Introduction of external wall plastering design code?

According to the technical regulations of external wall plastering in China, what are the regulations on external wall plastering design in China at this stage? What is the basic situation? The following is the basic content of Code for Design of Exterior Wall Plastering compiled by Bian Xiaozhongda Consulting Company:

Zhong Da Consulting combed the relevant materials and technical specifications of plastering mortar for external walls, mainly including: (1) basic requirements of plastering mortar; (2) raw materials of plastering mortar; (3) mix design of plastering mortar; (4) construction points, quality and acceptance. , in which the basic provisions of plaster mortar mix design are as follows:

1. General

What is the pressure test strength of plastering mortar mix design? M0, calculated according to the formula:? m0=k？ 2,? 2 is the compressive strength grade value of mortar (MPa); K is the reputation of mortar production quality level, which is divided into excellent, average and poor, and the k values are 1. 15 1.20 or 1.25 respectively. The mixing ratio is by weight. Mortar layering should be 10~20 mm, and plastering mortar for external walls should meet the frost resistance requirements.

2. Cement plastering mortar

The mixture ratio is shown in table 1, the apparent density of the mixture is not less than 1900 kg/m3, the water retention rate is not less than 82%, and the tensile bond strength is not less than 0.20 MPa.

Table 1 Mix ratio of cement plastering mortar Kg/m3

Strength grade cement sand water

M 15330~380

The bulk density of M20380~450 1m3 dry sand is 250~300.

M25400~450

M30460~530

3. Cement fly ash plastering mortar

See Table 2 for the dosage of mixture ratio. The apparent density of masonry cement mixture for preparation is not less than 1900 kg/ m3, the water retention rate is not less than 82%, and the tensile bond strength is not less than 0. 15 MPa. The dosage of this mortar for external wall cement should not be less than 250kg/ m3.

Table 2 Mix proportion of cement fly ash mortar Kg/m3

Strength grade cement fly ash sand water

M5 250~290

M 10 320~350 replaces cement 10%~30% 1m3 dry sand, with a loose density of 270~320.

M 15 350~400

4. Cement lime plastering mortar

See Table 3 for the dosage of mixture ratio. The apparent density of the mixture is not less than 1800 Kg/m3, the water retention rate is not less than 88%, and the tensile bond strength is not less than 0. 15 MPa.

Table 3 Mix proportion of cement lime plastering mortar Kg/m3

Strength grade cement lime paste sand water

M2.5200~230

M 5230 ~ 280(350 ~ 400)- cement dosage 1m3 loose density of dry sand 180~280

M7.5 280~330

M 10330~380

5. Gypsum plaster

When the compressive strength of gypsum plastering mortar is not less than 4 MPa, it should be professionally produced dry-mixed mortar, with initial setting time not less than 1h, final setting time not more than 8 hours, tensile bond strength not less than 0.4MPa, compressive strength 4.0 MPa, mortar gypsum dosage 450-650 kg/m3, loose density of sand 1 m3 and water 260-400.

6. Cement mortar mixed with plasticizer

Cement plastering mortar mixed with plasticizer can improve the construction performance of mortar. The strength grades are M5, M 10 and M 15. The apparent density of the mixture is not less than 1800 kg/ m3, the water retention rate is not less than 88%, the tensile bond strength is not less than 0. 15 MPa, and the service time is not more than 2 hours.

7. Polymer cement plastering mortar

Polymer cement plastering mortar can improve the density of mortar, and has the properties of waterproof, impact resistance and cracking resistance. Polypropylene fiber and polyvinyl alcohol fiber are often added, and their dosage is determined by experiments. Dry-mixed mortar is generally produced in professional factories, and it is made of 42.5-grade ordinary portland cement and fine sand with a particle size of not more than 1. 18mm, with a water retention rate of not less than 99% and a tensile bond strength of not less than 0.30 MPa. If impermeability is required, the impermeability shall not be lower than P6 grade.

8. Trial installation and adjustment

According to the design requirements, three kinds of construction mix ratios are designed, one of which is the benchmark mix ratio. After trial mixing test, the mixture ratio of mortar with the lowest cement content is obtained under the condition that its consistency and layering meet the requirements, and the mixture ratio of this mortar is revised according to Article 5.8.5 of the regulations, so as to finally determine the amount of materials in the mixture ratio.

For more information about bid writing and improving the winning rate, click on the bottom customer service for free consultation.