First, concrete strength testing
Concrete strength is the main indicator for evaluating its quality.
The basic method for concrete strength testing is to prefabricate the test block in the field for strength testing. The strength grade of concrete
is divided by the cubic compressive strength (in N/mm 2 or MPa). The standard value of the compressive strength of the cube refers to a value of the 150 mm test piece produced and cured by the standard method, and the overall distribution of the compressive strength measured by the standard test method at 28 d. When other sizes of test pieces are required, they can be converted according to regulations.
Non-destructive testing methods can be used for completed concrete structures, including rebound method, ultrasonic pulse method, and ultrasonic rebound comprehensive method. In addition, micro-breakage detection techniques such as pull-out test methods can also be used.

The calculation method and conformity assessment of the test strength
shall be carried out in accordance with the provisions of GB/T 50107 2010.
Second, the anchor construction project
1. Anchor pullout detection
The bolt (anchor) pullout resistance refers to its ability to resist pulling out of the rock mass in units of kN or N. The pull-out force is an important performance of the anchor (anchor) support capacity and an important indicator of its construction quality. A conventional method of detecting the pullout resistance of a bolt or anchor is to perform a tensile test using a bolt dynamometer.
2. Between the installation of the bolts, if the bolts are not covered by the shotcrete, they can be measured directly by the ruler. The obtained data is used as the basis for evaluating the quality of the bolt arrangement. If the anchor is covered by concrete, a bolt detector is required.
3. Tray according to Quality Inspection "coal mine roadway construction quality acceptance))
GB 50213-2010 and" Rock bolt and shotcrete engineering specification)) of the predetermined GB 50086- ~ 2015, requires the installation of bolt pallet Firm, adherent to the wall or tight to the rock face. The torque wrench test meets the requirements of 100 N. m. For the inspection of the anchor pallets that are not covered by the shotcrete, the on-site pulling and observation can be directly carried out; for the bolts that have been covered by the concrete, the construction inspection records on the inspection points are checked according to the concealed works. The quality inspection records of the bolt pallet installation are completed by the team in a row; in the middle or completion acceptance, the inspection requirements of the shaft are not more than 20m and the roadway is not more than 25m. The installation quality of the previous row of pallets is checked at each checkpoint.
4. Bolt hole depth, angle detection Bolt hole depth and angle are also important indicators to reflect the quality of bolt support. At present, it is still tested according to the method of concealed engineering.
The installation quality of the bolt includes the installation quality of the anchor pallet, the spacing between the anchors, the depth of the anchor hole, the angle, and the exposed length of the bolt.
Third, shotcrete construction project
1. Shotcrete strength testing
(1) Shotcrete strength test evaluation of shotcrete (sometimes referred to as shotcrete), its strength can be the same as ordinary sea concrete, using standard test methods to obtain 28d age compressive strength, and by comparing the same batch of test groups The average value and the lowest value are compared with the design specifications for conformity assessment. The procedure specifies the specific calculation method.
Shotcrete can also be determined by point load and pull-out test methods.
(2) Sampling
The shotcrete strength test specimens are subjected to on-site sampling methods, including spray slab method or drill method and chisel cutting method.
1) Drilling method. A shotcrete core with a diameter of 50 mm and a length of more than 55 mm was drilled on the actual structure that had been cured for 28 days, and the test was carried out after cutting at both ends.
2) Sampling by spraying the large plate method. Use 350mmX
450mmX 120mm mold (short side open), placed on the wall of the shotcrete work site; after normal operation, spray from bottom to top into the mold layer by layer, after 1d, release the mold under standard conditions for 7d, processed into Standard test pieces were tested after 28 days of curing.
3) Chiseling method. On the concrete structure that has been sprayed and cured for 14 days, a tear concrete block with a length of 350 mm and a width of 150 mm is drilled. It can be processed into a 100mmX
100mmX 100mm cube test piece and cured to 28d for pressure test on the press.
The number of test groups for each batch of tear-throated concrete varies according to the nature of the project.
2. Shotcrete thickness Shotcrete thickness detection commonly used needle detection method, perforation ruler or coring method.
3. Shotcrete engineering specification size
(1) For the detection of the size of the section of the Kunming Consolidation Engineering, there are mainly the following methods: hanging line measuring method, laser ranging method, ultrasonic ranging method and so on. Shotcrete smooth dense surface, and a ruler with measurements of 1m feeler gauge, the measuring point
within the range of 1m 2 irregularities not more than 50mm.
(2) The depth of the shotcrete foundation is generally measured by the ruler method.
4. perception of the quality of the concrete anchor spray anchor spray works to detect the perception of quality testing including leak spray from the drum phenomenon yuan is still expanding cracks or endanger the safety of use; in line with the amount of leaking water standards; reinforcing mesh (metal mesh) shall be exposed The molding is good, the profile of the section meets the design requirements, and the wall is straight and the arch is smooth.

