Gypsum block

                                                                      Gypsum block

Gypsum block: it is a light building gypsum product made of building gypsum as the main raw material by adding water, mixing, casting and drying.

brief introduction
Fiber reinforced material or lightweight aggregate or foaming agent can be added to the block picture in production. It has many advantages, such as sound insulation, fire prevention, convenient construction and so on. It is a new wall material with low-carbon, environmental protection, health and in line with the development requirements of the times.
Development prospect
1. Abroad
In the 1940s, semi hydrated gypsum made of natural gypsum was used as raw material to produce gypsum blocks by flat mold pouring method. In the mid-1950s, the production was changed to vertical mold pouring and jacking technology, and the output was significantly improved.
Since the 1970s, the molding technology has been continuously improved, and the mold erection and jacking process has developed from semi-automatic to full-automatic. For example, the hydraulic automatic knife covering gypsum block is used for pouring, and the gypsum block is poured to form an upper groove. The surface quality of the alloy mold is significantly improved by chromium plating. The multi-mode cavity mold is used to increase the output of a single machine, and the pneumatic telescopic fixture is used to correctly position, clamp, lift and move the whole row of blocks.
Since the 1990s, FGD gypsum has been used as raw material instead of natural gypsum, and the product quality has been continuously improved.
More than 60 countries around the world produce and use gypsum blocks, which are mainly used as non load-bearing internal partitions for houses, office buildings and hotels.
Gypsum block has been recognized internationally as a green building material product for sustainable development, accounting for more than 30% of the total consumption of interior wall in Europe. Countries producing and using gypsum blocks in Europe include Russia (100 million m2 / a), France (25 million m2 / a), Germany (8 million m2 / a), Belgium (4.5 million m2 / a), Spain (4 million m2 / a), Poland (4 million m2 / a), Italy, Austria, Switzerland, Luxembourg, Greece, Turkey, Finland, Czech Republic, Romania, Bulgaria, Serbia, etc.
In addition to Chinese Mainland, 15 countries and regions in Asia produce gypsum blocks, with a total of about 2000 production sites. The main gypsum block producing countries and regions in Asia include: India, South Korea, Singapore, Thailand, Indonesia, Pakistan, Afghanistan, Vietnam, Bangladesh, Taiwan and Hong Kong; The Middle East includes Iran, Saudi Arabia, Israel, Jordan, Lebanon, Syria, Iraq, etc. Gypsum block molding gypsum block molding African gypsum block manufacturers include Algeria (2 million m2 / a), Egypt, Morocco, Tunisia, Senegal, etc.
In North America, only Mexico produces gypsum blocks. South American gypsum blocks are produced in Brazil, Chile, Argentina, Venezuela and Colombia.
Only Australia produces gypsum blocks in Oceania.
2. Domestic
Gypsum blocks have been introduced into China since 1980s. In the past 30 years, gypsum block has not been widely used like other cement wall materials, but it is also developing steadily. Since 2000, with the advancement of China's wall reform, new wall materials such as gypsum blocks have been given a development space, which is also the initial period of the transition from original manual production to mechanized production. After 2004, dozens of mechanized equipment manufacturers have sprung up in Shandong, Hubei, Sichuan, North gypsum block storage, gypsum block storage, Beijing, Hebei and Inner Mongolia, with an annual output of 20 million m2.
classification
1. According to its structural characteristics, it can be divided into gypsum solid block (s) and gypsum hollow block (k).
2. According to its gypsum source, it can be divided into natural gypsum block (T) and chemical gypsum block (H).
3. According to its moisture-proof performance, it can be divided into ordinary gypsum block (P) and moisture-proof gypsum block (f).
4. According to the molding manufacturing method, it can be divided into manual gypsum block and machine-made gypsum block.
Specifications
Unit (mm)
project
Specifications
length
666(600)
height
five hundred
width
60、80、90、100、120、150、200
remarks:
1. The above are general specifications and models, and special specifications of blocks can be customized according to different requirements. In fact, there are no strict restrictions on the specifications.
2. The 60 thick block wall cannot be used as a separate partition wall except for the pipe well without sound insulation requirements in industrial buildings, but it is allowed to build a double-layer wall with blocks of other thicknesses.
