Bond and Flexural Behaviour of Locally Available Spent Catalyst Based Normal and High Strength Concrete

Environmental regulators put pressure on refineries to handle wasted catalyst in a safe manner. Spent catalyst, which is produced when petroleum is split to reduce its sulphur level and enhance its burning properties, is one of the petroleum refineries in Oman's industrial byproducts. Spent catalysts include cementitious material, which can be utilised in place of cement to some extent. The relationship between steel bond strength and the flexural behaviour of regular (C30) and high-strength (C60) spent catalyst-based concrete is the main topic of this study. Concrete cubes of the C30 and C60 grades, each measuring 150 mm × 150 mm × 150 mm, were made for optimisation after different amounts of leftover catalyst were added to the concrete, such as 3%, 6%, 9%, and 12% by weight of cement. Twenty-four cubes were cast for the bond research and forty-eight cubes for the compressive strength test as part of the optimisation procedure. For a bond study with a helical spring H8 diameter to avoid local shear an embedded vertical bar H12 at a length of 500 mm was inserted while casting of the cubes. Finally, for flexural strength test prism was cast of size 500 ×100 × 100 mm - 12 nos. for 0% and 9% for C30 and C60 grade concrete. The test was run on regular concrete more precisely, on leftover catalyzed-based concrete cubes after the concrete had been cured for 28 days. For the bond investigation, a 1000 kN capacity Universal Testing Machine (UTM) was used to perform a pull-out test. The optimum dosage of spent catalyst-based concrete cubes replacing cement is 9% under the compressive strength test. The bond study using a pull-out test of 9% replacement of concrete by spent catalyst gives better performance compared to other dosages of spent catalyst (3%, 6%, & 12%). It concludes that a 9% replacement of cement using spent catalyst gives an 11% increase in terms of pull-out strength with respect to conventional concrete.