What is Masonry?

Brick masonry, an integral material made of brick and mortar, is the most widely used building material. It is divided into unreinforced brick masonry and reinforced brick masonry according to whether or not reinforcing steel is arranged in the masonry.

Brickwork

1.Sintered ordinary brick

Sintered ordinary bricks are divided into clay bricks, shale bricks, coal gangue bricks and fly ash bricks according to their main raw materials.

Sintered ordinary bricks are divided into five strength levels: MU30, MU25, MU20, MU15, and MU10 according to compressive strength.

Sintered ordinary bricks are classified into three grades: superior, first-class, and qualified according to dimensional deviation, appearance quality, frost, and lime burst. The superior product is suitable for clean water wall, and the first-class product and qualified product can be used for mixed water wall.

The shape of the sintered ordinary brick is a right-angled hexahedron, and its nominal dimensions are: 240mm in length, 115mm in width, and 53mm in height. The specifications of bricks are 175mm × 115mm × 53mm.

2.Cinder brick

Cinder brick is a solid brick made of cinder as the main raw material, mixed with appropriate amount of lime and gypsum, and mixed, pressed and formed, steam-cured or autoclaved.

The shape of the cinder brick is rectangular, and its nominal dimensions are: 240mm in length, 115mm in width, and 53mm in height.

Cinder brick is divided into MU20, MU15, MU10, MU7.5 four strength levels according to compressive strength and flexural strength.

Cinder bricks are classified according to dimensional deviation, appearance quality, and strength grades: superior products, first-class products, and qualified products.

3.Sintered porous brick

Sintered porous bricks are made of clay, shale, and coal gangue as the main raw materials.

The shape of the sintered porous brick is rectangular, and its length, width and height dimensions should meet the following requirements:

a. 290, 240, 190, 180mm

b. 175, 140, 115, 90mm

The sintered porous brick is divided into five strength levels: MU30, MU25, MU20, MU15, and MU10 according to compressive strength and coefficient of variation.

The size deviation, appearance quality, strength grade and physical properties of the sintered porous brick are divided into three grades: superior product, first-class product and qualified product.

4.Sintered hollow brick

Sintered hollow bricks are made from clay, shale, coal gangue, etc.

The shape of the sintered hollow brick is rectangular, and a groove with a depth of 1 mm or more to increase the bonding force should be provided on the joint surface with the mortar.

The length, width and height of the sintered hollow brick shall meet the following requirements:

a. 290, 190, 140, 90mm

b. 240, 180 (175), 115mm

Sintered hollow bricks are divided into three density levels of 800, 900 and 1100 according to their density.

Each density grade is divided into three grades: superior grade, first grade and qualified grade according to the number of holes and their rows, dimensional deviation, appearance quality, strength grade and physical properties.

5.Autoclaved lime sand hollow brick

Autoclaved lime-sand hollow bricks use lime and sand as the main raw materials, hollow bricks with a porosity of less than 15% after blank preparation, pressing and curing.

Autoclaved lime sand hollow bricks are divided into five strength levels: MU25, MU20, MU15, MU10, and MU7.5 according to the compressive strength.

Autoclaved lime sand hollow is divided into three grades of superior product, first-class product and qualified product according to strength grade, size tolerance and appearance quality.

Under the action of uniform pressure, the horizontally reinforced joints in the brickwork are called reinforced brickwork.

When an empty bucket masonry is used as a load-bearing wall in a house, the shear and earthquake resistance are poor, which directly affects the strength of the masonry and its integrity. In addition, the building area of bricks and bricks is greatly reduced, and the shape and size of bricks also have a certain effect on the strength of the masonry. However, in the hollow bucket masonry, if the brick has a flat shape and a large thickness, the bending, shear and tensile capacity of the brick increases accordingly, and the compressive strength of the masonry increases accordingly.

