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Gerard Van Koten - One of the best experts on this subject based on the ideXlab platform.

Libor Dostal - One of the best experts on this subject based on the ideXlab platform.

  • reactivity of n c n chelated antimony iii and bismuth iii chlorides with Lithium reagents addition vs substitution
    Organometallics, 2015
    Co-Authors: Iva Vranova, Roman Jambor, Ales Růžicka, Robert Jirasko, Libor Dostal
    Abstract:

    N,C,N-chelated antimony(III) and bismuth(III) chlorides L1,2MCl2 (1–4: for L1, M = Sb (1), Bi (3); for L2, M = Sb (2), Bi (4)) containing ligands L1,2 (where L1 = C6H3-2,6-(CH═N-t-Bu)2, L2 = C6H3-2,6-(CH═N-2′,6′-Me2C6H3)2) were prepared by reactions of Lithium precursors with SbCl3 or BiCl3. The identities of 1–4 were established both in solution (1H and 13C NMR spectroscopy) and, in the case of 1–3, in the solid state using single-crystal X-ray diffraction analysis. Treatment of antimony derivatives 1 and 2 with 2 molar equiv of R′Li (R = Me, n-Bu, Ph) yielded the set of substituted 1,3-(R′)2-2-R-7-(CH═NR)-1H-2,1-benzazastiboles 5–10 (where R = t-Bu, 2,6-Me2C6H3 and R′ = Me, n-Bu, Ph) as a result of a nucleophilic attack of one of the Lithium Compounds across the imino C═N functionality. In contrast, analogous reactions between bismuth congeners 2 and 4 and R′Li (2 equiv, R′ = Me, Ph) gave L1,2BiR′2 (11–13: for L1, R′ = Me (11), Ph (12); for L2, R′ = Me (13)) as products of substitution of chlorine atoms...

Hongjian Du - One of the best experts on this subject based on the ideXlab platform.

  • effect of particle size on alkali silica reaction in recycled glass mortars
    Construction and Building Materials, 2014
    Co-Authors: Hongjian Du
    Abstract:

    Abstract The effect of particle size on alkali–silica reaction (ASR) was investigated to clarify the difference in long-term ASR expansions in mortars using recycled green and brown glass as fine aggregates. Test results revealed that green particles of 1.18 and 2.36 mm showed the highest reactivity while the other sizes resulted in relatively low ASR expansions. Brown glass less than 2.36 mm did not result in large ASR expansion. Furthermore, different ASR suppressors were explored to suppress ASR expansion in mortar using 1.18 mm green glass particles. These included supplementary cementitious materials, steel fiber reinforcement and Lithium Compounds.

  • use of waste glass as sand in mortar part ii alkali silica reaction and mitigation methods
    Cement & Concrete Composites, 2013
    Co-Authors: Hongjian Du
    Abstract:

    Abstract Waste glass may be used in concrete provided that the potential deleterious expansion caused by alkali–silica reaction (ASR) could be mitigated. In this study, the influence of glass content, color and particle size on ASR expansion of mortar was determined by the accelerated mortar bar method. Two approaches to control ASR expansion were investigated for green, brown and clear glass sand mortar. They were: (1) by replacing cement with pozzolans, that is, 30% fly ash, 60% GGBS, 10% silica fume, or 20% glass powder; (2) by adding a suppressor, that is, plain steel fibers, and Lithium chloride and Lithium carbonate Compounds. Test results showed that the ASR expansion increased with higher glass content in the case of clear glass sand mortar, but would decrease with increasing content for green and brown glass sand mortar. The ASR expansion also decreased with smaller glass particle size, regardless of glass color. Fly ash and GGBS were the most effective in mitigating ASR expansion, followed by silica fume, steel fibers and Lithium Compounds.

Pablo Steenwinkel - One of the best experts on this subject based on the ideXlab platform.

Xiangyin Mo - One of the best experts on this subject based on the ideXlab platform.

  • long term effectiveness and mechanism of lioh in inhibiting alkali silica reaction
    Cement and Concrete Research, 2003
    Co-Authors: Xiangyin Mo, Chenjie Yu, Zhongzi Xu
    Abstract:

    Excess expansion and cracking of concrete occurs when some of the alkali reactive rocks are used as coarse aggregate in concrete made with high-alkali cement. Although Lithium Compounds are one of the techniques used to reduce the effects of alkali-silica reaction ASR), the long-term effectiveness has not been tested thoroughly and the evidence to prove such effects is also lacking. This article used a practical alkali reactive aggregate-Beijing aggregate to test the long-term effectiveness of LiOH in inhibiting alkali-aggregate reaction (AAR) expansion. The mortar bars used had been cured at 80 deg C. for 3 years after being autoclaved for 24 h at 150 deg C. Under these conditions, LiOH was able to inhibit long-term alkali-silica reaction (ASR) expansion effectively. The authors include electron micrographs that illustrate the processes under discussion.