Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
299,162
result(s) for
"engineering properties"
Sort by:
Materials engineering and exploring properties
\"You might be surprised at the huge variety of materials we use every day, in the places we live, the vehicles we use, the clothes we wear, and in preparing the food we eat. This book explores how materials engineers research, design, and develop the materials needed to make these products a reality. Readers will also learn how to combine their understanding of materials science and the engineering design process to tackle a design challenge of their own.\"-- Provided by publisher.
Book
Engineering geological properties of weathered swelling mudstones and their effects on the landslides occurrence in the Yanji section of the Jilin-Hunchun high-speed railway
To identify the mechanisms that caused landslides during the construction of the Jilin-Hunchun high-speed railway line in Yanji, China, the engineering properties of weathered swelling mudstones extracted from a representative landslide site were investigated. The experimental results indicate that both yellow-brown and magenta mudstones exhibit significant swelling and shrinkage behaviour due to significant amounts of swelling clay minerals. The yellow-brown mudstone has an obvious schistose structure with stacked flaky plates interconnected with a face-to-face pattern, while the magenta mudstone has an aggregated structure cemented by iron oxides. Both mudstones are prone to disintegration when soaked in water. The shear strengths of swollen samples decrease dramatically compared with those of unsaturated samples, and the lower the initial water content is, the smaller the shear strength of a sample after swelling. By repeatedly increasing the repeated drying-wetting-freezing-thawing cycles, the shear strength decreases. According to the experimental findings, the effects of the engineering properties of mudstones on the landslides occurrence in the Yanji section are discussed. Heavy rainfall and the weathering of mudstones induced by fluctuating climatic conditions are regarded as the principal factors that triggered the landslides. Given the high landslide incidence on south-facing slopes, the influence of slope orientation on the stability of mudstone slopes is studied and discussed.
Journal Article
Studies on Engineering and Microstructure Properties of Chromium(VI)-Contaminated Soil
Hexavalent chromium [Cr(VI)]-contaminated soils have introduced a serious problem in China. Cr(VI) is hazardous to both the environment and public health and may degrade the engineering properties of soils. Accordingly, the effects of Cr(VI) on the physicochemical, mechanical, and microstructure properties of Chinese clay were investigated in this study. Results show that Cr(VI) had a considerable negative effect on the physicochemical, mechanical, and microstructure properties of soil. Specifically, Cr(VI) changed the physicochemical properties and degraded the mechanical properties of soil, led to the aggregation of soil particles, and created a large void space. Cr(VI) also changed the mineral composition of the soil and converted clay minerals into calcite. The changes in the microstructure and mineral composition of the soil were the primary reasons for the differences in the engineering properties of Cr(VI)-contaminated soil.
Journal Article
On the variations of geo-engineering properties of dunites and diorites related to weathering
Geo-engineering properties of rocks, including discontinuity properties, physical and mechanical properties and crack propagation under axial loads, are affected by weathering. All of these rock properties have an impact on various scales on engineering applications. Therefore, weathering-related variations on rocks and rock masses are of great importance. In this study, dunites and diorites are compared from the view of weathering-related geo-engineering property variations both on field and on laboratory scales. The studies were initiated in the field by measuring the discontinuity properties, including spacing, aperture fill material, roughness and Schmidt hammer rebound tests. Mineralogical and petrographic investigations were performed on thin sections gathered from different weathering grades. The quantitative petrographic studies were concentrated on the micropetrographic index and the quantification of microcracks. At this stage of the study, a new method to quantify microcracks was proposed. Basic physical and mechanical properties (e.g., specific gravity, dry and saturated unit weights, water absorption, effective porosity, P-wave velocity, uniaxial compressive strength and slake-durability index test) were also investigated on samples of all of the weathering grades where the sample preparation was available. The data obtained from the field studies suggest that dunite discontinuity spacing decreases from 577 to 1 cm and ranges from 487 to 1 cm for diorite. Schmidt hammer rebound test values (SHV) in the field were only obtained for fresh, slightly weathered and moderately weathered grades. SHV values range from 54 to 41 for dunite and 63 to 32 for diorite. The quantitative microcrack data obtained during the petrographic studies indicated that microcracks for diorite increase with increasing weathering, but a decrease was observed for dunite, which was related to the formation of serpentine minerals with weathering. Furthermore, with increasing weathering, the changes in the physical properties of dunite specimens exhibit a wider range than in the diorite specimens. Unconfined compressive test results for the rocks showed similar decreasing trends with weathering, but the dunite specimen started to slake by the highly weathered stage, where the diorite exhibited a considerable slaking by the completely weathered stage. This research concludes that the micropetrographic index and quantitative microfracture data provide useful input to recognize the weathering grades of studied rocks. It is also emphasized that serpentinization is the distinct process for dunite weathering and has a high impact on the weathering process, influencing physical and mechanical properties considerably. However, the increase of micro- and macrocracks is the dominant distinctive feature for diorite weathering.
Journal Article
Deriving an intelligent model for soil compression index utilizing multi-gene genetic programming
Multi-gene genetic programming (MGGP) is a new nonlinear system modeling approach that integrates the capabilities of standard GP and classical regression. This paper deals with the prediction of compression index of fine-grained soils using this robust technique. The proposed model relates the soil compression index to its liquid limit, plastic limit and void ratio. Several laboratory test results for fine fine-grained were used to develop the models. Various criteria were considered to check the validity of the model. The parametric and sensitivity analyses were performed and discussed. The MGGP method was found to be very effective for predicting the soil compression index. The prediction coefficients of determination were 0.856 and 0.840 for the training and testing data, respectively. A comparative study was further performed to prove the superiority of the MGGP model to the existing soft computing and traditional empirical equations.
Journal Article
Durability assessments of rare green andesites widely used as building stones in Buca (Izmir), Turkey
Miocene volcanism was active in the city area of İzmir, Turkey, where volcanic deposits formed predominantly made of gray and pinkish colored andesite. These rocks have been widely used in the construction of many buildings in the region. In the northern part of Izmir, known as the Buca region, there is an area where andesite presents green color. The occurrence of the green andesite is rather rare, and historically this rock type has been used in the construction of ancient valuable architectonic structures including aqueducts, historical buildings, and mosques. Some of these structures date back to the beginning of the first century AD when the region was under the control of the Roman Empire. Interestingly, the recent survey of these structures showed that after all of these years, the green andesite still appears pretty much well preserved, only showing slight deterioration in the form of limited crumbling. Although these rocks were used in this particular region in the past, their material properties have not been investigated so far. The purpose of this study was therefore to identify mineralogical, chemical, physical, and mechanical properties of these rocks, which eventually determine their durability. The first phase of the research focused on detailed site investigation, which resulted in the definition of the geological extent of the green andesite and the identification of two historical quarries, from one of which representative samples was collected for laboratory investigation, which was the main task of the second phase of the research. The main cause for the green color of the andesite resulted the presence of celadonite, which is also accompanied by cristobalite. The presence of cristobalite in the pores as a secondary mineral appears to have contributed to the increased strength and durability of Buca andesite. Laboratory evaluation of the durability was in general agreement with field observations, although some test gave ambiguous results. This discrepancy revealed some weakness of laboratory tests to precisely assess durability of building stones.
Journal Article