In order to reduce the use of class F fly ash in geopolymer parts, we investigated the compaction self-assembly (CSA) technology, which could greatly decrease the fly ash content from similar to 25 to similar to 10 wt%. In CSA, a compaction pressure was applied on the premixed material, to efficiently distribute the small amount of binder to the most critical microstructural sites. When the compaction pressure was 70 MPa, the flexural strength reached similar to 4 MPa, comparable with typical unreinforced concrete; when the compaction pressure was 200 MPa, the flexural strength was similar to 10 MPa, comparable with typical steel-reinforced concrete. The material strength increased with the binder content and was quite insensitive to the water glass to sodium hydroxide solution ratio. [GRAPHICS] .