In recent years, with the adjustment of national industrial structure, vigorously promoting new wall materials and establishing and implementing Scientific Outlook on Development have become the main theme of building materials production and development in China, and many environmental protection and energy-saving wall materials have emerged. However, whether it is used reasonably directly affects the quality of the project.

Keywords: concrete perforated brick wall management

In recent two years, the application of new materials, new technologies and new processes has been increasing. Among them, concrete perforated brick has been widely used in our county, but its unreasonable use or unaccustomed use has brought some negative effects on project quality management, such as cracks and water seepage in the wall. In view of the above situation, in order to ensure the steady improvement of engineering quality and greatly reduce the common quality problems. In this paper, the use of concrete perforated brick, combined with common quality problems in construction, for the reference of construction technicians.

Brief introduction of concrete perforated brick

1, cement as cementing material, sand, stone, etc. As the main aggregate, it is a kind of multi-row concrete small hole brick, which is mixed with water and cured according to regulations. The main specification is (240mm× 1 15mm×90mm). The main specifications and dimensions of brick splitting are: half brick (120mm×15mm× 90mm) and seven-part brick (180mm×15mm× 90mm).

2. The strength grades of concrete perforated brick are: MU30, MU25, MU 15, mu10; The age is 28d, and the age of concrete perforated brick for building should not be less than 28d.

Second, the common quality common fault technical solutions

1, which specifies the minimum strength grade of mortar used for concrete perforated brick.

The low strength of masonry is largely due to the low strength of masonry mortar. Therefore, in combination with the Technical Specification for Concrete Porous Brick Building (DB36/J003-2005), we often stipulate the mortar strength in the project as follows:

(1) When concrete perforated bricks are used for masonry of walls and foundations below the ground, the holes shall be filled with mortar, and the strength grade of cement mortar for masonry shall not be lower than M 10.

(2) the strength grade of bearing masonry above the ground shall not be lower than M 10, and the strength grade of mixed mortar for masonry shall not be lower than M7.5.

(3) The strength grade of masonry mortar for the top wall shall not be lower than M 10.

2. Measures to prevent and reduce wall cracks

(1) The roof of a concrete perforated brick building shall be provided with an effective thermal insulation layer or insulation layer.

(2) Reinforced concrete structural columns and capping beams should be added to the roof parapet, and other reinforced concrete structures can also be adopted.

(3) In the top wall, a long bidirectional horizontal steel mesh φ4 @ 60 with a vertical spacing of 500mm； should be set; At the corner of the wall and the junction of the interior and exterior walls, two φ 6 Rachel bars are set every 500mm along the wall height, and they extend into each side wall not less than 600mm. Make a 90-degree hook at the end of the tie bar.

(4) In the mortar joint of the wall under the bottom window sill, three welded steel mesh pieces or three φ 6 steel bars can be set, and the length of the wall between the windows on both sides should not be less than 600 mm ..

⑤ The walls on both sides of doors and windows should be at least one brick long, and the same strength porous brick filled with cement mortar should be used for masonry. The window sill should be cast-in-place reinforced concrete slab with the same width as the wall thickness, with a thickness of 90mm and both ends extending into the wall for 500 mm. The longitudinal reinforcement of the steel mesh should not be less than 3φ 8 and the transverse reinforcement should not be less than φ 6 @ 250.

⑥ The perforated brick at Rachel reinforcement of wall and constructional column should be built with mortar upward, with the length of 1m, and the rest should be built with mortar upward.

⑦ 1@ 10× 10 galvanized steel wire mesh with a width of 300 ~ 400 mm is hung at the joint of porous brick and different material structures. In order to prevent cracks caused by excessive drying shrinkage of wall plastering, it is necessary to spray water with a sprayer for maintenance.

The method of galvanized steel wire mesh is as follows: the vertical spacing of sticking nails 120mm, and the horizontal spacing is 250mm:

3, the construction technical requirements

(1) Concrete perforated brick should not be watered and laid on site. When the brick is dry, it should be watered and wetted 1-2 days in advance.

(2) When laying, the concrete perforated brick should be laid with mortar facing upwards.

