Based on the way she treats it, it’s safe to say that Mother Nature doesn’t like concrete. Luckily, repairing the chipped edges or corners of concrete steps is an easy afternoon’s task for a DIYer.
The first step is to remove any loose pieces with a chisel or a grinder (don’t forget to wear safety goggles), followed by a thorough scrubbing with a wire brush. Then, hose down the work area, leaving it damp.
Mix up a small batch of quick-setting concrete. It sets in 15 minutes or less, so only mix the amount that you can use in that time. Wet concrete is corrosive—it’ll eat away at your skin—so wear safety gloves.
For chipped corners, use a trowel to press the concrete in one-inch-thick layers, until it’s slightly proud of the existing surface. Let the concrete set for about 10 minutes, then use your trowel to scrape it level. Lastly, smooth it out with a damp sponge.
If you’re repairing the face or the edge of a step, press the concrete in place, then use a piece of lumber as a temporary form, holding it up with a heavy rock or a cinder block. Lubricate the wood with WD-40 or cooking spray to keep it from sticking to fresh concrete. After 10 minutes, remove the wood, and shape the profile of your step with a trowel and sponge. (Two trowels work too.)
Keep the new concrete damp with a fine mist every few hours for a day or two, or cover it with plastic to hold the moisture in if you won’t be around.