"粉煤灰混凝土" can be translated into English as "fly ash concrete".
Here, "fly ash" refers to the fine ash particles collected from the flue gases after coal combustion, which are commonly used as a supplementary cementitious material in concrete production. "Concrete" denotes the composite material composed of cement, aggregates (such as sand and gravel), and water, often with additional admixtures like fly ash to improve its properties.