The cementing materials used for masonry mortar are cement and lime.
The choice of cement varieties is the same as that of concrete. Cement label should be 4-5 times of mortar strength grade. If cement label is too high, it will
Insufficient cement consumption leads to poor water retention. Lime paste and hydrated lime are not only used as cementing materials, but also make mortar have good water retention.
(2) Fine aggregate
Fine aggregate is mainly natural sand, and the prepared mortar is called ordinary mortar. Clay content in sand should not exceed 5%; Strength, etc
When the gradation is less than M2.5, the clay content should not be greater than 10%. The maximum particle size of sand should be less than 1/4- 1/5 of the mortar thickness, and generally not more than 2.5 mm. As mortar for jointing and plastering, the maximum particle size is less than 1.25mm, and the thickness of sand has great influence on cement dosage, workability, strength and shrinkage. (A) the type of masonry mortar and the choice of strength grade
1, types of masonry mortar
Commonly used masonry mortar includes cement mortar, lime mortar and cement-lime mixed mortar.
Cement mortar is suitable for wet environment and masonry engineering with water; Lime mortar is only used for masonry projects with low strength requirements and dry environment; Mixed mortar not only has good workability, but also can be prepared into masonry mortar with various strength grades, which can be widely used in various masonry projects except masonry with high water resistance requirements.
2, the choice of masonry mortar strength grade
The masonry mortar of M 1-M 10 is generally used for the walls of multi-storey buildings; Masonry foundation, inspection well and rainwater well
Such as masonry, often use M5 mortar; M25-m10 masonry mortar is selected for the masonry of industrial workshops, substations and basements; Buildings below the second floor generally use mortar below M2.5; Simple bungalows and temporary buildings can choose lime mortar.
(2) Mix proportion of masonry mortar
The workability of mortar mixture should meet the construction requirements, and the volume density of new mortar: cement mortar should not be less than1900kg/m3; The mixed mortar shall not be less than 1800kg/m3. The mixing ratio of masonry mortar is generally checked in the construction manual or according to experience.
(3) Mixing of mortar
Mortar mixer is generally used for mortar mixing, which requires uniform mixing. Plasticizers such as clay, electro-gypsum and fly ash can be added to improve the water retention of mortar. Mortar should be mixed with it. If the mortar is bleeding, it should be stirred again. Cement mortar and mixed mortar must be used within 3h and 4h after mixing. If the temperature is above 30℃, they must be used within 2h and 3h. 1, decorative mortar
Decorative mortar refers to the mortar coated on the surface of the base material, which has the function of protecting the base and increasing the appearance. Plastering mortar is used to paint brick walls. Because of the strong water absorption of brick, the contact surface between mortar and grass-roots and air is large, and the water is lost quickly, so lime mortar should be used. Cement mortar should be used when meeting the requirements of waterproof and moistureproof.
2, waterproof mortar
Waterproof mortar is to mix a certain amount of waterproof agent into ordinary mortar. Commonly used waterproofing agents are chloride metal waterproofing agent and metal soap waterproofing agent. 1, composition of diagenetic mortar:
Diagenetic mortar is a dry powder mortar composed of dozens of inorganic elements. After being mixed with water, the cement particles are decomposed by four-step continuous chemical reaction, and act together with the metal elements of the mortar, so that the cement particles are completely hydrated, and the maximum utilization efficiency of the mortar is achieved, that is, waterproof, impervious, corrosion-resistant, oil-resistant, frost-resistant, non-shrinkage and cracking, and good durability.
2, the performance characteristics of diagenetic mortar:
The diagenetic mortar is waterproof, impervious and temperature resistant to 200 degrees, wear-resistant, with high strength, impermeability 1.85MPA, cohesive force 1.35MPA, shrinkage of 0.08% and good durability.
3, diagenetic mortar formula
A, waterproof mortar
Adding KFA to ordinary cement mortar can make high-performance waterproof mortar. The reference formula is 1: 3 (weight ratio) or 1: 2.5 cement mortar, with 10 kg KFA per cubic meter. It is equivalent to an increase of 5 kg KFA per ton.
1: 3 cement mortar
42.5 Ordinary Portland cement: 250kg.
(or Portland cement)
Graded medium sand: 750kg.
Water: 105 kg
KFA 5 kg class
Water cement ratio: 0.42
1: 2.5 cement mortar
42.5 Ordinary Portland cement: 300kg.
(or Portland cement)
Graded medium sand: 750kg.
Water:120kg
KFA 5 kg class
Water cement ratio: 0.4
Second, the corrosion-resistant mortar formula
KFA waterproof mortar has certain corrosion resistance, and general corrosion is no problem.
