Effect Of Cold-bonded Flyash Aggregate On Workability And Mechanical Properties Of Concrete

摘要

Cold bonding facilitates production of lightweight aggregate from flyash with minimum energy consumption. This paper investigates the effect of cold-bonded aggregate on the properties of fresh and hardened concrete mixtures with cement content ranging from 250 to 450 kg/m~3 and varying water-cement ratio for three volume fractions of cold-bonded aggregate. For constant water content, workability of concrete is highly improved with an increase in volume fraction of cold-bonded aggregate in the mix. A comparison of concrete strength with that of corresponding constituent mortar strength together with the observations on failure surface indicate that concrete strength up to 30 MPa is controlled by the matrix strength or aggregate matrix bond strength, while strength higher than 30 MPa is governed by the failure of cold-bonded aggregate. It appears beneficial to use relatively higher aggregate content in mixtures with lower cement content and vice versa.