Rate of carbonation in cement modified base course material

Abstract

In the absence of a carbonation model for soil cement, this research aims to assess the compatibility and applicability of an analytical model initially developed for concrete. Carbonation can be observed in any pavement layer which includes cement or lime. For instance, carbonation damages the cement-modified crushed rocks as a typical material for base course layer due to poor curing of material or cracking of asphalt. Experimental laboratory tests are utilised here in accelerated carbonation conditions to evaluate the analytical model. Cylindrical specimens are subjected to one-dimensional carbonation condition. Weight and ratio of constituents of mixes, as well as environmental factors, such as CO2 concentration and relative humidity are recorded for analytical estimation of failure progresses. Nanosilica is also introduced in mixes to explore its effects during carbonation reactions. Results show linear correlations between experimental records and analytical model calculations. Thus, it can be concluded that carbonation rate can be predicted in soil cement also. In addition, the inclusion of nanosilica has a positive influences by slowing of the carbonation progress.