Technical indicators
compressive strength
(MPa)
Breaking load (n)
Single point hanging force (n)
Sound insulation
(dB)
Fire resistance limit (H)
Weight of single block
(kg)
Apparent density
(kg/m3)
Softening coefficient
≥3.5
≥2000
≥800
≥35
1.5~3
≤30
≤ 800 (hollow block)
≤ 1100 (solid block)
≥ 0.6 (damp proof block)
remarks:
1. Blocks shall meet the requirements of gypsum blocks (JC / t698-2010) and radionuclide limits of building materials (GB 6566-2001).
2. In order to meet relatively high sound insulation requirements and increase the strength of blocks, high-density gypsum blocks can be specially customized, with a unit weight of 1200kg / m3 and a single unit weight of more than 30kg.
3. Where the long-term humidity is above 90%, moisture-proof blocks should be used, and waterproof measures should be taken as required.
Performance characteristics
1. Safety: mainly refers to its good fire resistance. This is mainly because dihydrate gypsum (CaSO4 · 2H2O) contains two crystal water, accounting for about 21% of the total weight. These two crystal water exist stably in gypsum at ordinary times and encounter high temperature. These water can quickly diffuse into the air on the wall surface, and then form a "water vapor film" on the wall material surface. The "water vapor film" can not only reduce the surface temperature of wall materials, but also isolate oxygen, so as to prevent and delay the further combustion of wall materials and buildings. Therefore, this crystalline water is called "fire extinguishing water" in Germany. The gypsum block is 66kg / m2 and contains about 13.86kg of "fire extinguishing water", and the fire resistance limit is more than 3 hours.
2. Comfort: refers to its "breathing function" and "warmth".
"Breathing function" refers to the function of gypsum block in regulating indoor air humidity. The microporous structure of gypsum is composed of dihydrate gypsum needle crystals, so there is a lot of free space in the needle crystal structure, that is, the porosity is very high. When the humidity in the air conditioning humidity is high, gypsum can absorb water in the air through the pore structure, and the water storage rate can reach 7-17g / m2, which is nearly twice that of cement mortar (water storage rate 6-9g / m2). Because the water vapor diffusion resistance coefficient of gypsum is much lower than that of cement mortar, when the humidity in the air is low, the water in the gypsum pore structure is easy to evaporate into the air, so as to adjust the indoor air humidity and make people feel comfortable.
"Warm" refers to the large proportion of gypsum blocks in our factory. After hydration and hardening, a large amount of free water is evaporated, leaving a large number of pores in the products. According to its bulk density, its thermal conductivity is 0.2-0.28 w / m.k, which is close to the average thermal conductivity of wood. When it is used as a wall, it feels warm. Compared with reinforced concrete and other building materials, it is called "warm material". At the same time, it can greatly improve building energy conservation, which is an important reason why many countries choose gypsum building materials indoors.
3. Fast: refers to the fast construction speed and high efficiency of gypsum blocks.
The construction of gypsum block belongs to dry operation. There are tenon slots and tenon keys around the block, and the masonry speed is very fast. In addition, our company has introduced high-precision German molds, so the size of the products is more accurate. The walls built with them do not need to be plastered and leveled on both sides. Each person can build more than 20 square meters every day, and the finished decoration of the built walls can be carried out after 24 hours. It is very convenient to install pipes and hang articles on the gypsum block wall, with high construction efficiency and greatly shorten the construction period.
4. Environmental protection: it means that gypsum blocks do not pollute the environment in terms of raw materials, production, construction, use and waste recycling. 1) Low production energy consumption.
2) It does not contain formaldehyde, radioactive elements and other harmful objects.
3) Recyclable reuse: only gypsum and water are included in the gypsum block formula. The waste gypsum block can be used as the raw material for the production of gypsum building materials after crushing and calcination.
4) Gypsum blocks produced with the industrial by-product dihydrate gypsum discharged from industrial production as raw materials belong to environmental protection and waste utilization.
5. Health care:
1) The water vapor permeability and pH value of gypsum blocks are surprisingly similar to the chemical physical properties of human skin. They are called "skin accessible" building materials. Plaster is also an excellent cosmetic facial mask material.
