Mechanical Properties of a 3D-Printed Wall Segment Made with an Earthen Mixture

This study provides a contribution to the research field of 3D-printed earthen buildings, focusing, for the first time, on the load-bearing capacity of these structures. The study involves the entire production and testing process of the earthen elements, from the design, to the preparation of the mixture and the 3D printing, up to the uniaxial compression test on a wall segment. The results indicate that 3D-printed earthen elements have a compressive strength of 2.32 MPa, comparable to that of rammed earth structures. The experimental data also made it possible to draw conclusions on the action of the infill, which seems to have the function of stopping the propagation of cracks. This has a positive effect on the overall behavior of 3D-printed earthen elements, since it avoids the onset of dilative behavior in the final stages of the load test and maintains ultimate load values higher than 50% of the maximum load.

Hydro-Mechanics Coupling on Rammed Earth Material: Drying Experiment at Structural Scale

Rammed earth structures are very sensitive to hydric conditions. Experimental studies have been undertaken to understand the link between liquid water transfer and mechanical behavior at structural scale. This study was done on a prismatic rammed earth sample of 15cm x 15cm x 45cm, structured as a wall element with several layers. Samples were subjected to one dimensional drying in an indoor environment. Humidity and temperature sensors were placed on each layer inside the sample. The kinetic of drying was monitored by continuous weighing the sample and humidity measurement at a regular interval. Results of water content evolution suggest that samples dry in two stages; the first stage is associated with relatively high evaporation flux of 13.88 g m-2h-1 while the second stage has very low flux of moisture evaporation. Unconfined compressive strength was performed in drying samples after 0, 2, 6 and 8 weeks of drying. In parallel, digital image correlation was used to determine the stiffness of samples. Results show an increase in compressive strength by the rate of 98 kPa per week in the first two weeks, then this rate reduces to 23 KPa per weeks after 8 weeks. These experimental results will allow to enhance the 3D hydro mechanical numerical model developed in the laboratory.

Mechanical Properties of a 3D Printed Wall Segment Made with an Earthen Mixture

This study provides a contribution to the research field of 3D printed earthen buildings, focusing, for the first time, on the load-bearing capacity of these structures. The study involves the entire production and testing process of the earthen elements, from design, to the preparation of the mixture and the 3D printing, up to the uniaxial compression test on a wall segment. The results indicate that 3D printed earthen elements have a compressive strength of 2.32 MPa, comparable to that of rammed earth structures. The experimental data also made it possible to draw conclusions on the action of the infill, which seems to have the function of stopping the propagation of cracks. This has a positive effect on the overall behavior of 3D printed earthen elements, since it avoids the onset of dilative behavior in the final stages of the load test and maintains ultimate load values higher than 50% of the maximum load.

Characterizing the Effect of Water Content on Small-Strain Shear Modulus of Qiantang Silt

Due to the impact of natural and artificial influence, such as waves, tides, and artificial dewatering, the small-strain shear modulus of soils may vary with the water content of soil, causing deformation of excavations and other earth structures. The present study used a resonant column device to investigate the effects of water content, void ratio, and confining pressure on the small-strain shear modulus of a silt extracted from an excavation site near Qiantang River in Hangzhou, China. The test results revealed that the effects of the three factors are not coupled and can be characterized by three individual equations. In particular, the small-strain shear modulus decreases with increasing water content under otherwise similar conditions, which can be characterized by a power function. The classical Hardin’s equation is modified to consider the effect of water content by introducing an additional function of water content.

Characterization of materials used for earth architecture in Eastern Croatia

Even though earthen architecture is recognized as cultural heritage in Croatia, most of existing buildings are in deteriorated and heavily damaged state. Until today, there has been no conducted research on earthen architecture in Croatia, nor was any preservation act proclaimed. Therefore, the purpose of this research is to learn more about behaviour of traditional earthen architecture to highlight the importance of sustainable building. For that purpose, earthen houses in Eastern Croatia, mainly Slavonia and Baranja area, were studied and in-situ samples were collected. In order to learn about characteristics and composition of mixtures, five samples were tested. Results gathered within this research will be the first step towards creation of national standard for designing rammed earth structures. In scope of future research, authors are planning to use verified recipe in making of walls that will be tested for seismic resistance.

Appraisal of Anchor Arrangement and Size On Sand-Geogrid Interaction In Direct Shear

Soil – reinforcement interaction is a major factor in the analysis and design of reinforced earth structures. In current research the effects of attaching elements of different size and numbers as anchors on enhancement of interaction at soil - geogrid interface under direct shear conditions were studied. Poorly and well graded sands (SC & Sf), a high density polyethylene geogrid, anchors with three different size and numbers (layouts) and clamping length of 2cm from shear surface were used. Samples were prepared dry at a relative density of 80% in a 30×30cm direct shear box and subjected to normal pressures of 12.5, 25 and 50kPa with the shear load applied at a rate of 1mm/min. Results of the assessment show that anchored geogrids improve shear resistance at interface mainly due to mobilization of passive soil resistance that is significantly influenced by the magnitude of the normal pressure and the number and size of anchors. Interaction enhancements achieved varied between a minimum of 8% and a maximum of 42%.

The Geologic Process of The Saka River area: Related to the History Woyla Elevated Ocean in The South Sumatra Island Region, Republic of Indonesia

The lithological and earth structures which compose the geologic process space are terribly fascinating to study. elaborated investigation of pre-tertiary rock subduction at the Woyla web site is rarely carried out. the variability of rocks derived from the Woyla oceanic plate, that folded on the West Sumatra continental plate within the Age of Reptiles era, illustrates the magnitude of the subduction impact mirrored in the structures that are still reflected in the abandoned rocks. The ways want to discover this subduction event are elaborated field observations, skinny section, XRD, and earth science structure measurements, supported by drones and satellite imagery. The lithology of basalt, flint, serpentine, marble, and arenaceous rock is vital to the presence of the Intraoceanic Arch of Woyla within the Saka phase. elaborated structural calculation show that the Saka segment went through several tectonic stages from the Mesozoic to Recent, that is mirrored in the Saka fault and therefore the Penanggungan fault.