Compaction of porous rocks can occur in two modes: uniform and localized. Recent experimental work has demonstrated that compaction can occur in tabular zones that expand with increasing applied deformation. The appearance of compaction bands and their growth has a strong influence on the measured permeability of the host rock. The rock behind the moving compaction front can be either uniformly...

The deposition of dry fiber materials in the placement (DFP) process with subsequent impregnation is becoming increasingly widespread. wing covers Irkut MS 21 are already being manufactured using DFP process, and research projects at major aircraft manufacturers incorporating technology. In this speed depends on temperature compaction force. However, it not only laying that counts during produc...

ters to characterize both agricultural and rangeland A DYNAMIC CONE PENETROMETER soils, however, has been limited by concerns about (i) FOR MEASURING SOIL instrument cost, (ii) measurement repeatability, (iii) limited ranges of soil resistance that can be measured by PENETRATION RESISTANCE a single penetrometer, and (iv) difficulties in comparing Jeffrey E. Herrick* and Tim L. Jones data collec...

Soil compaction can affect crop growth and greenhouse gas emission and information is required of how both these aspects are affected by compaction intensity and weather. In this paper we describe treatments of compaction intensity and their effects on soil physical conditions and crop growth in loam to sandy loam cambisol soils. Soil conditions and crop performance were measured over three sea...

Compaction characteristic of the surface layer asphalt mixture (13-type gradation mixture) was studied using Superpave gyratory compactor (SGC) simulative compaction tests. Based on analysis of densification curve of gyratory compaction, influence rules of the contents of mineral aggregates of all sizes and asphalt on compaction characteristic of asphalt mixtures were obtained. SGC Tests show t...

In a recent experiment, a single DNA double helix is stretched and relaxed in the presence of spermidine, a short positive polyelectrolyte, and the pulling force is measured as a function of DNA extension. In a certain range of spermidine concentration, a force plateau appears whose value shows maximum as a function of spermidine concentration. We present a quantitative theory of this plateau f...

The cold compaction of an aggregate of powder is treated from the viewpoint of crystal plasticity theory. The contacts between particles are treated as compaction planes which yield under both normal and shear straining. The hardening of each plane represents both geometric and material hardening at the contacts between particles; the macroscopic tangent stiffness can be written in terms of the...

Overtopping, internal erosion, and piping are the main causes of accidents and failures of embankments for dams, lagoons, and levees. A key parameter in the failure of these structures is the erodibility of the soil materials used in construction of the embankments. The soil materials are typically constructed based on compaction specifications. The jet erosion test (JET) has been developed to ...

Macroscopic resistivity measurements have been performed on TiC/Al2O3 random mixtures submitted to uniaxial compression (0–95 kN). Such a random mixture exhibits an insulator-conductor transition which appears at increasing force while decreasing the conductive composition of the TiC/Al2O3 mixture. It is demonstrated that the conductivity behavior may be understood in the framework of a site pe...