What is the purpose of the method known as "washing" in concrete finishing?

The method known as "washing" in concrete finishing aims primarily to remove the cement and sand mixtures from the aggregate surface. This process exposes the aggregate particles, giving the concrete a decorative look while also enhancing its texture and slip resistance. By removing the top layer of cement and finer particles, the aggregates become visible, providing an aesthetic appeal as well as improving the bond of any subsequent layers that may be applied.

This approach is commonly used in various decorative concrete applications, where the visual characteristics of the aggregate play a pivotal role in the overall design. The technique can be particularly beneficial in pathways, driveways, or areas where both functionality and appearance are important.

The other possible answers focus on smoothing, strength increase, or decorative finishes in different ways but do not capture the primary goal of the washing method, which is specifically to reveal the aggregates beneath the surface.