Many of us have probably bought more concrete bags than we needed for a project but figured we would use them down the road for another project. Like many people, you may not have a shed or garage to store the excess bags, or you don’t want to put in the time and effort to make room for them, so you store the bags outside. Eventually, the concrete hardens in the bag, so what can I do with a hardened bag of concrete?
One of the most common uses for hardened concrete bags is for landscaping projects, like forming terraces or embankments. You can also break up the bags’ contents for backfill when leveling slopes or using fill for large holes or dips in your yard. You can also apply it to paved pathways and at the bottom of planters for drainage.
Read on to find out what you can do with that hardened bag of concrete and how you might have avoided the situation entirely.
Why Bagged Concrete Hardens
Concrete is a building material made by mixing cement, sand, small stones, and water. A bag of ready-to-use concrete, such as Quikrete, is a mix of cement, generally Portland cement, sand, and gravel or stone.
Cement is a binding agent. When mixed with water, it creates a paste effectively binding together the sand and rocks. Therefore, once exposed to moisture in any form, the cement is activated, and the materials harden (source).
Even in the absence of moisture, concrete can settle and compact, making the concrete lumpy (source).
Determine if It’s Completely Hardened
Before you begin any project using the hardened bags of concrete, you must first determine if the bag has set all the way through, as some of its contents may be salvageable. To determine if a bag has completely hardened, you will need a hammer and chisel.
With the hammer and chisel, begin to break the outer surface. If you see powder, the concrete is not hard all the way through, and the powder is still viable for use. Salvage as much powder as possible and then follow the directions on the bag for mixing and usage.
Still, cement stored over three months should be, without question, tested for strength. You should not use the salvaged concrete powder for any project that requires structural integrity, such as a driveway, which needs to be able to bear a certain amount of weight without cracking or caving (source).
Projects Using Hardened Bags of Concrete
Even fully hardened bags of concrete may still have a use. All you need is a bit of knowledge and creativity. If you lack inspiration, a great place to start is Pinterest, a site that will have all the ideas you need for viable projects. Here, we list a few projects that can make use of hardened concrete bags.
Terraces and Gardens
You could use hardened concrete bags to make terraces as an attractive landscaping project. One option is to use hardened bags of concrete as steps for small hills.
Determine how many steps you’ll need to cut into the hill or slope. You can use one bag of hardened concrete for each, or you can cut the hardened bags into usable blocks with a concrete saw. Not many people have a concrete saw lying around in the tool shed, but you can always borrow or rent one.
Similarly, you could create a path to your garden using hardened bags by digging holes into the ground and placing the hardened concrete at intervals.
Terraced gardens are an incredibly eye-pleasing addition to any landscape. The premise is the same as steps only on a larger scale. However, before building the short retaining walls, the slope needs to be excavated in areas 5 to 10 feet wide into the hillside. Once all the digging is complete, build your retaining walls (source).
Raised beds are another beautiful yet functional landscape project where your crushed concrete will provide drainage, or your hardened blocks can become a base. Constructing raised beds on your terraced gardens ties the look together for unbeatable curb appeal.
You can also use bags of hardened concrete to form a retaining wall. Use a shovel to dig out where the first layer of the wall will reside, and place bags of concrete end to end until you have the desired length. You can use whatever bags of hardened concrete you have and continue with new bags until you reach the desired height and width.
Most retaining walls use concrete bags before they set. However, using hardened bags at the bottom and building up from there is an option not to be overlooked when saving money on a project is necessary.
Many projects require an enormous amount of fill dirt, such as patios and driveways, but you can also use hardened concrete for backfill. The only tools you’ll need are a good hammer and safety goggles.
Once the safety goggles are in place over your eyes, take your hammer and begin to bang on the bags of concrete until you have hammered the bags into pieces. You may also consider earplugs to safeguard your hearing, as this is a very loud endeavor.
Continue hammering until you have sizes you can use for your project, which will vary based on your project, whether for a driveway or fill for landscape holes. You can also fill potholes and dips in the landscape with small to medium-sized concrete chunks and cover with soil.
Broken-up pieces of concrete are also useful in place of pea gravel or crushed rock. You would need about four to six inches of concrete aggregate broken up under a patio or driveway to improve drainage. You can use smaller pieces to cover the bottom of your planters for drainage.
As a Driveway Border
This project is labor-intensive, but the outcome is stunning. This project uses blocks purchased from a home improvement store, but, again, you can cut the hardened bags into usable blocks with a concrete saw (source).
Of course, it may be easier to use the bags you have as fill for the ditch under the stone blocks you purchase. Either way, you’ll have improved drainage along the sides of your asphalt driveway and saved it from looking ragged and in need of repair.
Other Uses for Hardened Bags of Concrete
There are other, less conventional uses for your hardened bags of concrete. You can build a permanent fox hill or a low table to rest a rifle while taking target practice. This idea works best if you have a personal rifle range on your property (source).
What Should I Do With the Packaging?
When using unbroken, hardened bags of concrete, it is easiest to leave the packaging material alone. Most concrete uses biodegradable paper bags. It takes approximately six months for the bag to degrade around the hardened cement completely.
If the concrete packaging is plastic, it is best to take the plastic off and recycle it rather than ending up in landfills.
A type of concrete called Rip-Rap comes in jute or burlap sacks. This packaging is biodegradable and poses no harm to the environment. It contains no hazardous materials, such as dyes, to print information on bags.
For more environmentally friendly ways to use old concrete packaging other than allowing it to degrade around your retaining wall or steps, read our article How Old Concrete Bags can Have a New Life.
Preventing Concrete Bags from Hardening
While there are uses for bags of concrete that have hardened in the bag, it is much easier to avoid dealing with the situation in the first place.
No matter how or where you store your concrete bags, you need to consider atmospheric moisture, how long and where you’re considering storing the cement, arranging the bags, and which bag to use first.
Atmospheric Moisture Content
It’s essential to consider the level of moisture the concrete absorbs from the atmosphere, and the finer the quality of the concrete mix, the better its moisture absorption. Once the moisture content reaches over five percent while in storage, it is no longer usable for construction projects requiring structural integrity.
Where you store your bags of cement is of utmost importance. It is best to keep them from exposure to moisture in any form. There are sheds designed explicitly for cement bags with waterproof floors, roofs, and walls, well above ground level with airtight small windows and doors.
The storage area should also provide proper drainage inside and outside to prevent moisture from affecting the bagged concrete.
Storage Duration and Compaction
The duration or length of storage of cement is essential to its viability for construction. The longer it is in storage, the less strength it retains. For instance, concrete stored for over three months will begin to lose its structural integrity.
The arrangement of the bags is also of utmost importance. They should be on wooden platforms, one above the other offset, and each stack should not have more than ten bags each.
If you have multiple bags of stored concrete, always use the bags that were stored first to minimize warehouse-pack or mechanical compaction and compromise your concrete’s structural integrity.
When faced with hardened bags of concrete, it is unnecessary to dump them in a landfill if you can use your imagination. It’s best to recycle materials where possible, and concrete is among the most versatile materials for reuse.
Projects improving your yard’s beauty and function, including steps, retaining walls, terraced gardens, raised beds, backfill, and drainage under the soil; concrete is one of our most ecologically sustainable products.
With an open mind and a creative mindset, there is no end to what one can accomplish with hardened concrete.