The strength of a brickwork under axial tension, bending moment, and shear is called tensile strength, bending strength, and shear strength, respectively. When the brickwork is stretched, bent or sheared, it may be broken along the cross section of the gray joint, or it may be broken along the cross section of the brick or both. Damage often occurs on the interface between mortar and brick, and the hollow masonry is lighter. At this time, the tensile, bending and shear strength of brick masonry mainly depends on the bond strength between mortar and brick in the gray joint; when there is When pressure is applied, the shear strength is also determined by the compressive stress. There is a void in the middle, and the bond strength is not only related to the designation of the brick and mortar, but also to the way the force acts. There is also hollow masonry. Under the action of the axial tensile force of the parallel horizontal gray joint, the brickwork will be damaged along the section of the gray joint when the number of the brick is higher and the number of the mortar is lower.

Unreinforced brick masonry is usually made of solid bricks or porous bricks. The failure surface is tooth-shaped, which is called tension along the tooth gap section; when the brick number is lower and the mortar mark is higher, the brick and vertical gray joint sections will be destroyed, which is called tension along the brick section. When the direction of the tensile force is perpendicular to the horizontal gray seam, the tensile force is only borne by the normal bond strength of the mortar and the brick during the design, and it will be broken along the cross-section of the joint.

Placing reinforced or reinforced concrete masonry in brickwork. It is dense and uniform, which improves the bearing capacity of masonry and expands the application range of brick masonry. In particular, the application of porous bricks of various types and specifications is constantly expanding and developing.

1.The allowable deviation of the elevation of the top surface of the brickwork is ± 15mm;

2.The allowable deviation of the flatness of the brickwork surface is ± 5mm;

3.The allowable deviation of the height and width of the openings of brick doors and windows is ± 5mm;

4.The allowable deviation of the deviation of the lower window hole on the brick wall is ± 20mm;

5.The allowable deviation of the straightness of the horizontal gray seam of the brickwork is ± 10mm;

First, construction points

A. The type and strength of the brick must meet the design requirements, the specifications are consistent, there is no warpage, fracture, neat corners, and uniform color, and it can be used only after sampling inspection.

B. The type and strength of the mortar should meet the design requirements. It should have appropriate consistency and good water retention. It can be used with mixing. Samples should be taken for compression test.

C. During masonry, clean up the debris on the beam surface, knock out the loose cymbals on the beam surface and level them, and pop the position of the door and window holes on the beam.

D. When masonry is to be done, several bars should be erected, horizontal lines (per brick) should be pulled, and vertical lines should be hung on both sides.

E. The masonry method of brick walls should follow the principle of "inside and outside overlap, staggered up and down". Stagger length is generally not less than 60MM. Staggered overlap can ensure that the wall does not have continuous vertical through joints, so as to improve the strength and integrity of the wall.

F. The mortar should be covered with mortar, and the ash joints should be full, straight, and uniform in thickness, with a thickness of 10MM.

G. Bricks should be staggered up and down, built inside and outside, and firmly connected.

H. The wall surface should be flat and vertical, and the flatness and verticality must meet the requirements of the specification.

J. The corners and junctions of the masonry should be built at the same time. For temporary breaks that cannot be built at the same time and must be left, they should be built into oblique rafters.

K. Where corners and T-junctions meet, tie ties with 26 bends to 90o must be placed in horizontal joints, each side protruding into the wall 1000MM, the distance is 500MM along the wall, and the end should have 90o hooks.

L. Installation of reserved holes and embedded parts: Including the installation of lightning protection embedded parts and the reservation of reserved openings for drainage pipes.

Second, the main safety technical measures

A. The height of the scaffolding stands should be lower than the height of the bricks.

B. When taking bricks from the brick stack, you should take the high part first and then the low part to prevent the stack from smashing people.

C. When cutting bricks, the player should face inwards. Pay attention to the broken bricks that may cause injuries.

D. Before the typhoon arrives, the gables that have been built should be temporarily placed between the gables across the gables for stable connection. Otherwise, support measures should be made separately.

E. The tools and materials used for bricklaying should be placed in a safe place. After work, the scaffolding and broken bricks and mortar on the brick wall should be cleaned to prevent falling and hurting people.