A Study of Ordinary Portland Cement Hydration With Wood by Isothermal Calorimetry

Abstract

Summary As an essential preliminary to understand the hydration of wood-cement composites, the effects of some additives on the delayed setting due to wood of an Ordinary Portland Cement have been investigated by isothermal calorimetry. With the addition of calcium chloride and activated charcoal, an increase of 50% of the total enthalpy is observed in wood-cement composites hydration, because calcium chloride mostly influences aluminate phases and activated charcoal silicate phases.

Modification of cement hydration at early ages by natural and heated wood

“…C Ca al lo or ri im me et tr ri ic c i in nv ve es st ti ig ga at ti io on n The calorimetric curve of pure cement exhibits two distinct peaks ( Figure 1). According to Sauvat et al [17], they correspond to C3A and C3S hydration peaks respectively whereas Bensted et al [18] suggested the reverse order in a very high C 3 A containing cement. The shape of the curve, the time values and the thermogravimetric results suggest the first allocation.…”

“…Wood powder (150-200 μm) was preferred to shavings because of the small size of the cell and the higher specific surface area. Cement and water were mixed outside the calorimeter according to the Sauvat et al [17] and Ramachandran and Lowery [11] procedures. Consequently, only the exothermic hydration peak was encountered.…”

Effect of polysaccharides on the hydration of cement paste at early ages

“…Temperature of the calorimetric block was maintained at 25°C and the experiments were conducted on a 250 mg sample at a W/C ratio of 0.4. Cement and water mixing was done outside the calorimeter according to the procedure described by Sauvat et al [14] and Ramachandran et al [15]. Consequently, only the exothermic hydration peak was encountered.…”

“…The calorimetric curve of neat cement exhibits two separate exothermic peaks. According to Sauvat et al [14] they correspond to C 3 A and C 3 S hydration peaks respectively whereas Bensted et al [16] suggested the reverse order. Retarding ability of polysaccharides on cement hydration is obtained from curves of heat evolution rate.…”

Effect of calcium aluminate cement variety on the hydration of portland cement in blended system

“…According to literatures, there is an obvious lack of concerning investigations, so the hydration of PAC was further investigated and two kinds of CACs with different content of CA were compared in the present paper. The calorimetric measurement is a well established method to study the kinetics and mechanism of hydration in cementitious materials [18] since it shows great versatility in studying the hydration kinetics of cementitious systems and helps to monitor cement-admixture combinations with respect to the hydration process [9,[19][20][21][22][23] . In addition, compared with widely used SEM, the sample preparation of ESEM has no destruction on the original microstructure, so it enables the more reliable observation of microstructure.…”