Hydration behavior of wood cement-based composite I: evaluation of wood species effects on compatibility and strength with ordinary portland cement

Abstract

As an essential preliminary evaluation for understanding the hydration behavior of wood-cement-water mixtures, an isothermal calorimetry and experimental method were used to measure the hydration heat of woodcement-water mixtures. The compatibility of 38 wood species with ordinary portland cement was studied using this procedure. Based on the results, all the wood species tested were classified into two groups. The 24 species included in the first group showed a moderating influence on the hydration reaction of cement, and a maximum temperature (T max) peak during the exothermic reaction while the cement set appeared within 24h for each species. The other 14 species inhibited cement hydration completely. According to the maximum hydration temperature (T max) and the time (T max) required to reach the maximum temperature of the mixture, the suitability of each species in the first group was estimated when used as a raw material during production of cement-bonded particleboard. By testing mechanical properties [modulus of rupture (MOR) and internal bonding strength (IB)] during the board-making experiment using the same composition of wood-cement-water, a positive correlation was found betweenT max andt max and MOR and IB. The results imply that the method can be used as a predictor of the general inhibitory properties and feasibility of using wood species as raw materials prior to manufacture of cement-bonded particleboard.