engleski

Physical, mechanical and corrosion testing of grout

Portland cement grout is used in post-tensioned and retaining structures to provide bond between the tendon/anchor and the surrounding concrete/ground and also as corrosion protection for the tendons and the anchors. Grout for bonded post-tensioning is a combination of Portland cement and water, along with different admixtures needed to obtain required properties. An optimum grout combines desirable fresh properties along with good corrosion protection. In this research the effect of corrosion inhibitors on physical and mechanical properties of grout mixture was researched, as well as their effect on corrosion protection of prestressing steel in grout. Two types of corrosion inhibitors were tested in this study and have shown good efficiency when tested in simulated pore solution contaminated with chloride ions. Accelerated corrosion testing performed on high performance grout specimens with embedded prestressing steel bars, showed better efficiency of inhibitor type 1. This research showed that grout with good durability properties, such as with low chloride diffusion coefficient, homogeneity and volume persistency, can withhold to corrosion attack longer even when no inhibitor is added. Since there were other admixtures besides corrosion inhibitors added into the grout mix to enhance other important properties of high performance grout, authors are of opinion that more research has to be performed to investigate compatibility and effect of different admixtures when together added into the grout.

grout; mix-design; prestressing steel; corrosion; inhibitors

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