Research Highlights Details

Development of a Carbon-Dioxide and Steam Injected High-Strength Cementitious Composite for 3DpC-Concrete Printing

Interdisciplinary Research Center for Intelligent Manufacturing and Robotics,
September 2024
 

In collaborative research between the Interdisciplinary Research Center for Intelligent Manufacturing & Robotics (IRC-IMR), IRC for Construction & Building Materials, and the Department of Civil Engineering at KFUPM together with Saudi Aramco, a carbon-dioxide and steam-injected high-strength cementitious composite for 3D printing, satisfying the flow and strength requirements, has been developed at KFUPM.

Published studies on 3D-concrete printing indicate that developing a suitable cementitious composite to be used as ink in 3D-concrete printing has an equally high importance as designing the 3D-printing system. In the first phase, a cementitious composite was developed using local materials with different options to be used as a sustainable ink in 3D-concrete printing. Best results were obtained when carbon dioxide and steam were injected into the cementitious mixtures. High compressive strengths were achieved with and without water curing.

The cementitious composite mixture consisted of cement and fine sand with a water/cement and sand/cement ratios of 0.4 and 2.0, by mass, respectively. During the mixing process, carbon dioxide and steam were injected into the mixture at suitable selected rates for appropriate durations. After testing the mixtures to determine the flow, the mixtures were cast and subsequently water-cured for 3, 7, and 28 days for compressive strength testing. The best results were obtained when carbon dioxide and steam were injected into the cementitious mixtures for 90s, as evident from the high compressive strength of more than 50 MPa achieved after 28 days of water curing and around 40 MPa after 28 days of air curing.		 

Although, strong and durable cementitious composites were developed in the first phase of the project, efforts are progressing to develop commercially acceptable products.
The research team has achieved success in 3D-printing of the developed cementitious composite, as shown in Figure below. 3D printing technology has the potential to significantly reduce the construction time by allowing the fabrication of complex shapes, which were previously very difficult to achieve. This is a transformative approach reshaping the construction industry by offering faster and more efficient ways to build. In addition, formwork is not required, allowing automation and high architectural freedom.

Following the development of the strong and sustainable cementitious composite under the first phase of the study, efforts are underway to develop an efficient 3D-concrete printing system under the second phase.

The results are of enormous significance in an international context and are very promising in the quest of adopting a modern fast infrastructure construction approach which is competitive with that in other parts of the world.

We are aiming to develop an enhanced and improved 3D printed concrete exhibiting better mechanical characteristics than conventional concrete which is far better than what is available in the market. Sequestering carbon dioxide in the fabrication of 3D concrete is an added advantage of the process.