Dry-mixed mortar, a type of mortar supplied in a commercialized form, refers to a product whose ingredients are centrally mixed at a factory rather than on-site. Together with pre-mixed (wet) mortar, it constitutes the two major categories of commercial mortars.

1. Definition

Dry-mixed mortar, as a commercially available form of mortar, is prepared in a centralized manner at a factory rather than on-site. It falls under the category of commercial mortars and, together with pre-mixed (wet) mortar, constitutes the two main subcategories within this broad product group.

Ready-to-use Wet Mortar

Pre-mixed wet mortar, also known as ready-to-use wet mortar, is a type of mortar that is pre-mixed in a factory and kept in a wet state. Unlike dry-mix mortar, it is supplied directly in a wet form and can be used immediately without further mixing on the construction site. This type of mortar has unique characteristics in both its manufacturing process and performance, bringing convenience and efficiency to the construction industry.

Pre-mixed wet mortar is composed of cement, sand, water, fly ash or other admixtures, plus an appropriate amount of additives. After being precisely mixed at the factory, it is transported to the designated construction site by specialized mixing and transport vehicles. This type of mortar, when used under the specified construction conditions, is widely adopted in the construction industry due to its convenience and high performance, and is gradually becoming a favorite choice in modern construction.

Ready-to-use Dry Mortar

Dry-mixed mortar, as a precast construction material, is playing an increasingly important role in the construction industry. It is pre-mixed at the factory, containing cement, sand, aggregates, and other additives; when used, all that’s required is to add water according to the specified ratio and mix thoroughly. This type of mortar is characterized by its ease of use and consistent quality, making it widely applicable in a variety of construction projects.

Dry-mix mortar—a construction material meticulously crafted by specialized manufacturers—combines finely graded aggregates that have undergone dry screening, inorganic binding materials, mineral admixtures, and other carefully selected additives. These ingredients are precisely proportioned to form a powdered or granular mixture. At the construction site, all that’s required is to simply add water according to the instructions and mix thoroughly, transforming the dry mix into a high-performance mortar blend. Its packaging comes in various flexible forms, ranging from bulk delivery to bagged packaging. Moreover, dry-mix mortar is also referred to as dry-mixed mortar or dry powder material, highlighting its unique position in the construction industry.

2. General-purpose dry-mix masonry mortar :

Specifically pre-mixed for masonry work, ensuring efficient construction and superior quality.

3 General-purpose dry-mix plaster mortar

This universal dry-mix plaster mortar is tailor-made for plastering projects and pre-mixed to enhance construction efficiency and ensure quality.

4 General-purpose dry-mix plaster mortar

Specifically designed for plastering work, this product utilizes pre-mixed technology to ensure efficient construction and superior quality.

5 General-purpose dry-mix floor mortar

This dry-mix floor mortar is equally suitable for flooring applications, and its pre-mixed technology ensures both high construction efficiency and superior quality.

6 Application of universal dry-mix floor mortar

This pre-mixed dry mortar is not only suitable for floor applications but can also be used for roofing work, covering both the surface layer and the leveling layer of roofs. Its highly efficient pre-mixing technology ensures smooth construction processes and outstanding quality.

7 Special dry-mixed mortar

Special dry-mix mortar has carved out a niche for itself in the construction industry thanks to its unique performance and versatility. It boasts a wide range of applications, not only suitable for conventional flooring projects but also ideal for special environments—such as those requiring high strength, corrosion resistance, or freeze-thaw durability. Moreover, this mortar’s pre-mixing technology is equally impressive, ensuring both efficiency and high quality in construction operations.

8 Definition and Applications of Special Dry-Mixed Mortars

Specialty dry-mix mortars are specifically designed for construction and decoration projects with particular performance requirements. They cover a wide range of applications, including exterior insulation finishing mortars, self-leveling floor dry-mix mortars, interface agents, finish coats, and waterproof mortars. Compared to traditional mixing methods, these mortars offer numerous advantages, such as stable quality, diverse product varieties, efficient production, superior quality, and convenient construction.

9 Classification of Dry-Mixed Mortar

Dry-mixed mortars can generally be divided into two major categories: ordinary mortars and special mortars. Ordinary mortars are primarily used in masonry, plastering, and floor construction, whereas special mortars offer specialized solutions tailored to specific needs, such as tile adhesion, surface preparation, thermal insulation construction, self-leveling technology, waterproofing, and repair work.

Masonry mortar: Specifically designed for masonry work with block-shaped building materials such as bricks, stones, and concrete blocks.