PP Plastic Sheet

PP plastic, polypropylene, commonly known as "baijiao",Scientific name: polypropylene.

Description:

PP Plastic is a kind of semi crystalline material. It is more hard than PE and has a higher melting point. Due to the high crystallinity, the surface of the material stiffness and resistance to scratch characteristics very well. PP Plastic don't have the problem of environmental stress cracking.Polypropylene (PP Plastic) is a semi-crystalline thermoplastic.PP Plastichas high impact resistance, strong mechanical properties, resistance to many organic solvents and acid and alkali corrosion.

PP Plastic is widely used in industry and is one of the most common polymer materials.

Australian COINS are also made of polypropylene.

Polypropylene bonding:

K-720 is suitable for polypropylene PP plastic adhesion, suitable for large area plate lamination, high transparency, suitable for PP adhesion PP, PP adhesive PC, PP adhesive ABS,PP adhesive PVC, PP adhesive acrylic, PP sticky metal, PP stick wood.

K-7007 adhesion performance is roughly the same as k-720, light yellow and more economical.

K-620 is adhesive small area polypropylene PP glue, must be used with the k-650 treatment agent, the instant positioning, the strength is high.

Advantages:

1. Low density;

2. Heat resistance ;

3. Non deformation;

4. High stiffness;

5. High surface strength;

6. Good chemical stability;

7. Nontoxic and safe.

Disadvantage:

The main disadvantage of the fault polypropylene is that the high temperature rigidity is not enough, and the low temperature is brittle.

Poor environmental tolerance, outdoor use, easy to turn yellow and brittle.

Tensile strength of anisotropy, the products are easy to deform, continuous use of low temperature, high creep performance, and long - term load.

Poor printing performance.

Application:

1,Valve part, drinking water and sewage water pipe,

2,Sealing element, spraying carrier,

3,Corrosion-resistant trough and barrel, industrial applications that have acid and alkali-resistant requirement; wastewater and gas discharge equipment for industrial purpose,

4,Scrubbing tower, clean room, semiconductor plant and other related industrial equipment and machinery, food machinery and chopping board,

5,Electroplating process, toy part


Combustion characteristics: PP Plastic easy to burn, polypropylene from continue to burn after the fire, with the top of the flame is yellow, the bottom made in blue, with a small amount of smoke generated, burning melt dripping, and oil.

Specification: the thickness of PP sheet material can be produced from 0.3mm to 2mm, and the PP sheet material is of rolling material and width of 500-1000mm.

The thickness of the plate can be produced from 2mm to 200mm. The specification is 600*1200mm 1000*1000mm 1000* 2000mm. Other specifications can be customized as needed,and The diameter of the PP rod can be produced from 2mm to 250mm, the length is 1 meter, PP rod can be ordered to be more than 3 meters in length.

Color: white and black, other colors can be customized

Modified varieties: PP sheet have various enhancers and other auxiliaries can be added to make modified varieties, depending on the requirements


Storage methods:

Keep in tight, cool and dry place to ensure good ventilation

Product certification: most environmental certification reports and safety reports for raw materials, such as SGS report, CTI report, UL report, MSDS safety information, etc.

PP Plastic Sheet,Polypropylene Plastic Sheet,High Hardness PP Sheet,Non Deformation PP Sheet

Dongguan Noegem Plastic Products Co.,Ltd , https://www.noegempLastic.com