世界上许多发展小型混凝土砌块的国家中,英美两国是属于较早的国家之一,具有较悠久的历史。早在1850年,在英格兰就曾模仿天然石材砌体生产混凝土建筑预制件。19世纪末期,英美两国都能生产炉渣砌块。当今世界各国所采用的先进的砌块成型机,就是在美国人H.S.Palmer于1900年首次研 Of the many countries in the world that develop small concrete blocks, Britain and the United States belong to one of the earlier countries and have a relatively long history. As early as 1850, concrete building prefabricated parts were produced in England as a natural stone masonry. In the late 19th century, both Britain and the United States could produce slag blocks. The advanced block forming machines used by various countries in the world today were first studied by the American H.S. Palmer in 1900.