Author ORCID Identifier
Document Type
Report
Publication Date
6-2023
Abstract
Extensive research has been conducted on sulfate attack of concrete structures, however, the need to adopt use of more sustainable materials is driving a need for a quicker test method to assess sulfate resistance. Class F fly ash, which is a byproduct of coal combustion for electricity generation, has historically been used in concrete mixtures to improve sulfate resistance. However, environmental considerations and evolving energy industry has decreased its availability, requiring the identification of economically viable and environmentally friendly alternatives to fly ash. Another challenge in addressing sulfate attack durability issues in concrete is that the standard sulfate attack test (ASTM C1012) is time-consuming, designed for only standard mortars (not concrete mixtures), its ability to replicate field performance accurately is not always consistent, and it does not cover all types of commonly available sulfates. To expedite the testing process, accelerated testing methods for both mortar and concrete mixtures were adopted from previous work for further development and to assess the feasibility of testing sulfate resistance of mortar and concrete mixtures rapidly. This study evaluated 14 mortar mixtures and four concrete mixtures, using two types of portland cement (Type I and Type I/II) and various supplementary cementitious materials (SCMs). Mortar mixtures were subjected to testing using both ASTM C1012 and an accelerated mortar bar test, while the concrete mixtures were subjected to an ASTM C1012 based method and an accelerated method for concrete. The study also established criteria for interpreting sulfate resistance for each of the test methods used in this work. The accelerated testing methods significantly reduced evaluation time from 12 months to 21 days for mortar mixtures and from six months to 56 days for concrete mixtures. The proposed interpretation method for mortar accelerated test results showed acceptable consistency with the ACI 318-19 interpretations for ASTM C1012 results. The interpretation methods proposed for the two concrete sulfate attack tests demonstrated excellent consistency with the ASTM C1012 results from mortar mixtures with the same cementitious materials combinations. Metakaolin was shown to improve sulfate resistance for both mortar and concrete mixtures, while silica fume and natural pozzolan had limited impact. Using 15% metakaolin in mortar or concrete mixtures with Type I/II cement resulted in the excellent sulfate resistance.
Recommended Citation
Newtson, C., Mousavinezhad, S., Toledo, W., & Aguayo, F. (2023). Accelerated Sulfate Attack Testing for Concrete. Retrieved from https://repository.lsu.edu/transet_pubs/155
Comments
Tran-SET Project: 22CNMSU20