使用建筑材料,必须按照国家有关标准进行检验.合格后才能使用。下面介绍几种常用建筑材料的鉴别方法,作为目测建筑材料质量的参考。一、水泥1.抓一把水泥捏在手中,如果水泥不起团并且立刻从手缝中喷出来,属优质水泥。如果手中留下大小不等的小水泥块,说明这种水泥不是质量不好就是过期了。2.看出厂日期。水泥的有效期一般为3个月(从出厂日期 The use of building materials must be inspected in accordance with relevant national standards. Only qualified personnel can use them. The following describes the identification methods of several commonly used building materials as a reference for the visual inspection of the quality of building materials. 1. Cement 1. Grab a piece of cement and hold it in your hands. If the cement does not form a group and immediately spout it out of the hand, it is a high-quality cement. If you leave small cement blocks of different sizes in your hand, it means that the cement is not of poor quality or is out of date. 2. Look at the factory date. Cement is generally valid for 3 months (from the date of manufacture