2) No radioactivity. Her inherent radiation is lower than that of materials on the surface of the earth's crust, especially desulfurization gypsum, which is more pure after filtration and dehydration, highlighting its benefits to health.
3) The pH value of gypsum block is 5-7, and there is no water on the wall surface, which can greatly inhibit the growth of mold.
4) Pure gypsum is used as pharmaceutical base material in the Pharmacopoeia of Western medicine. In traditional Chinese medicine, it is a good medicine for clearing fire. It is recorded in Shennong materia medica classic and Kaibao materia medica that gypsum is pungent, sweet and cold in nature and belongs to lung and stomach meridian. It can nourish yin and clear away heat, eliminate annoyance and thirst, promote blood circulation and relieve pain, astringe and regenerate muscles. Therefore, it will make people feel comfortable in buildings built of gypsum building materials.
6. Not easy to crack: the hydration products of cement and various silicate based materials are mainly colloids, which are easy to expand and shrink when the external temperature changes. The hydration period is usually long (up to several decades), and certain deformation will occur during the hydration period. The hydration product of gypsum base is crystal, the hydration period is usually very short, and there is deformation in the hydration period, but after the hydration crystal forms a network, it is basically not affected by the change of external temperature, so the block itself is basically not deformed. Its expansion and contraction rate is 1 / 20 of that of cement and silicate products under equal conditions. In addition, the adhesive of masonry block is also prepared with gypsum, and their expansion and contraction rate is consistent. Under the action of tenon and groove bite, it can perfectly form an integral wall without cracking.
7. Good processability: the desulfurization gypsum block can be sawed, planed and nailed, which makes it extremely convenient for users to make indoor decoration modeling. The wall can be easily slotted to run pipelines and install wiring boxes. As long as the construction is carried out according to the correct construction method, the part of the pipeline still has good strength. If the wall is damaged, the repair is also very convenient and fast.
8. Cost effective:
1) The gypsum block wall is flat without plastering on both sides, which greatly increases the building clearance area.
2) The wall structure is light and the building cost can be reduced.
3) The construction period is fast and the construction cost is saved.
4) The wall is flat and saves the cost of fine decoration.
construction technique 
1、 Material requirements
1. Blocks shall be stacked in a room to avoid rain and moisture.
2. Handle with care during handling or installation, keep the vertical direction during stacking, and the continuous base shall not exceed nine layers.
3. The wall bonding materials and finishing layer materials must meet the specified quality standards and application requirements.
2、 Construction technology
Setting out of partition wall → installing wooden frame of door and window opening → making wall cushion → block arrangement and block placement → masonry block wall → installation of pipeline and pendant → wall leveling → construction of finishing layer
3、 Construction conditions
1. After completing the structural engineering and roof waterproof layer, it shall be constructed and accepted.
2. Finish plastering of wall, ground and ceiling.
3. When designing the wall cushion, the construction of the wall cushion belt shall be completed and reach the design strength before the installation of the partition wall.
4. The position of water, electricity and gas pipelines passing through the wall shall be marked.
5. According to the materials and construction tools proposed in the design and construction, make all preparations and make them complete.
4、 Construction requirements
1. Set out the center line of the wall. Remove the floating ash and excess mortar on the surface of the wall, ground, roof, beam, column, etc. at the location of gypsum block wall, level the surface, and set the wall center line according to the requirements of the design drawing.
2. Install the wooden frame of door and window openings. According to the design requirements, the door opening frame of the partition wall shall be installed first; If the partition wall has windows, the window opening frame shall be installed when the partition wall is built to the height of the window bottom frame.
3. Make wall cushion. This process shall be carried out when the wall cushion is required by the design. The cast-in-situ brick or concrete pad can also be used as the masonry wall. When making wall cushion, the center line must be aligned with the center line of the wall to ensure the correct position of the partition wall.
4. Masonry block wall.
(1) Before masonry, the blocks shall be placed according to the length direction of the partition wall. When the final position is less than one, the blocks can be sawn into the required specifications. Masonry (2) gypsum blocks shall be built in the form of steps from bottom to top, and the surrounding tongue and groove shall be accurately connected with staggered joints. During masonry, the length direction of the block is parallel to the wall, and the tenon is downward.
