Abstract:
Construction industries have started utilizing manufactured sand as an effective alternative for river sand in
concrete. High-grade parent rocks are crushed to obtain manufactured sand which also enables a considerable
amount of microfine aggregate. The higher percentage of microfine aggregate could lead to both positive and
negative effects on the performance of cement-based mixes. This research was done to examine the influence of
varying microfine aggregate levels such as 0%, 3%, 6%, 9% and 12% (by weight) as the partial replacements of
manufactured sand on bleeding and plastic shrinkage cracking of concrete. In addition to the varying microfine
aggregate levels, some concrete mixes also included fly ash and superplasticizer to investigate the effect of freewater content in the mixes. The bleeding test data were taken as the on-site measurements, while the cracks resulted
from plastic shrinkage cracking test were evaluated using an image processing technique. The results concluded
that the microfine aggregate replacements and the effective water-to-cement ratio have a dominant effect on the
selected concrete properties. With the increasing replacement levels, cumulative bleeding and crack initiation life
were gradually decreased while a progressive increase was noticed for crack width, crack length and crack area.
