Thesis Open Access
BELACHEW ASTERAY (PH.D.)
Concrete is the most common building material that is used prominently in construction industry. It
can be cast in any desired shape and fashion and should be workable whether on- site or in ready mix
concrete production. To achieve better performance and desired proprieties of concrete, the use of
chemical admixtures is priceless choice in concrete production. While, there are common problems
facing to optimize superplasticzer dosage with various types of cement to produce desirable
properties of fresh and hardened concrete due to lack of practices in construction industry in our
The purpose of this research was determining optimum Superplasticizer dosage for desired
workability using Marsh Cone Test at pre-determined water cement ratio. It was also analysis the
effect and influences of Superplasticizer dosage on concrete properties. Slump Cone test and testing
machine were used to determine such properties of concrete. The first conclusion that was drawn
from the research was deciding optimum dosage on cement slurry which was prepared using different
types of Super plasticizer and Cements for variable water cement ratio. Secondly, the test were
carried out to see effects of Superplasticizer dosage on improvement of workability and flowablity of
fresh concrete in specified doses. Also, it was also noticed changes of hardened concrete properties
using mechanical tests.
Using 0.45 and 0.40 water-cement ratio, optimum dosage of Superplasticizer (ODS) has found out,
with respect to different Superplasticzers on different brand of cement paste mix.
Secondly, it also observed the effect of superplasticzer dosage for pre- determined quantity (0.5%,
1.0%, 1.5% and 2.0%) on hardened concrete strength in addition to fresh concrete characteristics.
Thirdly, the demand of water reduced by 20%, 23%, 27% and 30% from total mix water using
0.5%,1.0%,1.5% and 2.0% of Superplasticizer respectively in concrete mix.
Generally, Superplasticzer is playing vitally role to achieve better physical properties and quality of
concrete, and resolving challenges in undesirable conditions during concrete work operations. Despite
these facts, over dosage of SP were found to deteriorate the properties of concrete with indication of
lower compressive strength and higher porosity due to bleeding and segregation occurrences.
OPTIMIZATION OF SUPERPLASTICIZER DOSAGE AND EFFECTS WITH LOCALLY PRODUCED CEMENTS.pdf