Application of Masonry Mortar

Masonry mortar—a material specifically designed for bonding bricks, stones, blocks, and other masonry units—plays an indispensable role in modern construction.

10 Plaster mortar

As an indispensable component of construction, plastering mortar must possess excellent workability to ensure that it can be easily applied in uniform and smooth thin layers, thereby simplifying the construction process. At the same time, it needs to exhibit strong adhesion to ensure that the mortar layer bonds firmly to the substrate, providing long-lasting durability and preventing cracking or delamination. Moreover, plastering mortar effectively protects buildings and walls against erosion caused by natural elements such as wind, rain, and snow, enhancing the structural durability of the building and giving it a smooth, polished, and aesthetically pleasing appearance.

11 Preferred characteristics of plastering mortar

Plastering mortar occupies a pivotal role in the construction industry. Its excellent workability allows construction workers to easily apply it as a uniform and smooth thin layer, not only simplifying the construction process but also significantly boosting efficiency. At the same time, its strong adhesion is an indispensable feature of plastering mortar—it ensures that the mortar layer adheres firmly to the substrate, thereby preventing cracking or delamination and making buildings more durable and long-lasting. Moreover, plastering mortar effectively protects buildings and walls from the erosive effects of natural elements such as wind, rain, and snow, enhancing the durability of the structure and giving it a smooth, polished, and aesthetically pleasing appearance.

12 Tile adhesive

Tile adhesives, also known as tile mortars, are specially designed for bonding ceramic tiles, polished tiles, and natural stones such as granite. These adhesive mortars feature exceptional bonding strength and can adapt to various substrates, including wood boards and cement fiberboards. They are optimally formulated to suit different finishing materials and a wide range of extreme climatic conditions, such as high humidity and temperature fluctuations. They provide a secure bond for inorganic, rigid decorative materials, ensuring both construction quality and durability.

13 Application of tile adhesives

Tile adhesives, specially formulated for bonding ceramic tiles, polished tiles, and natural stones such as granite, are widely used and deliver outstanding performance. This adhesive mortar not only boasts strong bonding strength but also adapts well to various substrates and extreme climatic conditions—such as wood boards, cement fiberboards, damp environments, and environments with significant temperature fluctuations. Through optimized design, it ensures a secure bond with inorganic, rigid decorative materials, providing robust assurance for construction quality and durability.

14 Interface mortar

Interface mortar, also known as an interface treatment agent, is a material with bidirectional affinity. It not only firmly bonds to the substrate but also ensures that the new adhesive can adhere tightly to its surface. Regardless of the substrate's varying surface characteristics—such as porous, highly absorbent materials, less-smooth, absorbent materials, non-porous, non-absorbent materials, or even cases where cohesive forces arising from subsequent expansion and contraction of overlay materials lead to bond failure—the interface treatment agent can effectively enhance the bonding strength between the two materials.

15 The reinforcing effect of interface mortar

Interface treatment agents, commonly referred to as interface mortars, exhibit outstanding reinforcing effects. They can significantly enhance the bond strength between two different materials and ensure a secure adhesion regardless of the surface characteristics of the substrate. Moreover, they effectively address bond failure issues caused by cohesive forces resulting from the shrinkage and expansion of subsequent facing materials applied to the substrate.

16 Characteristics and Applications of External Thermal Insulation Mortar

External thermal insulation mortar is a specialized mortar that combines lightweight aggregates with high-quality additives, offering outstanding thermal insulation performance. The materials used—such as polystyrene foam beads, expanded perlite, or glass microspheres—endow it with exceptional toughness. Meanwhile, the addition of additives like fibers, cellulose ethers, and latex powder further enhances its crack resistance, making this mortar not only easy to apply but also highly weather-resistant. Moreover, external thermal insulation mortar is lightweight and cost-effective, making it an ideal choice for energy-efficient buildings.

The advantages of external thermal insulation mortar

External thermal insulation mortar has carved out a niche for itself in the field of building energy conservation thanks to its unique properties. Not only does it boast outstanding thermal insulation performance, but it also incorporates lightweight aggregates and high-quality additives, giving the material exceptional toughness. Moreover, its crack resistance has been significantly enhanced, thanks to the clever use of additives such as fibers, cellulose ethers, and latex powder. During construction, this mortar performs exceptionally well—easy to handle yet highly weather-resistant—providing strong support for the development of energy-efficient buildings. Additionally, being lightweight and cost-effective, external thermal insulation mortar is undoubtedly an ideal choice for both energy-saving renovations and the construction of new energy-efficient buildings.

