目前,我国各地中小城市和广大农村都兴建了一些生产中小型钢筋混凝土构件的预制厂,主要产品有民用建筑的空心楼板、过梁和沟盖板等。在预制构件的生产过程中,为了保证构件结构性能的可靠性,必须按照国家规范《建筑安装工程质量检验评定标准》(TJ321—76)的 At present, small and medium-sized cities and rural areas throughout China have built some prefabrication plants for the production of small and medium-sized reinforced concrete components. The main products include hollow floor slabs, lintels and trench covers for civil buildings. In the production process of prefabricated components, in order to ensure the reliability of the structural performance of the components, it must be in accordance with the national standard “Quality Inspection and Evaluation Standards for Building Installation Engineering” (TJ321-76).