Assessment of sulphate resistance in fresh-to-fresh hybrid systems: a comparative study between SCC/ECC and SCC/UHPFRC


Baloch W. L., Siad H., Lachemi M., ŞAHMARAN M.

MAGAZINE OF CONCRETE RESEARCH, 2024 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Publication Date: 2024
  • Doi Number: 10.1680/jmacr.24.00025
  • Journal Name: MAGAZINE OF CONCRETE RESEARCH
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aerospace Database, Communication Abstracts, Compendex, ICONDA Bibliographic, INSPEC, Metadex, Civil Engineering Abstracts
  • Hacettepe University Affiliated: Yes

Abstract

Composites systems (CS) that incorporate various types of concrete have been introduced to enhance the performance of conventional concretes, while optimizing the economic applicability of modern concretes. CS consisting layers of high-performance fibre reinforced concrete (HPFRC) in tension were evaluated combined with compressive self-consolidating concrete (SCC) layers in a severe sulphate environment. A variety of HPFRC materials were utilized, including ultrahigh performance fibre reinforced concrete (UHPFRC) and engineered cementitious composites reinforced with steel and polyvinyl alcohol (PVA) fibres. A concentrated sodium sulphate solution was used to cyclically expose the samples and the physic-o-mechanical changes and microstructural variations in the bonded layers, particularly the interfacial properties were evaluated at 90 and 180 days. Exposed CS were examined for visual appearance, mass gain, flexural and compressive strength as well as tensile bond strengths. Compared to monolithic SCC, CS demonstrated superior chemical resistance under prolonged exposure to an extreme sulphate environment. Based on SEM-EDS, the UHPFRC-based system demonstrated higher resistance to the deteriorative effects. In addition, interfacial fibres had a varying effect with PVA fibres showing slightly better residual retention. CS interfacial zones were also affected by high concentrations of reaction products from SCC, although the effects were less pronounced for UHPFRC layers.