Properties of 3D-printed fiber-reinforced Portland cement paste

First insights into a 3D-printed composite of Portland cement paste and reinforcing short fibers (carbon, glass and basalt fibers, 3-6 mm) are presented, resulting in novel materials that exhibit high flexural (up to 30 MPa) and compressive strength (up to 80 MPa). Alignment of the fibers, caused by the 3D-printing process is observed, opening up the possibility to use the print path direction as a means to control fiber orientation within the printed structures. Apart from completely dense cementitious bodies, hierarchically structured bodies, displaying precisely adjusted macroporosity, are presented, the latter exhibiting a unique combination of strength and materials efficiency.