Use of hardened cement

[malakin]

There are 20,000 bags of 940lb bagged cement (9400 ST) which have gotten wet. I am considering their use for a buried revetment base layer. Neat cement is highly alkaline and might have detrimental effects on the marine life, even if buried. Neat hard cement does not have a high compressive strength. I would expect it to be very brittle and
fracture easily, possibly crumbling. The usual test to check the quality of rock is to drop it from about 4m (I think) onto a steel plate. I suspect they will fracture. I Would also expect it to have a low resistance to abrasion. Good abrasion resistance qualities are normally an essential requirement for coastal protection works; rocks in breakwaters, revetments and gabions do move. How soluble is neat hard cement and could it in time 'dissolve'? I have seen old bagged cement in old
shipwrecks which did not seem to have deteriorated.
I am interested in any experience in a similar
application. Or an alternative use.

Regards,

Michelle

 

[Ron]

You have a lot of cement there! Have you considered running it back through the kiln and re-grinding the material?

Absent that, if you slowly hydrate the cement so that you get confined, throrough wetting, it will gain relatively good strength and will generally hold together. The problem is usually that the wetting is inconsistent and there is much unhydrated cement left, resulting in weak areas.