Alkalisilicate corrosion in lightweight concrete with a cement binder and a porous aggregate of granulated foam glass.

Use of foam glass in the manufacture of lightweight Portland cement concretes cannot fail to raise questions about how it increases the risk of alkali-silicate reactions and alkaline corrosion in the concrete. The paper deals with manifestations of alkali-silicate corrosion in lightweight concretes on the basis of Neoporm granulated foam glass (from ZAO STES-Vladimir, city of Vladimir). Accelerated testing of concrete samples for expansion was conducted, and additional physical, mechanical and microstructural studies of the samples were made after the tests. During the accelerated and long-term tests in accordance with GOST 8269.0 the signs of alkali-silicate reactions (ASR) in the samples of lightweight concrete containing foam glass, although the expansion of samples in none of the cases exceeded the acceptable values as specified by GOST. Alkali-silicate hydrogel formed in the tests during the interaction of foam glass with alkalis of the pore fluid is deposited in the cavities of the lightweight aggregate, which deters the negative effects of ASR.

Author: M.Y. Popov, B.G. Kim, V.E. Vaganov, A.S. Brykov

Section: Concrete

Keywords: lightweight concrete, granulated foam glass, alkali-silica reactions