Increased durability of concrete toward elevated temperatures due to fire with ground granulated blast furnace slag
A H S Harahap (a*), Sumargo (b), Nursyafril (a)

a) Civil Engineering, Politeknik Negeri Bandung, Bandung 40012, Indonesia
*ahmadharahap298[at]ymail.com
b) Civil Engineering, Universitas Jenderal Achmad Yani, Cimahi, Jawa Barat, Indonesia

Abstract

This paper describes experimental results that focus on the effects of elevated temperature exposure on GGBFS concrete. GGBFS is a byproduct of steel factory PT Krakatau Steel. It is suitable for geopolymer cement as a substitute for cement in concrete. Normal concrete and GGBFS concrete beams (150×150×750mm) and cylindrical (150×300mm) concrete specimens with 40% GGBFS content as a substitute of cement weight was burned for two hours, which the first beam was burned at 600°C, second beam at 700°C and third beam at 800°C. After cooling to room temperature, cylindrical specimens and beams were tested. Compressive strength, loss mass, modulus of elasticity, crack developments and flexural strength were examined and compared. The results show that concrete strength decreases with increasing temperature, where this occurs in both normal and GGBFS concrete. However, GGBFS concrete is superior in initial strength and resistance to elevated temperature compared to normal concrete, because GGBFS increased the durability of concrete. High temperature exposure causes compressive strength of normal concrete decreased extremely up to 69,08%, compared to GGBFS concrete only 46,21%. Flexural strength decreased to 30,37% when the temperature rises from 600°C to 700°C. Furthermore, it decreased significantly to 50,82% when the temperature reached 800°C.

Keywords: Concrete; Durability; GGBFS; Temperatures

Topic: Civil Engineering