How to Mix Crushed Glass in Cement

Pour your dry concrete into a wheelbarrow. For every pound of dry cement you use, throw two handfuls of glass into the mix. Ask an assistant to hold the wheelbarrow steady while you stir the cement with a strong shovel.

Slowly add water to the dry cement mixture while an assistant stirs. Add water until the cement has a consistent texture similar to wet, thick mud.

Pour your cement into your mold. Shake the mold to spread and mix the wet cement. This helps reduce air bubbles in the cement, and prevents shrinkage as the cement dries.

Flatten the wet cement using a bull float (a piece of wood or metal on a pole, used to straighten cement). Don't go for perfection, though. The cement can remain a little lumpy and uneven once you finish.

Spread crushed glass over the surface of the concrete. Spread it consistently over the top so you don't end up with thick clumps of glass in one part of the cement, and thin concentrations of glass in other parts.

Gently press the glass into the cement using a trowel. Don't bury the glass, but apply enough pressure on the glass to sink it into the cement.

Smooth over the surface of the cement thoroughly with a trowel. Do not drag the glass across the surface of the cement while you smooth the surface. Clean your trowel regularly to avoid accidentally covering the glass shards with cement.