Construction Quality Control of Composite Geomembrane
The quality control of composite geomembrane construction includes the quality control of incoming raw materials, the control of the construction operation process, and the quality inspection after construction.
1. Quality control of raw materials
The incoming composite geomembrane must have the certificate of conformity provided by the manufacturer, the performance and characteristics indicators, and the instruction manual. Otherwise, it cannot be used for project construction. This project uses a two-cloth, one-membrane composite geomembrane. The technical parameters of the design composite geomembrane are: the design weight is 400g / m2, and the vertical permeability coefficient is <1010cm / s. After the composite geomembrane came into the field, the composite geomembrane was randomly selected and its performance indicators were entrusted to the Heilongjiang Provincial Water Conservancy Engineering Supervision Quality Inspection Central Station for re-inspection. The re-inspection results were all qualified.
2. Construction operation process control
Compile the construction organization design before laying the composite geomembrane, explain the laying method and technical measures, and use it after approval by the supervisor. Construction personnel should wear flat-bottomed shoes or soft rubber-soled shoes for laying. It is strictly prohibited to wear spiked shoes to prevent stepping on the geomembrane. When laying and pressing, the laying of the composite geomembrane should be coordinated with the laying of the protective layer. The quality of composite geomembrane welds during splicing is the key to splicing. In particular, joint testing must be strengthened during construction. Inspection methods include visual inspection and on-site leak detection.
Visual inspection method: After the composite geomembrane is welded, observe whether there is leakage, whether the joints are scalded, whether there are wrinkles, and whether the splicing is uniform.
On-site leak detection: All the welds are tested by the aeration method. The welds are double strips, with a cavity of about 10mm left between the two. Seal the ends of the section to be tested, insert the gas needle, and inflate to 0.05mpa ～ 0.20mpa, watch for 0.5min, observe the vacuum gauge, if there is no drop in air pressure, it shows that there is no leakage, weld the grid, otherwise, find the cause and repair in time. The anchoring of the upper and lower parts of the composite geomembrane is an important link, and construction is carried out in strict accordance with the construction drawings and inspection and acceptance.
3. Quality inspection after construction.
The quality inspection after construction is mainly sample inspection. Take a test piece for every 1000m2 of construction and perform a tensile strength test. The strength is required to be not less than 80% of the base material, and the sample fracture must not be at the joint, otherwise, the quality of the joint is not good. qualified. A total of weld joint samples were taken on-site for tensile strength testing. After passing the test, the pass rate was 100% and the weld quality was qualified.