STRENGTHS OF SULFOALUMINATE CEMENT CONCRETE AND ORDINARY PORTLAND CEMENT CONCRETE AFTER EXPOSURE TO HIGH TEMPERATURES

• Main Authors: Jean Jacques Kouadjo Tchekwagep, Shoude Wang, Mukhopadhyay Anol K, Huang Shifeng, Cheng Xin
• Format: Article
• Language: English
• Published: University of Chemistry and Technology, Prague 2020-05-01
• Series: Ceramics-Silikáty
• Subjects: sulfoaluminate cement; flexural strength; cracking load; high temperatures; porosity
• Online Access: http://www.ceramics-silikaty.cz/index.php?page=cs_detail_doi&id=1322

The use of SAC (sulfoaluminate cement) has been increasing in the constructions of diverse buildings with some close to reactors, which are often exposed to high temperatures in China. This study compares the flexural strength, compressive strength, crack load, mass weight loss, porosity, and flexural stress--strain of the sulfoaluminate cement concrete (SACC) to that of ordinary Portland cement concrete (OPCC) after both are exposed to high temperatures. The results show that the samples of SACC show a rapid decrease in the flexural strength, crack load, and compressive strength after heating, and, thus, cannot be repaired, but should be demolished. Samples made with OPCC can be repaired because the structural integrity remains acceptable after heating. 56% SACC is ˂ half of its initial strength after heating to 200℃, while OPCC remains at ˃ 90% of its compressive strength after heating at 200℃, and retains 80% of its compressive strength when heated to 300℃. SACC initially had a higher flexural strength and consequently a higher crack load; therefore, it performed better than the OPCC in terms of the load carrying capacity of the structure. Also, the OPCC had a constant decrease in the strength, compared to the SACC which did not. However, the OPCC has a better resilience strength rating as the temperatures increase than the SACC one because testing revealed a very rapid decrease in the strength after exposure to 100 °C, 200 °C, and 300 °C. The results agree on the better firm structure uniformity and density of the SACC at an ambient temperature (20 °C) compared to the OPCC. The severe deterioration (micro-crack) inside both concretes, revealed by the longer transmitting time and the small amplitude values of the waves, indicated the effective negative impact which is no longer demonstrated when the extreme temperature has a larger effect on the concrete made with SAC, therefore, the other results highlighted the rapid decrease in the strength of the SACC compared to that of the OPCC.