ANALYSIS OF ANTI-WASHOUT ADMIXTURE FOR UNDERWATER CONCRETE

the usage of natural antiwashout admixture for underwater structure in Malaysia is
studied for its behavior used as admixture. This study is iterated on finding potential natural
antiwashout admixture having similar properties as chemical antiwashout admixture. The
significance of this research would he important to find new resource of admixture, reducing
underwater construction cost and time. Sample such as starch, and agar will he taken into
au-count for its potential as antiwasho ut admixture. '11iis research starts by searching fair any other
relevant journal or article published by other researches and from there, the results would be
review and useful information will be summarize and taken as an infiirnurtion to this research.
Iligh-performance underwater concrete (III' IJW(') can incorporate a variety of chemical
admixtures, particularly AWA and supcrplasticiscr. Most AWAs are water-soluble polymers that
increase the viscosity and yield of cement paste and concrete (2,14). 11igh concentrations of
AWA are neccasaryy when the concrete is cast in flowing water, including the surface none, and
when the mix is designed to he highly flowahle to spread around obstacles with minimum
scgrvgation and water dilution and develop flat surfaces. The experiment is done using selection
of ordinary Portland cement, Sikament- IOOS(' antiwashout, starch based antiwushout, and course
and fine aggregate. Ir the coarse aggregate the site of aggregate used is passing 20 nom sieve
sire I he placement of concrete is done by trcmic pndxss, dropped and three diflcrent heights.
I or c. crr height three samples of data is taken into consideration. The result of the experiment
shows that Sikament has higher compressive strength compared to starch base antiwashout. The
strength of concrete samples using starch antiwushout were not uflccted by the height, dropped
from 0,9,0,6. and 0.4, tramples dropped from lower height yield higher compressive strength
than those dropped from 0.9m, and 0.4m. From the result obtained from experiment Sikamcnt
lOOM outperformed the natural starch based antiwashout admixture. however the strength of
concrete samples that uses starch were not afl'ectcd by the height of the dropped samples.