. On the backfill of two large...
