上海振苏砖瓦厂在1984年初,将四车间原设计生产标准砖(实心砖)的生产线,改造成生产20孔承重空心粘土砖(规格为240×115×90毫米,20个圆孔,孔洞率22%左右),取得了显著的经济效益。整个改造项目分两步进行。第一步:投资4.5万元,用于增加原料土的掺配、碾练设施,将塑性较高的原料土和砂性土按一定的比例掺 In early 1984, Shanghai Zhensu Brick and Tile Factory transformed the production line of the original design and production standard brick (solid brick) from the fourth workshop into a 20-hole load-bearing hollow clay brick (size 240×115×90 mm, 20 round holes, holes). The rate of 22% or so) has achieved remarkable economic benefits. The entire renovation project is divided into two steps. The first step: to invest 45,000 yuan, to increase the mixing of raw materials, grinding facilities, the higher plastic raw material and sand soil mixed in a certain proportion