Akademik Veri Yönetim Sistemi
International Asian Congress on Contemporary Sciences-V, Nakhchivan, Azerbaycan, 01 Haziran 2021
In this study, the effect of high range water reducing admixture (HRWR)
with different polymer ratios on some fresh state properties of cement systems
was investigated. For this purpose, 3 different HRWRs were synthesized
consisting of 30%, 40%, and 60% polymer by weight. Anionic/nonionic mol ratio,
side chain type, number and length, and main chain length were kept constant in
all admixtures. During the synthesis phase of all admixtures, 0.5% of
antifoaming agent was added to the mixture consisting of polymer and deionized
water. Utilizing these admixtures, paste and mortar mixtures were prepared.
CEMI 42.5R type Portland cement was used as a binder in all mixtures. The w/c
ratio and slump-flow value in mortar mixtures were kept constant as 0.485 and
27±2 cm, respectively. Marsh-funnel flow time was determined in paste mixture.
In mortar mixtures, admixture requirement, and time-dependent slump-flow values
were measured in order to achieve target spread. Regardless of the admixture
type, the admixture saturation point for all admixtures was determined when the
admixture/cement ratio is 1%. With the increase in admixture polymer content
from 30% to 40% and 60%, a decrease of 3% and 18% in Marsh-funnel flow time was
determined, respectively.
With the increase of the admixture polymer content to 40%, a 38%
reduction in the admixture requirement was obtained to achieve the target
slump-flow value in the mixture. However, it was observed that there is an
increase of 56% in need for admixture with the increase of the admixture
polymer ratio from 30% to 60%. When the slump-flow values of the mixtures at
the end of 60 minutes were examined, the admixture polymer content increased
from 30% to 40% and 60%, resulting in an improvement in the consistency
protection performance of the mixtures by 8% and 4%, respectively. Considering
all the features, it was understood that the best performance in terms of
spreading behavior and consistency protection performance is achieved when the
admixture polymer ratio is 40%.