A new National Concrete Pavement Technology Center (CP Tech) project, begun mid-December 2018, has the objective to investigate the enhancement of concrete durability through the use of penetrating sealers. The project focuses on developing test protocols and standards to be employed for sealer evaluation. In turn, this will produce guidelines and protocols enabling the assessment of the short- and long-term performances of sealers.
Low permeability is essential for the long-term durability of concrete used for infrastructure construction. Even though most modern concrete mixtures are designed to exhibit low permeability, the use of penetrating sealers can provide an additional level of protection for concrete elements. Other benefits of penetrating sealers are reduced capillary suction and reduced chloride ion intrusion.
Along with the research team at the CP Tech Center, researchers from Iowa State University’s Bridge Engineering Center and the University of Missouri-Kansas City will study the performance of a variety of sealers—covering the most widely used families of products available on the construction market.
The test matrix includes:
A typical control concrete and 3 additional experimental mixtures:
• Control: SAM number <0.20, high quality aggregate in terms of resistance to D-cracking,
and >25% Class C fly ash.
• Experimental mixture #1: Inadequate air void system, with a SAM number >0.40,
high quality aggregate, and >25% Class C fly ash.
• Experimental mixture #2: D-cracking susceptible, SAM number <0.20,
poor quality aggregate in terms of resistance to D-cracking, and >25% Class C fly ash.
• Experimental mixture #3: Oxychloride susceptible, SAM number <0.20,
high quality aggregate, and 100% ordinary Portland cement;
and 5 sealer families:
• Silane; solvent based
• Acrylic; solvent based
• Silicate; water based lithium silicate or colloidal silica
• Vegetable oil; SME solvent based
• Crystalline water proofer
The WORK PLAN INCLUDES:
• Characterization: contact angle, depth of penetration…
• Laboratory testing: transport, F/T, …
• Establish correlations…
• UV Exposure: effective life of sealers
• Field performance
• Quantify benefits through life cycle cost analysis (LCCA)
The resulting lab data will be analyzed throughout the various steps of the project and findings will be expanded to field trials for further verification of the observations over the long term.
For the details of the proposed experimental program and work plan are available, please click on image above, or go to: https://gallery.mailchimp.com/4bf55bc365dca0e5c928442da/files/801911e3-91e1-4dd4-b8c7-c49276080a80/CP_Tech_Penetrating_Sealer_Evaluation_Project.pdf