Concrete Grill Countertop Pour

Last weekend I placed the grill countertop using a fiber reinforced Type S mortar mixture. The mold had a knockout for a cutting board on the right. It is sloped to the front for drainage with some channels made from clay. The opening for the grill was split in half and wrapped with foam for easy removal.

The mix design was pretty simple, 1 bag of Type S mortar, 1 gallon of water, 1/2 gallon of latex modifier, and 5 pcy polypropylene fibers. The latex and fibers went into a bucket and then were broken apart using the mixing paddle on the drill. The water and mortar were mixed together by hand and then the latex and fibers were added.
All of those fibers gave it the consistency of wet manure. This was by far the cheapest countertop mixture I have ever tried.

The mortar was pressed into place by hand. It was very workable but needed pressing because of the fibers in the mix. I sprinkled some green dye here and there on the mold surface, just to see how it would turn out.

Finished, troweled, and resting. Since mortar isn't as strong as concrete I let everything sit 3 days before stripping the mold. Beforehand I rough ground the bottom and torched the loose fibers.

I have been impressed. The surface texture was as good as any countertop I have produced. It is curing a few more days under wet towels before a rough grind and sealer coat.

Concrete Fireplace Surround Reveal

After two days of curing in the mold, under plastic, and under wet towels the forms were carefully removed. As expected there were a few places that had honeycombing and need some slurry. The larger proportions make the fireplace stand out better.

Some honeycombing under the braces used to hold the mold together.

The concrete after a batch of colored slurry. The slurry was made using the same proportions of cement and pigment held together with just enough latex.

It is a little splotchy as the slurry dries. Another coat or two of slurry will be required to completely fill in all of the bug holes and honeycombing. A light grind will smooth the surface back out.

Placing the Concrete Fireplace Surround

The fireplace surround had reinforcing steel mesh embedded 1-inch into the surface. Since it is such a long piece (about 7 feet) which is restrained by the existing fireplace, the steel helps prevent shrinkage cracking. Even though the carpet here will get replaced it was covered with cardboard. Integrally mixed concrete pigment will stain pretty much everything.

The setup in the garage. The fireplace took 3.3 cubic feet of concrete so two different batches were required. The mixture was a modified quikcrete mixture containing lower w/c, latex, high range water reducer, viscosity modifier, fibers, and pigment.
Same mixer as last time, still too small. Each batch was 1.65 cubic feet.

The mixture was self-consolidating to minimize honeycombing against the small gap between the mold and the fireplace.

The surface was hard-troweled and covered with plastic.

And covered with wet towels for a couple days.