The Hawaii Department of Transportation (HDOT) is carrying out the testing of the concrete mix, which is designed to reduce the carbon footprint of road construction.
The test involves a pour of about 115m3 of carbon-injected concrete next to an equivalent pour of standard concrete mix on an access road for the second phase of the Kapolei Interchange.
This test will allow HDOT to do a side-by-side comparison of the two mixes to determine specifications for the use of carbon-injected concrete for road projects in the future.
The carbon-injected concrete used in the testing is produced by Island Ready-Mix Concrete using waste carbon dioxide from Hawaii Gas. The carbon dioxide is mixed into the concrete using CarbonCure technology. The resulting product traps carbon dioxide in mineral form within the concrete and improves the comprehensive strength of the material, said HDOT. The project is supported by Elemental Excelerator, a Hawaii-based start-up accelerator. “We are proud that Hawaii is looking at sustainable building practices to mitigate the effects of climate change,” said Aki Marceau, managing director for the Elemental Excelerator.
State governor David Ige said: “I am pleased to see HDOT moving ahead with CarbonCure, local concrete companies and Hawaii Gas to reduce the levels of carbon dioxide emitted during the construction process. As the daily baseline measurement for carbon dioxide in our atmosphere reaches the highest level in modern history, it is especially important for all of us to do all we can towards ensuring a sustainable Hawaii for future generations.”
HDOT said that the amount of concrete poured in the demonstration project will save 680kg of carbon dioxide, offsetting the carbon dioxide emissions from about 2,575km of highway driving.