MOISTURE EFFICACY OF IMPREGNANT IN CONCRETE PROTECTION

Despite adequate laboratory performance of Iso-butyl silane, the in-situ performance of this material to combat the effects of de-icing salt and freeze-thaw loading on concrete bridges, remains questionable. It is likely that environmental loading and internal moisture at the time of application are the main contributory factors for under performance. This paper deals with alternative materials, a high solids silane and an aqueous crystallization solution, operating moisture driven crystallization mechanism rather than demanding a dry application regime. Materials absorption for dry (0% moisture), half saturated (2.5% moisture) and fully saturated (5% moisture) states on two grades of concrete, C25 (25N/mm²) and C40 (40 N/mm²) were evaluated using a modified RILEM tube method. The results showed that increasing initial moisture content in the C25 and C40 concrete has a similar substantial reducing effect on absorption of the impregnation materials. There is greater take-up of protective materials for C25 concrete compared with C40 concrete, together with greater chloride reduction, indicating that the level of achieved dosing is a significant factor. The similarity between the absorption of water and the two protection materials relative to initial water content, points to a possible basis for predicting achievable dossing of surface applied protection materials. Testing for different levels of moisture content between 0% and 5% is required to provide adequate data for such analysis. The crystallization material achieved great application volume and chloride reduction than the silane material.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AHD45 Standing Committee on Corrosion.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Rahman, M M
  • Alkordi, N M
  • Ragrag, A M
  • Kamal, S
  • Chamberlain, D A
• Conference:
  • Transportation Research Board 95th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2016-1-10 to 2016-1-14
• Date: 2016

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; Photos; References; Tables;
• Pagination: 11p
• Monograph Title: TRB 95th Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Concrete bridges; Corrosion protection; Deicing chemicals; Freeze thaw durability; Impregnation (Engineering); Moisture content; Protective coating; Silane
• Subject Areas: Bridges and other structures; Highways; Maintenance and Preservation; Materials;

Filing Info

• Accession Number: 01592827
• Record Type: Publication
• Report/Paper Numbers: 16-3740
• Files: TRIS, TRB, ATRI
• Created Date: Mar 7 2016 10:18AM