混凝土骨料中一般规定粒径大于5毫米的颗粒为石子,小于或等于5毫米的颗粒为砂子。常用砂子中含有大于5毫米以上的颗粒,一般称为砂头,含量约占0～25%左右。当砂头含量过大时,如果不调整混凝土配合比的砂率,将直接影响混凝土的和易性和密实性。 In concrete aggregates, it is generally stated that particles with a particle size of more than 5 mm are stones, and particles with a size of less than or equal to 5 mm are sand. Commonly used sand contains particles larger than 5 millimeters, which are generally called sand heads, and the content is about 0 to 25%. When the sand content is too large, if the sand ratio of the concrete mix is ​​not adjusted, the concrete’s workability and compactness will be directly affected.