Effect of cellulose microfibrils on Portland cement properties

CATALINA GÓMEZ HOYOS; ANALIA VAZQUEZ

MATERIALS & DESIGN

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2013 vol. 51 p. 810 - 818

0261-3069

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 0 wt% and 3 wt% of MCC, were evaluated by flexural and compression tests within two curing procedures (i) regular curing: specimens were cured 28 days into lime stone saturated solution at room temperature (ii) accelerated curing: specimens were cured into a lime stone saturates solution for 7 days at room temperature followed by 7 days at 50 oC. Finally they were kept in a dry oven at 60 oC for 48 h. Thermogravimetric analysis was used to characterize the effect of curing procedure and MCC addition on hydration degree of cement materials with 0 wt% and 3 wt% 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 the increase in temperature during the curing process and because MCC release its water content, contributing to hydration process.