Open AccessRestriction of Cl- and SO4 2- Ions Transport in Alkali Activated Slag Cement Concrete in Seawater
Author(s) -
Pavlo Kryvenko,
Igor Rudenko,
Oleksandr Konstantynovskyi,
Olha Boiko
Publication year - 2021
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/1164/1/012066
Subject(s) - clinoptilolite , cement , materials science , corrosion , portland cement , alkali metal , seawater , nuclear chemistry , metallurgy , inorganic chemistry , chemical engineering , chemistry , organic chemistry , catalysis , zeolite , geology , oceanography , engineering
The relevance of alkali activated slag cement (AASC) concretes for structures operated in seawater is due to their enhanced resistance in aggressive environments. The application of high consistency fresh concretes is accompanied by negative changes in their structure with higher penetration of aggressive environments. Thus, the methods to prevent corrosion of steel reinforcement in plasticized AASC concrete are actual for investigations. It is shown, that modification of plasticized AASC concrete (consistency class S4) by the complex «alumina cement - portland cement - clinoptilolite - trisodium phosphate (Na 3 PO 4 ·12H 2 O)» restrict the transport of aggressive Cl - and SO 4 2- ions. The results of DTA, XRD, electron microscopy, microzond analysis show that mentioned complex limits transport of the mentioned aggressive ions due to their binding by AFm phases in hydration products, exchange with OH - ions in the structure of clinoptilolite, formation of hydrated products of apatite group Ca 5 (PO 4 ) 3 (OH, Cl). This was confirmed by qualitative reaction on Cl - and SO 4 2- ions in concrete structure, as well as by assessing of surface and mass loss of steel bars embedded in AASC concrete after 9 months in seawater. It was ensured the advanced crystallization with densification of microstructure, which increases corrosion resistance of artificial stone.