How to concretize in hot and dry weather
Concreting with a power trowel or any other method is one of the processes that requires high knowledge and understanding.
However, knowledge alone is not enough to do this serious work, and experience is one of the pillars of success in this huge and complex process.
This is exactly why it is always necessary to keep your knowledge in this field up to date and carefully read the important points that are raised in the field of concreting.
In this note, we are with you to review some important points about how to concretize in a particular situation.
In this note, we are going to take a brief look at the concreting process itself and its importance, and examine the concreting in hot and dry weather under a magnifying glass to get interesting and practical points in this regard.
If you also want to get new information about concreting in hot and dry weather, we are hosting your attention in the following topics. Our focus is on providing tips on improving the quality of concreting in this type of climate.
Concreting in hot and dry weather; what is the meaning of hot and dry air?
The first question that needs to be answered is basically what is meant by hot and dry air in this category. Hot and dry air refers to a climate in which the temperature is high and we see a low level of humidity in this air.
Of course, wind is also effective in creating hot and dry weather conditions.
In addition to this qualitative definition, quantitatively, in order to obtain hot and dry conditions, the temperature of concrete during concreting to setting should be more than 32 degrees Celsius.
In terms of humidity, if the rate of surface evaporation with an intensity of more than 1 kg per square meter, the humidity and temperature of the air tends to dry and hot. Ideally, however, we should not allow the rate of evaporation to reach more than 0.5 liters per square meter.
What are the effects of these conditions on the concreting situation?
The European standard ENV 206, which sets the temperature limit of concrete at 30 degrees, mentions the following:
Increase the rate of water loss in concrete and thus accelerate setting and hardening, which will lead to a significant reduction in efficiency.
Accelerate the hydration of cement and rapidly increase the temperature of concrete.
Increasing the possibility of the appearance of dough cracks in the concreting process.
Create the need for a fast processing process.
If the existing technical points and principles are not taken into account, the durability of concrete will be faced with serious joy.
But to get rid of these problems and prevent these events, what strategies should be used during concreting?
Required to prevent disruption of the concreting process in hot and dry weather
Moistening the ground surface and concreting molds.
Using of dry aggregates with high water absorption.
Use temporary canopies to provide shade and reduce concrete temperature.
Reduce the temperature of the concrete using cold water in the mix.
Maintaining the moisture of the concrete surface to reduce the rate of water evaporation in the early hours of concreting.
Protect the wet surface of concrete with a tool such as protective paper or other surfaces that provide heat reflection and repulsion.
On the other hand, in accordance with the national building regulations, it should be considered that:
In order to prevent cracking, special measures should be taken to prevent the decrease of humidity and increase of temperature during concreting.
These measures are as follows:
Keep concrete away from direct wind and sunlight, which disrupts the concreting stabilization process.
Prevent the evaporation of water in the concrete texture by performing continuous spraying in accordance with the schedule.
Also, in the case of structures where the presence of any crack in the concrete can cause the cancellation and inefficiency of the whole concreting process, the above precautions should be implemented in an intensified manner.
Some other side points about the concreting process in hot and dry weather
In accordance with the ABA standard, the following actions and measures are required to reduce the temperature of concrete and maintain its health during concreting.
A) Carrying out detailed planning for all stages of concrete paste making and concreting
B) Trying to find a suitable time window for concreting in such a way that the best time of day is selected in terms of low temperature.
C) In order to prevent the use of high cement, it is necessary to adopt a suitable mixing plan and in the case of cement itself, use suitable materials with low temperature.
D) Do not use cement that has a temperature of more than 75 degrees Celsius as it progresses
E) Attempts to keep the temperature of cement low by innovative methods such as storage in special silos that absorb less heat. This can be done with white silos to minimize light absorption and consequently heat.
C) Blowing cold air along with continuous spraying can lead to a drop in aggregate temperature and thus reduce the damage caused by concreting in hot and dry air.
In addition to these two techniques, this issue can be greatly facilitated by modifying the aggregate depot method.
G) The use of dry ice or other types of crushed ice to create a noticeable decrease in temperature in the water consumed can be effective provided that it is accompanied by planning and continuity during the process.
H) In the case of the bed of flowing water, it is also possible to try to reduce the water temperature by thinking of special measures. For example, trying to keep pipes away from direct sunlight is a logical and practical solution.
I) The same approach as before can be applied to other concreting tools and keep their temperature normal by keeping all concrete contact devices away from direct sunlight.
All machines involved in the process of transporting and making concrete mortar can be kept at a low temperature with this method.
