Glue for stone and concrete

Adhesives for stone and concrete describe adhesives that are used for bonding, repairing, and linking either natural stone or artificial stone and cement-based materials. Such adhesives are made with careful consideration of the characteristics of stone and concrete; hence, they must have the desired tensile strength required for construction processes.
Adhesive types. Adhesives come in different types, which serve many purposes, and differ on features such as strength, flexibility, curing time, and ability to stand certain conditions. The proper adhesive type can be chosen from the following types:
Epoxy Strong adhesive is a glue composed of resin and hardener, which is different from regular glue. This adhesive has many benefits such as the ability to stand curing, resist compressive force, with high bonding abilities. It can be used in cases where stable and durable use is required.
Characteristics: waterproof, resistant to high temperature, having high physical properties.
Common application: used for bonding different materials.
MS Polymer Adhesive is an elastic adhesive with high bonding capability, which is designed to solve the problem of brittleness of epoxy adhesive, caused by changing temperature and movement, and does not leave any marks on the light-colored stone.
Difference: Flexible bonding, waterproof, UV resistant, without toxicity, does not change color and suitable for being used on wet and dry surfaces, does not stain stone.Introduction: Different adhesives are meant for different purposes.
1.1 Epoxy Adhesive
Epoxy adhesive is chosen for bonding stone and concrete because of its strength and bonding power.
Properties: Good bonding ability, high bonding force, good durability, higher resistance to heat and humidity.
Common areas of use: Interior stone works like terrazzo flooring, marble tops, etc.
1.2 Polyurethane based adhesive
Polyurethane based adhesive is suitable for bonding light stone and concrete surfaces.
Properties: Good water resistance, heat resistance, versatility in bonding stone surfaces, etc.
Common areas of use: Joining interior walls or exterior walls, bonding concrete blocks, attaching tiles.
1.3 PU Concrete adhesive
PU adhesive has a high penetrating quality resulting in good penetration of concrete and stone.
Properties: High penetration, flexibility, and crack resistance along with efficiency in humid environments.
Common areas of application: Grout cracks in concrete.
1.4 Cement based adhesive
Cement based adhesive mixed with latex is what causes it to gain flexibility as well as bonding properties.
Properties: Compatibility to cement base, flexibility, and economical price.
Common areas of application: Stone tile flooring.Major engineering criteria for adhesives used in stone materials or constructed from concrete.
An adhesive that is suited to be used on stone and concrete products has to meet the following criteria to determine if it is of good quality:
• Adequate adhesion. Good adhesion to porous concrete, natural stones, or synthetic stones and construction materials
• Resistance to adverse weather. Resistance to freezing and thawing, rain and sunlight, and prevention from peeling and cracking when used outdoors
• Resistance to staining. There should be no infiltration of oil, no yellow or dark spots on the white marble, quartz, or porous stones
• Stability of performance. No shrinking, no hollowness, quick curing period (5 minutes for fast-setting types, one hour for normal structural types)
• Water and moisture resistant. There should be no penetration of water through the glued parts. Employ correct methods of treating both small and big cracks to protect concrete against damage causes by vibrations
• A big volume of stone buildings should be constructed using modified cement stone adhesive. The material to be used should be made from cost-effective materials used in construction requirements of all sorts of buildings and walls
• Special stone types vulnerable to humidity require the use of waterproof epoxy glue which will not allow the stone to change color or create holes.
Typical Construction Workflow
The necessary construction cycle ensures the expected quality and reliability of bonding.
1. Preparing the Base: Concrete and stone surfaces need to be cleaned up, being free of dust and oil. Surfaces may be either dry or even wet (depending on the glue used);
2. Preparing the Glue: In case of two-component epoxy glue, the glue components must be mixed in the required proportions. In case of the use of one-component MS polymer glue it is required to shake it well before application;
3. Applying and Connecting: Glue should be evenly applied on the overall bonding area (point or total bonding). The system should be bonded quickly relying on the indicated time frames;
4. Dismantling and Curing: Glued parts are held in place preventing them from shifting. Curing needs 30 to 60 minutes and takes full strength in 24 hours;
5. Finishing: The glue that has not been cured is removed.
Most Common Problems and Solutions
• Peeling or formation of holes: the reason is not cleaned base surface or the failure to wait for curing. It is necessary to clean the surface before bonding the stones and do not load it for the time taken for the glue curing;
• Staining of the surface: caused by wrong glue formula. It is necessary to use MS glue or glue suitable for stone products only;
• Cracking of the bonded area after curing: due to poor material of the used glue. The materials should use flexible MS/PU glue;
• Curing too slow: due to low temperature and wrong mixing. The construction should be held in 15-30 degrees and the proportions should be observed.