If it is necessary to strengthen the anti-corrosion effect, the dosage of KFA can be increased.
Reference formula of corrosion-resistant mortar:
1: 2.5 cement mortar
42.5 Ordinary Portland cement: 300kg.
(or Portland cement)
Graded medium sand: 750kg.
Water:120kg
KFA 7.5 kg
Water cement ratio: 0.4
The slump of the above formula is about 6cm~8cm, which is slightly drier than ordinary mortar, but it does not affect the working performance. Mortar is "fat", which is better as sprayed concrete and has excellent effect. If artificial plastering is needed, naphthalene series or carboxyl series water reducer can be added appropriately to adapt to workers' operation. The dosage is about 0.5% of cement, but the water consumption shall not be increased arbitrarily. The sand is preferably graded quartz sand or washed sand.
Three. Wear-resistant and corrosion-resistant floor formula
According to different requirements and construction conditions, there are three methods for wear-resistant and corrosion-resistant floors:
1, thin plastering, about 3mm~5mm thick.
42.5 Ordinary Portland cement: 300kg.
(or Portland cement)
Graded medium-fine quartz sand: 600kg.
Water:120kg
KFA 7.5 kg
Water cement ratio: 0.4
When the concrete or mortar at the grass-roots level is initially set, it will be better to apply a thin layer and combine it with the grass-roots level. When the upper layer is initially set, it will be calendered and smoothed, and then polished after it is completely hardened.
2, 1: 2 or 1: 2.5 cement mortar 2~3cm, leveling layer, surface layer completed at one time.
42.5 Ordinary Portland cement: 300kg.
(or Portland cement)
Graded medium-coarse quartz sand: 600kg (750kg).
Water:120kg
KFA 7.5 kg
Water cement ratio: 0.4
Calendering and screeding shall be carried out during initial setting, and polishing and grinding shall be carried out after complete hardening.
3, 40mm thick fine stone concrete, grass-roots, leveling layer, surface layer completed at a time.
42.5 Ordinary Portland cement: 380 kg
(or Portland cement)
Coarse aggregate (10 ~15mm): 780kg.
Fine aggregate (5 mm): 405 kg
Coarse sand (1mm): 555kg.
Fine sand (
Water: 170kg
Kfa: 7.5 ~ 10 kg
Water cement ratio: 0.45
If the floor has color requirements, white cement can be used, and other inert pigments such as iron oxide can be added.
Precautions for use:
When mixing concrete, please add it according to the above suggested amount of water. 7.5 ~ 10kg KFA powder is added to every m3 of fine stone concrete formula. Please dissolve KFA powder with water in advance. KFA dry powder can be directly added, and the mixing time is at least 5-7 minutes. When the concrete mixture hardens, only 0.5 kg of water can be added to each cubic meter of concrete formula, and the mixing time is an important factor affecting the quality of concrete. The slump should be around 10cm. Continuous stirring is required during construction, and the agitator cannot be turned off. According to the engineering needs, water reducing agents such as carboxylic acid or naphthalene sulfonic acid can be added appropriately, but the dosage can be halved.
Four, ultra-fine grouting, repair cement
Ordinary Portland cement (Portland cement) can be turned into superfine cement by adding about 2.0~2.5% KFA, which is used to repair cracks.
4, diagenetic mortar technical performance:
1, improving the early strength of 3-7 days by 20-25%.
2. Waterproof material
3. Early hardening strength
4. Impermeability
5. Able to work in extremely cold and hot environment.
6, improve the freeze-thaw cycle more than 400 times.
7. Shrinkage rate is reduced by 25%~50%, thus reducing shrinkage cracks.
8, improve wear resistance
9. Even if the water-cement ratio is very low, it still has high workability.
10, easy to pump, not easy to block the pipe.
1 1, the construction surface is smooth.
12, improve the tensile and bending strength.
13. Homogeneous material ensures hydraulic locking inside cement.
14, no warping foundation
15, increase the compactness.
16, 97% microcrack
17, which can be used in low temperature environment.
18, to prevent steel corrosion.
19, no maintenance required.
20. Reduce concrete water consumption by 8~ 15%.
2 1, without additives such as plasticizer, water reducer and expansion agent, and without fly ash, silica fume, screen, steel fiber or synthetic fiber;
22, shorten the construction time, the structure can be used within 14 days;
23, reduce or even eliminate weathering
24, reduce water absorption
25. High resistance to corrosive liquids and gases (including hydrogen sulfide).
26, can avoid the problem of high alkalinity and high humidity.
27, no bleeding
28, improve durability
29. This product has no problems such as pulverization, foaming, cracking and shrinkage.