Mechanisms of carbon black in multifunctional cement matrix: Hydration and microstructure perspectives

Carbon black (CB) possesses a good prospect for producing multifunctional building materials. The existing literature, however, mainly reported the electrical properties. Systematic reports on the influence of CB on hydration and microstructure are still lacking. Thus, the variations in fluidity, strength, hydration, porosity, and microstructure of CB-cement materials were thoroughly examined. It revealed that CB shows a clear negative effect on fluidity and early flexural strength, but proper CB increases compressive strength. The pore structure and the interfacial transition zone are optimized manifestly by 2% CB (by mass of cement).