What is the Curing of Concrete? | Home Concrete DIY

Concrete Curing Overview

Essentially the curing of concrete is when the concrete matrix develops within a concrete element. Concrete is delivered to a site in a semi-liquid state, with a general consistency defined as ‘concrete slump’. 

As the concrete is delivered to a site, it is poured(placed) at the location or element, such as a grade beam, concrete pile cap, foundation wall or other… and set up to cure. 

The concrete curing process is whereby concrete gains in compressive strength (MPa), achieving a design strength for the given mix design chosen for the given structural concrete element. 

Larger Construction Project Concrete Curing

Concrete curing generally is a process that is monitored on larger projects. For instance, concrete testing involves the process of testing concrete strength in cylinders, and usually this process is undertaken by a professional testing company. 

These testing companies have expertise in concrete curing inspection, and with the utilization of the design characteristics of the concrete mix design, can make judgments as to the progression of the concrete curing process.

Ultimately though, the suitability of a concrete element is up to the dictation of a structural engineer.

What is Concrete Curing?

Concrete curing takes the moisture from the concrete mix and ensures that the formation of concrete crystalized matrix is formed. That is one of the reasons wet curing or concrete curing sealers and compounds exist! They help to trap moisture within the concrete element so that it can cure properly. 

If the concrete element is not hydrated through the curing process, excess moisture loss can lead to a reduction in concrete strength and structural suitability, potentially requiring serious remediation efforts.

How long does concrete curing take?

Concrete curing usually takes about 28 days, whereby design strength is supposed to be achieved. Still, unforeseen factors, such as weather, poor concrete placing methods, improper sealing or slab hydration and more, can affect the final cure of the product. 

A concrete product is a fairly simple element that is provided a set of design characteristics based on the dictations of an engineer and basic standards. 

Concrete Mix Designs

Concrete mix designs can be complicated, such as high early mixes, air entrainment, and specific admixtures that can promote hardening. 

Concrete curing therefore is a process that is unique to each type of concrete product. It is essential to understand that the process is very different from your average concrete patio slab, to a major concrete element on a concrete project. 

For instance, with some concrete elements, high strength, up to 40MPa (~5800 psi) can be found in as little as 14 days! But for your typical backyard concrete slab or garage pad, you can start walking on it in as little as 12-36 hours for instance.

Concrete Curing vs Concrete Hardening

Concrete curing and concrete hardening are not the same thing. For instance, concrete hardening is the process whereby concrete becomes walkable, or suitable for vehicle traffic. 

Concrete curing is more akin to the process whereby compressive strength is achieved, which is more critical for structural concrete design, and supporting elements like columns, slabs, suspended slabs, transfer slabs and more!

What if concrete compressive strength is not achieved?

With larger construction projects, when concrete compressive strength is not achieved in a correct period of time, a structural engineer can be consulted to assess requirements for the lack of compressive strength. Accommodations for the lack of compressive strength could be, a later testing procedure, such as an extra testing cylinder, or even a concrete coring method. 

Even up to 56 days, an engineer may request a concrete break to see what MPa has been achieved. 

Conclusion | What is the curing of concrete?

In summary, concrete curing is a process whereby concrete achieves compressive strength. The process is really in the matrix of the concrete, whereby the formation of strength in the concrete element forms slowly, with testing typical at 3 days(early-break), 7 days, 14 days etc.

Factors that Affect Concrete Curing

Factors that affect concrete curing include hydration levels in the concrete, design of the concrete mix, temperatures, and concrete mix-additives. The services of a professional local concrete contractor should basically include the necessary provisions to properly cure your concrete. Whether you are looking to pour a concrete pathway, slab, concrete stairs or a concrete foundation, a reputable concrete contractor can take care of the curing.

Pick the Right Concrete Contractor

A reputable concrete contractor will be able to assess the ideal mix design for your home or structural requirements. Safe to say, a reputable and well experienced Calgary concrete contractor is a quality bet for choosing the right concrete contractor when it comes to ensuring proper curing. From expert Calgary concrete repair to concrete driveways, concrete foundations and everything in between, they are true professionals in their craft.

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Concrete Curing Frequently Asked Questions

Why is concrete curing important?

Concrete curing increases the strength of concrete up to 50% more if properly cured. This improves durability and resists cracking, shrinkage and surface dusting. This can also reduce the prevalence of scaling.

What are common methods of curing concrete?

Some typical methods for curing concrete include wet curing (water curing), sealing with curing compounds, plastic sheeting, wet coverings, and curing blankets. Some wet covering options include straw, burlap, or cotton soak mats. Wet curing helps to keep the hydration in the concrete to ensure proper development of the concrete matrix.

How soon does curing begin after pouring?

Curing of the concrete basically takes place as soon as the concrete is placed and finished. While some methods might require curing to carry on, such as wet curing, for up to 7 days, generally speaking curing is a process that initiates as soon as the concrete is finished in-situ.

Can I walk on cured concrete?

After about 24 hours concrete is typically fine to walk on. Concrete reaches a vast majority of strength in the first 7 days, so after that point, it is probably fine to drive on too!