商品混凝土因性能较稳定而备受施工企业青睐。目前,北京、上海、广州、大连、厦门等城市的商品混凝土使用量较大,己占混凝土总用量的60%～80%,分别占该城市混凝土总用量的60%以上,接近经济发达国家水平。此外,还有不少施工单位以自建搅拌站的方式来保证混凝土供给。商品混凝土行业的准入门槛较低,根据中国建筑业协会混凝土分会公布的数据,我国27个省、自治区、直辖市的预 Commodity concrete because of the more stable performance and favored by construction companies. At present, Beijing, Shanghai, Guangzhou, Dalian, Xiamen and other cities use a large amount of commercial concrete, accounting for 60% to 80% of the total amount of concrete, respectively, accounting for more than 60% of the total concrete in the city, close to the level of economically developed countries . In addition, there are many construction units to self-built mixing station to ensure the supply of concrete. Commodity concrete industry access threshold is low, according to the China Construction Association concrete branch data released in China’s 27 provinces, autonomous regions and municipalities of the pre-