How to Make a High Density Concrete Walkway

Measure the length and width of the walkway with measuring tape and mark the borders with hoses of ropes laid parallel on the ground. The width should be about 36 inches for a secondary walkway and 4 feet for a primary one. Add 3 inches of width to each side for the temporary forms.

Dig out sod and topsoil from the land within the rope outlines with a shovel, and dump it on a tarp to use over low areas in the yard. Dig until the depth is equal to the thickness of the concrete slab and foundation, typically 4 inches for the slab and 2 to 6 inches for the foundation, depending on the density of your soil.

Mark off every 10 feet of length along the site with stakes. Dig down 1/8 inch deeper at every stake so the floor of the site has a smooth, consistent slope for drainage.

Tamp the subsoil by pressing the flat end of a manual tamper over the entire site.

Shovel a 2- to 6-inch layer of 3/4-inch aggregate into the site, and spread it with a rake. Tamp the aggregate with a manual tamping tool until it feels stable under your feet.

Hammer the stakes into the ground until the tops are about an inch above ground level every 10 feet along the inner walls of the site. The top of the stakes marks where the surface of the walkway will sit. The stakes closest to the house should be 1/8 inch higher than the stakes 10 feet away to ensure the walkway will have a mild slope for drainage.

Fit two-by-four form boards against the stakes and screw them in place with a drill so the joints of the boards are flush.

Have high-density concrete mixed by a professional company and poured over the site. The types of aggregates used to increase density include steel, hematite and magnetite.

Spread the dense mix with a gauge rake so it is even in corners and sides. Push a long piece of metal or a wood board across the width of the walkway, moving slowly down the entire site to push excess into low areas so the surface is even. Smooth the thin layer of cement at the top with a long-handled squeegee.

Use a trowel to cut control joints every 4 feet across the walkway once the mix hardens for two hours. Make the cut 1/4 the depth of the slab. Control joints are planned cracks that enable concrete to shrink and expand as it needs to, preventing jagged cracks from developing in the future.

Cover the wet walkway with moist burlap to slow-dry the mix. Spray the burlap frequently throughout the next seven days to slow-dry it, maximizing its strength.