Abstract
Concretes mixed with seawater are characterised by enhanced performances, but action of chlorides and sulfates ensures the risk of reinforcement corrosion. Application of high consistency fresh concretes ensures changes in hardened concrete structure that causes the problem of steel reinforcement passive state ensuring. Thus mixing of plasticized concretes by seawater actualizes the search for means of steel corrosion prevention. Alkali-activated slag cements (further, AASC’s) reduce effect of ions Cl−and SO42−on steel reinforcement in concrete due to their exchange for ions OH−in the structure of zeolite-like alkaline hydroaluminosilicates. Complex additive «portland cement - calcium aluminate cement - clinoptilolite» was proposed to enhance the protective properties of AASC concretes to steel reinforcement. The results of DTA, X-ray diffraction, electron microscopy, microprobe analysis show that complex additive ensures to prevent steel reinforcement corrosion in AASC concrete mixed with seawater due to binding Cl−and SO42−ions in Kuzel’s salt in AASC hydration products and exchange of these aggressive ions with OH−ions in the structure of clinoptilolite. This effect of complex additive confirmed by surface state and the absence of mass loss of steel rebars embedded in plasticized AASC fine concrete mixed with seawater after 90 d of hardening.
Highlights
The actuality of green materials implementation is due to their conformity with modern tendencies in construction engineering concerning efficient consumption of raw materials and energy resources [1], as well as responsible attitude to ecology of the environment [2]
The aim of this research was to investigate the effect of seawater on the performances of plasticized AASC concrete and to ensure prevention of steel reinforcement corrosion due to application of CAD «portland cement calcium aluminate cement - clinoptilolite»
3.1 Structure formation of alkali-activated slag cement based on soda ash and mixed with seawater
Summary
The actuality of green materials implementation is due to their conformity with modern tendencies in construction engineering concerning efficient consumption of raw materials and energy resources [1], as well as responsible attitude to ecology of the environment [2]. Cements, which contain inorganic additives, fully comply modern tendencies for sustainable development of mankind [3]. Materials based on the mentioned cements are characterized by high quality, functionality and durability. Efficiency of high early strength multicomponent cements based on ground blast furnace slags (further, GBFS), zeolite and fly-ash in mortars was shown [5]. Addition of zeolite or highly dispersed chalk enhances strength of cements [7], as well as crack resistance [8] and freeze-thaw resistance of concretes [9]. Portland cements containing GBFS are characterized by increased corrosion resistance and can be used in protective materials [10]
Published Version (Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have