17 Application of self-leveling mortar

Self-leveling mortar, specially designed for uneven substrates. Whether it’s a surface undergoing renovation or an existing mortar layer, this product provides a stable, level, and smooth base—creating ideal conditions for laying various flooring materials such as carpets, wood floors, PVC, or tiles. Thanks to its highly efficient application properties, it easily handles large-area installations.

18 Advantages of self-leveling mortar

Self-leveling mortar not only provides a stable, level, and smooth substrate but also boasts efficient construction characteristics. Thanks to its unique self-leveling design, it can easily handle both small- and large-scale installations, significantly boosting construction efficiency. Moreover, it is suitable for laying a wide variety of flooring materials, such as carpets, wood floors, PVC, and tiles, making it an ideal solution for diverse flooring needs.

19 Waterproof mortar

Waterproof mortar, a cement-based waterproofing material, is primarily composed of cement and fillers. It is prepared by mixing in polymers, additives, admixtures, or special cements to form a dry-mix mortar that meets the requirements for waterproofing performance. On the market, this type of material is often referred to as JS composite waterproof coating.

20 Application of waterproof mortar

Waterproof mortar, a type of cement-based waterproofing material, plays a crucial role in the construction industry. Through a specific mixing process that incorporates polymers, additives, and other ingredients, this material not only exhibits outstanding waterproof performance but also proves suitable for a variety of complex construction environments. Highly acclaimed in the market, it is widely used in various construction projects.

21 Application of repair mortar

Repair mortars also occupy an indispensable position in the construction industry. They are not only used for decorative repairs of concrete that contains no reinforcement and serves no load-bearing function, thereby enhancing its aesthetic appeal; they can also be employed to restore damaged reinforced concrete structures, aiming to maintain and rebuild their stability and functionality. This material plays a crucial role in the repair and restoration of facilities such as bridges, roads, parking lots, and tunnels, ensuring the long-term durability and longevity of buildings.

22 The importance of repair mortars in the construction field

Repair mortars play a crucial role in the construction industry. They are not only widely used for decorative repairs of concrete structures that contain no reinforcing steel and serve no load-bearing function, thereby enhancing their aesthetic appeal; they also play an indispensable role in the restoration of damaged reinforced concrete structures. The application of this material aims to restore and rebuild the structural stability and functionality of buildings, ensuring their long-term durability. In repair and rehabilitation projects involving bridges, roads, parking lots, tunnels, and other infrastructure facilities, repair mortars have demonstrated their outstanding performance and critical importance.

23 Interior and exterior wall putty

Putty—a crucial auxiliary material in architectural decorative coatings—acts like a delicate veil, lending walls a smooth and even finish. It comes in two main categories: single-component and two-component. Often used in conjunction with latex paints, putty helps create a smooth, seamless wall surface, laying a solid foundation for subsequent coating processes.

24 Grout

Grout, also known as joint filler, is specially designed to fill the gaps between tiles or natural stone materials. Not only does it give walls an aesthetically pleasing appearance, but it also enhances the bond between facing tiles and provides waterproofing capabilities. Moreover, grout effectively protects the underlying tile material from mechanical damage and water penetration.

25. The Importance of Grout

Grout plays a crucial role in the installation of tiles or natural stone. It not only enhances the aesthetic appeal of walls but also strengthens the bond between facing tiles, effectively preventing water infiltration. At the same time, grout provides protection for the tile substrate, shielding it from mechanical damage and the threat of water penetration.

26 Grouting material

Grouting material, a cement-based material endowed with shrinkage-compensating properties, exhibits slight expansion characteristics. During both the plastic stage and the hardening process, it generates minute expansions that effectively compensate for shrinkage. This material finds extensive application in various fields, including dry-shrinkage compensation, early-strength enhancement, high-strength grouting, and repair work. Thanks to its hardened structure, which is characterized by high strength, density, and impermeability, this material maintains excellent fluidity even under low water-to-cement ratios, further optimizing the processes of construction pouring and repair application.

27 Analysis of Dry-Mix Mortar Issues

Dry-mixed mortar—a rising star in the construction materials sector—is increasingly gaining favor in the market. Its convenience and environmental friendliness help reduce resource waste, enhance construction quality, and effectively improve urban environments. However, along with its rapid development, dry-mixed mortar has also exposed numerous quality issues. If these problems are allowed to fester unchecked, not only will their inherent advantages be undermined, but they could also trigger unforeseen negative consequences. Therefore, from raw material procurement and finished-product manufacturing all the way to the construction site, stringent quality-control measures must be implemented at every stage to ensure that dry-mixed mortar can truly deliver its intended performance.

