Comprehensive performances of carbon nanotube reinforced foam concrete with tetraethyl orthosilicate impregnation

Foam concrete plays an important role on the roof, non load bearing walls and thermal pipe insulation layer application because of its special porous structure and excellent insulation performance. In this paper, the effect of multi-walled carbon nanotube (MCNT) loading (wMCNT) on the physical properties, water absorption, and AC impedance (Z) of MCNT reinforced foam concrete (MCNTFC) before and after tetraethyl orthosilicate (TEOS) impregnation were studied. Results reveal, MCNT can improve the pore structure and decrease the average pore diameter of the foamed concrete. When wMCNT alters in the range of 0%-0.1%, the dry density of MCNTFC smoothly changes between 290 and 320 kg/m3, the maximal compressive strength reaches 0.302 MPa, and has the increment of above 27% with respect to the plain; The Z with 0.05% wMCNT is the lowest, and wMCNT has almost no influence on the polar corrosion durability seen from electrochemical Nyquist curves. After TEOS impregnation, and its surface contact angle of MCNTFC is much larger than 90°, and the corresponding maximal water absorption rate is decreased by more than 40%. The surface hydrophobic feature of porous MCNTFC product is good for developing it to a kind of anti-permeable light-weight thermal insulation layer.