How do I freshen up my exposed aggregate concrete?

try a concrete sealer. You can purchase clear or color tinted sealer @ most DIY stores

I would start with renting a power washer and cleaning as good as possible. You may consider adding a solution/soap to the situation too. After that the above answer of a clear sealer is also a great idea, that will make it pop more.

Careful with power washer it could remove your stones.

Sealing aggregate concrete will further enhance its beauty and help protect it from the harsh elements and deicing salts. An exposed aggregate sealer will also reduce mold and mildew problems, stabilize the surface, protect color retention, and protect against freeze/thaw damage.

An exposed aggregate sealer can be easily applied with excellent results by any homeowner. Failure to maintain an aggregate surface can result in a color loss, pitting, cracking, and leave the surface exposed to stains from spills.

Cleaning and prepping the aggregate surface prior to sealing it is vital to the performance of the new sealer. Pressure wash the surface to remove dirt, mold, mildew, and grime. If necessary use a concrete cleaner to assist in removing stubborn stains. Use a degreaser on oil spots and rust remover on irrigation rust stains if necessary.

After cleaning the exposed aggregate allow the surface to dry for 2 days before sealing. The best exposed aggregate sealer is a solvent based acrylic sealer. Use a ½” nap roller and coat one section of concrete at a time. If the concrete is broken up into squares due to the saw cuts in the concrete, coat one of these sections at a time to avoid overlap marks. Otherwise apply the exposed aggregate sealer quickly.

Allow the exposed aggregate sealer to dry for 1-4 hours. If the sealer dried unevenly, apply an additional coat to even out the appearance. Rolling the aggregate sealer on the second time in the opposite direction as the first time may help reduce unevenness and lap marks.

Most exposed aggregate sealers will last 1-2 years depending on climate, traffic, and type of sealer used. Protecting your exposed aggregate concrete surfaces with a quality concrete sealer will enhance their natural beauty and give lasting protection for extended use.

Best Sealers to Use for Exposed Aggregate:

• SuperSeal 25
• SuperSeal 30
• SuperSeal Matte
• SuperSeal VOC for restricted states
• Masonry Saver Decorative Concrete Sealer