28 In-depth Analysis of Common Causes

In the course of application, dry-mix mortar often encounters several common issues that affect its quality. To address these challenges at their root, it is essential for us to conduct an in-depth analysis of the underlying causes behind these prevalent problems. Through scientifically rigorous analysis, we can pinpoint the crux of the issues and then propose effective solutions, thereby ensuring a comprehensive improvement in the quality and performance of dry-mix mortar.

29 Detailed Explanation of Crack Issues

In the application of dry-mix mortar, cracking is a widespread phenomenon that significantly affects product quality. To better understand and address this issue, we have conducted an in-depth analysis of four major types of cracks: cracks caused by uneven settlement of the substrate, temperature cracks, drying shrinkage cracks, and plastic shrinkage cracks. Among these, uneven settlement of the substrate refers to cracking resulting from the settling of the wall itself; whereas temperature cracks are induced by thermal expansion and contraction of materials. When thermal deformation is constrained, sufficient thermal stress builds up, ultimately leading to wall cracking. Through this thorough analysis, we can more accurately identify the root causes of cracking and thereby propose effective solutions.

30 . Drying shrinkage cracks and plastic shrinkage

Drying shrinkage cracks, often referred to as dry-shrinkage cracks, primarily occur in masonry materials such as aerated concrete blocks and fly ash blocks. As the moisture content of these materials decreases, they undergo significant drying shrinkage deformation. It is worth noting that materials that have undergone drying shrinkage will expand when exposed to moisture, but upon subsequent dehydration, they will again experience drying shrinkage.

Plastic shrinkage, on the other hand, occurs primarily in the early stages following mortar plastering. At this stage, the mortar is still in a plastic state, and as the moisture content decreases, shrinkage stresses begin to develop. Once these shrinkage stresses exceed the mortar's own bond strength, cracks will start to appear on the surface of the structure. The rate of this plastic drying shrinkage is closely related to factors such as time, temperature, relative humidity, and the water-retention capacity of the plastering mortar.

In addition, design deficiencies, non-standard construction practices, substandard material quality, and the lack of targeted crack-prevention measures are all significant factors contributing to wall cracks.

31 Causes of drumming phenomena

The occurrence of hollow-sounding phenomena can be attributed primarily to four main factors. First, the surface of the base wall has not been properly prepared—dust, residual mortar, and release agents have not been thoroughly cleaned, making it difficult for the plaster to adhere firmly during application. Second, the wall was not given sufficient curing time before plastering commenced; rushing into plastering too soon also compromises the bond between the plaster layer and the base wall. Third, applying a single-layer plaster that is excessively thick results in an excessive weight for the plaster layer itself, making it challenging for it to bond tightly with the base wall. Finally, using inappropriate plastering materials—such as those with improper mix ratios or poor quality—can significantly increase the risk of hollow-sounding phenomena.

Applying plaster to walls before they have undergone sufficient curing can lead to inconsistencies between the substrate and the plaster layer during the shrinkage process, thereby causing hollowing. Additionally, applying a single-layer plaster that is excessively thick is also a significant contributing factor. Particularly when the wall surface is uneven or has defects, if no prior preparatory treatment is carried out and the plastering process is rushed to completion in one go, the shrinkage stress in the plaster layer may exceed the bonding strength of the mortar, thus resulting in hollowing. Furthermore, improper selection and use of plaster materials are also critical factors that cannot be overlooked—for instance, if the strength of the plaster mortar does not match the strength of the substrate wall, or if there is an excessive difference in their shrinkage rates, these issues can all become sources of hollowing.

The phenomenon of surface sand loss is primarily attributed to an insufficient proportion of cementitious materials in the mortar, a low fineness modulus of the sand, excessive silt content exceeding the standard limits, and inadequate mortar strength. Additionally, low water retention capacity of the mortar, rapid water loss, and improper or absent curing measures after construction are also significant contributing factors to sand loss.

The phenomenon of powder shedding and skinning is primarily attributed to insufficient water retention in the mortar, which in turn compromises the stability of the mortar’s various components. When the proportion of admixtures is excessively high, the rubbing and smoothing processes can cause some of the powdered materials to rise to the surface and accumulate there, thereby reducing the surface strength and ultimately leading to powder shedding and skinning.