Microstructure of a planting material consisting of nutrition-expansive perlitic-cement composites

Abstract

An ecotypic revetment material consiting of nutrition-expansive perlitic-cement composites is introduced. This planting material can combine vegetation recovery with slope protection. The XRD, SEM and image analysis techniques were used to study its composition and microstructure. Its strength was measured by an electro-hydraulic servo-controlled testing machine. The results show the uncofined compressive strength is about393.6 kPa, and the average elastic modulus is about47.0 MPa. The quartz, felspar, chlorite and calcite are the main non-clay minerals in the planting material. Its particles are mainly spherical, and the range of the equivalent diameter is1.83 to15.96 μm. The results also show the planting material contains a large amount of micro non-capillary and capillary pores, and has a microstructure characteristic of honeycomb and coralline. CSH gel produced by hydration of cement increases the strength and water stability of the particles. The anisotropy and slight orientation of the particles increase the void cross-section area, providing and explanation of the high permeability for the planting material. The better porosity of the planting material is apt tokeep moisture and nutriment, provides oxygen for plant root breathing, and aids to exhaust the carbon dioxide by means of exchanging with atmosphere, hence it can facilitate vegetation.

Keywords

microstructure / planting material / nutrition / expansive perlitic / cement composite

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