Dimensional instability of cement bonded particleboard: Modelling CBPB as a composite of two materials

Abstract

Summary. Previous papers have quantitatively indicated that the total movement of cement bonded particleboard (CBPB) is equal to the sum of the movement of its components. This paper examined the efficacy of the law of mixtures when applied to the movement of a wood-cement composite under internal swelling or shrinkage stresses. Abundant data generated in companion papers were first manipulated to develop the universal formulae for predicting the movement of components. In conjunction with previous numerical results from image analysis of the structure of CBPB, and the orientated elasticity and stress algorithms, the models for theoretically predicting mass and dimensional changes of CBPB were derived. Validation studies were conducted and these demonstrated an excellent agreement of the theoretical predictions with experimental data for both mass and dimensional changes of CBPB due to internal swelling or shrinkage stresses during adsorption and desorption. The success also implied that CBPB can be treated as a composite and its properties can be well derived by the law of mixtures even though CBPB is an unusual type of composite having a very high volume fraction of wood chips, but a very high mass fraction of cement paste.

Effect of Rice Straw Amount Portion on Physical Properties of Adding Admixtures Hollow Block

“…With the rapid growth of our country economy, many constructions of society have made huge achievements. However，in energy conservation and emission reduction, low carbon environmental protection time, people begin to pay more attention to the construction, the energy conservation and emission reduction of building materials [1][2][3][4][5][6][7][8] . As a result, people begin to use crop straw to make building materials for them who have cheaper price, convenience and big annual output.…”