Discussion on The Fixture For Tensile Test of Steel-plastic Geogrid
Abstract: The ultimate tensile strength of steel-plastic wholesale polyester geogrid is an important indicator to determine whether the product is qualified. There is no uniform standard for test fixtures. This paper summarizes the experience of mechanical performance testing for many years. The test was carried out, and a set of special fixtures for tensile testing of steel-plastic polyester geogrid for sale was developed and verified by a large number of tests for peer reference learning.
Keywords: steel wholesale polyester geogrid, ultimate tensile strength, special fixture
1. Overview
The steel-plastic polyester geogrid for sale is composed of longitudinal and transverse steel-plastic composite ribs as the force-receiving components. After the joints are processed by special processes such as ultrasonic waves, the grid-like sheets with high tensile strength and integrity are formed polyester geogrid factory price. The body is subjected to a strong interlocking action to maintain good overall stability (as shown in Figure 1). Due to its high tensile strength and small deformation, it is widely used in soft foundation treatment and uneven settlement of roadbed polyester geogrid manufacturers, especially for the treatment of uneven settlement of new and old roadbeds. Well, it is the material of choice for uneven settlement of roadbeds. The manufacturers are mostly in Shandong, others are distributed in Harbin, Shanghai, Changzhou, Ningxia, Jiangsu, and other places, with nearly 20 large and small manufacturers polyester geogrid factory price, with an annual output of nearly 10 million square meters.
Figure 1 Single bidirectional plastic wholesale polyester geogrid
In recent years, it has been found that steel-plastic grids have general standards, such as JT/T480-2002 “Traffic Geosynthetics for Traffic Engineering” and JTG E50-2006 “Test Procedures for Geosynthetics for Highway Engineering”, etc. Product standards, such as JT/T925.1-2014 “Geological Engineering Geosynthetics polyester geogrid for sale Part 1: Steel-plastic Grille”, however, in these standards, there is no specific limit tensile strength test fixture The organizational structure or the unrealistic test method proposed, the lack of uniform standards for manufacturers and testing departments to test the authenticity of the technical indicators polyester geogrid factory price, so the development of standards is imperative. At the same time, the formulation of standards is conducive to standardizing the market order, which is conducive to the steady development of the product market, and is conducive to the correct guidance of product production, so as to provide a scientific basis for product inspection, provide reliable guarantee for product quality, and put forward reasonable requirements for product technical indicators. Because steel-plastic high quality polyester geogrid is widely used in highway engineerings such as retaining wall, abutment, slope, and roadbed reinforcement, steel-plastic polyester geogrid manufacturers and various inspection departments urgently require the development of steel-plastic polyester geogrid factory price stretching fixture transportation industry. Standards, clear test methods, easy for manufacturers to produce and control the ultimate tensile strength of steel-plastic high quality polyester geogrid and the testing department to test the ultimate tensile strength of the product.
2. Tensile test method
According to JT/T925.1-2014 “Geological Engineering Geosynthetics wholesale polyester geogrid Part 1: Steel-plastic Grille” 6.4, the strength and elongation are tested according to JTG E50 “Test Procedure for Geosynthetics for Highway Engineering”. However, there are two test methods in the specification, namely a wide strip tensile test and a single tensile test.
2.1 Wide strip tensile test
Each sample is at least 200 mm wide and of sufficient length polyester geogrid factory price. The clamping line of the sample shall be at the node, in addition to the node or cross-structure held by the clamp, it shall contain at least 1 row of nodes or cross-structure; for products with a lateral pitch greater than or equal to 75 mm, the width direction It should contain at least two complete tensile units polyester geogrid manufacturers. The tensile strength results are calculated according to formula (1).
Where: αf——tensile strength (kN/m);
Ff – maximum load (kN);
Nm – the number of stretching units in the width of the sample 1 m;
Ns – the number of stretching units in the sample polyester geogrid factory price.
