Design of a Modern Electrochemical Migration Device for Infrastructure and Building Materials

Overview

Chloride-induced corrosion of steel reinforcement in concrete is a major worldwide infrastructure challenge costing $2.6 trillion annually to prevent, mitigate, and repair. ASTM C1202 standard is a testing method to detect chloride permeability in portland cement and estimate the service life of infrastructure. It uses an electrical current to drive ionic transport of chloride ions through the cement sample. However, this testing method does not quantitatively measure the rate of diffusion of chloride ions traveling through the material. Additionally, with the advent of new low CO2 concrete materials, it yields very little information about their chloride permeability. Thus, their durability against chloride induced corrosion is not well understood further limiting their in-service application to decarbonize our infrastructure.

Objectives

– Design a prototype using sustainable metal alloys resistant to corrosion in chloride, sulphide, and hydroxide solutions.

– Utilize additive manufacturing and polymeric materials for construction of test cell prototype.

– Develop digital design documents used for additive manufacturing and for ease of reproduction.

– Integrate Electrochemical Impedance Spectroscopy (EIS) compatibility into digital and prototype designs for measurement of diffusion coefficient.

– Assemble electrical circuitry and readout components for high precision measurement of voltage, temperature, and current.

Approach

– Conduct research on metal alloys with resistance to chloride, sulphide, and hydroxide environments.

– Develop digital design documents for test chamber which are used to 3D print physical prototypes.

– 3D print test cells using thermally stable PETG filament, and print a sample covering using flexible NinjaTek Cheetah filament.

– Implement thermal control and temperature monitoring with thermocouples and ensure compatibility with EIS connections.

– Verify electrical circuitry and make necessary adjustments to accommodate potential test environment.

– Assemble a complete test cell using 3D printed test cells, sample covering, clamping bolts, and test its functionality with a leak test.

Outcomes

– Constructed a prototype that cost $471 to produce, effectively reducing manufacturing cost by approximately 50%.

– Replaced brass metal with Monel 400 metal to increase lifespan and integrated recyclable plastic materials to 3D print the test cell.

– Provided digital versions of the test cell prototype.