(3) The horizontal and vertical bonding joints of gypsum block wall shall be horizontal and vertical, with uniform thickness, dense and full. During masonry, the horizontal and vertical joints shall be squeezed by hand at any time, or the special base plate with tenon shall be aligned with the tenon groove for compression, the base plate shall be knocked with a rubber hammer to compact the joint, and the adhesive extruded from the joint shall be scraped off by hand.
(4) At the corner of gypsum block wall and the junction of vertical and horizontal walls, the blocks shall be overlapped with each other.
(5) In order to ensure the rigidity of gypsum block wall and prevent cracks, the connection between gypsum block partition wall and main wall, ceiling, ground (or wall pad), beam and column shall be made. A glass fiber cloth with a width ≥ 400 mm can be set at these connections. If necessary, a layer of glass fiber cloth can also be fully paved.
(6) When the height of the wall exceeds 3M, a ring beam shall be set; When the height of the wall exceeds 4m or 6m, reinforcing columns shall be set at the 3M long wall in accordance with the provisions of code for design of masonry structures gbj3-88.
(7) Gypsum bonding powder is used for gypsum block masonry. The mixing amount is calculated from the time of adding water and will not be used after hardening for 40 ~ 60 minutes.
(8) During the masonry of gypsum block wall, the flatness of the wall and the verticality of the facade shall be checked and adjusted at any time. It is forbidden to knock and correct after the gypsum binder is solidified.
(9) After the masonry of gypsum block wall is completed, the defects and cavities shall be filled with gypsum putty.
5. Installation of pipelines and hangers
(1) The buried pipeline shall be grooved first. The length of horizontal pipe groove shall not be greater than 400mm; The width of vertical pipe groove shall not be greater than 100mm; The depth of pipe laying shall not be greater than 50mm. After the pipeline is installed, it shall be filled with gypsum bonding powder. If the pipe groove must be larger than the above provisions, measures to increase the integrity of the wall shall be taken in the construction method.
(2) When cutting the pipe slot or passing through the wall, the coarse tooth saw or electric slotting machine or electric drill shall be used, and the metal chisel or hammer shall not be used to chisel the slot and hole. If the hole is slotted and drilled, the hole shall be filled with gypsum bonding powder first. When the pipe trough passes through the ring beam, the reinforcement shall not be cut off, and the damaged part of the concrete shall be filled with micro expansion cement.
(3) When sanitary ware, hanging cabinet and household appliances are hung on the gypsum block wall, a tripod can be installed on the wall for fixation.
(4) When large hanging parts need to be installed, they can be fixed with through wall bolts. The specific method shall be designed and constructed separately according to the design requirements.
6. Wall leveling. For the blocks produced by semi-automatic and full-automatic formwork forming and hydraulic jacking gypsum block production equipment abroad, due to the high accuracy of the size of the mold box, pay attention to controlling the thickness of the adhesive during masonry, and timely remove the excess adhesive extruded from the joint. Generally, only local leveling is required. If the flatness of the wall is not enough, it shall be leveled with full putty. For the wall with moisture-proof requirements, it shall be leveled with moisture-proof putty.
5、 Reference quantity of labor and materials
（1） Assumed conditions of gypsum block wall
1. The thickness of partition wall is 100mm and the floor height is more than 3m.
2. The concrete wall is 100 mm high and 100 mm thick.
There is one 1m in the 3.10m2 partition wall × 2 m door, 100 mm above the door × 100 mm with 4 ×ф 6mm reinforced concrete tie beam with galvanized iron sheet connectors and nails.
（2） Reference quantity of labor and materials for 10 M2 gypsum block wall
See the following table for the reference quantity of labor and materials of 10m2 gypsum block wall.
6、 Quality standard
1. The block must be free from defect, breakage and fracture after being put on the wall.
2. After the wall is embedded, the shell shall not be lifted, and the block joint shall be dense (up to 80%) without gap by visual inspection.
3. The quality requirements of gypsum block works are as follows:
project
Allowable deviation
Inspection method
Flat surface
three
Use 2m ruler
Vertical elevation
five
Use 2m straight edge or wire support plate
Perpendicularity of yin and Yang
five
Use 2m straight edge or wire support plate
Remarks: refer to the national building standard design atlas 04j114-2 gypsum block internal partition wall for the construction technology of gypsum block.