Electrical Current Flow and Cement Hydration: Implications on Cement-Based Microstructure

Abstract

Stray current is an electrical current "leakage" from metal conductors and electrical installations. When it flows through cement-based materials, electrical energy is converted to thermal energy that causes increasing temperature due to Joule heating phenomena. The aim of this paper is to shed light on the influence of electrical current flow on cement hydration, thermal properties and pore structure changes of cement-based materials. Calorimetry tests show that degree of cement hydration increases as a results of temperature increase due to electrical current flow through cement-based materials. To evaluate the influence of electrical current on the thermal properties of cement paste, the specific heat of cement paste was calculated based on the degree of cement hydration and temperature development during the hydration process. MIP tests were carried out to quantify changes in the pore structure due to electrical current flow. The results shows that if no other factors are present, leaching is avoided and for relatively early cement hydration age, the electrical current flow accelerates cement hydration, leading to an initial decrease in porosity of the cement paste.

Electrokinetics Application in Concrete and Well Construction

“…Under an external electric field, the electrical energy, produced from current flow, converts to thermal energy. This results in additional temperature rise in the system, which has the potential to enhance the cement hydration rate, resulting in microstructural changes in the cement system [45,46]. Susanto et al [47] have investigated the impact of electrical current flow on cement hydration.…”

A Comparative Study on the Mechanical Properties and Microstructure of Cement-Based Materials by Direct Electric Curing and Steam Curing

“…In response to the advantages and disadvantages of SC, a new direct electrical curing (EC) [15] method has been discovered by research scholars .EC uses fresh specimens with low resistivity [16] to generate uniform Joule heat under the current to accelerate the hydration of cement and enhance early mechanical properties. Existing studies mentioned in the literature [17] include the feasibility of EC application [18,19], field application [20], electrodes arrangement [21], curing regime [22,23], effects of hydration process and microstructure [24,25], mineral admixtures [26], durability [16,27] etc. The current mainstream research direction mainly uses Joule heating to solve the problem of winter construction at ultra-low temperatures [28][29][30][31], repair and reinforcement of building structures [32], strengthening concrete [33][34][35].…”

A Comparative Study on the Mechanical Properties and Microstructure of Cement-Based Materials by Direct Electric Curing and Steam Curing

“…EC uses fresh specimens with low resistivity [ 16 ] to generate uniform Joule heat under the current to accelerate the hydration of cement and enhance early mechanical properties. Existing studies mentioned in the literature [ 17 ] include the feasibility of EC application [ 18 , 19 ], field application [ 20 ], electrodes arrangement [ 21 ], curing regime [ 22 , 23 ], effects of hydration process and microstructure [ 24 , 25 ], mineral admixtures [ 26 ], durability [ 16 ], etc. The current mainstream research direction mainly uses Joule heating to solve the problem of winter construction at ultra-low temperatures [ 27 , 28 , 29 , 30 ], repair and reinforcement of building structures [ 31 ], and strengthening concrete [ 32 , 33 , 34 ].…”