If you’re going to use concrete for your new driveway or patio, you should know about the curing process. In this post, we’ll go over what the curing process is, why it’s important, and tips for taking care of your new driveway or patio in its first week.
Curing is the process of controlling the rate and extent of moisture loss from concrete during cement hydration. It may be either after it has been placed in position (or during the manufacture of concrete products), thereby providing time for the hydration of the cement to occur.
Since the hydration of cement takes time – days, and even weeks rather than hours – curing must be done for a reasonable period of time if the concrete is to achieve the most potential strength and durability.
Curing is designed primarily to keep the concrete moist, by preventing the loss of moisture from the concrete during the period in which it’s gaining strength.
Curing may be applied in a number of ways and the most appropriate means of curing may be dictated by the site or the construction method.
However, many of these ways, tend to be limited to large scale projects - road work, airports, bridges, etc. These objects need the absolute maximum care in order to achieve the highest possible concrete strength, and thus employ these expensive and tedious practices.
Residential projects, while unable to benefit from these processes, can also achieve high quality with proper care in just the first seven days after pouring. This is also where the difference between a properly reinforced slab and a poorly reinforced one lies.
A thin slab with small, widely spaced out rebar will show severe contraction and crack much sooner than one reinforced with thicker, more tightly spaced rebar, while concrete slabs reinforced evenly with synthetic or metal fibers will fare even better. Even if the slab does not crack visibly in the first days, higher contraction rate will significantly lower its overall lifespan.
Since moisture loss is inevitable, it’s of utmost importance to moisten the concrete slab as much as possible, and as consistently as possible. The less drying out in those first 7 days, the better. The industry offers many solutions for higher end projects, such as thick plastic sheets and membrane forming curing compounds, but even at the residential level, proper curing is possible when concrete is watered or moistened consistently.
Sprinklers can work well, but even manual watering with a hose is better than nothing. An uncured concrete surface can have its total yield strength reduced by as much as 60%, with other adverse effects such as early cracks and other damage.
With proper curing in the first 7 days, you can maintain much more yield strength and have a pristine, desirable surface. Please note that reducing drying is very important, so every bit of vigilance in those first 7 days counts.