4. Alkali-Silica Reaction inhibiting Lithium-containing Zeolite material

  • A synthesis method was developed to produce a lithium-containing alkali adsorbent (Li-containing zeolite) and prototype grouting material, which produces excellent results in restraining ASR.

When Alkali-Silica-Reaction (hereinafter ASR）occurs in concrete, the latter’s resistance to load and life span are reduced and significant intervention becomes necessary for maintenance (Fig1). Despite the development of a range of repair methods, there are still many cases of fresh weakness following renovation work, indicating the need to discover a more effective ASR mitigating material. Hence, a method was elaborated to easily synthesize lithium-containing zeolite in order to produce a lithium-ion and alkali adsorbent (zeolite) compound which is known for its strong ASR inhibiting properties. This was then used to produce a prototype grouting material.

Holes were pierced into the sample mortar block with induced ASR. The holes were then filled with the prototype lithium-containing zeolite ASR restraining material. Expansion was then measured and results showed that the new lithium containing zeolite mixture was significantly more effective in preventing swelling than existing calcium (Ca)-containing products (Fig 2). Tests also demonstrated that the lithium-containing zeolite grouting material could also be used for cracks of 0.04 mm in width (Fig 3).

The next step in the plan for this development will be to convert the ASR-restraining grouting material into a marketable product and apply it to concrete structures suffering from the effects of ASR in order to assist maintenance.

  • fig 1
    Fig. 1 Example of structural weakening due to ASR
  • fig 2
    Fig. 2 Effectiveness of lithium containing zeolite on ASR expansion control
  • fig 1
    Fig. 3 Image of grouting work on cracks