{"id":8725,"date":"2022-07-01T00:00:57","date_gmt":"2022-06-30T22:00:57","guid":{"rendered":"https:\/\/mlzconstruccion.com\/?p=10507"},"modified":"2026-10-16T14:48:08","modified_gmt":"2026-10-16T12:48:08","slug":"beware-concreting-very-cold-weather","status":"publish","type":"post","link":"https:\/\/mlzconstruccion.com\/en\/beware-concreting-very-cold-weather\/","title":{"rendered":"Beware of Concreting in very Cold Weather."},"content":{"rendered":"
You must beware of concreting in very cold weather<\/strong>, do you want to know why? At MLZ Construcciones, we will tell you about it below:<\/p>\n

Concreting in cold climates is a procedure that requires special attention because it can mean irreparable damage to this material<\/strong>. Therefore, allowing concrete to reach temperatures below freezing point means that it can no longer be used.<\/p>\n

Even in cases where temperatures do not drop to below freezing, it is quite likely that the concrete will gain strength much more slowly. This is why it is important to be careful when concreting in very cold weather.<\/p>\n

What the regulations say about Concreting in very Cold Weather<\/h2>\n

It is so important to follow the provisions regarding this issue that the regulations have very specific sections. The regulation currently in force in Spain is the Structural Code (C\u00f3digo Estructural, Royal Decree 470\/2021), which replaced the former Structural Concrete Instruction EHE-08. Among other measures, it requires that when the concrete is poured into the formwork its temperature must not be below 5 \u00b0C.<\/strong><\/p>\n

In other words, concreting must be suspended<\/strong> if it is predicted that the ambient temperature could fall below zero degrees Celsius within the next 48 hours.<\/strong><\/p>\n

If there is an urgent need for concreting during frosty weather, it is of great importance to take the necessary measures to ensure that the concrete sets and first hardens without any deterioration in its strength characteristics.<\/p>\n

In this case, setting-accelerating additives<\/strong> must be used in the manufacture of the concrete, as well as anti-freeze products.<\/strong><\/p>\n

Why does this happen?<\/h2>\n

It happens because low temperatures delay the hydration<\/strong> of the cement paste and permanently damage the concrete<\/strong>, which does not harden as the water contained in its pores eventually freezes. This results in the inevitable breakdown of the material.<\/p>\n

To ensure an appropriate hardening process that avoids frost damage, it is essential to adopt specific measures <\/strong>on both small and medium-sized jobs.<\/p>\n

Two different temperatures<\/h3>\n

Concreting in cold climates requires taking<\/strong> into account two different temperatures<\/strong>, which should not be mistaken: one is the temperature of the ambient air, the other is the temperature of the concrete itself.<\/p>\n

The water in the mix freezes and expands when the concrete is placed below 0 \u00b0C, rendering the material unusable. How to resist this expansion? Experts say that one way is to achieve a resistance of about 2 N \/ mm2 , which is achieved by keeping the concrete at 5 \u00b0C or more for a period of 48 hours.<\/strong><\/p>\n

However, it should be pointed out that low temperatures decrease the strength development even if a strength of about 2 N\/mm2 <\/strong>has been achieved<\/p>\n

What to do when concreting in very cold weather?<\/h4>\n

The concrete should be kept above 5 \u00b0C for the first 48 hours<\/strong> and then ensure that the strength has developed.<\/p>\n

It is advisable to seek expert advice from industry specialists <\/strong>who know how to take the appropriate precautions depending on the harshness of the climate, based on three categories regarding the coldness of the concreting process:<\/p>\n