ДОСЛІДЖЕННЯ ВЛАСТИВОСТЕЙ МАЛОУСАДКОВИХ БЕТОНІВ ДЛЯ SEAMLESS FLOOR TECHNOLOGY, ЩО РОЗРОБЛЕНІ ІННОВАЦІЙНИМ ЦЕНТРОМ КОМПАНІЇ ТОВ «АСТОР і КО» З КОМПЛЕКСНОЮ ДОБАВКОЮ ФІРМИ ТОВ «МАПЕІ УКРАЇНА»

Abstract

The paper contains information on obtaining
non-shrinkable concrete. Deformations of special
low-shrink concretes for seamless floor technology
have been investigated. Experts of the Astor & Co
Innovative Center and Mapei Ukraine developed
these concretes. Developed concretes are characterized
by a complex granulometric composition, the use of
various cements and the use of chemical additives
Dynamon SR3 (superplasticizer), Expancrete
(expanding additive), and Mapecure SRA25. The
technologies of obtaining non-shrink and expanding
concretes are analyzed taking into account the
hardening conditions. It is shown that in the early
stages of hardening of the questioned concretes, there
is expansion, and then show slight shrinkage. The
maximum value of concrete expansion deformations
is recorded on the 3rd day of hardening under normal
conditions. So, for concrete on PCII/А-Ш-500Р-Н
cement, expansion deformation is +0.568 mm/m,
while for concrete on ПЦІІ/А-В-500Р-Н cement
is +0.494 mm/m. It has been established that the
processes of concrete expansion in the first stages
of hardening are explained by moisture, which
contributes to the formation of neoplasms similar
to natural ettringite, which requires a significant
amount of water for its synthesis. In the subsequent
periods of concrete hardening in air-dry conditions

which are close to the conditions of hardening in
the initial periods for concrete floors, there is a
slight shrinkage. Further shrinkage deformations are
smaller for concretes based on ПЦІІ/А-В-500Р-Н
cement than for concretes made of ПЦІІ/А-Ш-
500Р-Н cement. ПЦІІ/А-В-500Р-Н cement includes
limestone. It has been established with the help
of electronic microscopic analysis that in concrete
made based on ПЦІІ/А-В-500Р-Н cement, with time
there is a significantly larger number of neoplasms
similar to ettringite, which however have Ca(СО)3
in the content, than in concrete made based on
ПЦІІ/А-В-500Р-Н cement. Therefore, the value
of concrete shrinkage deformations over time in
ПЦІІ/А-В-500Р-Н cement is negligible. The obtained
results of concrete deformations are correlated with
the data obtained at Mapei Italy. The obtained results
have been confirmed in industrial conditions when
making floors using seamless floor technology.