ABSTRACT

NaOH was used as a solid alkali initiator for fly ash eco concrete. The porosity, water permeability, compressive strength, pH, vegetative and microscopic properties of eco concrete with different fly ash contents were studied. The results show that the activation effect is best when the solid NaOH doping is 2% of fly ash. Under this condition, the 28d compressive strength of alkali-activated fly ash eco concrete was the highest when the fly ash content was 17%, reaching 19.15 Mpa, and the mechanical properties were effectively improved, its permeability and porosity meet the engineering application standards. The surface porosity of each section is similar to the law of total porosity, and the size and number of pores are suitable for plant growth. Manila grass has better alkali tolerance and is more affected by pore size. At 43d, the plant height, root length, and LRWC grown in FA0% and FA7% were the best, and the plant height could reach up to 23 cm. In addition, through SEM and EDS analysis of the sample, it was found that the amorphous product of the sample was mainly N(C)–(A)-S-H gel, which can form an interconnected spatial network structure and has strong bonding ability.