High Performance Concrete Pipe from Chemically Activated Fly Ash (CAFA)

摘要

Chemically activated Fly Ash (CAFA) is a newly developed material for construction application which are exposed to aggressive environments such as sewage pipes and chemical containment. CAFA concrete utilizes fly ash, activating chemicals, fine and coarse aggregates in its mix design. CAFA concrete has been used to produces a variety of prototype items. These items ranging from wet cast chemical containment to dry cast pipes and blocks. All prototypes were made at the existing concrete plants without any modifications.rnThe CAFA is capable of creating materials with high performance properties including: rapid strength gain (up to 90% of Ultimate in 24 hours), high ultimate strengths (over 16,000 psi), and dramatically improved acid resistance. CAFA's resistance to chemical attack, such as, sulfuric (H_2SO_4), nitric (HNQ_3), hydrochloric (HCI), and organic acids, is excellent CAFA is a heatrncured system- heat is required for optimal results (130℉-200℉). The heat causes a polymerization reaction in the fly ash and activating solution creating a solid, dense microstructure. CAFA concrete was used to create 8' long, 12" diameter pipes. CAFA concrete pipe were tested after 14 days according to ASTM C-497. Ultimate load of 11,250 pounds per linear foot and load to 0.01in crack was 8,750 pounds per linear foot. In addition to excellent chemical resistant and high strength, CAFA concrete is attractive economically.