(3) Masonry should be staggered, built inside and outside, and the masonry form of Yishun or plum blossom ding should be adopted.

(4) Masonry mortar joint should be horizontal and vertical, with uniform thickness. The thickness of horizontal mortar joint and vertical mortar joint shall be 10mm, but not less than 8mm and not more than 12 mm.

(5) Masonry mortar joint should be full. The mortar fullness of horizontal mortar joint shall not be less than 80%, and the vertical mortar joint shall be filled with cement slurry to make the mortar full. It is forbidden to flush the grouting with water.

⑥ Except for the part where the constructional column is set, the corner and junction of masonry shall be laid at the same time. For temporary breaks that cannot be laid at the same time and must be retained, an oblique if should be built, and the length of the oblique if should not be less than 2/3 of its height.

All landowners masonry if, if the surface must be cleaned, water wet and filled with mortar, keep the mortar joint straight.

Today, the constructional column wall should be built first and then poured with concrete. Masonry at the joint should be built by laying bricks or stones, and the template must be close to the masonry. It is forbidden to leak slurry at joints.

Pet-name ruby before pouring concrete constructional column, brick masonry and template must be watered and wet, and the floor ash and brick slag in the template must be removed.

Attending the construction needs to reserve a temporary hole in the concrete perforated brick masonry, and its side is not less than 0.5m； away from the junction wall; Reinforced concrete lintels should be set at the top of the hole, and Rachel bars should be set on both sides of the hole as required.

Third, the advantages of concrete perforated brick

1, saving energy and reducing consumption

The energy saving of concrete perforated brick is embodied in two aspects, one is to save the coal consumption of brick burning, and the other is to save the energy consumption of building heating and temperature. (1) Save energy consumption for brick burning.

Traditional clay brick production consumes a lot of coal, with an average consumption of 654.38+10,000 bricks 1.3 tons of standard coal, and brick burning is about 60 million tons of standard coal every year, accounting for about 5% of the total coal production in China, which has caused great waste of resources. Replacing clay brick with concrete perforated brick can save a lot of coal for the country.

② Save energy consumption of heating and cooling.

The annual heating energy consumption in northern China is about 65.438+0.2 billion tons of standard coal. In dry and hot areas such as southern China, the energy consumption of refrigeration in summer is about three times that of heating, and the energy consumption is about 300-400 million tons of standard coal. Building houses with concrete perforated bricks can save 30% and 65.438+0.50 billion tons of standard coal every year, with remarkable energy-saving effect.

2, multiple functions and good performance

Compared with solid clay brick, concrete perforated brick has the advantages of heat preservation, sound insulation, fire prevention, light weight and beauty, and the houses built with it have strong seismic capacity, which is conducive to the realization of lightweight, comfortable and beautiful buildings and the people's living in high-performance houses.

3, high strength, good rigidity and stability

Concrete perforated brick has high strength and good stability. Because of its inverted trapezoidal opening design, too many inscribed circles, multi-row hole arrangement, inverted masonry structure and mortar spreading, grey keys are formed under the action of two-way holes on the mortar surface, which greatly improves the overall stiffness and shear resistance of masonry.

4, economy and construction operability

Compared with clay brick, building with concrete perforated brick can save cost 15%, construction period 25%, steel 20%, masonry mortar 30%, plastering mortar 25%, labor 25% and heating energy consumption 30%. At the same time, some templates and scaffolding are reduced, which greatly reduces the labor intensity and improves the safety and scientificity of construction work. In addition, because the width of concrete perforated brick is the same as the thickness of the wall, it is light, so it is convenient to build. When building the wall, only the plane error of one side of the wall is controlled, and the thickness is controlled at about 6-8 mm, which greatly improves the plastering efficiency (1-2 times). Therefore, concrete perforated brick has good economic benefits and is easy to operate.

Reference: [1] Code for Quality Acceptance of Masonry Engineering (GB50203-2002).

Beijing: China Building Industry Press, 2002.

[2] Jiangxi Building Materials Industry Scientific Research and Design Institute, Jiangxi Wall Materials Innovation Office.

Technical Specification for Concrete Porous Brick Building (DB36/J003-2005).