1. What is masonry mortar? What materials do masonry mortars consist of? A: The mortar that bonds bricks, stones, blocks, etc. into a masonry is called masonry mortar. The material composition of the masonry mortar: cement, other cementitious materials (such as lime paste, clay paste, hydroxypropyl methylcellulose, etc.), fine aggregate and water. 2. What should I pay attention to when choosing masonry mortar? Answer: Cement can choose the appropriate cement type according to the design requirements, the masonry location and the environmental conditions. Choosing medium and low strength cement can meet the requirements. The cement used in cement mortar should not exceed 32.5 grades; the cement used in cement mortar should not exceed 42.5. When the quicklime is matured into lime paste, the mesh with a pore diameter of not more than 3 mm×3 mm should be used for filtration, and the ripening time should not be less than 7 days; the ripening time of the ground fine lime powder should not be less than 2 days. The lime paste stored in the sedimentation tank should be taken to prevent drying, freezing and pollution. It is strictly forbidden to use dehydrated and hardened lime paste. The consistency of the lime paste used should be controlled to about 120 mm. Sand for masonry mortar should be selected from medium sand. The coarse sand should be used for masonry. The mud content should not exceed 5%. The cement mortar with strength grade of M2.5 should not exceed 10 mud. %. Mix the mortar with water, and use clean water without harmful impurities to mix the mortar. 3. What materials are used to build the mortar? What are the construction mortars used for? A: Building mortar is composed of inorganic cementitious materials (hydroxypropyl methylcellulose, redispersible latex powder), fine aggregates and water, and sometimes blended with certain admixtures. Construction mortar is often used for masonry (such as brick, stone, block) structures, plastering of interior and exterior surfaces of buildings (such as walls, floors, ceilings), joints of large wall panels, masonry walls, and decorative materials. Bonding, etc. 4. What properties should the mortar after mixing have? Answer: The mortar after mixing should have the following properties: meet the requirements of workability; meet the design type and strength grade requirements; have sufficient adhesion. 5. What are the properties of masonry mortar? What is the content of mortar and workability? A: The properties of masonry mortar include the workability of the mortar, the strength of the mortar and the adhesion of the mortar. Mortar workability, including fluidity and water retention, has a lot to do with the additive hydroxypropyl methylcellulose. 6. How is the construction mortar classified? Answer: Building mortar is classified according to the purpose: it can be divided into masonry mortar and plastering mortar. The plastering mortar includes ordinary plastering mortar, decorative plastering mortar and special mortar. Special mortars include waterproof mortar, acid-resistant mortar, thermal insulation mortar, sound-absorbing mortar and so on. Construction mortar is classified according to cementitious materials: it can be divided into cement mortar, lime mortar and mixed mortar. Mixed mortar can be further divided into: cement lime mortar, cement clay mortar, lime clay mortar, lime fly ash mortar and the like. 7. What is the fluidity of the mortar, and what are the influencing factors? A: The fluidity of mortar is also called consistency. It refers to the performance of flow under the action of self-weight or external force. It is expressed by “sinking degree”. The degree of sinking is large, the mortar has great fluidity, but the fluidity is too large, and the strength will be reduced after hardening; if the fluidity is too small, the construction operation is not convenient. The fluidity of the mortar is related to the types of masonry materials, construction conditions and climatic conditions. For porous water-absorbing masonry materials and dry and hot weather, the fluidity of the mortar is required to be larger; on the contrary, for dense non-absorbent materials and wet and cold weather, the fluidity is required to be smaller. The additive hydroxypropyl methylcellulose plays the role of thickening and water retention, and the dispersible latex powder can increase the strength and improve the overall quality of the mortar. 8. What is the water retention capacity of the mortar, and what is the water retention capacity of the mortar? What are the requirements? A: The ability of fresh mortar to retain moisture is called water retention. Water retention also refers to the property that the various constituent materials in the mortar are not easily separated. The appropriate hydroxypropyl methylcellulose is selected to adjust the water retention effect of the mortar. The water retention of the mortar is expressed by “stratification”. The stratification should be between 10 and 20 mm, and should not be greater than 30 mm. Mortars with a stratification of more than 30 mm are prone to segregation and are not convenient for construction; mortars with a stratification close to zero are prone to dry shrinkage cracks. 9. What are the factors that affect the strength of the mortar? A: There are many factors affecting the strength of mortar. Experiments have shown that when the quality of the raw materials is constant, the strength of the mortar mainly depends on the strength grade of the cement and the amount of cement. The strength of the mortar can also be appropriately adjusted by adding the redispersible latex powder. 