Brick mortar plays a very important role in the construction process, as it is an important part of bonding bricks together. However, many problems can arise when using brick mortar, one of which is the issue of shrinkage when the mortar dries. So, will brick mortar shrink when it dries? Let’s discuss this issue in detail below.
Will brick mortar shrink when it dries?
The answer is yes. During the drying process of brick mortar, volume changes occur due to the evaporation of water, which inevitably leads to a certain degree of shrinkage. The shrinkage rate of mortar is related to various factors such as water-cement ratio, powder mixing ratio, porosity, pore size, and material water absorption.
Reasons for shrinkage of brick mortar?
Evaporation of water
Water is a very important component of mortar, which makes it plastic and easy to use. However, during the drying process of the mortar, the water gradually evaporates, causing volume reduction.
Cement is the main binding material in the mortar, but it is also one of the main factors that cause shrinkage of the mortar. During the solidification process of cement, hydration reactions occur, which generate heat and shrinkage force.
External environment influence
External factors such as temperature and humidity also affect the shrinkage rate of the mortar. In a high temperature and low humidity environment, the water in the mortar evaporates more quickly, thereby accelerating the shrinkage process.
How to prevent shrinkage of brick mortar?
Select suitable mortar materials
Before construction, it is necessary to select suitable mortar materials, such as mortar with special additives. These additives can change the cement hydration reaction of the mortar, reduce the degree of cement shrinkage, and thus reduce the shrinkage rate of the mortar.
Control water-cement ratio
The water-cement ratio in the mortar refers to the ratio of the mass of water in the mortar to the mass of cement. A high water-cement ratio will lead to a large shrinkage of the mortar after drying, so the water-cement ratio should be reasonably controlled.
Control mortar humidity
During the construction process, it is necessary to control the humidity of the mortar, avoid excessive drying, and use covering and moisturizing methods, such as covering the surface of the mortar with a wet cloth, to prevent the water from evaporating too quickly.
In construction, attention should be paid to the ambient temperature and avoid construction in excessively cold or hot environments to reduce the degree of shrinkage of the mortar.
Control construction quality
During the construction process, attention should be paid to the quality of construction, ensuring even application of the mortar and reducing the generation of bubbles to minimize the degree of shrinkage of the mortar.
How to improve the shrinkage problem of brick mortar?
Use special additives
Before construction, special additives can be added to reduce the degree of cement shrinkage, thereby reducing the shrinkage rate of the mortar.
Select appropriate mortar materials
Before construction, it is necessary to select appropriate mortar materials. Choosing high-performance mortar materials that can control shrinkage can reduce the shrinkage rate of the mortar.
Control the proportion of mortar mix
The proportion of mortar mix refers to the ratio of cement, sand, and water. By controlling these ratios properly, the shrinkage rate of the mortar can be reduced.
Increase the fine sand and aggregate in the mortar
Appropriately increasing the fine sand and aggregate in the mortar can increase the density of the mortar and reduce the degree of shrinkage.
In short, during the use of brick mortar, mortar shrinkage is a common problem, but the shrinkage rate of the mortar can be reduced by selecting appropriate materials, controlling the degree of cement shrinkage, controlling the water-cement ratio of the mortar, construction quality, and other methods, thus ensuring construction quality and extending service life.