在毛主席革命路线指引下,铁道部科学研究院,大桥工程局,第三、四工程局组成的混凝土附加剂三结合研究组,以阶级斗争为纲,密切结合生产实际,经过两年多的试验研究和较大量的工程实践,研制成功三种新的混凝土附加剂,并在12万米~3的混凝土工程中使用, Under the guidance of Chairman Mao’s revolutionary line, the Joint Research Unit for Concrete Additives composed of the Research Institute for Railways, the Bridge Engineering Bureau, and the Third and Fourth Engineering Bureaus, taking the class struggle as the key link and in close connection with the actual production, after more than two years Experimental research and a large number of engineering practice, the successful development of three new concrete additives, and 120,000 m ~ 3 in the concrete works,