scholarly journals Durability Assessment of Clay-Bearing Soft Rocks By Using New Decay Index

2018 ◽  
Author(s):  
Mojtaba Heidari ◽  
Aliakbar Momeni ◽  
Yazdan Mohebbi
Keyword(s):  
Physical And Mechanical Properties ◽  
Test Methods ◽  
Index Test ◽  
Durability Test ◽  
Weak Rocks ◽  
Slake Durability ◽  
Decay Index ◽  
Durability Assessment ◽  
Engineering Projects ◽  
Slake Durability Test

Clay-bearing rocks are known as most important problematic weak rocks. Due to the importance of disintegration of clay-bearing rocks in engineering projects, several simple test methods have been proposed to assess durability of these rocks. In this study, a comprehensive research program was conducted on twenty different clay-bearing rocks to assess their disintegration characteristics under laboratory conditions. In order to carry out the research, at the first step some physical and mechanical properties of the studied rocks were measured. After that, three durability test methods were employed. These tests include the standard slake durability test to obtain index durability (Id2 ), slake durability test with sieving the remained materials in drum to obtain disintegration ratio (DR) and new time series slake durability test to obtain decay index (DI). The results of this research indicated that for most of samples, using the standardized slake durability index test (Id2 ) may not be adequate to understand the disintegration characteristics of clay-bearing rocks and shows overestimated values. The new decay index (DI) has overcome the most limitations of the standard slake durability test and clearly will realize deterioration potential of clay bearing rocks. Finally, based on the results of decay index a new durability classification was proposed.

scholarly journals An analysis on the slaking and disintegration extent of weak rock mass of the water tunnels for hydropower project using modified slake durability test

2019 ◽  
Vol 79 (4) ◽  
pp. 1919-1937 ◽  
Author(s):  
Lena Selen ◽  
Krishna Kanta Panthi ◽  
Gunnar Vistnes
Keyword(s):  
Rock Mass ◽  
Test Method ◽  
Weak Rock ◽  
Hydropower Project ◽  
Durability Test ◽  
Slake Durability ◽  
Operational Life ◽  
Heterogeneous Rock ◽  
Weak Rock Mass ◽  
Slake Durability Test

AbstractWater tunnels built for hydropower passing through weak and heterogeneous rock mass pose challenges associated to slaking and disintegration, as they are first exposed to dry condition during excavation and are then filled with water to produce hydropower energy. Over the period of operational life, these tunnels are drained periodically for inspections and repair leading to drainage and filling cycles. The weakening of rock mass caused by cycles of drying, saturation and drainage may lead to the propagation of instabilities in the tunnels. Therefore, it is important to study the slaking and disintegration behavior of the weak rock mass consisting of clay and clay-like minerals. This paper assesses the mineralogical composition of flysch and serpentinite from the headrace tunnel of Moglicë Hydropower Project in Albania. Further, to determine the slaking and disintegration behavior of these rocks, extensive testing using both the ISRM, Int J Rock Mech Min Sci Geomech Abstr 16(2):143-151, (1979) suggested test method and a modified variant of this test are performed. Finally, comprehensive assessments, discussions and comparisons are made. It is found that the modified slake durability test better suits for the tunnels built as water conveying systems such as hydropower tunnels.

Controls on shale durability: the response of two Ordovician shales in the slake durability test

1982 ◽  
Vol 19 (1) ◽  
pp. 1-13 ◽  
Author(s):  
D. J. Russell
Keyword(s):  
Durability Test ◽  
Georgian Bay ◽  
Slake Durability ◽  
High Durability ◽  
Calcite Cementation ◽  
Slake Durability Test

The slake durability test has been proposed as a means of predicting the engineering performance of shales. Testing of sections in the two major shale units of Ontario show that the test is capable of making distinctions between apparently similar shale samples. Queenston Shale has generally lower durability than the Georgian Bay Formation samples. Inspection of the shale fabric shows that this is due partly to inefficient cementing by calcite in Queenston Shale, but is primarily because the microcracks in Queenston Shale are more curved than those in Georgian Bay Formation. Variation in shale durability within the shales is controlled by mineralogy. In Queenston Shale, it is controlled almost entirely by calcite cementation. In Georgian Bay, where hard bands (shaly limestone) are present, these dominate the test, giving a high durability. However, pure shale durability is controlled by clay content.Comments on the performance of the test are made that aim to make the testing process and interpretation of the results more reliable. The method appears suitable for shale index testing and should be used as widely as possible in order to establish reliable correlations.

scholarly journals Applying laboratory methods for durability assessment of vitrified material to archaeological samples

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Lorena Nava-Farias ◽  
James J. Neeway ◽  
Michael J. Schweiger ◽  
José Marcial ◽  
Nathan L. Canfield ◽  
...  
Keyword(s):  
Nuclear Waste ◽  
Iron Age ◽  
Test Methods ◽  
Durability Test ◽  
Laboratory Methods ◽  
Near Surface ◽  
Glass Corrosion ◽  
Durability Assessment ◽  
Nuclear Waste Forms

AbstractLaboratory testing used to assess the long-term chemical durability of nuclear waste forms may not be applicable to disposal because the accelerated conditions may not represent disposal conditions. To address this, we examine the corrosion of vitrified archeological materials excavated from the near surface of a ~1500-year old Iron Age Swedish hillfort, Broborg, as an analog for the disposal of vitrified nuclear waste. We compare characterized site samples with corrosion characteristics generated by standard laboratory durability test methods including the product consistency test (PCT), the vapor hydration test (VHT), and the EPA Method 1313 test. Results show that the surficial layer of the Broborg samples resulting from VHT displays some similarities to the morphology of the surficial layer formed over longer timescales in the environment. This work provides improved understanding of long-term glass corrosion behavior in terms of the thickness, morphology, and chemistry of the surficial features that are formed.

scholarly journals Issues in Engineering Geological Classification of Weathered Sedimentary Rocks: Case Study of Kati Formation, Parit, Perak

2018 ◽  
Vol 7 (4.35) ◽  
pp. 131
Author(s):  
Wong Jia Mang ◽  
Abdul Ghani Md Rafek ◽  
Goh Thian Lai
Keyword(s):  
Laboratory Tests ◽  
Sedimentary Rocks ◽  
Point Load ◽  
Uneven Distribution ◽  
Index Test ◽  
Durability Test ◽  
Rock Samples ◽  
Slake Durability ◽  
Laboratory Test Results ◽  
Weathered Rocks

Kati Formation consists of alternating layers of sandstone, siltstone and mudstone that results in non-uniform weathering. The presence of surficial features due to weathering such as iron bands, iron recementation, iron staining and lithobionts coating in an uneven distribution on the outcrop causing more complexity to the heterogeneous sedimentary rocks which are also tectonically deformed. The presence of iron recementation in highly weathered rocks causing the rock strength to be higher than the moderately weathered rocks. Thus, several laboratory tests are conducted in this study to characterise the weathered rocks which are uniaxial compressive strength (UCS), point load strength index, slake durability test, jar slake test and Schmidt hammer rebound test. Among the laboratory tests conducted in this study, slake durability index test, Id2 is the ideal test to characterise the rock samples of different weathering grades as it gives a large range of laboratory test results which is 0.3 % to 15.0 % for completely weathered, 22.0 % to 67.0 % for highly weathered, 68.0 % to 83.0 % for moderately weathered and 87.0 to 98.0 % for slightly weathered to fresh rocks. The values obtained are not affected by the uneven distribution of iron oxide present in the rock samples.

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