This article details the sampling and testing methods for bitumen to ensure that bitumen samples are representative for quality inspection. The article first describes the purpose and scope of sampling, which is suitable for various types of asphalt materials, including viscous, solid, liquid asphalt and asphalt emulsions. Then, the technical requirements of sampling instruments and materials were clarified, and the selection of sample containers and samplers was emphasized. The article details the steps for sampling from different storage and transportation sites, including storage tanks, tankers, transport vessels, etc., and provides sampling methods for solid asphalt. In addition, the protection and storage measures of the samples are discussed to ensure the quality and stability of the asphalt samples during storage. Through the standardized sampling and testing methods, this paper provides an important basis for the quality control and subsequent application of asphalt materials.
Purpose and Scope of Application
The sampling and testing method of asphalt is mainly used to collect representative samples of asphalt at the production plant, storage or delivery acceptance site for quality inspection. This method is suitable for all types of asphalt materials, including viscous asphalt, solid asphalt, liquid asphalt and asphalt emulsions. According to different testing needs,
The number of asphalt samples required for routine inspection is not less than 4.0kg of viscous or solid asphalt, not less than 1L of liquid asphalt, and no less than 4L of asphalt emulsion.
Technical requirements for sampling equipment and materials
During the sampling process, it is crucial to select the right container for the type of asphalt
Sample Containers - Liquid or viscous bitumen should be used in wide-mouthed, sealed metal containers with lids, such as pots, barrels, etc.; Polyvinyl chloride plastic drums can be used for emulsified asphalt; Solid asphalt can be used in plastic bags, but it needs to be packaged.
Sampler – The sampler should be made of metal with a long metal handle and designed to facilitate sampling in the tank.
Sampling methods and procedures
Sampling from oil storage tanks
Storage tank without mixing equipment
Close the inlet and outlet valves first.
Use a sampler to take samples on the surface, middle and lower layers (1/3 parts each), and after sampling in each layer, it should be poured as clean as possible.
After mixing the removed sample thoroughly, take out 4kg as a sample.
Tanks with mixing equipment
Liquid asphalt needs to be thoroughly mixed.
Samples are taken from the middle of the asphalt layer to ensure that the sample volume is in accordance with the regulations.
Samples are taken from tankers and tankers
Sampling valve - if there is a sampling valve, unscrew it and wait for at least 4kg or 4L to flow out before sampling.
Discharge valve – If there is only a discharge valve, take a sample after half of the asphalt has been released.
Top Cap – A sampler can be used to sample from the middle to ensure representativeness.
Sampling is taken during loading or unloading
Samples are taken evenly at time intervals during loading and unloading, with a minimum of 3 samples taken.
These samples were mixed thoroughly, and 4 kg was taken out as a sample for testing.
Samples are taken from asphalt storage ponds
After heating and melting, it is flowed to the heating pot through a pipeline or asphalt pump for sampling.
Take at least 3 samples in each pot, and then take 4kg as a sample after mixing.
Sampling from an asphalt carrier
Upon arrival at the port, samples were taken separately from each asphalt tank.
Three 4kg samples were taken from each chamber, and 4kg was taken out as a chamber of asphalt samples after mixing.
Samples are taken from asphalt drums
Confirm the same batch of production, random sampling can be taken; If it cannot be confirmed, it should be randomly selected according to the number of barrels.
The asphalt drum is heated to a fluid state and then sampled to ensure that the sample meets the specified 4.0kg requirement.
If heating is inconvenient, it is necessary to chisel and take samples in the middle of the barrel height to prevent sample contamination.
Solid asphalt sampling
Samples are taken from at least 5 cm below the surface and sides of the container.
If the asphalt can be broken, use a clean tool to take the middle part of the sample; If the asphalt is soft plastic, cut and sample with a hot tool.
Protection and storage of samples
Storage Containers – Except for liquid bitumen and emulsified bitumen, other bitumen samples should be stored in a sealed metal container with a lid, avoiding the use of paper or plastic bags to prevent contamination.
Environmental conditions – Samples should be stored in a cool, dry place away from direct sunlight and high temperatures.
Anti-freezing measures - Effective anti-freezing measures should be taken to ensure the quality of samples for emulsified bitumen in winter.
Marking and Recording – Samples should be marked with the source, variety, date and location of the sample, and the information of the person who took the sample, so as to facilitate traceability and management.
summary
Through the standardized asphalt sampling and testing method, the quality of asphalt products can be effectively ensured, and reliable data support can be provided for subsequent applications. Taking reasonable storage and management measures is also an important part of ensuring the accuracy of test results. The implementation of the above sampling method lays a solid foundation for the smooth implementation of highway engineering and related fields, and ensures the stability and reliability of asphalt materials.
