Effects of graphene sulfonate nanosheets on mechanical and thermal properties of sacrificial concrete during high temperature exposure

Abstract

Using nanomaterials is a new method to improve concrete material, and graphene or its derivatives are currently the most attractive nanomaterials. This paper aims to experimentally evaluate the effects of graphene sulfonate nanosheets (GSNSs) on physical, mechanical, and thermal properties of sacrificial concrete. The microstructure, porosity, compressive strength, thermal analysis, coefficient of thermal expansion, thermal diffusivity and ablation behaviour of sacrificial concrete with different contents of GSNSs before and during exposure to various temperatures up to 1000 ºC were comprehensively investigated. A new experimental apparatus was proposed and used to measure the compressive strength of sacrificial concrete during elevated temperature exposure. It was found that, (1) the compressive strength, thermal diffusivity, and decomposition enthalpy of sacrificial concrete increased by 10.14-23.11%, 6.51-27.66%, and 7.48%, respectively, when adding 0.1 wt% GSNSs; (2) the porosity and ablation velocity of sacrificial concrete reduced by 2.00-6.00% and 7.48%, respectively, due to the incorporation of GSNSs.

Mechanical and thermal properties of graphene sulfonate nanosheet reinforced sacrificial concrete at elevated temperatures

“…The relative residual splitting tensile strength is defined as the ratio of residual splitting tensile strength at high temperature to splitting strength at ambient temperature. As seen in Fig.6a, the residual splitting tensile strength of sacrificial concrete declined continually as temperature increased, which is in good agreement with previous studies on siliceous sacrificial concrete [28,36] and high-strength concrete [47] exposed to elevated temperatures. The decrease in splitting tensile strength of sacrificial concrete was associated with their increasing porosity.…”

“…5 shows the residual compressive strength and relative residual compressive strength of sacrificial concrete at elevated temperatures that is defined as the ratio of residual compressive strength at elevated temperature to compressive strength at ambient temperature. As seen in Fig.5a, the compressive strength of sacrificial concrete decreased monotonically with the increase of temperature, which is consistent with the change of compressive strength of self-consolidating concrete [31,44,45] and siliceous sacrificial concrete [36] exposed to elevated temperatures. The compressive strength loss can be attributed to the increase in porosity of sacrificial concrete over the same range of temperature (see Fig.4a) and to the decrease in both stiffness and cohesive strength of C-S-H gel [46].…”

“…The main purpose of this paper is to investigate the mechanical and thermal properties of sacrificial concrete without and with GSNSs before and during high temperature exposure, which extends authors' recently published work [36] from siliceous sacrificial concrete to ferro-siliceous sacrificial concrete. Two new experimental facilities for measuring the compressive strength and splitting tensile strength of sacrificial concrete during elevated temperature exposure are developed.…”

Carbon nanomaterials enhanced cement-based composites: advances and challenges

“…The thermal conductivity increased to 1.75 from 1.23 W/m•K, and cement enhanced by paraffin/diatomite/CNTs showed faster heat storage and release rates. Chu et al [153] found that the value of λ for concrete containing 0.1 wt.% graphene solfonate nanosheets (GSNSs) was increased by 32.6%; this increment remained at 19.2% to 50.9% even when the temperature was increased to 1000 ∘ C (with a maximum increment at 600 ∘ C, Figure 15a), leading to increased thermal diffusivity (6.8-27.6%, Figure 15b). In [154], it was reported that the surface temperatures of cement containing Figure 16: Resistivity-temperature characteristics during the heating and cooling of a cement paste containing (a) 0.4wt.% CNFs; (b) 0.4wt.%CNFs and 1.5wt.% CNTs [160] expanded graphite donated paraffin and GNPs donated paraffin were lower than for plain cement, indicating an improved thermal energy storage capacity.…”

Assessment of Mechanical Properties and Damage of High Performance Concrete Subjected to Magnesium Sulfate Environment

“…It should be noted that the compressive strength and splitting tensile strength of HPC were measured in accordance with the Chinese standard GB/T 50081-2002, and the cubic specimens were also used in recent published paper for splitting tensile strength of sacrificial concrete [25].…”