2.2 Single tensile test
The single-strand specimen shall be of sufficient length that the gripping line of the specimen shall be at the joint polyester geogrid for sale, in addition to the nodes or cross-sections held by the clamp, and shall contain at least one node or cross-structure. The tensile strength results are calculated according to formula (2).
Where: αf——tensile strength (kN/m);
F——the maximum tensile force (kN) of the test piece;
n – the number of ribs on the width of the sample;
L – sample width (m).
Because the steel-plastic polyester geogrid for sale is a band-shaped reinforced material composed of high-strength steel wire wrapped polymer materials, high-strength steel wire is the main tensile component. The author believes that if a wide-strand tensile test is used, the sample clamping difficulty during the test Large, not easy to operate, so a single tensile test is recommended.
3. Development of steel plastic geogrid tensile test fixture
Because the steel-plastic wholesale polyester geogrid is a strip-shaped reinforced material composed of high-strength steel wire wrapped with polymer materials, the high-strength steel wire is the main tensile element, and the polymer material cooperates with the steel wire to protect the steel wire from corrosion. How to accurately test its true ultimate tensile strength is a difficult problem we will study. On the basis of summarizing the experience of mechanical property testing for many years, this paper has repeatedly tested and developed a set of special fixtures for tensile testing of steel-plastic polyester geogrid manufacturers, which is suitable for the stretching of a single steel-plastic high quality polyester geogrid. The strength test, the way to clamp the sample is shown in Figure 2 to 5:
Figure 2 Stretching fixture of a single steel plastic polyester geogrid manufacturers
Figure 3 Form of the sample loaded into the fixture
Figure 4 Wave jaw clamping sample polyester geogrid factory price
Figure 5 Insert the specimen into the fixture as shown in the figure, and then rotate the handle to clamp the specimen.
Due to the high strength of the steel high quality polyester geogrid, if the sample is clamped by a manual clamp, it is difficult to clamp the sample and cause the sample to slip during the test. Therefore, our fixture adopts the winding method. During the test, most of the pulling force is shared by the winding wheel 1 and the winding 2, so that the force received at the clamping jaw is not so large, and the sample slip phenomenon does not occur. Because the steel-plastic polyester geogrid for sale is a combination of multiple steel wires and resin, their elongation is different. The steel wire in the same grid will be broken during the test, and the breakpoints are also inconsistent. Therefore, it is difficult to ensure the breakpoint of such a sample, and it may break at the winding wheel.
4. Application effects and experience
This set of special fixtures has been successfully applied to the ultimate tensile strength test of steel-plastic wholesale polyester geogrid for more than one year, and the batch of steel-plastic high quality polyester geogrid tested has reached more than 100 times.
This paper selects the steel-plastic polyester geogrid for sale with the specification model GSGS80-80, and performs the cutting, loading, testing and data processing according to the single tensile test specified in JTG E50 “Testing Regulations for Geosynthetics for Highway Engineering”, as shown in Table 1.
Table 1 Statistical Table of Steel-Plastic high quality polyester geogrid Test Results
Average tensile strength:
The experimental standard deviation of tensile strength αf:
Relative uncertainty caused by repeatability:
From the relative uncertainty of reproducibility obtained by using this set of special fixtures polyester geogrid manufacturers, it can be seen that the special fixtures of this set have good stability, simple structure, convenient and flexible clamping, and the operation and use process is safe and reliable.
5. Conclusion
In the current national industry standards, only the technical requirements for the ultimate tensile strength of the plastic wholesale polyester geogrid are proposed, and the test methods are not specified. The relevant specifications do not specifically apply the applicable force clamps for their characteristics. To this end, the author through the repeated analysis, development, testing, and finally developed a suitable set of the special tensile strength of steel-plastic polyester geogrid manufacturers and verified by a large number of field tests. The use of the fixture not only improves the utilization rate of the universal material testing machine but also further enhances the authenticity of the test data of the steel-plastic high quality polyester geogrid for reference by peers.