Akademik Veri Yönetim Sistemi
Hazır Beton Dergisi, cilt.69, sa. Mayıs-Haziran 2005, ss.42-43, 2005 (Hakemli Dergi)
High
performance concrete is a novel construction material, which exhibitis higher
workability, greater mechanical properties, and better durability than the
concentional concrete. Most important
criteria for preparation of high performance concrete are addition of
superplasticizers in cement mixtures. Only a small amount of superplasticizers
can siginificaltly improve the properties of concrete. Water-solube resins
called superplasticizers have been applied in many areas such as paint industry
and dye manufacturing. Other important areas of applications in construction engineering
as water reducers. The roles of this water-soluble polymer are to improve the
reological properties of fresh concrete without segregation or bleeding, act as
a lubricant or a dispersing agent so that solid particles become more uniformly
dispersed, interact with cement of hydrated products to modify the morphology
of materials. The superplasticizers were originaly develeped in Japan and
Germany in the early 1960s; they were introduced in the United States in the
mid-1970s. Superplasticizerr are linear polymers containing sulfonic acid
groups attached to the polymer backbone at regular intervals. Most of the
commercial formulations belong to one of four families; sulfonated
melamine-formaldehyde condensates, sulfonated naphthalane-formaldehyde
condensates, modified lignosulfonates, polycarboxylates derivatives. In the future, superplasticizers will be more
valuable additives in construction engineering.