Effects of lignosulfonate on synthesis products of the pozzolanic reaction
Kanako Toda,
Daisuke Minato,
Takumi Saito,
Ryosuke Kikuchi,
Tsubasa Otake,
Tsutomu Sato
Affiliations
Kanako Toda
Nuclear Professional School, School of Engineering, The University of Tokyo, 2-22 Shirakata Shirane, Ibaraki 319-1188, Japan; Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan; Corresponding author at: Nuclear Professional School, School of Engineering, The University of Tokyo, 2-22 Shirakata Shirane, Ibaraki 319-1188, Japan.
Daisuke Minato
Central Research Institute of Electric Power Industry, Chiba, Japan
Takumi Saito
Nuclear Professional School, School of Engineering, The University of Tokyo, 2-22 Shirakata Shirane, Ibaraki 319-1188, Japan
Ryosuke Kikuchi
Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
Tsubasa Otake
Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
Tsutomu Sato
Division of Sustainable Resources Engineering, Faculty of Engineering, Hokkaido University, Sapporo, Japan
Soil organic matters may inhibit the pozzolanic reaction, and thus influence the strength development of soil-employed construction materials. To understand their interaction, the effect of lignosulfonate, here used as model soil organic matter, on the pozzolanic reaction was investigated through batch experiments. Lignosulfonate inhibited the pozzolanic reaction, suppressing calcium silicate hydrate (C-S-H) formation. The suppression did not take place in a continuous way with the addition of lignosulfonate but was triggered at a certain dosage of lignosulfonate. We propose that the inhibition was primarily due to formation of Si-(Ca)-lignosulfonate complex. Such interaction may illustrate the inhibition of the pozzolanic reaction by organic matters in soils at alkaline activation. Below the threshold, lignosulfonate allowed C-S-H formation though modified its structure, which also suggested the possibility of soil organic matters to influence the strength development of construction materials in coexistence of C-S-H formation.
