The improvement of setting time and early strength of fiber-reinforced concrete with high-volume fly ash

Abstract An engineered cementitious composite (ECC) is a micromechanically based designed high-performance fiber-reinforced cementitious composite with high ductility and durability, represented by strain-hardening behavior in uniaxial tension. However, the setting time of ECC is retarded and early strength is decreased due to the presence of high volume of fly ash (HVFA). Therefore, shortening the setting time and increasing flexural strength of HVFA-ECC will be of obvious economic importance. The experimental study on setting time and flexural strength of HVFA-ECC proved that the setting time can be shortened by adding alkali accelerator and the optimum content is 4.0%, while the flexural strength of HVFA-ECC can be increased by applying fine particles fly ash, modified fly ash or adding exciting agent of fly ash. Keywords: fly ashsetting timeearly flexural strengthHVFA-ECC Acknowledgments We are thankful for the financial support of NSFC (20676149 & 2107227).