Dennis Wingo summarizes the historical context and business case for ISRU to enable lunar settlements: https://denniswingo.wordpress.com/2019/07/25/chicken-egg-chicken-on-the-moon/
Solar additive manufacturing using lunar regolith
Researchers at the German Aerospace Center (DLR) and the European Space Agency have published a paper in in the November 2018 Acta Astronautica demonstrating the feasibility of using solar energy to sinter lunar regolith in additive manufacturing. The in-situ resource utilization technique can be used to automate building roads and shielding lunar habitats prior to arrival of astronauts. https://www.sciencedirect.com/science/article/pii/S0094576518303874