Wood Concrete Modified with Ground Granulated Blast Furnace Slag
Increasing requirements for the physical and mechanical properties of building materials give impetus to the creation and improvement of new high-performance building materials, which include slag-silicate wood chip concrete. The object of research is high-performance wood chip concrete materials obtained using modified slag-silicate binders. On the first stage of the work, the physical and mechanical properties of fine-dispersed granulated blast furnace slag and wood chips were studied. Methods: The phase composition of the fine-dispersed granulated blast furnace slag was determined by x-ray phase analysis. Also, the microstructure of the sample of the ground granulated blast furnace slag was studied using electron microscopic analysis. Results: It was founded that that slag consists of a crystalline and amorphous phase. The content of its most active amorphous phase is on the level of 59.8%. The chemical composition for the ground slag sample was also done. As a result of that, the element composition of the ground slag was obtained. In particular, the slag basicity factor which value equals to 1.04, was defined. During the experiment, it was found that the slag mainly consists of large thickened irregular-shaped particles and their aggregates which diameters are from fractions of microns to several microns. At the same time, finer particles are subject to aggregation. On the second stage of the study, three experimental composition of slag-silicate wood chip concrete with different grouting fluid/slag ratio was developed. A water glass solution with a density equal to 1.31 g/cm3 was used as a grouting fluid. As a result of the study, the composite material with an average density of 730 kg/m3, and the strength in 1.92 MPa was obtained. The dependence of the strength changing of slags-silicate wood chip concrete on the ratio of the grouting fluid/binder and the functional relationship of its strength and density were determinate. Based on the results of the experiments, it was founded that the optimal physical and mechanical properties of the slag-silicate wood chip concrete are achieved for the composition with the grouting fluid slag ratio equal to 0.52.