Effect of elevated temperatures on concrete incorporating ferronickel slag as fine aggregate

Abstract

Summary This study evaluates the effect of elevated temperature exposure on concrete incorporating ferronickel slag (FNS) as a replacement of natural sand. Concrete cylinders were exposed up to 800°C, and the changes in compressive strength, mass, ultrasonic pulse velocity (UPV), and microstructure were investigated. The concretes containing up to 100% FNS aggregate showed no spalling and similar cracking to that of the concrete using 100% natural sand. For exposures up to 600°C, the residual strengths of concretes containing 50% FNS were 7% to 10% smaller than the concrete with 100% sand. Use of 30% fly ash as cement replacement improved residual strength by pozzolanic reaction for exposures up to 600°C. An equation has been found from the correlation between residual strength and UPV. Therefore, UPV can be used as a nondestructive test to estimate the extent of postfire damage and residual strength of concrete incorporating FNS aggregate and fly ash.

Test methods for characterizing concrete properties at elevated temperature

“…A typical heating device is an electric furnace (shown in Figure ) which can heat a specimen to target temperature at a specified heating rate. Lining the furnace heating chamber with fire insulation can prevent possible damage during abrupt failure of test specimen, as in the case of higher strength concrete specimens which can undergo explosive spalling under certain conditions . The loading device is primarily a strength testing machine (typical example shown in Figure ) that allows the user to monitor and apply load on the test specimen at a specified strain rate.…”

“…Lining the furnace heating chamber with fire insulation can prevent possible damage during abrupt failure of test specimen, as in the case of higher strength concrete specimens which can undergo explosive spalling under certain conditions. 39,40 The loading device is primarily a strength testing machine (typical example shown in Figure 6) that allows the user to monitor and apply load on the test specimen at a specified strain rate. The instrumentation needed for monitoring temperature is thermocouple and for monitoring displacement is Linear Variable Differential Transformer (LVDT).…”

The Utilization of Waste Marble Dust as a Cement Replacement in Air-Cured Mortar

“…The decrease in compressive strength proves that the presence of WMD, which does not have pozzolanic properties, reduces the effectiveness of the hydration process [29,38]. The air-curing conditions that caused water evaporation and thus created voids and internal cracks [39], as well as the decrease of apparent density and the significant reduction of the clinker content of the mixture [30], may explain the fall in compressive strength.…”

Compressive Strength Prediction of PVA Fiber-Reinforced Cementitious Composites Containing Nano-SiO2 Using BP Neural Network

“…Related research results indicated that cementitious materials work against environmental pollution by minimizing the emission of CO 2 , other pollutant gases and waste dust, exhibit important feasibility and application prospects, and may become an appropriate substitute for traditional cement mortar in the future [5]. Some researchers have produced some new materials 2 of 24 to replace the traditional cement totally or in part, such as concrete incorporating ferronickel slag (FNS) as a replacement of natural sand [6] and engineered cementitious composite layered reinforced concrete beams [7]. Simultaneously, descriptions of fibers in cementitious composites containing polydispersed hollow and core-shell microparticles [8], waste recycled hollow glass microspheres [9], multiwalled carbon nanotubes [10], nano reservoir silts [11], SiO 2 nanoparticles [12], palm oil fuel ash [13], inclined steel fiber [14], cellulose nanocrystals [15], cobalt ferrite and nanoparticles [16] are abundant.…”