Doubling the Service Life of Concrete Structures. 1: Reducing Ion Mobility Using Nanoscale Viscosity Modifiers.
Doubling the Service Life of Concrete Structures. 1:
Reducing Ion Mobility Using Nanoscale Viscosity
Bentz, D. P.; Snyder, K. A.; Cass, L. C.; Peltz, M. A.
Cement and Concrete Composites, Vol. 30, No. 8,
674-678, September 2008.
concretes; structures; mobility; viscosity; diffusion;
nanotechnology; service life; electrical resistivity;
new approach for increasing the service life of concrete
structures is presented. While conventional approaches
have focused on producing a more impermeable matrix by
reductions in water-to-cementitious materials ratio and
the addition of fine particles such as silica fume, in
the new approach, focus is shifted to the remaining pore
solution through which diffusive transport will always
be occurring. By adding appropriate nano-sized viscosity
modifiers to the pore solution, conductive and diffusive
transport can be reduced by basically the same factor as
the viscosity increase relative to the viscosity of
water (pore solution). Since in many degradation
scenarios, service life is directly proportional to the
diffusion coefficient of an ingressing ionic species
such as chloride or sulfate ions, it is envisioned that
a doubling of the service life of structural concrete
can be achieved by increasing the pore solution
viscosity by a factor of two. In part I of this series,
viscosities of bulk solutions and electrical
conductivities of solutions containing various
concentrations of potassium chloride are examined to
verify the viability of this revolutionary approach.