Thermal and Electrical Resistances of Carbon Nanotube-Reinforced Foamed Concrete

Orthogonal experimental method was employed to optimize the parameters (water-cement ratio W/C, H2O2 loading w(H2O2), and nanotube loading w(MNT)) for the physical properties (dry density rho(d), compressive strength f(cu), thermal conductivity coefficient lambda(c), and electrical conductivity sigma(c) ) of multi-walled carbon nanotube-reinforced foamed concrete (MNT/FC) by the analysis of means (ANOM) and variances (ANOVA). The ANOM and ANOVA results both indicate that the factor w(H2O2), w(H2O2), W/C, w(MNT) has the principle effect on the response rho(d), f(cu), lambda(c), sigma(c) of MNT/FC, respectively. The nanotubes with w(MNT) at 0.05% can present superior nucleating effect, fiber bridging effect and macroscopic quantum tunneling effect, which make for the pore stabilization, the pore size reduction and the formation of netlike conductivity pathways. The confirmatory experiment results demonstrate that the rho(d), f(cu), lambda(c), sigma(c) of MNT/FC with W/C of 0.8, w(H2O2) of 4%, and w(MNT) of 0.05% have the balanced values of 358 kg/m(3), 0.42 MPa, 0.0778 W/m center dot k, and 1.35x10(-4) S/cm, respectively.