Engineering Properties of Reactive Powder Concrete without Portland Cement

This paper reports the properties of a new type of high-performance composite material developed as an alternative construction material to reactive powder concrete (RPC) with a compressive strength over 200 MPa (29.0 ksi). This composite has been developed by the activation of slag and silica fume, without using portland cement. A comparative experimental study on the mechanical properties, microstructure, fresh-state properties, leaching of ions, bond to steel, and dimensional stability of RPC produced with portland cement (CRPC) and alkali-activated cement (ARPC) has been implemented. Test results show that ARPC has a very different micrbstructure with a great number of nano-sized pores compared to CRPC. Although these two RPC mixtures have similar compressive strength values, ARPC has significantly higher flexural performance, fracture energy, and bond to steel compared to CRPC. ARPC composites seem to be a good alternative to CRPC because of these superior properties and reduced environmental problems.