A Retraction of concrete It is the reduction of its volume due to different factors, such as the elimination of water retained inside it, the dosage of the trace, form of mixture, or the strength of chemical and climatic agents.
This phenomenon, also known as exudation, is considered a true nightmare for builders, because if it happens, the entire structure of the building could be compromised.
Because of the omnipresence of concrete, the extreme care taken in its application is one of the main actions that lead to the success of the work. In this article, we'll help you learn about shrinkage problems and how to avoid them. Follow up!
A retrenchment It is the volume reduction process in concrete mass. Technically, this movement occurs due to the outflow of water, characterizing different types of retractions. Chemical, autogenous, and thermal factors can also influence this decrease in volume, causing problems.
What are the main types of retraction?
According to engineering studies, the shrinkage of concrete can be divided as follows.
Plastic retraction
Water is eliminated by exudation (“concrete sweat”) shortly before the hardening begins. Being the most popular type of retraction, it can happen due to factors such as:
exposure of the material to strong winds;
exposure to excessive heat;
low relative air humidity.
Chemical shrinkage
Water is eliminated during the concrete hydration stage due to the difference in volume between water, cement and the substances that result from this hardening. What decreases the volume of concrete are the formations of substances that have a reduced volume when compared to cement and water. These include calcium hydroxide and hydrated calcium silicate.
Hydraulic retraction
In hydraulic shrinkage or drying, the decrease in volume is caused by the loss of water from the material already in a solid state. Errors in concrete dosage can cause this loss, just as the uncontrolled healing of the concrete in the early days can cause this type of shrinkage.
Thermal shrinkage
In the process of concrete hardening, there is an increase in its volume before its reduction in the cooling phase. Thermal shrinkage (or exothermic shrinkage) occurs due to the release of heat during this process. What happens, basically, is a chemical reaction resulting from the transmission of heat from inside the body of the part to the environment.
We just sent you a message in your email. See if it arrived in the inbox or in the spam.
Oops! There was an error. Check that you filled it out correctly.
Subscribe and Receive Exclusive Content
How to prevent the problem?
If you are wondering about the consequences of concrete shrinkage, know that, in more extreme cases, the entire structure of the work may be compromised at once. When concrete retracts, cracks can appear everywhere, presenting a danger.
To solve this problem, the first step is to carry out the concrete curing process in a perfect way. It can be done by sprinkling water, with the use of chemicals and blankets. The objective is always the same: Keep the concrete moist for as long as necessary. Even days after concreting, it is important that the material always remains hydrated. Healing can inhibit cracks through plastic retraction and healing for many days, so be aware.
The use of additives is one of the most efficient ways to reduce harm, since chemical solutions (such as Blok Cure) can offer more strength and better concrete finish at the same time.
Did you like to know more about the effects of concrete shrinkage and how to prevent it? Then subscribe to our newsletter right now and don't miss our articles anymore!
BLOK'S BLOG
Join the team of the best professionals in the construction industry and always be informed about the greatest advances in your profession.
.webp)