10. What are the effects of the bonding strength of masonry mortar? Answer: The bonding strength of masonry mortar increases with the increase of its strength. The higher the mortar strength grade, the greater the adhesion. The adhesion of the mortar is related to the surface state, cleanliness, wetting condition and construction and maintenance conditions of the masonry. Therefore, the bricks before the masonry should be watered and moist, and the moisture content should be controlled at 10%~15%. The surface should not be soiled to improve the adhesion between the mortar and the brick to ensure the quality of the masonry. 11. How should brick walls, slat walls or slat roofs, concrete walls, etc., and underlying plasters that are prone to collision or moisture? A: The bottom layer plaster used for brick walls, mostly with lime mortar; the bottom layer plaster used for slat wall or slat roof is mixed with mortar or lime mortar; the concrete wall, beam, column, roof and other bottom plastering multi-purpose mixed mortar , hemp stone mortar or paper gluten lime slurry. 12. What are the basic requirements for masonry mortar mix design? Answer: The mix design of masonry mortar should meet the following basic requirements: (1) The workability of the mortar mixture should meet the construction requirements, and the bulk density of the mixture: cement mortar <1900kg/m3; cement mixed mortar <1800 kg/m3. (2) The strength and durability of the masonry mortar should meet the design requirements. (3) It should be economically reasonable, and the amount of cement and admixture should be less. 13. What are the applications of masonry mortar in the project? Answer: Cement mortar should be used for masonry with high humidity and high strength; cement lime mortar should be used for masonry in dry environment; wall of multi-storey building is generally cement mortar with strength grade M5 Brick mortar, brick arch, reinforced brick lintel, etc. generally use cement mortar with strength grade M5~M10; brick foundation generally adopts cement mortar not lower than M5; limestone mortar can be used for low-rise houses or bungalows; lime can be used for simple houses Clay mortar. 14. What are the requirements for plastering mortar? A: The mortar is required to have good workability, and it is easy to be smeared into a uniform flat layer for easy construction. It should also have a high cohesive force, and the mortar layer should be able to bond firmly to the bottom surface without cracking or falling off for a long time. In a humid environment or vulnerable to external forces (such as the ground, wall skirts, etc.), should also have high water resistance and strength. 15. What are the main functions of ordinary plastering mortar? A: The function of ordinary plastering mortar is to protect the wall and the ground from the wind and rain and harmful impurities, improve the moisture resistance, corrosion resistance, weathering resistance and durability, and at the same time make the building surface smooth, clean and beautiful. effect. 16. What is the plastering mortar? Which types can be classified according to the different building functions of the plastering mortar? A: Any mortar applied to the surface of a building or building component is collectively referred to as a mortar. According to the different functions of the plastering mortar, the plastering mortar can be divided into ordinary plastering mortar, decorative mortar and plastering mortar with certain special functions (such as waterproof mortar, thermal insulation mortar, sound absorbing mortar, acid-resistant mortar, etc.). 17. Why is the compressive strength often used as the main technical index of mortar in the project? How is the strength grade of the mortar determined? What are the strength grades of the masonry mortar? Answer: Mortar mainly plays the role of transmitting load in the masonry. The test proves that the bond strength and durability of mortar increase with the increase of compressive strength, that is, there is a certain correlation between them, and the test method of compressive strength is mature, the test is simple and accurate, so engineering The compressive strength is often used as the main technical index of the mortar. The strength grade of the mortar is a cube test piece with a side length of 70.7mm. The standard curing conditions (cement mixing mortar is 20±2°C, relative humidity is 60%~80%; cement mortar is temperature 20±2°C, relative humidity). Above 90%), the compressive strength at 28 days of age was determined by standard test methods. The strength grade of masonry mortar is M20, M15, M10, M7.5, M5, M2.5. 18. Ordinary plastering mortar is usually divided into several layers. What is the difference between the functions and requirements of each layer of mortar? A: Ordinary plastering mortar is usually divided into two or three layers for construction. The mortar requirements vary from layer to layer, so the mortar used for each layer is different. Generally, the bottom mortar acts as a bonding base layer, and the mortar should have good workability and high adhesion. Therefore, the water retention of the bottom mortar is better, otherwise the moisture is easily absorbed by the base material and affects the adhesion of the mortar. The rough surface of the base layer is advantageous for bonding with the mortar. The middle plaster is mainly for leveling, sometimes it can be omitted. The surface plastering is mainly for the sake of smoothness and beauty, so fine sand should be selected. For more questions for technology or products, pls mail to sales@icelluloseether.com