Effect of cellulose microcrystalline particles on properties of cement based composites

Abstract

The hydrophilic character and water retention capability of cellulose microcrystalline particles (MCC), are useful properties to achieve new developments in cement based materials. This work evaluates the influence of interactions between MCC, cement particles, hydration products and water; on rheology, hydration kinetic, microstructure and mechanical properties of cement based materials. The effect of MCC on mechanical properties of cement mortars with 0wt.% and 3wt.% of MCC, were evaluated by flexural and compression tests within two curing procedures (i) regular curing: specimens were cured 28days into lime stone solution (pH 13) at room temperature, (ii) accelerated curing: specimens were cured into a lime stone saturated solution for 7days at room temperature followed by 7days at 50°C. Finally they were kept in a dry oven at 60°C for 48h. Thermogravimetric analysis was used to characterize the effect of curing procedure and MCC addition on hydration degree of cement materials with 0wt.% and 3wt.% of MCC. Results showed that interactions between MCC, cement particles, hydration products and water, decreased the workability and delayed the hydration reaction. Additionally, results from thermogravimetric analysis showed that, both accelerated curing and MCC addition increased the hydration degree of cement materials because of increases in temperature during the curing process and because of MCC releases its water content, contributing to hydration process. From results discussion it was found, that MCC could be added to increases the hydration degree of based composites; additionally it was concluded that cement based composites with MCC could be used to elaborate precast pieces.