GB/T 17669.1-1999 focuses on the general test conditions of building plasters. It specifies the environmental conditions when conducting building plaster-related tests, such as temperature and Humidity requirements, and standardizes the standard process of sample preparation, covering raw material selection, mixing and molding. The standard provides a unified benchmark for subsequent performance tests of building plasters, ensures the comparability of test results in different laboratories and different batches, and helps to accurately evaluate building plaster mass. It is widely used in building plaster production, mass testing and scientific research. It is the basic specification to ensure the scientific and accuracy of building plaster tests.