Construction & Contractors/Limestone
Can limestone fines be compacted enough to keep water in, as in lining a swimming area. My soil is very sandy.
It depends on how fine but yes, the rate of water percolation would greatly decrease. It will probably not be comparable to a clay, plastic, or concrete lining, though, because crusher fines are still particulate materials with void spaces.
The percolation rate depends on the size distribution of the material (the smaller the particles the better), whether the particles are uniformaly graded or not (if there is a variety of particle sizes the smaller particles can nest in between the larger particles, reducing void space and therefore porcolation pathways), the degree of compaction (the denser the better), and the length of the percolation pathway (the thickness of the lining, the greater the better). And, if you are going to have an outside swinning area, you need to think about sources of disturbance to the lining, such as foot traffic and aquatic vegetation.
Darcy's law states that Q-KiA, where Q is the volume rate of percolation, K is the hydraulic conductivity (units of distance/sec) which is a function of the material type, grain size, density, and the characteristics of the percolating medium, i is the hydraulic gradient (in units of length/length -- essentially the drop in hydraulic head over the distance in the medium at issue) and A is the area perpendicular to the direction of percolation. There are all kinds of mitigating factors -- people argue about the applicability of Darcy's Law all the time -- but it's a pretty good start.
If you had a pond with 10 ft of water in it, and you expect the flow to be zero at the bottom of a lining that is 3 ft thick, the hydraulic gradient is 3.3333 because the head at the top of the lining is 10 ft and at the bottom it is zero. The area is whatever you want to calculate the water losses over. The problem is figuring out the hydraulic conductivity of the limestone fines you want to use, which as I said will depend on their density as well as their character. That is just something you will need to research.