A new strategy to improve quality of ready mixed concrete using rice husk ash

Abstract

Quality improvement of ready mixed concrete would be achieved by control of surface properties of its constituents, which are cement and additives. Rice husk ash (RHA) which is solid waste received from rice husk fire combustion process would help improve such cement properties and reduce environmental burden due to land-filling.  A new strategy to improve quality of ready mixed cement has been experimentally explored using ground RHA as an additive to mix with cement.   Because of amorphous silica within ground RHA which could involve with the pozzolanic reaction, control of particle size distribution of RHA and weight ratio of RHA to cement would lead to quality improvement of ready mixed concrete.  In this work, particle size distribution of RHA is represented by the fineness of RHA which is set from 3,200 to 5,100 cm²/g.  Meanwhile, the mixing ratio of RHA to cement is set from 5 percent to 20 percent by weight. It was found that the RHA fineness and the mixing ratio of RHA to cement could affect the 3, 7 and 28-day compressive strength of the ready-mixed concrete.  RHA with a fineness of 5,100 cm²/g could provide the highest compressive strength with the 10-15 percent of RHA is mixed with cement.