Title: Effects of Glass Powder (GP) on the Pore Solution of Cement Pastes

Author(s): Isabelle Fily-Paré, Benoît Fournier, Josée Duchesne, Arezki Tagnit-Hamou

Publication: Symposium Paper

Volume: 320

Issue:

Appears on pages(s): 45.1-45.12

Keywords: Glass powder, Alkali-Silica Reaction, Pore solution, Alkali content of cement

DOI: 10.14359/51701083

Date: 8/1/2017

Abstract:
Finely ground glass produced from recycling facilities is an alternative supplementary cementing material that is often considered for eco-friendly concrete mix designs. However, documentation on its behaviour in concrete is limited or somewhat contradictory. Many studies suggest that glass powder can suppress the expansion of concrete due to alkali-silica reaction (ASR), while others suggest that its high alkali content maintains the expansive potential in concrete due to ASR and consequently limits its preventive character. The present work seeks to clarify the overall availability of alkalis in the pore solution of cementitious matrices incorporating glass powder. For this purpose, pore solution extraction had been conducted, on pastes containing 0%, 20% and 40% of Glass Powder and cements of alkali levels of 0.25%, 0.63%, 0.94% and 1.25% Na2Oe. The concentration of alkalis available in the pore solution was analysed after 28 and 91 days. Results showed that the effect of GP on the hydroxyl concentration of the pore solution is limited for cement of high alkali content and important for low alkali cement. Also GP tends to reduce the potassium concentration and increase the sodium concentration of the pore solution.