Effects of fire on the strength performance of reinforced concrete beam mixed with seawater

• Main Authors: Cu, Jaymar P., Nobleza, Don C., Jimenez, Justiniel O., Tiu, Christian Lawrence T.
• Format: text
• Language: English
• Published: Animo Repository 2016
• Subjects: Concrete beams > Testing
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/7091
• Institution: De La Salle University

Large amounts of freshwater are used in construction especially when using reinforced concrete. Freshwater is essential for its mixing and curing. At present, there are already reports on the impending risk of global water scarcity in the near future. Alternatives to freshwater must be used to help address this problem. There are already studies that suggest the possibility of the use of seawater in concrete but the findings are varying and sometimes contradicting. Currently, seawater is still prohibited to be used in construction. There are still no guidelines or standards on how seawater will be used in reinforced concrete. The use of seawater in concrete must further be studied and verified. This paper focuses on the effects of fire on the strength performance of reinforced concrete beams mixed with seawater. Sixteen reinforced concrete beams measuring 150 X 200 X 800 mm and twenty-four concrete cylinders measuring 150 x 300 mm were constructed. Two groups of specimens were cast with different mixing water, freshwater and seawater, were exposed to fire at an average temperature of 300 degree celcius at varying durations (1, 2, and 3 hours). The age of the specimens at testing day were at around 50 days. The comprehensive strength of concrete, the tensile strength of the steel reinforcing bars, and the bending strength of the beams were obtained. Center point loading test was conducted on the beams. The effect of the varying exposure times and the different mixing water were determined based on the obtained strength parameters through various tests performed. Generally, results show that the freshwater specimens are stronger than the seawater specimens. However, the difference between the strength of the two specimen groups were very minimal and non-significant.